JP3144885U - Cap nut for insert - Google Patents

Abstract

Provided is an insert cap nut that has an excellent detent function and a retaining function, has excellent dimensional accuracy in the height direction, and can prevent the inflow of resin into a female screw portion.
A female screw 3 is formed in a through hole 2 provided in the center of a nut body 1 and a lid 5 is fitted in an annular recess 4 provided in an upper end surface of the nut body 1. An insert cap nut in which the periphery is caulked and the lid 5 is integrally coupled to the nut body 1. On the outer periphery of the lower part of the nut body 1, a stepped portion 7 is provided as a contact surface for retaining. In addition, a shaft portion 8 having a diameter smaller than the outer diameter of the nut body 1 is connected to the stepped portion 7, and a locking piece 9 for preventing rotation is provided on the outer periphery of the shaft portion 8.
[Selection] Figure 2

Description

  The present invention relates to a cap nut for an insert that has an excellent detent function and a retaining function, has excellent dimensional accuracy in the height direction, and can prevent the inflow of resin into the female screw part. .

  Conventionally, when fixing parts to synthetic resin workpieces or fixing and assembling each other workpieces, screw members are screwed directly to the workpiece and fastened, or through holes are formed in the workpiece. For example, a method of sandwiching a workpiece with a bolt and a nut member and fastening it is widely used. Recently, due to demands for miniaturization and weight reduction, insert cap nuts are integrated with synthetic resin workpieces by insert molding instead of the conventional fixing method, and this insert cap nut is formed. A method of fixing a synthetic resin product by screwing a screw member to a female screw has also been generalized (see, for example, Patent Document 1 and Patent Document 2). In particular, in the case of use with precision parts, it is necessary to prevent the ingress of water and the fall of foreign matter at the time of fastening, so that the need for cap nuts also tends to increase from this point.

  However, in conventional cap nuts, the internal thread is usually formed by tapping, but it is necessary to reciprocate the tap in order to process it so that the bottom remains, and tapping is performed on the bottom. There is a problem that a long space is required. In particular, in the case of insert-molded cap nuts, the height of the workpiece is reduced because of the dimensional restrictions associated with the thinning of the workpiece and the fact that the resin flows into the nut during insert molding when the height varies. The dimensional accuracy in the direction is under strict control, and there is a problem that a finishing process by cutting is required as a final process, resulting in poor productivity and high production cost. Furthermore, in the case of the conventional cap nut, since plating was performed in the state of the cap nut, there was also a problem that plating did not adhere to the inner portion of the nut.

On the other hand, a general cap nut has been proposed in which a screw is formed in a state of being penetrated by tapping, and then integrated by attaching a lid to the opening of one hole. However, since such a cap nut is not for inserts, a rotation preventing part and a retaining part are not formed, and cannot be applied as an insert nut as it is.
Also, as a forging technique, it is difficult to process only the forging part and the retaining part having a shape protruding from the reference surface by forging because of the die-cutting relationship. In order to form the retaining portion, it is necessary to add cutting after forging, or finish by adding rolling and cutting. As a result, there is a problem that productivity is inferior and production cost is increased. there were.
JP 2004-106468 A JP 2001-138309 A

  The present invention solves the above-mentioned problems, can exhibit excellent anti-rotation function and anti-separation function, and finishes the anti-rotation part and anti-retention part by adding rolling or cutting. In addition, it can be molded only by forging, and it is excellent in productivity and production cost. Further, it has excellent dimensional accuracy in the height direction and can prevent the inflow of resin, and plating is not attached to the inner part of the nut The present invention has been completed for the purpose of providing a cap nut for an insert that can prevent the occurrence of the above.

  The cap nut for inserts of the present invention made in order to solve the above-mentioned problems has a female screw formed in a through hole provided in the center of the nut body, and a lid body in an annular recess provided in the upper end surface of the nut body. Is a cap nut for an insert in which the lid is integrally joined to the nut body by caulking the periphery of the recess, and a stepped portion serving as a contact surface for retaining is provided on the outer periphery of the lower portion of the nut body, A shaft portion having a diameter smaller than the outer diameter of the nut main body is continued to the step portion, and a locking piece for preventing rotation is provided on the outer periphery of the shaft portion.

It is preferable that the locking piece for rotation prevention is a projecting body that hangs downward from the step portion, and this is a device according to claim 2.
The outer diameter of the locking piece for preventing rotation is preferably equal to or smaller than the outer diameter of the nut body so that the die can be removed. However, it is preferable that a plurality of the shaft portions are projected evenly, and this is a device according to claim 4.

  Further, it is preferable that the retaining step and the locking piece are formed only by a forging process, and this is a device according to claim 5.

  In the present invention, a cap nut for an insert in which a lid is integrally coupled to a nut body, a stepped portion serving as a contact surface for retaining is provided on the outer periphery of the lower portion of the nut body, and the nut body is provided at the stepped portion. Since the shaft portion reduced in diameter from the outer diameter is continued and a locking piece for preventing rotation is provided on the outer periphery of the shaft portion, the lid prevents the resin from flowing into the female screw portion. In addition, the retaining function and the detent function are also exhibited.

  Further, in the device according to claim 2, since the locking piece for rotation prevention is a projecting body that hangs downward from the stepped portion, it can be removed from the mold, and the stepped portion for locking and the rotation prevention Both of the locking pieces can be formed by forging.

  Further, in the invention according to claim 3, since the outer diameter of the locking piece for preventing rotation is set to be smaller than the outer diameter of the nut main body so that the die can be removed, similarly, the outer diameter of the locking portion for the stopper is prevented. Both the locking pieces for stopping can be formed by forging.

  Further, in the device according to claim 4, since a plurality of locking pieces for rotation prevention are projected evenly on the shaft portion, the rotation prevention function is more reliably exhibited.

  Further, in the device according to claim 5, since the retaining step and the locking piece are formed only by the forging process, the rolling or cutting process is performed after forging as in the prior art. There is no need to finish and finish, and excellent productivity will be exhibited.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
The drawings show an insert cap nut according to the present invention. FIG. 1 is a front view, FIG. 2 is a cross-sectional view thereof, and FIG. 3 is a perspective view as viewed from below.
In the figure, 1 is a nut body, 2 is a through hole provided in the center of the nut body 1, and 3 is a female screw formed in the through hole 2. Further, an annular recess 4 is provided on the upper end surface of the main body 1, and a lid 5 is fitted into the recess 4, and a claw piece 6 on the periphery of the recess 4 is caulked, An insert cap nut in which the lid 5 is integrally coupled to the nut body 1 is used.

  In such a nut, since the female screw 3 can be formed through the through-hole 2 by tapping, unlike the conventional cap nut, one end of the screw is very easy to machine. In addition, since the lid body 5 is fitted into the opening at the upper end of the through hole 2 to form a cap nut, the resin can be transferred into the female screw portion even when integrated with a synthetic resin workpiece (not shown) by insert molding. There is no inflow. Further, when the lid body 5 is fitted in the recess 4 and the claw piece 6 on the periphery is caulked, the nut body 1 can be accurately measured in the height direction. The desired dimensional accuracy can be ensured without going through the process, and excellent productivity is exhibited.

On the outer periphery of the lower part of the nut body 1, a stepped portion 7 is provided as a contact surface for retaining. The step portion 7 prevents the nut body 1 from being lifted by a reaction force when the bolt is screwed. When the step portion 7 is integrated with a synthetic resin workpiece by insert molding, the step portion 7 and the bitten synthetic resin are bitten. Prevents the nut body 1 from coming off.
In the prior art, the retaining function is normally swelled and formed on the outer peripheral surface of the shaft portion, which is not possible with a forging die alone because of die cutting. Therefore, after forging, it is necessary to finish by adding cutting or the like, and there is a problem that productivity is inferior and production cost is increased.
On the other hand, the present invention makes it possible to form the stepped portion 7 serving as a contact surface for retaining the nut simultaneously with the molding of the nut body 1 in the forging process, and the conventional problems as described above. It can be solved.

Further, the stepped portion 7 is followed by a shaft portion 8 having a diameter smaller than the outer diameter of the nut body 1, and a locking piece 9 for preventing rotation is provided on the outer periphery of the shaft portion 8. .
A through hole 2 is provided inside the shaft portion 8, and a female screw 3 is formed therein. Further, the locking piece 9 protruding from the outer periphery of the shaft portion 8 is for preventing the nut body 1 from being rotated around when the bolt is screwed, and is integrated with a synthetic resin workpiece by insert molding. In addition, the nut 9 is prevented from being rotated by the contact between the side surface portion 9a of the locking piece 9 and the synthetic resin biting into the side surface portion 9a.

The locking piece 9 for preventing rotation is a projecting body that hangs downward from the stepped portion 7. In the illustrated example, the locking piece 9 is composed of a rectangular strip-shaped bulging body, and is arranged so that the longitudinal direction is along the axial direction. Further, the outer diameter of the locking piece 9 is set to a dimension equal to or smaller than the outer diameter of the nut body 1 so that the die can be removed.
In the prior art, the stepped portion for retaining and the locking piece for preventing rotation are in a state of protruding from the reference surface, and therefore, after forming the nut main body by forging, it has been formed by adding cutting or the like . Accordingly, although it was inferior in productivity, in the present invention, it is possible to perform die-cutting, and the step 7 for retaining and the locking piece 9 for preventing rotation are processed by forging simultaneously with the formation of the nut body 1. As a result, productivity can be greatly improved.

  In addition, it is preferable that a plurality of the locking pieces 9 for preventing rotation can be provided on the shaft portion 8 evenly so that the effect of preventing rotation can be obtained.

  In the present invention, it is possible to form the retaining step 7 and the locking piece 9 only by a forging process. That is, in the insert cap nut of the present invention, a stepped portion 7 is provided on the outer periphery of the lower portion of the nut body 1 as a contact surface for retaining, and a shaft portion 8 having a reduced diameter is connected to the stepped portion 7. A locking piece 9 for preventing rotation is provided on the outer periphery of the shaft portion 8, and the outer diameter of the nut body 1 is the maximum outer diameter in the axial direction. Therefore, if the nut body 1 is pulled upward after forging, there is no projecting part having an outer diameter larger than the maximum outer diameter at the lower part, so that the die can be punched. In this case, a product in which both the retaining portion and the retaining portion are firmly formed can be obtained.

Thereafter, the female screw 3 is formed through the through hole 2 by tapping, and further, the lid 5 is fitted into the recessed portion 4 and the peripheral claw piece 6 is caulked to complete the insert cap nut.
In addition, since the accuracy in the height direction of the nut body 1 can be obtained when caulking, a desired dimensional accuracy can be ensured without passing through a finishing process by cutting as a final process. Moreover, when integrating with a resin workpiece by insert molding, there is also an advantage that the resin can be reliably prevented from flowing into the female screw. Of course, the step 7 for retaining and the locking piece 9 for preventing rotation exhibit an excellent detent function and retaining function. Furthermore, since the nut main body and the lid can be separately plated, there is also an advantage that it is possible to prevent the occurrence of unplated plating on the inner side of the nut.

It is a front view which shows embodiment of this invention. It is sectional drawing which shows embodiment of this invention. It is a perspective view which shows embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nut main body 2 Through-hole 3 Female screw 4 Recessed part 5 Cover body 6 Claw piece part 7 Step part 8 Shaft part 9 Locking piece 9a for rotation prevention Side surface of locking piece

Claims (5)

  A female screw is formed in the through hole provided in the center of the nut body, and a lid is fitted into an annular recess provided on the upper end surface of the nut body, and the periphery of the recess is crimped to integrate the lid with the nut body. An insert cap nut connected to the outer peripheral portion of the nut body is provided with a stepped portion that serves as a contact surface for retaining, and a shaft portion having a diameter smaller than the outer diameter of the nut body is connected to the stepped portion. In addition, an insert cap nut characterized in that a locking piece for preventing rotation is provided on the outer periphery of the shaft portion.   The insert cap nut according to claim 1, wherein the locking piece for rotation prevention is a protruding body that hangs downward from the stepped portion.   The insert cap nut according to claim 1 or 2, wherein an outer diameter of the locking piece for rotation prevention is set to be equal to or smaller than an outer diameter of the nut body so that the die can be removed.   The insert cap nut according to any one of claims 1 to 3, wherein a plurality of locking pieces for rotation prevention are provided so as to project evenly on the shaft portion. The insert cap nut according to any one of claims 1 to 4, wherein the retaining step and the locking piece are formed only by a forging process.

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