JPH0622614U - Bolt tightening tool - Google Patents

Abstract

(57) [Summary] [Purpose] It is an object of the present invention to provide a bolt tightening tool that can obtain manufacturing cost and simplicity in manufacturing. [Structure] A bolt tightening tool interposed between the bolt head 1A or the nut and the fastening object 2. A spring washer 3 having circumferentially divided split portions 3a and 3b, a first loosening prevention member 4 that engages with the fastening target 2, and the bolt head 1
A or a second loosening prevention member 24 that engages with a nut, and the split end 3a displaced downward of the spring washer 3 when the spring washer 3 is slightly loosened is the first loosening prevention member 4
The divided end portion 3b which is fitted into the concave portion 4d of the
Is fitted into the concave portion of the second loosening prevention member 24 to prevent the bolt 1 or the nut from rotating in the loosening direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bolt tightening tool used as various machine elements, and more particularly to a bolt tightening tool for preventing loosening of various bolts such as through bolts, holding bolts, stud bolts, and nut bolts.

[0002]

[Prior art]

 The bolts are prevented from loosening by means such as spring washers, rubber washers, or bite-type spring washers.The tightening action is to urge the screw threads to engage in opposite directions by tightening reaction force. However, increasing the friction between the two threads prevents the screws from loosening. When this type of spring washer is used, when tightening the bolt or nut, a large frictional force can be applied to the threads that are screwed together by the force that the increased spring washer tries to restore, preventing the bolt or nut from loosening. However, once a slight loosening occurs due to vibration etc., there is a gap in which the spring washer can be elastically displaced, so that rather the elastic restoring force rather acts to promote the loosening, and as a result, the bolt Or the situation where the connection of the nut was disconnected was reached.

Therefore, in order to solve the problems of the prior art, the present inventor has proposed a bolt tightening tool in Japanese Patent Application No. 3-132323. As shown in FIGS. 3 and 4, this bolt tightening tool is a bolt tightening tool interposed between the bolt head 1A or the nut and the object to be fastened 2, and is divided at one position in the circumferential direction. When not compressed, the split parts 3a and 3b are displaced in the axial direction X of the bolt 1 and formed into a flat ring shape when compressed, and on the upper surface 3c thereof that contacts the bolt head 1A or the nut. At least one spring washer 3 provided with at least one engaging projection 3d is interposed between the lower surface 3e of the spring washer 3 and the object 2 to be fastened, and the lower surface 4a corresponding to the object 2 to be fastened is at least It comprises a loosening prevention member 4 provided with one engaging projection 4b and at least one engaging recess 4d on an upper surface 4c thereof which abuts a lower surface 3e of the spring washer 3. When relaxing Serial split ends 3a displaced downward spring washer 3 is inserted engages the bolt 1 or in the recess 4d is one that is configured to prevent rotation of the loosening direction of the nut.

Thereby, for example, between the bolt head 1A and the object 2 to be fastened, the spring washer 3 is positioned on the upper side, the relaxation preventing member 4 is positioned on the lower side, and the bolt head 1A is rotated by a spanner. Then, the engaging projection 3d on the upper surface 3c of the spring washer 3 contacts the lower surface of the bolt head 1A, and the engaging projection 4b on the lower surface 4a of the loosening prevention member 4 contacts the fastening object 2. Since the spring washer 3 having no engaging projection and the loosening prevention member 4 are tightened while slipping, the projection 3d on the upper surface 3c of the spring washer 3 and the lower surface of the bolt head 1A and the loosening prevention member 4 are provided. The engagement protrusion 4b of the member 4 and the fastening target object 2 are pressed in the vertical direction (in the axial direction of the bolt) without slipping (point contact), and bite in the fitted state can be obtained. .

Therefore, relative rotation between the bolt 1 and the spring washer 3 and between the loosening prevention member 4 and the fastening object 2 is prevented. After that, when the bolt 1 is slightly loosened, a slight gap is also generated between the spring washer 3 and the loosening prevention member 4, but this causes the spring washer 3 to be divided. The parts 3a and 3b are slightly displaced in the axial direction X of the bolt 1 due to the restoring force, and the divided part 3a displaced downward is fitted into the engagement recess 4d of the relaxation preventing member 4. As a result, the loosening prevention member 4 receives and prevents the shifted divided portion 3a from further turning. At this time, in the case where the number of the engaging concave portions 4d is one, when the bolt 1 is initially tightened, it depends on how much the circumferential position is displaced with respect to the divided portion 3a. It may not be possible to immediately engage the engaging recess 4d when the bolt 1 is loosened, but the engagement between the two is obtained within at least one rotation. Thus, the relative slip between the spring washer 3 and the loosening prevention member 4 in the loosening direction is prevented, and as a result, the loosening of the bolt 1 is prevented.

[0006]

However, the above-mentioned invention proposed by the present inventor has a remarkable effect that the loosening of the bolt 1 can be prevented, but the upper surface 3c of the spring washer 3 has the above-mentioned effect. Since the projection 3d is provided, the spring washer 3 must be manufactured as a special one. Therefore, since the spring washer 3 uses a spring rope in addition to increasing the manufacturing cost, it is necessary to heat-treat only the protrusion 3d formed on the spring washer 3 to make it relatively hard. Since it is necessary to perform a local heat treatment while maintaining the elasticity as a whole, there were difficulties in manufacturing.

It is an object of the present invention to improve the above-mentioned prior invention and to provide a bolt tightening tool which can obtain manufacturing cost and manufacturing simplicity.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the bolt tightening tool according to the present invention is divided at one position in the circumferential direction in the bolt tightening tool interposed between the bolt head 1A or the nut and the fastening object 2. A spring washer 3 configured such that the divided portions 3a and 3b are displaced in the axial direction X 1 of the bolt 1 when not compressed and has a flat ring shape when compressed, a lower surface 3e of the spring washer 3 and the fastening object. 2 and at least one engaging projection 4b is provided on the lower surface 4a facing the fastening object 2 and at least one engaging projection is provided on the upper surface 4c that contacts the lower surface 3e of the spring washer 3. At least one engagement member is provided on the upper surface 24e which is interposed between the first relaxation prevention member 4 having the recess 4d and the bolt head 1A or the nut and the spring washer 3 and faces the bolt head 1A or the nut. A second relaxation preventing member 24 provided with a projection 24f and at least one engaging concave portion on a lower surface 24g facing the upper surface 3f of the spring washer 3 is provided when the spring washer 3 slightly relaxes. The split end 3a of the spring washer 3 that is displaced downward engages with the recess 4d of the first loosening prevention member 4, and the split end 3b that is displaced upward is in the recess of the second relaxation prevention member 24. It is configured to be fitted and engaged so as to prevent the bolt 1 or the nut from rotating in the loosening direction.

[0009]

[Action]

 According to the bolt tightening tool of the present invention, as shown in FIGS. 1 and 2, for example, the spring washer 3 is interposed between the bolt head 1A and the object 2 to be fastened, and the first loosening prevention member is provided. 4 is located on the lower side, the second relaxation prevention member 24 is located on the upper side, and the bolt head 1A is rotated by a spanner, the first relaxation prevention member 4 and the second relaxation prevention member 4 through the spring washer 3. The distance from the blocking member 24 becomes narrower, the engaging protrusion 4b of the first loosening preventing member 4 bites into the fastening object 2, and the engaging protrusion 24f of the second loosening preventing member 24 becomes the lower surface of the bolt head 1A. Cut into 1B. At this time, since the upper and lower surfaces of the spring washer 3 having no engaging projection and the first relaxation preventing member 4 and the second relaxation preventing member 24 are tightened while causing a slip, the second relaxation preventing member 4 The engaging projection 24f of 24, the lower surface of the bolt head 1A, the engaging projection 4b of the first loosening prevention member 4, and the fastening target 2 are in the vertical direction (point contact) without causing slippage (point contact). Pressure is applied in the axial direction of the bolt), and biting in the fitted state can be obtained.

Therefore, in this state, relative rotation between the bolt 1 and the second loosening prevention member 24, and between the first relaxation prevention member 4 and the fastening target object 2 is prevented. After this, if the bolt 1 is slightly loosened, a slight gap is also generated between the spring washer 3 and the first and second relaxation preventing members 4 and 24, respectively. As a result, the divided portions 3a and 3b of the spring washer 3 are slightly displaced by the restoring force in the axial direction X direction (vertical direction) of the bolt 1, respectively, and the divided portion 3a displaced downward is caused. The divided portion 3b, which is fitted into the engaging recess 4d of the first loosening prevention member 4 and is displaced upward, is fitted into the lower surface 1B of the bolt head 1A. As a result, the shifted divided portions 3a and 3b are received by the engaging recesses 4d of the first and second relaxation preventing members 4 and 24, and are prevented from rotating.

At this time, when the number of the first and second engaging recesses 4d is one, when the bolt 1 is initially tightened, the circumferential direction of the divided parts 3a and 3b is increased. Depending on whether or not the bolt 1 is in the displaced position, it may not immediately engage with the engaging recess 4d when the bolt 1 is loosened, but the engagement between the two does not occur within at least one rotation. It is obtained (if there are many, they can be engaged immediately). In this way, the spring washer 3 and the first and second loosening prevention members 4 and 24 are engaged with the bolt 1 and the fastening object 2 in a biting engagement with each other. As a result of the relative slippage between the loosening prevention members 4 and 24 in the loosening direction being prevented, the loosening of the bolt 1 is prevented.

[0012]

【Example】

 A preferred embodiment of the bolt tightening device of the present invention will be described in detail below with reference to FIGS. 1 and 2.

As shown in FIGS. 1 and 2, bolt tightening when interposing between the bolt head 1 A of the presser bolt 1 (which is a nut in the case of an implant bolt) and the object to be fastened 2. The ingredients will be described. Reference numeral 3 denotes a spring washer, which is divided at one position in the circumferential direction, and is configured such that when the non-compressed portions 3a and 3b are displaced in the axial direction X of the bolt 1, both are flat ring-shaped when compressed. Has been done.

Reference numeral 4 denotes a first relaxation preventing member, which is interposed between the lower surface 3 e of the spring washer 3 and the fastening target object 2 and has at least one engagement with a lower surface 4 a facing the fastening target object 2. The projection 4b is provided, and at least one engaging recess 4d is provided on the upper surface 4c of the spring washer 3 which comes into contact with the lower surface 3e.

Reference numeral 24 denotes a second relaxation prevention member, which is interposed between the first relaxation prevention member 4, the bolt head 1A and the spring washer 3, and is an upper surface 24e facing the bolt head 1A. Is provided with at least one engaging projection 24f, and at least one engaging recess (not shown in the figure, for engaging the first loosening prevention member 4) is provided in the lower surface 24g of the spring washer 3 facing the upper surface 3f. The recess 4d has substantially the same structure as that of the recess 4d.

In the first relaxation prevention member 4, the second relaxation prevention member 24, and the spring washer 3, the split end portion 3 a displaced downward of the spring washer 3 when the spring washer 3 slightly relaxes is the first relaxation. The split end 3b which is fitted into the recess 4d of the blocking member 4 and is displaced upward is fitted into the recess of the second loosening blocking member 24 to rotate the bolt 1 or the nut in the loosening direction. It is configured to block.

The spring washer 3 may be a generally used one, and the first relaxation block member 4 and the second relaxation block member 24 can be made of appropriate materials, and their structures are substantially the same. The structure is advantageous in terms of manufacturing. For example, as a specific structure, a chrysanthemum shape can be adopted as shown in FIGS. 1 and 2.

The engaging protrusions 4b and the engaging protrusions 24f only need to have a hardness that can bite into the fastening object 2 and the lower surface 1B of the bolt 1, and the hardness can be obtained by surface hardening. The engaging projections 4b and the engaging projections 24f themselves may be constructed by arranging with pins or screws made of a hard material.

[0019]

[Effect of device]

 According to the present invention, it is possible to provide a bolt tightening tool having the anti-loosening effect of the prior application while using a normal vane washer, and it is difficult to provide a protrusion for engagement on the spring washer. Compared with the structure, there is an advantage that the manufacturing cost can be drastically reduced. The first relaxation prevention member and the second relaxation prevention member can have substantially the same structure, which is advantageous in manufacturing.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a bolt tightening tool according to the present invention.

FIG. 2 is a vertical cross-sectional side view of a bolt tightening tool according to the present invention in use.

FIG. 3 is an exploded perspective view of a bolt tightening tool showing a conventional technique.

FIG. 4 is a vertical cross-sectional side view of a conventional bolt tightening tool in use.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 bolt 1A bolt head 1B lower surface of bolt 2 object to be fastened 3 spring washer 3a split portion of spring washer 3b another split portion of spring washer 4 first relaxation prevention member 24 second relaxation prevention member

Claims (1)

[Scope of utility model registration request] 1. A bolt head 1A or a nut and a fastening object 2
In the bolt tightening tool interposed between and, it is divided at one position in the circumferential direction, and when not compressed, the divided portions 3a, 3b
Is displaced in the axial direction X of the bolt 1 and is interposed between the spring washer 3 configured to have a flat ring shape when compressed, the lower surface 3e of the spring washer 3 and the fastening object 2, and First relaxation prevention in which at least one engaging projection 4b is provided on the lower surface 4a facing the fastening object 2 and at least one engaging concave portion 4d is provided on the upper surface 4c that abuts the lower surface 3e of the spring washer 3. An upper surface 24e that is interposed between the member 4, the bolt head 1A or the nut, and the spring washer 3 and faces the bolt head 1A or the nut.
Of the spring washer 3 and at least one engaging projection 24f on the lower surface 24g of the spring washer 3 facing the upper surface 3f of the spring washer 3. When the spring washer 3 slightly relaxes, the split end 3a displaced downward is fitted into and engaged with the recess 4d of the first loosening prevention member 4, and the split end 3b displaced upward is the second relaxation inhibiting member. A bolt tightening tool configured to be fitted into the concave portion of 24 and prevent rotation of the bolt 1 or the nut in a loosening direction.