Aoyama Seisakusho Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Sadayoshi Hasegawa

Satoshi Konagaya

Yoshihiro Murase

Kenya Yamada

Mitsuru Kozawa

Satoshi Iida

Masahito Iwata

Seiichi Toyonaga

Satoshi Fujiura

Kouichirou Kouguchi

Tetsuya Oosawa

Provided is a nut into which a bolt () including a male-threaded portion with a male-threaded external diameter d and a male-threaded core diameter dis screwed, wherein a bolt insertion side end of a female-threaded portion () formed in a nut body () is provided with an incompletely threaded female portion () that is formed by one to three pitches so that an internal diameter dimension D is larger than (d+d)/2 and is smaller than the male-threaded external diameter d. Accordingly, even when the bolt is screwed into the nut in the inclination direction, the bolt may be rotated about a contact surface with respect to the incompletely threaded female portion (), and hence seizing may be prevented.

Anti-seizing nut

A female thread member capable of preventing seizing caused by inclined insertion, and being smoothly fastened from any directions in which a bolt is inserted, and a fastening member using the female thread member. A non-thread portion is formed on an inner peripheral surface of a female thread member body having a female thread for a length corresponding to at least one pitch from an end surface on a bolt-inserting side, and a projection which comes into contact with a flank surface of a male thread of an inserted bolt is formed on a line extending from a helical line of the female thread. The female thread member is used in combination with the bolt having no incomplete thread portion, and there is no adverse possibility of seizing regardless of any directions in which the bolt is inserted.

Female screw component and fastening component utilizing the same

An anti cross-thread bolt which prevents the bolt from being cross-threaded without the need for correcting its posture by a pilot portion. The bolt is screwed into a female screw having a nominal diameter D and an inner diameter D. At the tip of a regular thread part formed on the bolt shank, a small-diameter thread part is formed by one pitch or more, the small-diameter thread part having an outer diameter d which is larger than an inner diameter D of the female screw and smaller than (D+D)/2. When the bolt is obliquely screwed into the female screw, the small-diameter thread part is brought into contact with the female screw at one point, but the bolt is allowed to rotate around the point. Thus, the occurrence of cross-threading is prevented.

Anti cross-thread bolt

In a bolt of the present invention, a guide portion having a small diameter is formed at the distal end of a shaft portion and ridge having an inverted direction screw configuration relative to the ridge formed on a constant diameter portion is formed. When the bolt is inserted obliquely into a nut and the ridge gets into engagement with a female screw portion of the nut, an effect of floating the bolt is generated, and the bolt cannot be driven into the nut unless it is set in an appropriate tightening posture. Consequently, biting and seizing of the bolt to the nut can be prevented securely. If the ridge is formed into a double threaded screw having an inverted direction screw configuration, the effect can be further intensified.

Bolt

A fastening device permitting two separate members to be fixed together with a relative interval between them including a bolt with a male screw portion formed at a front end side of a cylindrical shaft portion thereof and a spacer having a female screw portion engaging a male screw portion and screw-fastens with a screw of a first member side and rotates while receiving a rotation torque from the bolt and moves up to a position in which it comes into a contact with a second member. The root diameter of a male screw portion is smaller than the diameter of a cylindrical shaft portion while the inside diameter of the female screw portion is larger than the diameter of the cylindrical shaft portion. Consequently, the cylindrical shaft portion can be passed through the female screw portion even if the diameter of the cylindrical shaft portion is not reduced in diameter by cutting processing.

Growing community of inventors

Inazawa, Japan

Sadayoshi Hasegawa