JP2012007625A - Locking washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a locking washer, which avoids the occurrence of looseness at a fastening part by a fastening member such as a bolt and a nut and obtains a more stable looseness preventive effect even when stronger vibration shock is applied.SOLUTION: There is provided the locking washer which is used by being sandwiched between the fastening member and a fastened body 40 when the fastened body 40 is fastened using a screw-fastening action by the fastening member of the bolt 20 and the nut 30. The washer for preventing sag includes: a tapered cylindrical part 11 formed in a cylindrical body which gradually increases toward a washer bearing surface 19 abutting on the fastened body 40 from a press-contacted surface 12 on which a bearing surface of the fastening member is abutted; and a recessed step part 13 into which the bearing surface 21 side of the fastening member is fit for centering to be engaged with the fastening member in the press-contacted surface 12.

Description

  The present invention provides a locking washer that is sandwiched between the fastening member and the fastened body when the fastened body is fastened by using a screw fastening action by a bolt or nut fastening member. About.

Fastening members for bolts and nuts are widely used in various fields as means for fastening and fixing fastened bodies such as members and parts. Conventionally, a flat washer or a spring washer is used as a countermeasure against the slack that occurs when a vibration shock is repeatedly applied to the fastening portion of the fastening member.
However, in the conventional flat plate washer and spring washer, it is inevitable that the fastening portion by the fastening member is loosened by a stronger vibration impact.

On the other hand, in the conical elliptical washer, the inner surface of the bolt hole has a conical surface with a diameter increased from the seating surface of the nut seat toward the body to be fastened, and the outer peripheral surface of the locking washer is concave. Has been proposed in advance (see Patent Document 1).
According to this, a to-be-fastened body can be reliably fixed by absorbing a strong vibration and impact suitably, and an excellent loosening prevention effect can be obtained.

  In addition, the bolt and nut tightening members share the technical idea with the locking washer of Patent Document 1, and are fastening members that fasten the body to be fastened by a screw action. A head portion for rotating around, and a cylindrical shape in which the extending end side gradually expands from the base portion of the head portion so as to be concentric with the head portion and larger in diameter than the head portion, integrally with the head portion A taper portion formed on a seating surface that abuts against the body to be fastened, an inner surface of the taper portion is formed in a conical curved surface, and an outer surface of the taper portion is a concave surface. The fastening member characterized by being formed in the curved surface is disclosed (refer patent document 2).

Japanese Patent Laying-Open No. 2005-207568 (Claims) Japanese Patent No. 3860200 (Claims)

The problem to be solved with respect to the locking washer is that there is play between the inner diameter of the washer and the outer diameter of the bolt in the previously proposed one. It may be difficult to obtain a stopping effect.
Accordingly, an object of the present invention is to prevent a loosening washer that can prevent a loosening portion from being fastened by a bolt or nut fastening member even when a stronger vibration impact is applied, and can provide a more stable loosening prevention effect. Is to provide.

The present invention has the following configuration in order to achieve the above object.
According to one form of the locking washer according to the present invention, when the fastened body is fastened using the screw fastening action of the bolt or nut fastening member, the fastening member and the fastened body In a slack stopper washer that is sandwiched between, a cylindrical body that gradually increases in diameter from a pressure contact surface to which the seat surface of the tightening member is pressed to a washer seat surface that is in pressure contact with the body to be fastened. And a concave step portion into which the seating surface side of the tightening member is fitted so as to be aligned with the pressure contact surface so as to align the axial center with the tightening member.

  Further, according to one form of the slack stopper washer according to the present invention, the inner peripheral surface of the tapered cylindrical portion is provided on a conical curved surface, and at least a part of the outer peripheral surface of the tapered cylindrical portion is concave. It is characterized by being provided on the curved surface.

  Further, according to one form of the locking washer according to the present invention, the convex step formed on the pressure contact surface by providing the concave step corresponds to the shape of the hexagon bolt or hexagon nut, The outer shape may be intermittently provided on the pressure contact surface having a circular shape.

  According to the lock washer according to the present invention, even when a stronger vibration impact is applied, it is possible to avoid the occurrence of slack in the fastening portion by the tightening member of the bolt or nut and to obtain a more stable locking effect. It has a special advantageous effect of being able to.

It is a front view which shows the example of a form which concerns on the slack stopper washer of this invention. It is a top view of the example of a form of FIG. It is a bottom view of the example of a form of FIG. It is a side view of the example of a form of FIG. It is an AA line sectional view of the example of a form of Drawing 1. It is a BB line sectional view of the form example of FIG. It is the top view which showed the state in which a bolt head etc. fit about the example of FIG. It is a top view which shows the other example of a form which concerns on the slack stopper washer of this invention. It is sectional drawing which shows the screw slack test method which concerns on the slack stopper washer of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode of a slack stopper washer according to the present invention will be described in detail based on the attached drawings (FIGS. 1 to 9).
The loosening washer 10 according to the present invention is provided between the fastening member and the fastened body 40 when the fastened body 40 is fastened by using the screw fastening action of the bolt 20 or the nut 30. It is used by being sandwiched (see FIG. 9).

  Reference numeral 11 denotes a tapered cylindrical portion, which gradually increases in diameter from the pressed contact surface 12 to which the seating surface 21 (see FIG. 9) of the fastening member is pressed into contact with the washer seating surface 19 in pressure contact with the fastened body 40. It is formed in a cylindrical shape. Reference numeral 17 denotes a bolt hole through which the shaft portion of the bolt 20 is inserted (see FIG. 2 and the like).

A concave step 13 is provided on the pressure contact surface 12 so that the seating surface 21 side of the tightening member can be fitted to align the shaft core with the tightening member.
14 is a convex stepped portion, and the concave stepped portion 13 is fitted to the outer edge portion of the pressure contact surface 12 so that the seating surface 21 side of the tightening member can be centered to align the axial center with the tightening member. It is provided to form.
Since the centering can be performed, the tightening force can be received in a balanced manner, the stress can be appropriately dispersed, and a more stable loosening prevention effect can be obtained.

In this embodiment, the convex step 14 formed on the pressure contact surface 12 by providing the concave step 13 corresponds to the head shape of the hexagon bolt 20 and the outer shape of the hexagon nut. It is provided intermittently on the surface 12 (see the hexagonal shape 22 shown by the one-dot chain line in FIG. 7).
The convex portion 14 can be centered by guiding the outer periphery of a cap bolt having a circular head shape (see a circular shape 23 shown by a two-dot chain line in FIG. 7).
Moreover, the shape of the convex step part 14 and the number of protrusions which are intermittently formed are not particularly limited as long as the head shape of the hexagon bolt 20 and the outer shape of the hexagon nut can be appropriately guided.

Furthermore, the convex step portion 14 may not be formed intermittently, but may be formed in a concentric ring shape as shown in FIG.
Also by this, the concave step portion 13 can be appropriately formed, and the head shape of the hexagon bolt 20 and the outer shape of the hexagon nut can be suitably guided (see the hexagon shape 22 shown by the two-dot chain line). The accuracy of matching can be increased. Therefore, a more stable loosening prevention effect can be obtained.

The inner peripheral surface 15 of the tapered cylindrical portion 11 is provided on a conical curved surface, and at least a part of the outer peripheral surface 16 of the tapered cylindrical portion 11 is provided on a concave curved surface 16a.
In the present embodiment, the thickness corresponding to the flat plate washer on the washer seating surface 19 side of the outer peripheral surface 16 is formed to be a standing surface 16b that stands vertically from the fastened body 40. That is, the outer peripheral surface 16 of the tapered cylindrical portion 11 is not entirely a concave curved surface 16a. According to this, it is possible to appropriately reduce the outer dimension while maintaining the loosening prevention performance.
9, the seat surface side of the tapered cylindrical portion 11 integrally formed as a flange portion is formed in the same manner as the washer seat surface 19 side according to the present invention.

Next, the results of the loosening test when the loosening washer 10 according to the present invention is used as a test washer for the bolt 20 will be described with reference to FIG.
The M16 bolt 20, nut 30, and locking stopper washer 10 are tightened through a washer 51 to a vibration barbell (fastened body 40) provided on a vibration table 50 of a high-speed screw loosening tester. And set in a fixed state.
The screw looseness test using this high-speed screw looseness tester was conducted with a vibration frequency of 1780 rpm, vibration table stroke of 11 mm, impact stroke of 19 mm, vibration direction perpendicular to the bolt axis, tightening torque of 250 N · m, and no loosening in 17 minutes. The measurement was performed under the condition that the return torque was measured.

The test results did not relax even for 17 minutes, and the return torque was 210 N · m.
This high-speed slack test is a device that repeatedly applies vibration and impact at a high speed, and a normal nut loosens within a few seconds to a few tens of seconds. Further, even a double nut structure that is said to have the highest tightening holding force currently on the market can only be held for several minutes. With this test method, it was confirmed that the configuration including the bolt 20, the nut 30 and the locking washer 10 that can maintain the tightening force for 17 minutes has the highest performance.

  As described above, the present invention has been described in various ways with preferred embodiments. However, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. That is.

DESCRIPTION OF SYMBOLS 10 Locking washer 11 Tapered cylindrical part 12 Pressure contact surface 13 Concave step part 14 Convex step part 15 Inner peripheral surface 16 Outer peripheral surface 16a Concave curved surface 16b Standing surface 19 Washer seat surface 20 Bolt 21 Seat surface 30 Nut 40 Fastened body

Claims (3)

When the fastening body is fastened by using the screw fastening action of the bolt or nut fastening member, in the loosening washer used sandwiched between the fastening member and the fastened body,
A tapered tubular portion formed in a tubular shape that gradually increases in diameter from a pressure contact surface to which the seat surface of the tightening member is press-contacted toward a washer seat surface in pressure contact with the fastened body;
A loosening washer having a concave step portion into which a seating surface side of the tightening member is fitted so that the pressure contact surface can be centered to align the axial center with the tightening member.   2. An inner peripheral surface of the tapered cylindrical portion is provided on a conical curved surface, and at least a part of an outer peripheral surface of the tapered cylindrical portion is provided on a concave curved surface. Sag stopper washer.   The convex step formed on the pressure contact surface by providing the concave step portion is intermittently provided on the pressure contact surface having a circular outer shape corresponding to the shape of a hexagon bolt or hexagon nut. The slack stopper washer according to claim 1 or 2.

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