SU1433574A1 - Tool for expanding tubes - Google Patents

Description

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The invention relates to the processing of metals by pressure, specifically to devices for the expansion of pipes, and can be used for fastening pipes in pipe grids.

The purpose of the invention is to increase the degree of flaring by increasing the working stroke of the distribution unit.

FIG. 1 shows a tool, a cut; in fig. 2 - tool, general view; in fig. 3 - tool in work.

A pipe flaring tool consists of a dispensing unit, produced in the form of end faces of disks 1, 2 and 3, which are in contact with each other, mounted on a mandrel 4. The working disk 2 is cut with a cut angle greater than two times friction of his material. The end surfaces of the working disk 2 are tapered with the direction of the tapering inside the disk and each is associated with the corresponding end surface of the adjacent auxiliary disk 1 or 3 at an angle, more than twice the friction coefficient of their materials. Disks 1, 2 and 3 are made of a material with:) φ (|) with an ectom pa.mt of form and with reduction of cross sections in the same way, equally direction- lennoii and siphaznoy, in this case, all faces 1, 2 and 3 increase and. HJ imene ipn corresponding thermocycling cycle and noah then. The disks 1, 2 and 3 are fixed on the mandrel 4 with the help of nuts 5 and 6, for which the first shank of the mandrel 4 is made (Fig. 1). Energy is supplied to the mandrel and to the set of disks 1,2 and 3, which heats the disks 1,2 and 3 up to a temperature of about 1.:1 with the effect of pa.m. Energy sources can be, for example, hot water and cold air or vice versa. It is possible to use an electric current when part of the mandrel 4 is placed in an induction heater. The work disk 3 has a slit 7.

As a material for disks 1, 2, 3, for example, a titanium – nickel alloy containing 54–56% nickel can be used. The interval of martensitic transformations is in the temperature range from 40 to 60 ° C. In this case, the ultimate strength of such a material is about 80 kgf / mm, the first generated voltage when it is heated is 150–200 ° C for the up-interval of the martematic transformation of 60 kgf / mm. The number of accessible thermal cycles is about 10 times.

The working part of the tool for flaring pipes is made in the following way.

Disks 1, 2 and 3 are annealed at 50 () ° C for I h in an overcrowded chip and then cooled there to 20 ° C. Discs 1, 2 and 3 are then removed from the die and subjected to thermoplastic processing.

Moreover, the working disk 2, having a cut 7, flatten, save its outcome0

This is the outer diameter, which is smaller than the inner diameter of the undeveloped tube. Flattening is carried out with a degree of deformation of 10% over the entire thickness of disk 2, with the conic surface remaining at the ends with the angle of concurrence with it greater than the double value of the friction coefficients of the materials of disk 2 and the disks 1 and 3 contacting with it.

Additional disks 1 and 3 flatten ana ;, in a very conspicuous way and along the ends with which they will have to contact with disk 2, they maintain a mating conical surface. At this m, the outer diameter of disks 1 and 3 after their flattening should not be larger than the internal diameter.

S nerazvaltsovnogo pipe (f ig. 2, the pipe is shown conditionally).

Then disks 1,2 and 3 are assembled on the mandrel 4, they are fastened with a nut. 5 and 6 and connected to the SOURCE of energy (not shown). The tool works as follows.

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In the initial state (Fig. 1), the tool is introduced into the pipe (Fig. 2) and heat is supplied to it from the energy source. Under the action of heat, the disks 1,2 and 3 are heated

5 to a temperature of 100-1 10 ° C, which leads to the manifestation of a memory effect in their materials. As a result, the cross sections of all the disks are reduced (1,2,3), in one direction and in the same way, the disks 1,2,3 begin to increase their total headroom and mutually

0 push each other. Nuts 5 and 6 prevent axial misalignment of disks 1, 2 and 3, which leads to the working disk 2 sliding out of the gap between the auxiliary disks 1 and 3 and increasing its outer diameter, as a result of which the pipe is expanding (Fig. 3). Thus, changing the invention provides an increase in the working stroke of the tool, and the angle of contiguity of the frontal comic surfaces of the disks must be greater than twice the coefficient of friction of their materials. The cut of cut 7 in the working disk 2 gives it spring properties that are actively displayed when the tool is cooled. Cooling is carried out after the pipe breaks by supplying to the working part, for example, cold air, water and other coolants. As a result, discs 1, 2 and 3 begin to reduce their cross sections in the opposite direction. Moreover, the presence of section 7 in the working disk

0 2 and the residual elastic deformation of the pipe creates the initial pressure; 1) to return to the initial state of the working part of the tool. Upon reaching room temperature, the instrument takes on the form as in FIG. 2, and it can be easily removed from the pipe. Toolkit l otov to the next cycle of work.

The use of the proposed tool} 1ta improves the reliability of the fas

laziness of pipes in tube plates, since the increased working stroke of the working part of the tool allows you to choose the gaps between the tube and the tube plate, as well as the technological tolerances on the diameters of pipes and holes in the tube plate, deviations in dimensions of the wall thickness of the tubes before the tool starts .

Claims (2)

1. A tool for flared tubes containing a distribution unit mounted on a mandrel, the working elements of which are made of a material with a shape memory effect, characterized in that, in order to increase the degree of flaring by increasing the stroke of the distribution unit. the latter is made of at least one set of disks, consisting of a working split disk with conical end surfaces, the taper of which is directed inside the disk, and auxiliary disks installed on both its sides, which on the side of their interaction with the working disk have end conical surfaces its face surfaces, while all the disks are made with the same directional and in-phase reduction of their cross sections in the temperature range of the shape memory effect. 2. The tool of claim 1, wherein the work disk is made with an oblique incision, the angle of which is greater than twice the friction coefficient of its material.