JPH06159344A - Screw loosening stop device - Google Patents

Abstract

PURPOSE:To tighten a screw member easily by light force and prevent it from loosening after it is tightened. CONSTITUTION:A washer 3 is provided on the rear side of the head 2 of a screw member 1. Several wide head projections 4 and recessed sections 5 are provided in the peripheral direction on the rear face of the head 2, many washer projections 6 which are narrower than the head projections 4 are provided in the peripheral direction on the surface of the washer 3 at the ratio of two or more washer projections for one head projection 4, and several bite projections 7 are provided in the peripheral direction on the rear face of the washer 3. Also, the washer projections 6 are quenched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw loosening prevention device capable of preventing loosening of screw members such as bolts, nuts and tacks after tightening.

[0002]

2. Description of the Related Art Conventionally, as a screw loosening prevention device,
Application for utility model registration No. 54774 published in 1987 (hereinafter referred to as Device 1), application for utility model registration No. 895 for 1987
There was a device (hereinafter referred to as device 2) published in Japanese Patent No. 15 publication.

Of these, device 1 is as shown in FIG.
As shown in FIG. 7 (a), the invention 2 has a washer D attached to the back surface C side of the head B of the screw member A, and the back surface C of the head B rises in the direction of rotation when tightening the screw. Is provided with a saw-toothed protrusion E that is a slope of
A saw-toothed protrusion F that meshes with is provided, and both protrusions E and F are free to rotate in the tightening direction, but are engaged with each other in the opposite direction to prevent rotation and prevent the screw member A from loosening. I am doing it.

Further, in Invention 1, as shown in FIG. 6 (b), when the washer D is fastened by the screw member A to the right half of the center line X-X of the back surface of the washer D, the bite that bites into the object G to be fastened. The protrusion H is provided, and the left half is provided with a loosening protrusion I that restricts rotation of the washer D in the opposite direction to prevent the washer D from loosening.

Further, in Invention 2, as shown in FIG. 7 (b), in the opposite direction of the washer D and the biting protrusion H that bites into the mounting material G when the washer D is tightened by the screw member A on the back surface of the washer D. A plurality of loosening-stopping projections I that restrict the rotation of the sheet and prevent the loosening are provided as a pair.

[0006]

In any of the above inventions 1 and 2, when the screw member A is tightened, a large number of projections E on the back surface C of the head B and a large number of projections F on the surface of the washer D are formed. Since the screw member A must be rotated in a state where the screw member A is meshed with each other, a large tightening force is required. Also,
There is a problem that the protrusions E and F meshing with each other during rotation are slid to generate an offensive metal sound, which is uncomfortable and the working environment is deteriorated.

Further, in the above-mentioned device 1, since the biting projections H and the loosening preventing projections I are symmetrically provided in the same number on both sides of the center line XX of the washer D, the resistance of the biting projections H at the time of tightening. Is large, it is difficult to bite into the mounting material G, and a large tightening force is required.

In Invention 2, since the biting projections H and the loosening projections I are formed in pairs in the same number, Invention 1
Similar to the above case, the resistance of the biting protrusion H at the time of tightening is large, it is difficult to bite into the mounting material G, a large tightening force is required, and there is a problem that the biting is not enough and it loosens easily.

Further, in any of the first and second inventions, the number of the protrusions H and I is reduced in order to smooth the rotation of the screw in the tightening direction and facilitate the bite of the protrusion H into the mounting material G. However, there is a problem that the loosening prevention after tightening becomes insufficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide a screw loosening preventive device which can easily tighten a screw member with a light force and which is hard to loosen after tightening.

[0011]

A screw locking device according to claim 1 of the present invention comprises a screw member 1 such as a bolt and a nut and a head portion 2 thereof as shown in FIGS. 1, 4 and 5. A washer 3 arranged on the back surface side, and several head projections 4 and recesses 5 each having a wide width are provided in the circumferential direction on the back surface of the head portion 2. A large number of washer projections 6 having a width narrower than the head projection 4 are provided at a ratio of two or more with respect to one head projection 4, and several biting projections 7 are formed on the back surface of the washer 3 in the circumferential direction. Is provided.

According to the first aspect of the present invention, the screw loosening prevention device is such that the washer protrusion 6 of the first aspect is hardened.

[0013]

In the screw loosening prevention device of the present invention, the head 2 of the screw member 1 is provided with a plurality of wide head projections 4 and recesses 5 on the back surface thereof, and the washer 3 has a head projection 4 on the surface thereof. Since a plurality of narrower washer protrusions 6 project from one head protrusion 4 at a ratio of two or more, when the head 2 of the screw member 1 is rotated to tighten the screw member 1, the washer The tip of the projection 6 does not come into contact with the concave portion 5, and as shown in FIG. Therefore, the frictional resistance when tightening the screw member 1 is reduced (about 1/2 of the case where a large number of head projections 4 are provided on the entire peripheral surface on the back surface), and the screw member 1 is easily rotated and is light. It can be tightened by force. Moreover, since the washer projections 6 intensively bite into the small number of head projections 4, the washer projections 6 easily bite into the head projections 4 due to the concentrated rolling pressure. Further, since two or more washer protrusions 6 bite into one head protrusion 4, the washer 3 is less likely to loosen.

Further, when the screw member 1 is tightened, several biting protrusions 7 provided on the back surface of the washer 3 bite into the object 10 to be tightened, so that the washer 3 itself is less likely to come loose.
As a result, the engagement of the washer projection 6 with the head projection 4 is also less likely to loosen, and the screw member 1 is even more difficult to loosen.

When the washer protrusion 6 is quenched as in claim 2, the hardness of the washer protrusion 6 increases, and when the washer 3 vibrates after tightening, the tightening force of the screw member 1 itself causes an arrow X in FIG. Internal stress is generated in the −X direction, and the close contact degree of the washer projection 6 is increased, so that the loosening prevention effect is further increased. Along with this, the bite protrusion 7 also tightens the object 10 to be tightened.
It becomes difficult to loosen.

In the screw loosening prevention device of the present invention, the tightening can be loosened by applying a constant force to the head 2 of the screw member 1 in the direction opposite to the tightening direction with a spanner or a suitable tool. In addition, if the screw member 1 is tightened again after being loosened once, the screw member 1 can be tightened as it is, and the screw member 1 is hardly loosened as it is.

[0017]

Embodiment 1 FIGS. 1 to 5 show various embodiments of a screw locking device according to the present invention. Among them, the embodiment of FIG. 1 is a case where the screw member 1 is a bolt, and a metal screw member 1 is used. A metal washer 3 is attached to the back side of the head 2. The washer 3 loosely covers the screw material rod 11 before rolling the screw of the screw member 1 shown in FIG. 3, and then the screw 12 is pressed on the screw material rod 11, and the outer diameter of the screw 12 is set to the washer. By making the inner diameter of the screw rod 3 larger than the inner diameter of the screw rod 3, the screw rod 11 is prevented from coming off, and further, the root portion 13 of the screw material rod 11 where the screw 12 is not cut can slide up and down.

The lower surface of the head 2 of the screw member 1 is shown in FIG.
As clearly shown in (a) and (b), a wide head projection 4
And several recesses 5 having substantially the same width are provided alternately (six in FIG. 4). The bottom surface of each head projection 4 is formed flat. The number of head projections 4 may be larger or smaller than that, but if it is too large, the frictional resistance with the washer projection 6 at the time of tightening becomes large, so 6 or less is desirable.

A large number of washer projections 6 having a width narrower than that of the head projection 4 are provided in the circumferential direction on the surface of the washer 3. Each washer protrusion 6 is formed in a serrated shape with a sharp tip, and is hardened to increase hardness so that the head protrusion 6 is easily bited. In FIG. 1, the washer protrusions 6 are provided so as to protrude from one head protrusion 4 at a ratio of three or more, but four ratios are most desirable, and other ratios can be set. When the number of washer protrusions 6 increases, the number of washer protrusions 6 that bite into one head protrusion 4 also increases, and the frictional resistance during tightening also increases. Therefore, the number of washer protrusions 6 is the number that bites into the head protrusions 4. Is selected to such an extent that the friction resistance during tightening does not become too large.

A plurality of biting protrusions 7 are provided on the back surface of the washer 3 in the circumferential direction. This biting protrusion 7
Also, the number of is selected so that the resistance at the time of tightening does not become so large and the timber and other articles are surely bited into the object 10 to be tightened. Desirably, the number is about 3 to 5. Each biting protrusion 7 is formed in a sawtooth shape that is sharpened downward, but its shape and direction are not particularly limited.

[0021]

Second Embodiment The embodiment shown in FIG. 4 is a case where the screw member 1 is a nut. Also in this case, one head 2 of the metal screw member
Similar to the case of FIG. 1, the metal washer 3 is caulked on the back side of the so as not to fall off.

A head projection 4 and a recess 5 are also formed on the back surface of the head 2 in FIG. 4, and their shape, number, etc. are the same as those of the head projection 4 and recess 5 in FIG.

The washer 3 shown in FIG. 4 also has a washer projection 6 on its front surface and a biting projection 7 on its back surface, which are the same as the washer projection 6 and the biting projection 7 in FIG.

[0024]

Third Embodiment The embodiment of FIG. 6 is a case where the screw member 1 is a tack of a golf shoe. Also in this case, the metal screw rod 11
Loosely fit the washer 3 to the root part 13 of the
The washer 3 is inserted into the annular fitting recess 14 formed on the outer periphery of the washer 3.
The washer 3 is prevented from coming off by press-fitting the protrusion 15 on the inner periphery of the fitting hole.

Further, as in the case of FIGS. 1 and 4, the head 2
Head projections 5 and recesses 6 are alternately formed on the back surface 3, and washer projections 6 are formed on the front surface of the washer 3 and biting projections 7 are formed on the back surface thereof. The tightening member 10 of FIG. 6 is a shoe sole,
The screw rod 11 of the screw member 1 is screwed into the receiving jig 15 which is embedded in the tightening member 10 in advance and tightened.

[0026]

The loosening prevention device of the present invention has the following effects. ． Since the number of head projections 4 is small, frictional resistance with the washer projection 6 when tightening the screw member 1 is small, and the screw member 1 is easy to rotate and can be tightened with a light force. ． When the screw member 1 is tightened, the tip of the washer protrusion 6 is concentrated on the head protrusion 4 so that the washer protrusion 6 is fixed to the head protrusion 4.
It becomes easier to cut into. ． Since several washer protrusions 6 bite into each head protrusion 4 one by one, the washer 3 is less likely to loosen. ． Loosening of the screw member 1 is prevented by biting the washer protrusion 6 into the head protrusion 5, and loosening of the washer 3 is prevented by the loosening prevention protrusion 7 of the washer 3. Therefore, loosening of the screw member 1 is doubly regulated. And there is almost no loosening. ． Since the number of the biting protrusions 7 is small, the resistance of the biting protrusions 7 at the time of tightening is small, and it is possible to tighten with a weak force. ． If the washer protrusions 6 are hardened as in claim 2, the head protrusions 5 are more easily eroded, and when the washer 3 vibrates after tightening, the washer protrusions are generated by the internal stress generated by the tightening force of the screw member 1 itself. Since the degree of bite adhesion of No. 6 is increased, the anti-loosening effect is further increased.

[Brief description of drawings]

FIG. 1 is a side view of a screw locking device of the present invention before tightening a screw member.

FIG. 2 is a side view showing a state in which a screw member of the locking device is tightened.

FIG. 3A is a side view showing an embodiment of a screw locking device of the present invention, and FIG. 3B is a rear view of a washer in the locking device.

FIG. 4 is a side view of another embodiment of the screw locking device according to the present invention.

FIG. 5 is a side view of yet another embodiment of the screw locking device of the present invention in a partially cut state.

FIG. 6A is a side view in a partially cut state showing an example of a conventional screw locking device, and FIG. 6B is a back view of a washer of the screw locking device.

FIG. 7A is a side view in a partially cut state showing another example of a conventional screw locking device, and FIG. 7B is a back view of a washer of the screw locking device.

[Explanation of symbols]

 1 is a screw member 2 is a head 3 is a washer 4 is a head protrusion 5 is a recess 6 is a washer protrusion 7 is a biting protrusion

Claims (2)

[Claims] 1. A head projection 4 comprising a screw member 1 such as a bolt and a nut, and a washer 3 arranged on the back side of a head 2 thereof, the head projection 4 having a wide width in the circumferential direction on the back surface of the head 2. And a plurality of recesses 5 are provided, and a plurality of washer projections 6 having a width narrower than that of the head projection 4 in the circumferential direction of the surface of the washer 3 are provided at a ratio of two or more to one head projection 4. A screw loosening prevention device, characterized in that it is provided with a plurality of biting protrusions 7 provided in a circumferential direction on the back surface of the washer 3 in a protruding manner. 2. A screw loosening prevention device, wherein the washer protrusion 6 of claim 1 is quenched.