SU1224475A1 - Detachable joint - Google Patents

Description

The invention relates to mechanical engineering and can be used in various devices with increased requirements on the fatigue strength of detachable clamping connections.

The purpose of the invention is to increase the reliability of the connection under cyclic variable tensile loads.

FIG. 1 shows a detachable connection, a longitudinal section in FIG. 2 is a view A of FIG. 1 in FIG. 3 is a view B in FIG. 1 j in FIG. 4 shows a section B-B in FIG. one ; in fig. 5 - rod; in fig. 6 - threaded sleeve, FIG. 7 - smooth sleeve with a collar.

A detachable connection, for example, of the main connecting rod 1 and the connecting rod bolt 2 with smooth coaxial holes, consists of a bolt 3 with an external thread and a head 4, passed through the smooth coaxial holes of the parts to be connected 1 and. 2 until the head 4 stops against the part 2, and the nut 5 is screwed onto the bolt all the way into the part 1 In this case, the bolt, which is similar in technical essence and functional features to the ordinary bolt, is made composite and consists of a smooth cylindrical rod 6 ending on both sides; conical heads 7 and 8 in its cylindrical hour, tightly fitting dimis with their conical holes when tightening with a nut 5. On the rod 6 on one side there is a threaded sleeve 9 with an external thread, freely passing through smooth Axis opening the joined parts 1 and 2, and the other - the sleeve 10 is smooth simulated head 4 bzgrtikom outer tightly with a coupling tsilind-symmetric outer surface with a smooth bore and the workpiece 2 with a upirayuscha Her outer burtikrm. To ensure collectability of the rod 6 with sleeves 9 and 10. The rod 6 is made to satisfy the condition D, D2, where I diameter of the head. 7 for threaded sleeve 9i Dj - diameter of the head 8 for smooth sleeve 10, while threading sleeve 9 satisfying the condition d (D, where d is the diameter of the cylindrical part of its opening, and the smooth sleeve 10 is made split in the axial plane and with diameter dj of cylindrical and gtm OR

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the holes coinciding with the diameter d of the cylindrical part of the rod 6. To ensure the assembly of the joint, the diameter of the threaded sleeve 9 is made smaller than the diameter of the holes of the parts to be joined, and the outer diameter of the smooth sleeve 10 before the shoulder coincides with the diameter of the holes indicated, and the sleeve 9 and 10 mutually fixed against rotation on the rod 6 by engagement with each other with the help of protrusions 11 and grooves 12, made on their opposite ends, and the collar of the smooth sleeve 10 is shaped as a turnkey, for example estigrannika.

The assembly of the compound is carried out as follows.

First, bolt 3 is assembled, for which on. the rod 6 is put on from the conical side: the head 8 and advances on the conical head 7 of the rod-n 6 threaded sleeve 9, and then on the conical head 8 superimposed both halves of the smooth sleeve 10 so that the end tabs 11 of the threaded sleeve 9 fit in the end depressions 12 of the smooth sleeve 10. Holding the assembled bolt-3 with the smooth sleeve 10 with one hand so that both its halves do not break up, put the coaxial holes of the connected parts 1 and 2 into the smooth sleeve of the smooth sleeve 10 into the joint part 2, pic e then the other hand nut 5 screwed onto the threaded sleeve 9 completely into the connecting piece 1. Further emuyu puff compound with the necessary force effected taken vshis wrenches for smooth collar sleeve 10 and the nut 5.

Detachable connection works as follows.

When the joint is loaded with axial tension by means of force, the latter, due to the tapered junction of the rod 6 with the sleeves 9 and 10, are closed on a smooth cylindrical rod 6, which thus works under tension. When this threaded sleeve 9 works in compression, and smooth sleeve 10 - to cut the collar. The reliability of the connection is also increased due to the redistribution of the load in the threaded joint of the nut 5 with the threaded bushing .9, expressed in German

in that the load distributed over the threads of the thread decreases from the free end of the nut, where it has the greatest value, to the supporting end of the nut, in which it has the smallest value. The most favorable from the point of view of operational reliability is a threaded joint loaded with cyclic variable tensile forces with load distribution over the threads provided by the simultaneous and simultaneous operation of both elements of the threaded connection (nuts 5 and threaded sleeve 9) for compression under loading of the entire joint with axial growth givi forces. For this reason, the threaded sleeve 9 cannot collapse (break), since it is compressed and not stretched. In addition, the better contact (overlapping) on the sides of the thread profile provided by the radial tensile elastic deformations of the threaded bushing 9 under the action (radial components) contributes to a more favorable load distribution over the threads of the thread in the threaded connection of the nut 5 with the threaded sleeve 9. The force arising due to the tapered coupling of the threaded sleeve 9 with the stem 6, from the axial tensile forces applied to the joint as a whole. The latter circumstance allows the manufacture of threads elements of a threaded joint (nuts 5 and threaded bush 9) are more

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coarse accuracy class, since the adverse effect of inaccurate threading on the quality of overlapping on the sides of the thread profile will be compensated for by radial elastic deformations of the threaded sleeve 9 when tightening the joint, which will ensure a qualitative overlap on the side of the thread profile. The manufacture of threaded connection elements (nuts 5 and threaded bush 9) with a thread of a rougher accuracy class will reduce the overall cost of the connection.

Removing the extreme (lower) turn of the threaded sleeve 9 from the bearing surface of the nut 5 increases their compliance and thereby also improves the distribution of the load on the turns.

Due to the tapered junction of the rod 6 with the sleeves 9 and 10, which can be likened to the hinged sealing of the rod ends, the errors (distortions) of the bearing surfaces of the parts to be joined 1 and 2 under the nut 5 and the smooth sleeve 10 do not affect the quality of the load distribution over the turns of the threaded connection nuts 5 with a threaded bushing 9, and also do not worsen the conditions of loading the rod 6 with a tensile axial force.

Since when the joint is tightened, the rod 6 does not test twisting from the tightening moment, and therefore does not have tangential stresses after tightening, this increases its fatigue strength.

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Editor M.Petrova

Order 1906/32

Circulation 777 Subscription

VNIIPI State Committee of the USSR

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

Compiled by V.Golov

Tehred I.Popovich Proofreader I.Musk

Claims (1)

REMOVABLE CONNECTION OF PARTS, containing a nut, a composite bolt in the form of a smooth cylindrical rod with a conical head on the nut side, a sleeve mounted on a head made with an external thread under the nut and internal conical bore, a counter head of the rod, and a sleeve with a shoulder mounted on the second the end of the rod, characterized in that, in order to increase the reliability of the connection under cyclic variable tensile loads, the second end of the rod is made conical, the sleeve with a shoulder is made axially split th plane with a conical bore, mating the second end of the rod and the facing ends of the sleeves - with alternating ridges and depressions. 5S fm. 1