SU781422A1

SU781422A1 - Fastening element

Info

Publication number: SU781422A1
Application number: SU782692339A
Authority: SU
Inventors: Лев Давыдович Арсон; Александр Григорьевич Гребеников; Вячеслав Николаевич Желдоченко; Алексей Михайлович Тимченко; Евгений Тимофеевич Василевский; Виктор Петрович Рычик; Валерий Николаевич Стебенев
Original assignee: Харьковский авиационный институт
Priority date: 1978-12-06
Filing date: 1978-12-06
Publication date: 1980-11-23

Description

(54) КРЕПЕЖНЫЙ ЭЛЕМЕНТ(54) FASTENING ELEMENT

Изобретение относитс к машиностроению , в частности авиационному, и может быть использовано при проектировании потайных соединений салюлетных конструкций.The invention relates to mechanical engineering, in particular, aviation, and can be used in the design of hidden connections salouletnyh structures.

Известен крепежный элемент с потайной головкой, угол конусности которой меньше угла конусности зенковки отверсти в соедин емой детали, а переходна зона между конической и цилиндрической поверхност ми крепежного элемента выполнена радиусной , йлноспивость соединений деталей с таким крепежным элементом повышаетс вследствие создани упруго-пластического радиального нат га в зоне зенйовки, смежной с цилиндрической частью отверсти 1 .The countersunk head fastener is known, the taper angle of which is less than the countersink taper angle of the hole in the component being connected, and the transition zone between the conical and cylindrical surfaces of the fastening element is made radially and spatially connected with such a fastening element by creating elastic spring plastic in the zone of zenyovka, adjacent to the cylindrical part of the hole 1.

Однако зона смежности зенковки отверсти с наружной поверхностью детали.остаетс неупрочненной и вл етс источником зарождени усталостных трещин. Кроме того, практически невозможно при серийном производстве соединений и с учетом допусков на размеры обё спечить прилёганиё приторцовой части головки к поверхности зенковки отверсти в детали. Это приводит к проникновению среды кHowever, the adjacency zone of the countersink hole with the outer surface of the part remains loose and is a source of fatigue crack generation. In addition, it is almost impossible when mass-producing compounds and taking into account the dimensional tolerances of both fitting the primordial part of the head to the surface of the countersink, the holes in the part. This leads to medium penetration.

сильно напр женной зоне зенковки и возникновению щелевой коррозии, коррозии под напр жением, коррозионному растрескиванию.strongly stressed zone of countersink and the occurrence of crevice corrosion, stress corrosion, stress corrosion cracking.

Известен также крепежный элемент, содержащий стержень и потайную ступенчатую головку, причем угол конус-, ности первой ступени потайной годов10 ки,. прилегающей к стержню, меньше . угла конусности зенковки в соедин емой детали, а угол конусности второй ступенипотайной головки равен углу конусности зенковки в соедин емойAlso known is a fastener comprising a rod and a countersunk stepped head, with the angle of taper of the first step of the secret year. adjacent to the rod, less. the countersink taper angle in the connected part, and the taper angle of the second step of the countersink head is equal to the taper angle of the countersink in the joined

5 детали Н .5 details H.

Этот крепе)сный элемент вл етс наиболее близким к изобретению по техническому существу и достигаемому результату, однако и он не лишен ука2Q занных выше недостатков.This fastening element is the closest to the invention in its technical essence and the achieved result; however, it is also not deprived of the above disadvantages.

Цель изобретени - повышение выносливости соедин емых деталей.The purpose of the invention is to increase the endurance of the connected parts.

Эта цель достигаетс за счет того, 25 что потайна головка выполнена сThis goal is achieved due to the fact that the secret head is made with

Claims

an additional step adjacent to the end of the second step, this is the angle of the taper of the additional step greater than the angle of taper of the countersink in the co3Q of the single piece, and the transition zones between the steps of the countersunk head are radius. FIG. 1 shows the proposed fastening element, FIG. 2 - connect. details of this element; in fig. 3 - diagrams of radial tensions along the hole when used in connection of the proposed fastener, for example, a bolt. The fastener contains a secret stepped head consisting of steps 1, 2 and 3, and a rod 4 placed in the parts to be connected x 5 and 6. The heights of the truncated cones of the steps of the secret head are h - (0.1-0.2), h (0.23-0.25), h ,, (0.1-0.15) of the diameter of the rod (d the diameters of the large bases of the cones are determined by the formulas: II, - d + 2 & /, ll, jd + 2l, + hj; HZ d + 2 (D, + Aj) + „2 t„ J where D 0.12-0, 2 mm for slip-on fasteners it is fitted, L 0.08-0.16 mm for fasteners installed with 1% radial tension,, A, j 0.15-0.35 mm. The rounding radii of the transition zones between the cones are R "(0 , 08-0,.. The fixing element, when the joint is assembled with the side surface of the cone 3, hardens plastically and creates an elastic radial tension on the countersink surface adjacent to the outer surface of the connected part, with the side surface of the cone 1 strong from cylindrical to horses. the surface of the hole in the part, the side surface of the cone is adjacent to the rest th surface countersinking; As a result, the most dangerous, from the point of view of endurance, zones of the hole are strengthened plastically, and elastic radial tension is created in these zones. The contact zone of the end part of the foundation head with the corresponding countersink surface reliably isolates (seals) the connection from the environment. During the work of connecting parts to the cut, the embedded head lies on the surface of the countersink of the part along its entire height and thus improves the condition of the clear material of the parts. Claims A fastener comprising a rod and a stepped blind head, the angle of taper of the first stage of the blind head adjacent to the rod is less than the angle of taper of the countersink of the joint part, and the angle of taper of the second stage of the countersink head is equal to the angle of taper of the countersink in the component to be joined, differing in that, in order to increase the stamina of the parts being joined, the head is made with an additional step adjacent to the end of the second step, while the angle of taper of the additional st tim greater than the angle of taper of the countersink in the removable part is connected, and the transition zone between the stages countersunk heads are radiused. Sources of information taken into account in the examination 1. US patent number 3748948, cl. 85-1; 1973.

2. US patent number 3849964, cl. 85-1, 1974.

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