摘要:
A threaded fastener includes a lead having bosses separated from one another by bases along the thread crest. Two such leads may be formed such that lead-in profiles for of one lead are disposed at locations corresponding to locations of lead-out profiles for the other lead. The lead-in and lead-out profiles of the bossed, and other features of the bosses and bases may differ from one another along the fastener shank. The boss profiles may be selected to reduce insertion torque and to provide excellent resistance to pullout. The fastener may be formed by roll threading via a tool made by a plunge EDM process.
摘要:
The present invention provides an improved method of forming improved dies for rolling an article, such as a lock thread convolution. The dies are formed by roiling a circular hob along a flank of a thread form ridge on the die. As the hob is rolled along the thread form ridge, teeth on the hob are pressed against the thread form ridge with a constant force to form uniform indentations and/or projections in the thread form ridge. The indentations and/or projections which are formed in the thread form ridge by the hob all have the same configuration since the hob is pressed against the thread form ridge with a force of a constant magnitude as the hob is rolled along the thread form ridge. During the rolling of an external thread convolution on a bolt blank with the improved die, the indentations and/or projections on the thread form ridge shape teeth on the flank of an external thread convolution on the bolt. Since the indentations and/or projections were originally rolled into the thread formed ridges on the die with a circular hob and since the indentations and/or projections on the die roll teeth on a circular bolt blank, the teeth formed on the flank of the external thread convolution have the same configuration as the teeth on the hob.
摘要:
Une vis (11) formant son pas de vis presentant un pas helicoidal (18) et une section d'entree conique (14) ayant une section transversale polygonale est formee a partir d'une ebauche conventionnelle (24) par cylindrage de l'ebauche entre une paire de filieres de cylindrage de pas de vis (70) presentant des moyens sur leurs surfaces pour former alternativement des lobes convexes (25) et des zones de decharge concaves (33) a la surface en tronc de cone (28) de l'ebauche. Ainsi la vis peut etre formee avec une extremite de taraudage de forme polygonale sans creer un travail prealable de la surface en forme de cone de l'ebauche (28). Des surfaces courbes de rampes (34) s'intercalent de maniere lisse entre les lobes (25) et les concavites (33) afin de permettre au metal, dans une piece a tarauder, de rouler dans les concavites (33) reduisant ainsi le couple necessaire pour creer un pas de vis dans la piece a travailler.
摘要:
A self-tapping screw according to the present invention includes a head (1) and a shank (2) extending from the head. The shank includes a cylindrical shank (2a) immediately below the head and a truncated conical shank (2b) following an end of the cylindrical shank, the cylindrical shank is provided with a plurality of first external threads (3a), the truncated conical shank is provided with a plurality of second external threads (3b) following the first external threads, and a peak of each of the second external threads is provided with a biting surface (4) having a concave-convex form.
摘要:
Disclosed is a method for manufacturing a screw (4) with helical chip discharge channel, including providing a blank (41), subjecting an end of the blank to form a head (42) and subjecting the blank to rolling to form one or more sections of threads (43). The screw (4) is formed with one or more helical chip discharge channels (442), which can be of different helical angle according the different applications. The chip discharge channel (442) can be formed by milling, rolling, or combined rolling and milling. The chip discharge channel is extended into the threads (43) to form tapping edges. As such, the tapping operation is made effortless and the shape of the tapped thread excellent. The extending angle of the chip discharge channel (442) can be changed according to different materials of the workpiece to be fastened. The length of the chip discharge channel can be selected according to different applications.
摘要:
A method for fastening components (18, 20) at critical joints in a motor vehicle powertrain. An unthreaded hole (22) is provided in a first component part (20), and a clearance hole (16) in a second component part (18). The shank (14) of a screw (10) that has a multi-lobed lead capable of creating a thread in the unthreaded hole is passed through the clearance hole to engage the multi-lobed lead with the unthreaded hole. Axial force and rotary torque are applied to the screw to cause the lead to form a desired helical thread in the unthreaded hole.
摘要:
Zur Herstellung eines Bolzenelements mit einem Schaft, der im Bereich seines freien Endes einen verringerten Durchmesser aufweist, wird vorgeschlagen, ausgehend von einem zylindrischen Drahtstift die Reduzierung des vorderen Abschnitts durch einen Walzvorgang herzustellen. Bei einem Bolzenelement mit Gewinde, also beispielsweise einer Schraube, kann das Reduzieren des Durchmessers und das Aufwalzen des Gewindes in einem Vorgang mit Hilfe eines einzigen Walzbackenpaares erfolgen. Das Walzbackenpaar enthält eine Reduzierfläche, mit deren Hilfe die Durchmesserverringerung durchgeführt werden kann.