JP3272265B2 - Lock nut - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates <br/> to the self-locking nuts.

[0002]

2. Description of the Related Art Conventionally, various lock nuts have been devised.

[0003]

However, there is no one that is low in cost, has high productivity, and can exert a stable loosening prevention function even when it is used more than once. Therefore, an object of the present invention is to provide a locking nut that is low in cost, has high productivity, and can exhibit a stable locking action even when used multiple times.

[0004]

Means for Solving the Problems In order to solve the above problems, the present invention has taken the following technical means. That is, the present invention provides a nut having a tool mounting portion and a projecting portion projecting in the axial direction from the tool mounting portion, and a bolt hole is provided over the tool mounting portion and the projecting portion. A plurality of vertical grooves are formed in the circumferential direction on the outer peripheral side of the projecting portion,
At least one of the blocks between the vertical grooves is pressed and deformed radially inward.

In such a locking nut, since a vertical groove is formed between a block to be pressed and deformed and a block adjacent to the block, only a required block is pressed by pressing or the like while suppressing deformation of the adjacent block. The required amount can be deformed, and the deformation is performed without difficulty,
Productivity can be improved and costs can be reduced. Further, before fastening to the bolt, the bolt hole is reduced in diameter at the inner peripheral portion of the pressed and deformed block, and when the bolt is fastened, the block is pushed and expanded radially outward by the bolt. However, at this time, since the vertical groove forming portion exerts a resilient action and is elastically deformed, when the nut is removed from the bolt, it returns to the original reduced diameter deformation state by elastic force, and when multiple times of attaching and detaching, Also exerts a large locking action stably.

Further, a plurality of blocks deformed by pressing are
If the plurality of blocks are uniformly arranged over the entire circumference at a constant interval in the circumferential direction, at the time of manufacturing, when the plurality of blocks are pressed and deformed from the outside, the pressing force acting on these blocks is offset, and the deformation is performed. The support of the nut at the time can be simplified, and the plurality of blocks can be deformed almost uniformly. Further, when the product is used, a load acts between the inner surface of the deformed block and the outer surface of the bolt when screwing into the bolt,
Since such a load acts uniformly in the circumferential direction, there is almost no deviation between the bolt axis and the nut axis, and the workability of fastening to the bolt is good, and a large compressive force is applied only to a part in the circumferential direction. Can be prevented from acting. The number of such a plurality of modified blocks is preferably three .

The outer diameter of the pressed and deformed block is
It is preferable to make the diameter larger at least before deformation than the outer diameter of the block that is not pressed and deformed. According to this configuration, the block to be deformed is projected radially outward compared to the other blocks, so that the block to be deformed can be easily deformed by pressing.

Further, when the protruding portion has a truncated conical shape whose outer diameter is reduced in the axial direction outward, it is easy to use a press body having a truncated conical concave portion into which the protruding portion fits. The required blocks can be deformed quickly and the productivity can be further improved and the cost can be reduced. Further, by adjusting the compression stroke of the press body, the amount of deformation can be easily adjusted. Since the protruding portion gradually becomes thinner on the protruding tip side, the deformation on the tip side is performed relatively easily.

The following is preferred as a method of manufacturing the above-mentioned locking nut. First, it has a tool mounting portion and a projecting portion projecting from the tool mounting portion in the shape of a truncated cone that tapers outward in the axial direction, and on the outer peripheral side of the projecting portion, in the circumferential direction. While forming a plurality of vertical grooves, manufacture an intermediate product formed by forming a bolt hole over the tool mounting portion and the projecting portion, and, from above the projecting portion of the intermediate product,
By pressing a press body in contact with at least one outer surface of the blocks between the longitudinal grooves against the intermediate product along the axial direction, a part of the blocks is radially deformed.

According to this method, a large pressing force can be applied to a required block in the diameter reducing direction by a wedge action (taper action) of a contact portion between the projecting portion and the press body. Deformation processing can be performed, and by synchronizing the transfer of the intermediate product and the reciprocating operation of the press body, it is possible to manufacture a locking nut of a certain quality with extremely high productivity. Furthermore, since the contact portion between the press body and the protruding portion is tapered, the deformation amount of the protruding portion linearly changes according to the stroke amount of the press body, so that a small amount of deformation can be adjusted.

[0011]

1 to 4 show a lock nut 1 according to an embodiment of the present invention. The nut 1
Has a hexagon nut-shaped tool mounting portion 2 and a projecting portion 3 protruding in the axial direction from one axial end of the tool mounting portion 2. It is desirable that the tool mounting portion 2 and the projecting portion 3 are integrally formed by cold forging, but it is also possible to use hot forging or other forming methods.

The protruding portion 3 has a truncated conical shape whose outer diameter decreases in the axial direction toward the outside, and a plurality of vertical grooves 6 are formed on the outer peripheral side of the protruding portion 3 in the circumferential direction. Is formed. The longitudinal groove 6 is a long concave groove formed over the entire length of the projecting portion 3 in the axial direction, and can be formed simultaneously with the above-described cold forging. Further, a bolt hole 7 extending over the tool mounting portion 2 and the projecting portion 3 is formed.

In the illustrated embodiment, six longitudinal grooves 6 are provided as shown in FIG. If two vertical grooves 6 are paired, a total of three vertical groove pairs are formed, and the circumferential width of the block 4 between the pair of vertical grooves 6 is different from that of the block between adjacent pairs of the vertical grooves 6. 5 is about half of the circumferential width. The block 4 between the pair of vertical grooves 6 is formed after the bolt hole 7 is formed.
It is pressed and deformed slightly inward in the radial direction, and
Distorting the bolt hole 7 in the inner surface portion of the block 4,
It is designed to provide a locking action when attached to a bolt.

That is, in the illustrated embodiment, there are three blocks 4 that have been pressed and deformed, and these three blocks 4 are arranged uniformly over the entire circumference at a constant interval in the circumferential direction. ing. The outer diameter of the pressed and deformed block 4 is larger than the outer diameter of the block 5 that is not pressed and deformed.

A method of manufacturing the above-described locking nut 1 will be described below. First, by cold forging, the outer shape of the hexagon nut-shaped tool mounting portion 2 and the outer shape of the tapered truncated cone-shaped protruding portion 3 projecting outward from the tool mounting portion 2 in the axial center direction. To form At this time, the vertical groove 6 is formed in the protruding portion 3 and the outer diameter of the deformable block 4 is forged so as to be larger than the outer diameter of the non-deformed block 5. After the forging, the bolt holes 7 are formed by cutting to obtain an intermediate product 9 before deformation (before caulking). The female thread root diameter P of the bolt hole 7 in the intermediate product 9 is
The same is true over the entire axial length. Note that the bolt holes 7 may be formed at the same time during the forging.

The intermediate product 9 is conveyed to a press by a conveyor or the like, and the block 4 to be deformed is pressed by the press.
Is pressed and deformed radially inward. This press machine has a press body 10 having a recess 11 into which the protruding portion 3 of the nut 1 fits.
By moving the press body 10 up and down, the block 4 to be deformed of the projecting portion 3 of the intermediate product 9 that is sequentially conveyed is reduced in diameter by a required amount. . After this deformation, the female screw root diameter S at the end of the bolt hole 7 on the protruding portion 3 side on the inner surface side of the deformation block 4 is changed.
Is slightly reduced from the diameter P before deformation, as shown in FIG. Assuming that the amount of deformation of the block 4 inward in the radial direction is ds, the relationship of P = S + 2ds is substantially established.

The inner peripheral surface of the concave portion 11 is formed in a truncated conical shape, and is configured to be able to make surface contact with the outer surface of the block 4 to be deformed. By pressing only the required stroke,
The block 4 is strongly deformed by a taper action while being in surface contact with the outer surface of the block 4 to be deformed.

According to this manufacturing method, the required block 4 is adjusted by adjusting the stroke amount of the press body 10.
Can easily and accurately adjust the amount of deformation, thereby improving quality and productivity.

The present invention is not limited to the above-described embodiment, and the design can be changed as appropriate.

Although the outer diameter of the deformable block 4 is made larger than the outer diameter of the non-deformable block 5, the outer diameter of the deformable block 4 may be the same as that of the non-deformable block 5. It can be smaller than the diameter. As a deformation method using the press body 10 in this case, the shape of the press body 10 is designed so that the press body 10 abuts only on the outer surface of the small-diameter deformation target block 4 (for example, in the inner periphery of the concave portion 11 of the press body 10). It is possible to provide a ridge.

The shape of the tool mounting portion 2 is not limited to a hexagonal nut shape, but may be any shape that matches any tool present and future.

[0022]

According to the present invention, a locking nut that exhibits a stable locking action even when used in a plurality of times of attachment and detachment can be obtained at low cost, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a locking nut according to an embodiment of the present invention.

FIG. 2 is a plan view of the locking nut.

FIG. 3 is a longitudinal sectional view showing a manufacturing process of the locking nut.

FIG. 4 is a sectional view taken along line AA of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Loose lock nut 2 Tool mounting part 3 Projecting part 4 Block to be deformed 5 Non-deformed block 6 Vertical groove 7 Bolt hole 9 Intermediate manufactured body 10 Pressed body

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-71549 (JP, A) JP-A-53-70257 (JP, A) JP-A-10-169628 (JP, A) 41928 (JP, U) JP-A-59-105650 (JP, U) JP-B-45-12176 (JP, B1) JP-T-Hei 6-511304 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B21J 1/00-13/14 B21J 17/00-19/04 B21K 1/00-31/00 F16B 39/02

Claims (1)

(57) [Claims] A tool mounting portion (2) and a projecting portion (3) projecting from the tool mounting portion (2) in the axial direction, the tool mounting portion (2) and the projecting portion being provided. part (3) in the nut bolt hole (7) is provided over, on the outer peripheral side has a plurality of longitudinal grooves in the circumferential direction (6) is formed of the projecting portion (3), the longitudinal grooves (6 ) Is a protruding part
(3) a long concave groove formed over the entire length in the axial direction;
And at least one block (4) of the blocks (4, 5) between the vertical grooves (6) is pressed and deformed inward in the radial direction , thereby tightening the bolt.
The block (4) pressed and deformed by the
On the inner periphery of the block (4) so that it can be expanded
To reduce the diameter of the bolt hole, and two vertical grooves
A total of three pairs of vertical grooves are formed with (6) as a pair, and this pair is
Block (4) between the vertical grooves (6)
(4) between different pairs of adjacent flutes (6).
The block (5) is a block (5) that is not pressed and deformed.
Self-locking nut, characterized in that that.