WO2010122645A1

WO2010122645A1 - Washer for bolt

Info

Publication number: WO2010122645A1
Application number: PCT/JP2009/058023
Authority: WO
Inventors: 通山田
Original assignee: Yamada Toru
Priority date: 2009-04-22
Filing date: 2009-04-22
Publication date: 2010-10-28

Abstract

A washer for a bolt has an upper portion (1) and a lower portion (2) which are integrally formed from an elastically deformable material. The upper portion (1) has, on the inner side thereof, an upwardly open fitting hole (4) into which a head (3a) of a bolt (3), which fastens an object to be fastened, or a nut (7) is fitted. The lower portion (2) is of a plate-like shape and has a bottom surface (5) formed as a recessed surface. The washer also has a bolt hole (6) for allowing a shaft (3b) of the bolt (3) to penetrate through from the bottom of the fitting hole (4) to the lower portion (2). The washer can be configured such that the outer periphery of the upper portion (1) has a polygonal shape so that the washer can be rotated by a spanner. The washer can effectively prevent the bolt from loosening.

Description

Bolt washer

This invention relates to a washer for a bolt that is used when an appropriate body to be fastened is fastened with a bolt.

Conventionally, as a bolt washer used when a fastened body is fastened with a bolt, there is a flat washer as shown in FIG. 5.3 (page 98) of Non-Patent Document 1 shown below. Since this flat washer is not integrated with the bolt, when the bolt is tightened and after tightening, it rotates relative to the bolt and the upper surface is scraped by the bolt head, or it becomes sagging or sinking, It may cause a decrease in the axial force of the bolt and cause the bolt to loosen.

Also, the most important thing in fastening with bolts is to maintain the frictional force at the joint surface between the parts related to fastening so as not to cause the bolt to loosen. It is essential to keep the tightening force in the proper range. The tightening force is generated by a tensile force generated in the bolt when the bolt is fastened. This tensile strength maintains the tightening force while increasing with the elastic deformation of the bolt.

The elastic deformation of the bolt appears mainly in the form of extension of the bolt shaft. The longer the shaft length, the larger the amount of elastic deformation and the greater the tightening energy. Often done. Further, in order to compensate for the elastic deformation of the bolt, a spring washer having a large amount of elastic deformation has been used together with the bolt.

However, there is a limit to increasing the axial length of the bolt, and even if a spring washer is used, the spring washer is sandwiched between the bolt head (or nut) and the body to be fastened. In the thickness, shape, size, surface roughness, accuracy, strength, etc., elastic deformation sufficient to compensate for the tightening force could not be generated. The spring reaction force of the conventional spring washer is said to be only one third of the appropriate axial force of the bolt at the maximum, which is insufficient to compensate the axial force of the bolt.

In addition, the plain washer and the spring washer generate a frictional force with the fastened body, but in these conventional washers, the frictional force is generated at an arbitrary joint surface, Such a frictional force is not generated at a specific position so that it can be used to the maximum as a torque for preventing the bolt from loosening.

Accordingly, an object of the present invention is to provide a bolt washer having a structure that can effectively prevent loosening of the bolt.

In order to solve the above problems, the present invention takes the following technical means.

The bolt washer of the present invention has an upper part and a lower part integrally formed of an elastically deformable material, and the upper part is located above an upper part of a bolt head or nut for fastening a fastened body inside. It has an open fitting hole, the lower part is plate-like and the bottom surface is concave, and the bolt hole for penetrating the bolt shaft part from the bottom to the lower part of the fitting hole Yes.

Also, the outer peripheral shape of the upper part can be a polygon and can be rotated by a spanner.

The bolt washer of the present invention has the above-described configuration, and the bolt head or nut is fitted into the upper fitting hole so as to be integrated with the bolt. It can be made tough and excellent in durability without being scraped by the nut, sagging or sinking, and without the washer wearing the screw of the shaft portion of the bolt.

Also, the washer of this invention can compensate for the shortage of the bolt axial force by elastically deforming. Moreover, because the bottom surface of the lower part is concave, main frictional force is generated near the outer periphery of the bottom surface, and a large friction torque can be obtained, which can significantly reduce the slip of the washer. it can. Further, since the friction surface can be specified, processing that increases the friction coefficient is easy.

It is the perspective view seen from the upper surface side of the washer for bolts of the embodiment of this invention. It is the perspective view seen from the bottom face side of the washer for bolts of the embodiment of this invention. It is explanatory drawing which shows the state which inserted the volt | bolt in the washer for volt | bolts of embodiment of this invention. It is explanatory drawing in the case of fastening with a pair of upper and lower washers and bolts and nuts of the embodiment of the present invention. It is explanatory drawing at the time of fastening with the washer and bolt of embodiment of this invention, without using a nut. It is the perspective view seen from the upper surface side of the washer for bolts of other embodiments of this invention. It is the perspective view which looked at the washer for bolts of other embodiments of this invention from the bottom face side. It is explanatory drawing of the decomposition | disassembly state of the attachment structure of the cultivation nail | claw using the washer for bolts of other embodiment of this invention. It is explanatory drawing of the attachment structure of the tilling nail | claw using the washer for bolts of other embodiment of this invention.

[First Embodiment]
The bolt washer according to the first embodiment has an upper part 1 and a lower part 2 which are integrally formed of an elastically deformable material. It has a joint hole 4, the lower part 2 is plate-shaped and its bottom surface 5 is concave, and a bolt hole for allowing the shaft part 3 b of the bolt 3 to penetrate from the bottom of the fitting hole 4 to the lower part 2. 6.

The material and manufacturing method of the washer for bolt are not particularly limited, but it is desirable that the bolt washer is a high-elasticity body having high pressure and tensile strength. For example, a steel material having high elasticity can be formed by using a forging technique. In addition, special steel, non-ferrous alloy (for example, beryllium copper), non-metallic material (for example, synthetic material of carbon fiber and plastic) ) Etc. as a material, and can be produced by an appropriate method.

The upper part 1 is shaped like a hole in the vertical direction inside a short hexagonal column, its outer peripheral shape is hexagonal, and its inner peripheral shape is a reduced hexagonal shape of the outer peripheral shape. Each corresponding side is made parallel.

The inner peripheral shape of the upper portion 1, that is, the shape of the fitting hole 4 is in accordance with the shape of the head 3 a of the bolt 3 to be used. In this embodiment, the head 3a of the bolt 3 to be used is a hexagon, and the shape of the fitting hole 4 is a hexagon in which the head 3a is fitted with almost no gap. The depth of the fitting hole 4 is such that about one third of the head 3a of the bolt 3 at the time of fastening is exposed upward (see FIG. 3), but is not limited to this. The head 3 a may be exposed to an appropriate length upward or may be completely buried in the fitting hole 4.

The lower part 2 has a substantially disk shape larger than the diameter of the upper part 1, and its upper surface is exposed in a region outside the outer periphery of the upper part 1. The upper surface is a convex curved surface corresponding to the curvature of the concave curved surface of the bottom surface 5 described later, but may be a flat surface.

The bottom surface 5 of the lower part 2 is a part in contact with the body to be fastened, but the bottom surface 5 is not a flat surface but a concave surface as shown in FIG. Therefore, the region around the bolt hole 6 in the bottom surface 5 is in a state of being spaced apart from the fastened body without contacting the fastened body at the time of fastening. In the illustrated example, the bottom surface 5 is a concave curved surface that is in contact with a part of a spherical surface of an appropriate size, but is not limited thereto. The thickness of the lower portion 2 and the curvature of the bottom surface 5 can be appropriately set according to the required fastening state.

The shape of the lower part 2 is not limited to the disk shape as illustrated, and can be appropriately set so as to be adapted to the fastened body. For example, an oval shape, a square shape or a rectangular shape is provided. Further, as shown in FIG. 6 and later, a protruding portion is provided around the periphery, or the edge portion is bent into a substantially U-shaped cross section. You may make it engage.

Further, a circular hole is formed from the bottom of the fitting hole 4 of the upper part 1 to the lower part 2, and this is a bolt hole 6 through which the shaft part 3 b of the bolt 3 can be passed.

As shown in FIG. 3, the washer has a structure in which the head 3a of the bolt 3 is built in the fitting hole 4 of the upper portion 1 as shown in FIG. It will not be loose with the bolt 3 like a washer. Therefore, the washer and the bolt 3 rotate relative to each other when the bolt 3 is tightened or after the bolt 3 is tightened, and the washer is not scraped by the head 3a of the bolt 3, and does not sag or sink. And the loosening of the bolt 3 due to this decrease is prevented. Further, the washer does not hit the screw of the shaft portion 3b of the bolt 3 and wear it. In addition, the upper portion 1 and the lower portion 2 are integrated, and are tough and excellent in durability.

Moreover, the upper part 1 can be easily tightened by using a spanner by forming the outer shape as a polygon (hexagon) so that the outer peripheral shape can be rotated by the spanner. Moreover, since the upper portion 1 has a larger diameter than the head 3 a of the bolt 3, it can be tightened more strongly than when the head 3 a of the normal bolt 3 is rotated. The upper portion 1 does not necessarily have to be a polygon so that a spanner can be used, and may be a circle or the like. However, the upper portion 1 has a good appearance by making it a polygon according to the shape of the head 3a of the bolt 3 and the nut 7. can do.

In addition, this washer has a completely different structure from that of the conventional washer so that the resistance force against elastic deformation is increased as much as possible to bring it closer to the appropriate axial force region of the bolt 3. In addition, the frictional force at the joint surface with the fastened body can be utilized to the maximum.

That is, the washer as a whole is an elastic body having high toughness, and the amount of elastic deformation becomes large, so that it is possible to sufficiently compensate for the shortage of the three-axis bolt force. In addition, since the bottom surface 5 of the lower portion 2 is concave, a gap is formed between the bottom surface 5 and the body to be fastened, and a main frictional force is generated at a position near the outer periphery of the bottom surface 5. It has become. The position at which this frictional force is generated is the longest distance (arm) from the axis of the bolt 3 that is the center of rotation, so the value of the friction torque is also the maximum (the friction torque is the friction at the contact surfaces at a number of locations. The sum of the product of the force and the distance to the center of rotation). Therefore, the slip of the washer can be remarkably reduced, and furthermore, since the friction surface can be specified, processing that increases the friction coefficient is facilitated.

In addition, if the thickness of the lower part 2 is increased, the washer can obtain a larger amount of elastic deformation, and the effect of the spacer function for preventing non-rotational loosening is enhanced. That is, increasing the thickness of the lower portion 2 increases the axial length of the bolt 3 and the thickness of the fastened body, lowers the spring constant of both the bolt 3 and the fastened body, and reduces the bolt 3 and the fastened body. Since the elastic deformation resistance increases, the axial force can be prevented from decreasing and the tightening force can be reduced less.

Next, a specific example of using this washer will be described.

[Usage example 1]
FIG. 4 is an explanatory diagram when a fastened body is fastened by a pair of upper and lower washers and bolts 3 and nuts 7. Two fastened

bodies

8 and 9 that are vertically overlapped between the pair of washers are shown. The state which pinched | interposed and fastened with the bolt 3 to the bolt holes 8a and 9a formed in these is shown. Here, the upper body to be fastened 8 can be a tilling claw in the flange type tillage claw mounting structure of a rotary tiller, and the lower body to be fastened 9 can be a flange.

In this example, of the pair of washers, the upper washer has the head 3a of the bolt 3 fitted in the fitting hole 4 of the upper part 1 and the bottom face 5 of the lower part 2 is the upper fastening body 8 ( It comes in contact with the cultivating claws. On the other hand, the lower washer is turned upside down, and the nut 7 to be screwed into the bolt 3 is fitted into the fitting hole 4 of the upper part 1, and the bottom surface 5 of the lower part 2 is the lower fastening body 9. (Flange) is in contact.

The bottom surface 5 of the lower part 2 of each washer has an air gap 10 between the fastened

bodies

8 and 9 in the vicinity of the center thereof, so that the position near the outer periphery becomes a contact surface, which causes a large friction torque. As a result, loosening of the bolt 3 can be effectively prevented.

[Usage example 2]
FIG. 5 is an explanatory view when a fastened body is fastened with one washer and the bolt 3 without using a nut, and the bolt 3 is passed through a hole 8a formed in the upper fastened body 8 and below it. The cross section of the state in which the bolt 3 is screwed into the hole 9a formed in the plate of the body 9 to be fastened is shown.

Even when fastening with only the bolt 3 without using a nut in this way, if this washer is used, it is possible to effectively compensate for a reduction in the axial force of the bolt 3 due to elastic deformation of the washer, and to lower the lower portion 2. Because of the presence of the gap 10 between the bottom surface 5 and the body 8 to be fastened, the frictional force on the joint surface with the body 8 to be fastened can be utilized to the maximum, so that loosening of the bolt 3 is effectively prevented. .

[Second Embodiment]
6 to 9 relate to a structure for attaching a tilling claw using a bolt washer according to another embodiment of the present invention.

This tillage claw attachment structure is composed of a washer (upper part 1 and lower part 2), a fastened body 8 (cultivation claw), a fastened body 9 (flange), a bolt 3 and a nut 7. The washer from above. The tillage claw 8 and the flange 9 are arranged, the bolts 3 are passed through the bolt holes 6, 8 a, 9 a provided in these respectively, and the nut 7 is screwed onto the bolt 3 from below the flange. Yes.

The flange 9 is provided with a cylindrical portion 12 that is fitted around a tilling shaft (not shown) around the tilling shaft through hole 11 located at the center thereof. The cylindrical portion 12 is formed so as to extend perpendicular to the tillage claw attachment surface of the flange 9 and the back surface thereof, that is, in the axial direction of the tillage shaft. An end portion of the tilling claw 8 is brought into contact with the tubular portion 12.

The flange 9 has a protruding first stopper 13 that abuts against the washer placed on the tillage claw 8 at a position closer to the outer peripheral edge than the bolt hole 9a on the tillage claw mounting surface. The load applied to the tilling claw 8 is absorbed.

Further, the flange 9 has a second stopper 14 in the form of a straight wall extending from the vicinity of the cylindrical portion 12 to the edge on the opposite side of the first stopper 13 across the bolt hole 9a on the surface of the tilling claw. . The second stopper 14 contacts the tillage claw 8 and absorbs the load when a load having a size or direction different from normal is applied to the tilling claw 8.

As shown in the figure, the flange 9 is provided with two bolt holes 9a, a first stopper 13 and a second stopper 14 symmetrically about the tilling shaft through hole 11. In FIG. 9, the tilling claw 8 is fastened only on one side thereof, but the tilling claw 8 can be similarly fastened on the other side.

The basic structure of the washer of the second embodiment is the same as that shown in FIG. 1 and the like, but the lower part 2 has a quadrangular shape that covers the upper surface of the base of the tilling nail 8, and a pair of diagonal parts. In addition, a protruding portion 15 protruding downward is formed. In this washer, the bottom surface 5 of the lower part 2 is in contact with the upper surface of the base of the tilling claw 8, and the projections 15 are in contact with the side surfaces of the base of the tilling claw 8, thereby preventing relative rotation with the tilling claw 8. It has become so.

The above is the embodiment of the present invention. However, the present invention is not limited to the above-described embodiment, and can be implemented in various fields such as industrial machinery. Can be changed.

Claims

It has an upper part (1) and a lower part (2) integrally formed of an elastically deformable material, and the upper part (1) has a head (3a) of a bolt (3) for fastening a fastened body inside. Or it has the fitting hole (4) opened upwards which a nut (7) fits, the lower part (2) is plate shape, and the bottom face (5) is made into the concave surface, and also the said fitting hole A bolt washer having a bolt hole (6) for allowing the shaft (3b) of the bolt (3) to pass from the bottom of (4) to the lower part (2).
The washer for bolts according to claim 1, wherein the outer peripheral shape of the upper part (1) is polygonal and can be rotated by a spanner.