JPH0716094Y2 - Anti-rotation device for bolts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a co-rotation preventing device for bolts.

[Conventional technology]

When a nut is attached to or detached from a rusted bolt or a bolt whose thread part is scratched, it is often experienced that the nut rotates together and causes a great obstacle to the attaching and detaching work.

In addition, nuts such as U nuts and nylon nuts (both are trade names) that have elastic members such as leaf springs and nylon resin in the screw part are hard to loosen, but the friction resistance of the screw part is large, and the bolt is fixed with a spanner. Otherwise, the nut could not be screwed in, and handling was troublesome.

As a co-rotation prevention device for this type of bolt,
No. 94, No. 30-2512, No. 30-6612, No. 33-2
No. 507 and the like are known.

[Problems to be solved by the device]

In the method of Japanese Utility Model Publication No. 10-10394, an eccentric large-diameter portion is formed on the bolt, and correspondingly, the bolt insertion hole of the member to be fastened also needs to be eccentrically formed, which requires special processing of the bolt. Not only is it expensive, but the holes formed in the member to be fastened must be formed eccentrically with respect to each other, which is a very complicated problem.

In addition, in Japanese Utility Model Publication No. 30-2512, one eccentric small diameter portion is formed in the bolt body and one crescent-shaped wedge is attached to this portion to prevent co-rotation.
-6612 has two eccentric small diameter parts formed on the bolt body, and each part is equipped with a crescent-shaped wedge to prevent rotation in both directions.
-For No. 2507, one small oval diameter part is formed on the bolt body, and in this part, a wedge with a circular outer circumference and an elliptical inner circumference and a notch on one thin part is attached in both directions. In both cases, since the eccentric small diameter portion and the elliptical small diameter portion are formed in the bolt body portion, special processing is required for the bolt, which is disadvantageous in that it is expensive.

[Means for Solving the Problems]

In view of the above problems, the present invention has an engaging portion for engaging the head portion of a bolt or a nut on the upper surface, and is inserted into the gap between the circular hole of the member to be fastened and the bolt body portion at two locations on the inner circumference. A first washer having a convex portion and a second washer having a convex portion to be inserted into a gap between the circular hole of the member to be fastened and the bolt body portion at one position on the inner circumference.
Of the second washer, and the protrusions of the second washer are positioned between the protrusions of the first washer for combined use.

Further, according to the present invention, the first washer and the second washer are used in a form in which they are loosely rotatably engaged with each other by an engaging portion of an outer peripheral portion so as to be integrated with each other.

Further, according to the present invention, a bolt having protrusions to be inserted into a gap between a circular hole of a member to be fastened and a bolt body is formed at two positions in a circumferential direction, and a circular hole of the member to be fastened at one position on an inner circumference. And a washer having a convex portion that is inserted into a gap between the bolt body portion and the bolt body portion, and the convex portion of the washer is positioned between the convex portions of the bolt for use.

Further, according to the present invention, when there is almost no gap between the bolt body and the circular hole of the member to be fastened, one annular concave groove concentric with the bolt is provided near the head of the bolt body. The convex portion of the second washer is inserted into the concave groove and is used while being positioned between the convex portions of the first washer.

[Action]

According to the configuration of claim (1), when the bolt or the nut starts to rotate clockwise, the first washer rotates clockwise with respect to the second washer, so that the right convex portion () of the first washer ( A) moves away from the convex part (C) of the second washer,
Within the circular hole of the member to be fastened, there are three points (A) and (C), and one point (D) on the outer circumference of the bolt on the bisector of the central angle of these (A) and (C). Upon contact, the convex portion (A) acts to drive a wedge into the crescent-shaped gap to fix the bolt in the circular hole. Therefore, even if a large frictional resistance acts on the threaded portion of the nut and the bolt, the bolt does not rotate and co-rotation is prevented. When starting to rotate counterclockwise, the left convex portion (B) of the first washer moves away from the convex portion (C) of the second washer, and within the circular hole of the fastened member, the points (B) and ( The point (C) is in contact with the point (D ') on the outer circumference of the bolt on the bisector of the center angles of these points (B) and (C), and it does not rotate any further, preventing co-rotation. In this way, the co-rotation preventing action is performed by always contacting one point on the outer circumference of the bolt with the inner wall of the circular hole of the member to be fastened, so that the axis of the bolt is held parallel to the central axis of the circular hole. Therefore, the inclination of the axis is prevented.

According to the structure of claim (2), the first washer and the second washer can be handled as one component.

In the structure of claim (3), the first washer is omitted and the two convex portions are directly formed on the bolt. The operation is the same as that of claim 1, and therefore its description is omitted.

The structure of claim (4) is applied when there is almost no gap between the bolt body and the circular hole of the member to be fastened.
The washer and the second washer prevent the bolt from rotating in both directions with respect to the circular hole of the member to be fastened in the annular groove of the bolt.

〔Example〕

1 to 3 show a first embodiment of the present invention,
(1) is the first washer, (2) is the second washer,
(3) shows bolts, (4) shows nuts, (5) and (6) show fastened members, and (7) shows circular holes of fastened members (5) and (6).

The first washer (1) has an engaging portion (1a) for engaging a square head portion of a bolt (3) or a nut (4) on the outer circumference, and fastened members (5) (6) at two locations on the inner circumference. ) The convex portion (A) inserted into the gap between the circular hole (7) and the body portion of the bolt (3).
Having (B).

The second washer (2) has a convex portion (C) inserted into a gap between the circular hole (7) of the fastened members (5) and (6) and the body of the bolt (3) at one location on the inner circumference. ) Has.

As shown in FIG. 3, both washers (1) and (2) are used by being overlapped with each other in a relatively rotatable state, and at that time, the convex portion (C) of the second washer (2) is used. Are positioned between the convex portions (A) and (B) of the first washer (1) to be combined. Both convex portions (A) of the first washer (1)
In (B), the central angle may be 180 ° or less, but 120 ° is the best. In addition, the sum of the heights of one of the convex portions (A) and (B) of the first washer (1) and the height of the convex portion (C) of the second washer (2) is the fastening target member (5). ) (6) is set to be larger than the clearance between the circular hole (7) and the body of the bolt (3), and the height of each protrusion (A) (B) (C) alone is It is set smaller than the gap.

The first embodiment of the present invention is constructed as described above, and its operation will be described with reference to FIGS. 4 (a) (b) (c).

First, the bolt (3) has the first and second washers (1).
When the convex portions (A), (B) and (C) of (2) are in the state shown in FIG. 4 (a), they can be inserted into the circular holes (7) of the fastened members (5) and (6). . When the nut (4) starts to rotate clockwise in this state, the first washer (1) rotates clockwise with respect to the second washer (2) due to the existence of the engaging portion (1a). , The right side convex portion (A) of the first washer (1) moves away from the convex portion (C) of the second washer (2), and within the circular hole (7) of the fastened member (5) (6). , The points (A) and (C) mentioned above are in contact with the points (D) of the outer circumference of the bolt (3) on the bisector of the central angle of these points (A) and (C), and more than this It does not rotate clockwise and prevents co-rotation (see Fig. 4 (b)). At this time, the convex portion (B) on the left side of the first washer (1) is not in contact with the circular hole (7).

When the bolt (3) or nut (4) begins to turn counterclockwise, the left protrusion (B) of the first washer (1) moves to the second
Away from the convex portion (C) of the washer (2) and the points (B) and (C) in the circular holes (7) of the fastened members (5) and (6), and these (B) and (C). The bolts (3) on the bisector of the center angle of 3 contact with each other at one point (D ') on the outer circumference of the bolt (3) and do not rotate counterclockwise any more, preventing co-rotation (Fig. 4 (c)). reference).

Due to the above phenomenon, co-rotation can be prevented both when the bolt (3) or the nut (4) is tightened and when it is removed.

5 and 6 show a modified example of the engaging portion (1a) of the first washer (1), and in FIG. 1, the bolt (3) is shown.
Alternatively, a hexagonal peripheral wall that fits the square head of the nut (4) is shown, but FIG. 5 shows the hexagonal wall of the bolt (3) or nut (4) every other contact. Engage 3
Fig. 6 shows a case where two contact pieces are used, and Fig. 6 shows that notches (1b) are made at three locations on the outer periphery of the first washer (1), and the notches (1b) are erected to make the engaging portion (1a). It shows the case. 7 and 8 show that tangential cuts (1c) are made at 120 ° intervals in the width of the first washer (1), and
The case where the engaging part (1a) is formed by projecting from the position of this cut (1c) to the upper surface side in a hemispherical shape is shown.

FIG. 9 shows another embodiment of the second washer (2) in which the engaging portion (2a) is formed by bending at three equidistant positions on the outer circumference. The first washer (1) shown in FIG. 5 or FIG. 6 is engaged with the outer periphery of the portion except the engaging portion (1a), and as a result, as shown in FIG. 10, both washers (1) ( 2) is integrally rotatably fitted in a relatively rotatable manner. With this structure, the handleability is simplified so that the washers (1) and (2) are not separated during the tightening work or the removing work of the bolt (3) and the nut (4). As a method of forming the convex portion (C) of the second washer (2), the method shown in FIGS.
As shown in the drawing, a notch (2b) may be formed in one place close to the inner peripheral edge, and this portion may be formed so as to project to the lower surface side. Further, the convex portion (C) may be formed by forming a substantially L-shaped cut (2c) as shown by a chain line in FIG. 11 and bending the lower surface side. In the above embodiment, both washers (1) and (2) are used.
Is applied to the bolt (3) side, the same applies when applied to the nut (4) side.

FIG. 13 shows another embodiment of the present invention, in which the convex portions (A) and (B) of the first washer (1) are directly formed on the body portion of the bolt (3) to form the first washer. (1) is omitted, and it is combined with the second washer (2) shown in FIG.
It is used in the form shown in Fig. 14. In this case, the formation conditions of the convex portions (A) and (B) are the same as the formation conditions of the first washer (1) shown in FIG. 1, and the co-rotation preventing operation is also shown in FIG. b) The same as (c).

In each of the above embodiments, the shape of the convex portions (A), (B), and (C) may be any of a semi-circular cross section, a semicircle, a triangle, and a quadrangle.

In the above embodiment, the case where there is a gap between the bolt (3) and the circular hole (7) has been described, but when the convex portion is difficult to fit in the gap, the convex portion in FIGS. 1 and 2 is used. (A)
The heights of (B) and (C) are low, and it is difficult to make them robustly. Therefore, as shown in FIG. 15, one annular groove (8) concentric with the bolt (3) is formed near the head of the bolt (3), and the second annular groove (8) is formed in the annular groove (8). The convex portion (C) of the washer (2) of FIG. 1 to the convex portion (A) (B) of the first washer (1)
It is used by inserting it in a state in which it is located between them, and the protrusions can be made thick and strong. Further, the co-rotation preventing action is the same as that described in FIGS. 4 (a), (b) and (c). In this case, the protrusions (A), (B), and (C) of both washers (1) and (2) are formed to extend inward from the inner circumference of the washer, and are elastically deformed for mounting, or the washer is used. The inner diameter of the bolt (3) is made larger than that of the thicker portion of the bolt (3), that is, the convex portion (A) (B) (C) is formed in this inner diameter portion, and the convex portion (A) (B) (C) is slid into the annular groove (8) for fitting. .

[Effect of device]

According to the invention of claim (1), the bolt or the nut and the first washer can be integrally rotated by the existence of the engaging portion, and as a result, the first washer is rotated when the bolt or the nut is rotated. Since it is possible to contact the circular hole of the member to be fastened and prevent co-rotation at three points, one of the two convex portions of the above, the convex portion of the second washer, and the one portion of the bolt, the axis line of the bolt can be prevented. The effect is that the member to be fastened can always be held parallel to the axis of the circular hole. Further, as the bolt, a commercially available product can be used, and a simple circular hole may be formed in the member to be fastened.

According to the invention of claim (2), the first washer and the second washer can be integrally handled, which is convenient in terms of work.

According to the invention of claim (3), there is an effect that the first washer can be omitted and the bolt axis can be always kept parallel to the axis of the circular hole of the member to be fastened in combination with the second washer.
In addition, a simple circular hole may be formed in the member to be fastened.

According to the invention of claim (4), even if the bolt and the circular hole of the member to be fastened have almost the same diameter, the co-rotation preventing device of the present invention can be applied. And in any of the claims, the nut or the threaded portion of the bolt is rusted, so even if the bolt rotates together when the nut is removed, the bolt works in the hole of the object to be fastened by the wedge action. Fixed. Therefore, the bolt can be removed by simply rotating the nut without fixing it with a spanner.

[Brief description of drawings]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a perspective view of a first washer, FIG. 2 is a perspective view of a second washer, and FIG. FIG. 4 (a) (b) (c) is a plan view for explaining the co-rotation preventing action of the present invention, and FIG. 5 is a perspective view showing another embodiment of the first washer. FIG. 6 is a plan view showing still another embodiment of the first washer, FIG. 7 is a plan view showing another embodiment of the first washer, and FIG. 8 is a sectional view taken along the line VIII-VIII of FIG.
FIG. 9 is a perspective view showing another embodiment of the second washer,
FIG. 10 is a vertical sectional side view showing a combined state of the second embodiment of the present invention, FIG. 11 is a plan view showing another embodiment of the second washer, and FIG. 12 is a sectional view taken along the line XII-XII of FIG. FIG. 13 is a perspective view of a bolt showing a third embodiment of the present invention, FIG. 14 is a vertical sectional side view showing a combined state of the third embodiment of the present invention, and FIG. 15 is a fourth embodiment of the present invention. It is a vertical side view shown. (1) ... first washer, (2) ... second washer,
(1a) ... engaging part, (2a) ... engaging part, (3) ... bolt,
(4) ... nut, (5) (6) ... fastened member, (7) ...
Circular hole, (8) ... annular groove, (A) (B) (C) ... convex portion, (D) (D ') ... contact point between bolt body and circular hole.

Claims (4)

[Scope of utility model registration request] 1. A bolt or nut has a head engaging portion on its upper surface, and two convex portions inserted in a clearance between a circular hole of a member to be fastened and a bolt body at an inner periphery. A first washer and a second washer having a convex portion to be inserted into a gap between the circular hole of the member to be fastened and the bolt body portion at one position on the inner circumference are provided, and the convex portion of the second washer is provided. A co-rotation preventing device for bolts, which is used by combining it by positioning it between the convex portions of the first washer. 2. The first washer and the second washer are integrally movably engaged with each other by an engaging portion of an outer peripheral portion so as to be relatively rotatable. Co-rotation prevention device for bolts. 3. A bolt having protrusions to be inserted into a gap between a circular hole of a member to be fastened and a bolt body at two circumferential positions, and a circular hole of the fastened member at one position on the inner circumference. A co-rotation preventive device for bolts, comprising: a washer having a protrusion inserted into a gap between the bolt body and the washer, wherein the protrusion of the washer is used between the protrusions of the bolt. 4. An annular groove, which is concentric with the bolt, is provided in a portion of the bolt body that contacts the head, and a second annular groove is provided in the annular groove.
The washer convex portion of the above is used by being inserted while being positioned between the convex portions of the first washer.
Alternatively, the co-rotation preventing device for the bolts according to item 2.