RU2347637C2 - Mandrel for tubes dressing - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: mandrel for tubes dressing comprises body, coiler rolls installed with the possibility of free rotation around their own axes, hollow plungers with protrusions that serve as roller-holders for coiler rollers. At that body is arranged with radial bores of cylindrical shape in the form of hydraulic cylinders for installation of mentioned hollow plungers, and also with axial and radial channels for supply of working fluid under specified plungers. At that plungers are arranged with the possibility of adjustment by angle of roller installation relative to mandrel axis and stationary fixation at selected angle of installation.

EFFECT: technological resources are expanded.

2 dwg

Description

The invention relates to the field of metal forming, in particular to the production of long multi-pass profile pipes having, in particular, smooth, non-profiled ends.

Known mandrel for crimping pipes with an internal seam seam (patent of the Russian Federation No. 2270731 from 02.27.06, B.I. No. 6). According to this patent, the mandrel has a cylindrical working rod in which several rollers are fixed with an eccentricity relative to the axis of this rod. The shape of the generators of these rollers is different in order to ensure consistent bending of the seam fold. In this case, the plastic deformation of the bending is carried out along one generatrix of the processed pipe, along which the seam is located.

The disadvantages of this device when used for profiling pipes include the impossibility of obtaining smooth ends during profiling, the constant value of the eccentricity of the rollers and the impossibility of obtaining different profiling depths, the inability to obtain multi-starting profiled pipes, since all the rollers are placed in one plane.

Known design flare (patent of the Russian Federation No. 2144128 from 06/09/98). In this design, the plastic deformation of the pipe is performed by a rotating tool, which is a cylindrical tubular body, in which several conical rollers are installed at an angle to the longitudinal axis of this body. The rollers have support journals installed in the housing in sliding bearings. Rotation and axial feed of the housing together with the rollers lead to flaring of the pipe. The disadvantage of the flare tool is the lack of control of the radial position of the tapered rollers, since they are stationary in the housing, the lack of the ability to receive pipes with protrusions or cavities of the profile, the inability to manufacture multi-start pipes, as well as pipes having smooth cylindrical non-profiled ends at the ends in combination with the profiled part.

As a prototype adopted the design shown in the patent SU 719770, B21H 3/08, 03/05/1980, 3 C. According to this patent, a thread rolling tool is proposed comprising thread rolling rollers located in the housing, as well as two support conical elements having the ability to interact with thread rolling rollers, characterized in that in order to expand technological capabilities, it is equipped with a mandrel with a pin mounted in the housing for rotation and a spring connected at one end to the pin and the other to the body, wherein a screw groove is made in the body, the free end of the pin is placed in this groove, and one of ornyh conical elements placed in the body of the mandrel.

The disadvantages of the prototype are due to the fact that the design does not allow you to control the distribution and reverse cleaning of the rollers directly in the profiling process, for example, to obtain non-profiled sections of the profile. In addition, it is not possible to adjust the angle of elevation of the pipe profile, as well as the shape of the groove of the profile, for example, to obtain pipes with small and large angles of profile rise. The proposed design with the installation of rollers resting directly on two supporting conical elements can lead to increased wear of the friction surfaces, which will require frequent technological maintenance.

The objective of the invention is to provide the possibility of obtaining multi-sectional profile heat transfer pipes having smooth cylindrical ends necessary for installing such pipes in a tube plate (collector) of a heat exchanger, increasing the efficiency of such a process, creating mass production, creating the possibility of producing pipes with different depths, shapes and angles lifting profile.

This problem is solved by creating the design of the mandrel for profiling pipes, comprising a housing, profiling rollers installed with the possibility of free rotation around their own axes, characterized in that it is equipped with hollow plungers with protrusions serving as roller holders for profiling rollers, the housing is made with radial bores of cylindrical shape in in the form of hydraulic cylinders for installing the above-mentioned hollow plungers in them, as well as with axial and radial channels for supplying the working fluid and for said plungers, wherein the plungers are configured to adjust the installation angle of the roller relative to the mandrel and soybean stationary fixing on the selected installation angle.

The above technical solution allows us to profile heat engineering pipes and other purposes with the help of internal spiral knurling to obtain a multi-start profile with a significant range of pipe profile elevation angles. At the same time, it is possible to obtain smooth end sections, which is necessary for the subsequent embedding of pipes in the tube boards of heat exchangers.

The mandrel for profiling pipes is shown in figure 1, the installation of the profiling roller (section AA in figure 1) is shown in figure 2.

The mandrel (figures 1 and 2) contains a housing 1 having axial 2 and radial 3 channels for supplying a working fluid. The profiling rollers 4 are mounted on the roller holders 5 by means of axles 6 and bearings 7, which are axially fixed by bushings 8. The axles 6 are fixed in the roller holders by nuts 9. The housing is provided with radial bores into which hollow plungers 10 with protrusions-roller holders are installed 5. The bores of the housing are cylinders for installing the plungers 10, a seal 11 is placed between these elements. The plungers have internal slots on their inner surface. In the housing, with the help of fastening elements 12, bushings 13 are fixed, having external slots on the outer cylindrical surface. The bushings 13 have holes on the axis that coincide with the radial channels 7 of the housing 1 and are necessary for supplying the working fluid. The inner slots of the plungers 10 and the outer slots of the bushings 13 are inserted into each other, which fixes the plungers in a certain angular position. The housing 1 also has internal threads, into which round nuts 14 are screwed, resting on the hole level and fixing the extreme radial position of the plungers. A mandrel 15 having an axial channel 16 is used to feed the mandrel into the profiled pipe. A flat washer made of soft metal (for example, copper), which acts as a seal, is placed between the end face of the rod 15 and the axial bore of the housing. The rod 15 is connected to the housing by a thread. In one housing, you can install several sets of rollers having the design described above. Figure 1 as an example shows the installation diagram of two sets of rollers. In this case, the pairs of rollers must be connected by the axial channel 16 of the rod using the lead-through drilling of channels in the housing so as to ensure a constant supply of fluid at any position of the rollers.

) необходимо вывинтить кольцевые гайки 14 и плунжер вместе с роликом на роликодержателе установить на шлицах (внутренних на плунжере и наружных на неподвижной втулке 13) на необходимый угол α. Далее вращением гаек 14 установить предельное радиальное положение плунжера 10 в цилиндрической расточке корпуса. Последняя регулировка определяет глубину вдавливания роликов в трубу.Before starting work, you must configure the mandrel to the angle of elevation of the rolling helix and the depth of indentation of the resulting profile. To adjust the angle of elevation of the helix (figure 1 - angle

) it is necessary to unscrew the ring nuts 14 and install the plunger together with the roller on the roller holder on the slots (internal on the plunger and external on the stationary sleeve 13) to the required angle α. Next, by rotating the nuts 14 to establish the maximum radial position of the plunger 10 in the cylindrical bore of the housing. The last adjustment determines the depth of indentation of the rollers into the pipe.

The work of the adjusted mandrel proceeds as follows. For profiling, a drawing mill of a known design is used. The hollow core 15 is fixed in the clamp of the mill, to which the working fluid can be supplied through the channel 16. The pipe prepared for profiling is put on the mandrel so that the pipe is placed in front of the clamp of the mill, while the other end of the pipe is placed behind the front free end of the mandrel. Next, this end is captured by the clamp of the pulling cart of the drawing mill. A design feature of this cart for profiling pipes using the mandrel in question is that the cart clamp must be able to freely rotate around its longitudinal axis, which is quite simple in design terms.

After capturing the end of the pipe with a rotating clamp of the trolley, channel 16 is fed into the mandrel with working fluid under pressure. In the axial channels 2 and 18 and the radial channel 3, the fluid enters under the plunger 10. This plunger is shifted along the cylinder in the radial direction, pressing the roller 4, mounted on the protrusions of the roller holder 5, into the pipe. This ensures its profiling. If it is necessary to obtain the front smooth end of the pipe, the fluid is supplied to the cylinders somewhat later than the beginning of the movement of the pulling carriage of the drawing mill, and in order to obtain a non-profiled rear end, the pressure of the liquid should be turned off a little earlier than the passage of this end along the profiling mandrel.

Claims (1)

A mandrel for profiling pipes, comprising a housing, profiling rollers installed with the possibility of free rotation around their own axes, characterized in that it is equipped with hollow plungers with protrusions serving as roller holders for profiling rollers, the housing is made with radial bores of cylindrical shape in the form of hydraulic cylinders for installation in said hollow plungers, as well as with axial and radial channels for supplying working fluid under said plungers, enes with the possibility of adjusting the angle setting axis roller relative to the mandrel and fixing the selected fixed angle of installation.

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