SU1206542A1 - Threaded joint - Google Patents

Description

one

The invention relates to mechanical engineering, in particular, to threaded connections with tension mainly of oil pipe assortment (drilling, casing, pump-compressor, etc.), and can also be used to connect pipes, rods, shafts.

The purpose of the invention is to increase the corrosion and fatigue strength of the joint under alternating loads, as well as the maintainability of the parts to be connected due to an equal distribution of stress concentration in the joint, as well as to improve the maintainability of the connected parts.

FIG. 1 shows the proposed threaded connection; in fig. 2 — node 1 in FIG. one.

On a pipe G with a threaded joint 2, annular grooves 3 are made on the conical stabilizing cable, which make it possible to create annular landing protrusions 4 with the same taper. On the coupling 5, similar annular grooves 6 and 1 are mounted, and the protrusions 7. the extreme points of the protrusions on the pipe 1 and the coupling 5 coincide in the direction from the end of the pipe 1.

The connection works as follows.

Since, in conjunction with a tension, the maximum stress occurs at its edges, when the joint is made in the form of multiple alternating annular landing protrusions 4 and 7, the concentration of the stresses at the extreme edges in the joint, i.e. ultimately, a more uniform stress distribution is achieved along the entire length of the joint. Con-

065422

the stress concentration on the edges of alternating landing pads, while maintaining the total landing area, is lower than on the edges in a similar connection with a solid landing area. Multiple places of stress concentration on the edges of alternating annular landing pads increase the tightness of the joint.

A change in the landing area of the joint (. With equal other parameters; it is possible to achieve or decrease

15 zheniy on ring landing ledges. The presence of alternating annular grooves 3 and 6 on the pipe 1 and the coupling 5, which coincide, gives flexibility to the connection. Finding such a connection of drill pipes in the bends of the boreholes makes it possible to reduce the bending stress occurring in the pipe 1 near the coupling 5, due to

25 of the same deformation of the pipe and coupling. Improving the maintainability of the joint is achieved by the fact that the annular grooves between the landing protrusions 4 on the pipe 1 in

30 1.5-2 times smaller than the width of the annular grooves between the projections 7 of the coupling 5. The extreme points of the projections in the assembled state, measured from the end of the pipe 1, coincide in the initial state. When re-threading the pipe and thereby reducing its outer diameter in the same section, the landing protrusions 4 during reassembly are shifted

35

40

45

deeper into clutch 5, and the protrusions 7 are displaced to the left relative to the protrusions. 4 (Fig. 2, shown by dashed line 8). The same displacement occurs in the case of thread re-cutting on the coupling 5 and the cut of its ends within allowable limits.

BNIIPI Circulation 880

Order 8684/38 Subscription

Branch Patent,

Uzhgorod, st. Project, 4

Claims (3)

1. THREADED CONNECTION WITH TENSION, comprising a female coupling and a male pipe with a conical stabilizing belt and thread, characterized in that, in order to increase the corrosion-fatigue strength of the connection under alternating loads, alternating alternating landing rings are made on the surface of the conical stabilizing belt of the pipe and coupling. protrusions, the width and quantity of which are selected from the condition of ensuring the bearing ability of the interface. 2. Connection according to p. ^ Characterized in that, in order to increase the maintainability of the parts to be joined, the annular grooves between the protrusions on the pipe are 1.5 • 2 times narrower than on the female coupling, and from the end side the extreme points of the protrusions on the coupling coincide with the extreme points of the protrusions on the pipe. _ 3 C Figure 1