JP2005106263A - Castle nut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a castle nut preventing cutting of a split pin caused by the corner part of a cut groove for inserting the split pin. <P>SOLUTION: In this hexagonal castle nut 1 having a screw hole 11 in its center and comprising by radially forming six cut grooves 12 for inserting the split pin from a center on one end surface, the nut peripheral surfaces and inner circumferential surface side corner parts 13, 13, 14 of the cut grooves 12 are formed to have a rounded shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Detailed Description of the Invention

  The present invention relates to a polygonal castle nut having a screw hole in the center and a plurality of slits for inserting split pins radially formed from one end surface.

  Conventionally, this type of castle nut is, for example, shown in FIG. 6 in which one end surface of a hexagonal nut portion 4 having a screw hole 41 at the center portion is subjected to a split cutting process and radially split from its center. A plurality of insertion cut grooves 42 are formed. In use, the castle nut 4 is screwed onto the screw portion 51 and the bolt 5 having a through hole 52 in the screw portion 51. At that time, the castle nut 4 is rotated and screwed so that the cut groove 42 is positioned in linear communication with the through hole 52 of the bolt 5. Thereafter, the leg portions 61 and 62 of the split pin 6 are inserted until the neck portion 64 of the folded portion 63 comes into contact with the outer edge of the cut groove 42 communicating with the through hole 52. The tips of the protruding leg portions 61 and 62 are bent by plastic deformation along the outer peripheral surface of the castle nut 4 using a jig (not shown) to prevent the castle nut 4 from falling off the bolt 5. Yes.

Problems to be solved by the invention

  However, in the above-described conventional castle nut 4, since one end surface of the nut portion 4 is subjected to split cutting, a plurality of split pin insertion kerfs 42 are formed radially from the center. As shown in FIG. 6, the nut outer peripheral side ends 43 and 43 of each kerf 42 are sharply sharpened. Therefore, if the split pin 6 rattles due to the clearance between the split pin 6 and the cut groove 42 or the bent state of the leg portions 61 and 62, the neck 64 of the split pin 6 and the leading end of the leg portions 61 and 62 are bent. The portion is struck by the acute angle corners of the nut outer end portions 43 and 43 of the kerf 42. As a result, there is a problem in that the neck 64 of the split pin 6 and the bent end portions of the legs 61 and 62 are cut during use, and the split pin 6 comes off the castle nut 4. Further, the nut inner peripheral ends 44 and 44 of the kerf 42 also have acute corners, so that when the split pin 6 rattles, an intermediate portion between the leg parts 61 and 62 of the cotter pin 6 becomes the kerf 42. There is a risk that the nut will be struck by the sharp corners of the nut outer end 44, 44 and cut.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a castle nut capable of preventing the split pin from being cut by the corner portion of the split pin insertion groove.

Means for solving the problem

  In order to solve the above-mentioned problems, the invention according to claim 1 of the present application is a polygonal shape having a screw hole at the center and a plurality of slits for inserting the split pins radially formed from one end surface. The castle nut is characterized in that the corner portion on the nut outer peripheral surface side of each kerf is formed in a round shape.

  The invention according to claim 2 of the present application is a hexagonal castle nut having a screw hole at the center and six slits for inserting the split pins radially formed from one end surface. The nut outer peripheral surface and inner peripheral surface side corner of the kerf are formed in a round shape.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In FIG. 1, reference numeral 1 denotes a castle nut according to the present invention. The castle nut 1 is formed in a hexagonal cylindrical shape having six outer peripheral surfaces and a screw hole 11 formed in the center. A plurality of slits 12 for split pin insertion are formed radially from the center on one axial end surface of the castle nut 1, and nut outer peripheral surface side corner portions 13, 13 and inner peripheral surface side corners of each of the slits 12. The portion 14 is formed in a round shape. In the embodiment shown in the figure, each corner portion on the nut inner peripheral surface side of the kerf 12 is formed by one large round portion, but may be formed by two small round portions.

  Reference numeral 2 denotes a shaft member (hereinafter referred to as a bolt) having a threaded portion 21 that is screwed into the screw hole 11 of the castle nut 1. The threaded portion 21 is substantially the same as the width dimension of the kerf 12 in the radial direction. A through hole 22 having the same diameter is formed.

  Further, reference numeral 3 denotes a split pin. The split pin 3 folds an intermediate portion into an arc shape to form a folded portion 31, and from the base portion of the folded portion 31, that is, from the neck portion 31a of the split pin 3 toward the tip side. Leg portions 32 and 33 extending in abutting manner and having an overall outer diameter smaller than the diameter of the through hole 22 are provided.

  The folded portion 31 has a diameter larger than the width of the kerf 12 of the castle nut 1 and is formed so as not to be inserted into the kerf 12. The rounded corner surfaces 13 and 13 of the kerf 12 have rounded surfaces. It is made to come into contact gently.

  The castle nut 1 is forged by a cold or hot forging machine depending on the material. In that case, when the windmill-like ridge part (not shown) for forming the kerf 12 is raised on the insert surface of the die for forming the kerf 12 of the castle nut 1, the tip part of each ridge part is provided. The rounded corner portions 13, 13, and 14 can be formed into a thicker round shape than the width dimension of the cut groove 12 by the amount of molding. As a result, it is possible to raise the strength of the tip portion and the base portion of the protruding portion, and to improve the life of the die, that is, the die life. Moreover, because of the forging, a kerf shape is freely required, the weight of the nut is reduced, and mass production is easy and can be obtained at low cost.

  In addition, the screw hole 11 may be continuously formed in the inner peripheral surface of the portion where the kerf 12 is formed in the castle nut 1 or may not be formed. When the screw hole 11 is not continuously formed, the inner diameter of the inner peripheral surface of the portion where the kerf 12 is formed may be set to a diameter that does not interfere with the screw portion 21 of the bolt 2.

  Next, the operation of the above embodiment will be described.

  First, an appropriate member (not shown) to be fixed to the bolt 2 is inserted, and then the castle nut 1 is screwed into the screw portion 21 of the bolt 2 so that the groove 12 is positioned on the side from which the screw portion 21 protrudes. At the same time, it is tightened until the kerf 12 communicates with the through hole 22 of the bolt 2 in a substantially straight line, and the member is appropriately attached to the bolt 2.

  Next, the leg portions 32 and 33 of the split pin 3 are inserted into the cut groove 12 on the other end side through the through hole 22 of the bolt 2 from the cut groove 12 on the one end side of the castle nut 1. Then, as shown in FIG. 1, the folded portion 31 of the split pin 3 is brought into contact with the rounded corner surfaces 13 and 13 of the rounded groove 12 on the one end side from the cut groove 12 on the other end side. The tips of the legs 32 and 33 projecting outward are bent by plastic deformation along the outer peripheral surface of the castle nut 1 using a jig (not shown). Due to the bending of the leg portions 32 and 33, the split pin 3 is attached to the cut groove 12 of the castle nut 1 and the through hole 22 of the bolt 2 so as not to come out. That is, the detachment of the castle nut 1 from the bolt 2 is prevented.

  In this case, since the corners 13 and 13 on the outer periphery of the nut of each of the kerfs 12 are formed in a rounded shape, they are split at the time of use depending on the clearance between the cotter pin 3 and the kerfs 12 and the bent state of the legs 32 and 33. Even if the pin 3 is rattled, the neck portion of the split pin and the bent portion of the leg portion are not hit by the acute corner portion of the corner portion as in the prior art. That is, the rounded outer corner portions 13 and 13 and the neck portion 31a of the split pin 3 interfere with each other gently. As a result, it is possible to effectively prevent the split pin 3 from being disconnected from the castle nut 1 by cutting the neck portion 31a of the split pin 3 during use. In addition, since the distal end bent portions of the leg portions 32 and 33 in the split pin 3 also gently interfere with the rounded outer peripheral side corner portions 13 and 13, Local wear and tear can be prevented at the same time. Further, in the present embodiment, the nut inner peripheral corner portion 14 of each of the kerfs 12 is also formed in a round shape, so that even if the split pin 6 may rattle, the round inner peripheral corner is formed. The portion 14 and the intermediate portions of the leg portions 32 and 33 of the split pin 3 will gently interfere with each other. As a result, it is possible to prevent the intermediate portions of the leg portions 32 and 33 of the split pin 3 from being cut during use. Moreover, when the nut inner peripheral corner portion 14 of each of the kerfs 12 is formed in a round shape, when the split pin 3 is inserted into the kerfs 12, the tips of the leg portions 32 and 33 of the cotter pin 3 are on the back side. There is no problem of being caught in the kerf 12, and the rounded surface of the corner portion 14 can be smoothly inserted as a guide surface.

  Also, when the nut inner peripheral corner portion 14 of each kerf 12 is formed in a rounded shape, as shown in FIG. 4, bent engagement portions 32a, If 33a is formed, the folding | returning part 31 of the split pin 3 will be struck, and the bending engagement parts 32a and 33a of the leg parts 32 and 33 will be elastically deformed using the rounded surface of the rounded corner parts 13 and 14. However, it can be forced. Thus, the leg portions 32 and 33 can be quickly and easily locked by simply inserting the split pin 3 having the bent engaging portions 32a and 33a into the groove 12 without bending the legs 32 and 33 using a jig. . In addition, since the cut groove 12 having the rounded corner portions 13 and 14 matching the split pin 3 can be formed by forging, the split pin 3 is not damaged by chattering, and the short split pin 3 can be used.

  In the above embodiment, the nut outer corner portions 13 and 13 of the kerfs 12 and the inner corner portions 14 are formed in rounded shapes. However, as shown in FIG. Only 12 nut outer peripheral side corner portions 13 and 13 are formed in a round shape to prevent cutting of the neck portion 31a of the split pin 3 and the bent portions of the leg portions 32 and 33 due to rattling during use. Good.

The invention's effect

  As described above, according to the present invention, in each of the polygonal castle nuts having a screw hole in the central portion and forming a plurality of split pin insertion kerfs radially from the center on one end face, Because the outer periphery of the nut is rounded, even if the split pin may rattle during use due to the clearance between the split pin and the groove or the bent state of the leg, And the neck of the split pin will gently interfere with each other. As a result, it is possible to effectively prevent the split pin from being disconnected from the castle nut due to the neck portion of the split pin being cut during use as in the prior art. Further, since the bent leg portion of the split pin also gently interferes with the rounded corner portion, local wear and breakage of the bent leg portion can be prevented at the same time.

  In addition, in a hexagonal castle nut having a screw hole in the center and radially forming six slits for inserting split pins from the center on one end face, the nut outer peripheral surface and inner periphery of each of the slits If the surface side corner is formed in a rounded shape, even if the split pin may rattle during use due to the clearance between the split pin and the cut groove or the bent state of the leg, The outer peripheral surface of the nut and the inner peripheral surface side and the neck and legs of the split pin gently interfere with each other. As a result, the neck and leg of the split pin are cut during use, and the split pin becomes a castle nut. It can be prevented from falling off. In addition, when inserting the split pin into the kerf, it is possible to smoothly insert the rounded surface as a guide surface without the problem that the tip of the leg part of the cotter pin is caught by the inner peripheral surface side corner of the rear kerf. Can do. In addition, when the inner peripheral surface side corner portion of the kerf is formed in a rounded shape, if the bent engaging portion is formed in advance at the tip of the leg portion of the split pin, the leg of the split pin is hit by hitting the head. It is possible to forcibly fit the bent engaging portion of the portion while elastically deforming using the rounded surface of the rounded corner portion, thereby enabling the split pin to be quickly and easily locked into the groove. .

  It is a perspective view which shows embodiment of the castle nut of this invention.   It is a front view of the castle nut.   It is a side view of the castle nut.   It is explanatory drawing of a split pin with a bending engagement part.   It is a front view of the castle nut which shows another embodiment.   It is explanatory drawing of a prior art example.

Explanation of symbols

1 Castle nut 3 Split pin 11 Screw hole 12 Groove 13 Corner part 14 Corner part

Claims (2)

  A polygonal castle nut having a threaded hole in the center and a plurality of slits for inserting split pins radially from the center on one end surface. A castle nut characterized by being formed into   A hexagonal castle nut having a screw hole at the center and six slits for inserting split pins radially from the center on one end surface. A castle nut characterized by a rounded corner.

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