Slack preventive fastener for screw tool, and method and device for manufacturing the same

Abstract

The present invention provides a slack preventive fastener for a screw tool formed in a relatively simple structure, easily manufacturable at low cost by mass production, and capable of easily and securely preventing a screw tool from being loosened as a fastener for a screw tool miniaturized or refined by precise processing for assembling various types of small-sized products; and a method and a device for manufacturing the fastener. The fastener comprises a fastening device (10) such as a nut, an insert, etc. to be fastened with the screw device such as a screw, a bolt, etc. A recessed part (18) formed by press-molding from the outside is provided in a part of the outer peripheral wall of the fastening device to form a diameter-reduced deformation part (20) where the diameter of the crest or bottom of a female thread is partially reduced in the inner peripheral wall of the fastening device.

Description

technical field [0001] The present invention relates to a connecting piece such as a bushing, a partition, a nut, etc. used for connecting with a threaded piece such as a screw or a bolt, and especially relates to a threaded piece that can be easily and reliably prevented from being screwed into and fixed on the connecting piece from loosening or falling off Connectors and manufacturing methods and manufacturing devices thereof. Background technique [0002] In the past, when threaded parts such as screws or bolts were combined with connecting parts such as nuts or bushings used for screwing and fixing them, sometimes due to reasons such as vibration, the threaded parts screwed in and fixed on the connecting parts loosened, and even fall off. From this point of view, in the combination of threaded parts and connecting parts, various anti-loosening methods and mechanisms have been proposed and put into practical use for the screwed parts and connecting parts respectively. ...

AI Technical Summary

Problems solved by technology

[0021] From this point of view, in the anti-loosening mechanism of the above-mentioned conventional threaded parts and connecting parts, in the anti-loosening mechanism in which the connecting part is provided with a recess or a through hole and an elastic member is installed, it is miniaturized or even miniaturized, and it is necessary to Being precision machined, not only are they very difficult to manufacture, but they are also extremely structurally unsuitable

[0022] Moreover, in the anti-loosening mechanism that coats the resin or the like with elasticity, friction, viscosity, adhesion, etc. Difficulties such as scattering or being unusable due to deterioration of resin, etc., and it is also very difficult to manufacture screw parts that are miniaturized or even miniaturized similarly to the above by precision machining

[0023] On the other hand, the bushing member disclosed in the above-mentioned Patent Document 1 uses a self-tapping thermoplastic resin material, and the applicable object is restricted due to the characteristics of the raw material used. The miniaturized or even miniaturized screw parts or connecting parts of the product assembly are not suitable for the structure

[0024] In addition, the covered female threaded body disclosed in the above-mentioned Patent Document 2 is configured such that the female threaded body is covered with an outer covering member made of a thin synthetic resin material having shrinkability, and the locking part engaged with the male thread Heating is performed to shrink the outer covering part and increase the degree to which the above-mentioned locking part is in close contact with the male thread surface. Therefore, similar to the above, it is structurally unsuitable to produce miniaturized or even miniaturized screw parts or connecting parts through precision machining. And there are difficulties that are also complicated in its manufacture and use

[0025] In addition, the metal washer disclosed in the above-mentioned Patent Document 3 and the joint structure using the metal washer are configured such that, as an object to be attached to a bolt, it is necessary to provide a joint hole with a spot-faced hole in the upper part, and the metal washer is formed over the entire length. The hole is longer than the above-mentioned connection hole, and is compressed and deformed in the above-mentioned countersink hole. Therefore, in this case, miniaturized or even finer screw threads for assembling various products that are miniaturized as described above are manufactured by precision machining. Parts or connecting parts are not structurally suitable, and especially have the difficulty of complicating the method of use

[0026] Furthermore, in the structure and manufacturing method of the anti-loosening female thread part disclosed in the above-mentioned Patent Document 4, at the outlet side end part of the female thread part screwed with the male thread member, the internal diameter of the female thread is smaller than that of the middle part along the entire The reduced diameter of the outer circumference is tapered to form a conical section of the reduced diameter female thread part, and the thread teeth of the reduced diameter female thread part are formed with repeated and continuous concavities and convexities in the circumferential direction, because the shape and structure of the above continuous concavities and convexities are extremely complicated Therefore, it is difficult to manufacture miniaturized or even miniaturized screw parts or connecting parts for the assembly of various products that are miniaturized as described above through precision machining.

[0027] Moreover, the locknut and its manufacturing method disclosed in the above-mentioned Patent Document 5 are configured to form a The annular groove portion having a diameter equal to or larger than the thread inner diameter of the main female thread portion causes the secondary female thread portion formed on the inner peripheral wall of the above-mentioned extending portion to produce a desired phase displacement with respect to the above-mentioned main thread portion, Since the shape and structure of the above-mentioned annular groove are extremely complicated, it is difficult to manufacture miniaturized or even miniaturized screw parts or connecting parts for the assembly of various products that are miniaturized as described above through precision machining.

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