SU1237269A1 - Method of continuous tube rolling - Google Patents

Description

The invention relates to pipe production and can be used in the manufacture of pipes on a continuous mill with a forced displacement of a long mandrel.

The aim of the invention is to increase the productivity of the process.

FIG. 1 shows a scheme for implementing the method, the initial position before the task of the sleeve in the first caliber; in fig. 2 - the same, the gradual filling of all working calibers in FIG. 3 is the same steady state rolling in FIG. 4 is the same; sequential release of the working gauges from the rolled pipe i in FIG. 5 - the same, complete separation of the pipe and mandrel; in fig. 6 is a diagram of the hydropneumatic mechanism in FIG. 7 is a section A-A in FIG. 6, in FIG. 8 is a section BB in FIG. 6J in FIG. 9 is a sectional view BB in FIG. eight.

The method is carried out as follows.

The sleeve 1 is set on the mandrel 2 through its rear end, which is clamped by the clamps 3 supported on the plungers 4 located in the hydrochamber 5 communicating with the gas chamber 6 by connecting channels 7 of the pneumo-hydraulic mechanism 8 having an adjustable chamber 9 with the screw 10. Then the sleeve is set rollers 11 into the first caliber 12, while the mandrel is installed with the front end in the last caliber and after the rollers grab the liner and squeeze it onto the mandrel, a force acts and is transmitted through the shank of the mandrel and the grips to the hydropneumatic plungers mechanisms. The plungers moving in the hydrochamber 5 displace the working fluid into the gas chambers 6, compressing the gas and thereby accumulating the energy of the compressed gas.

As the caliber is filled with a tube, the force on the mandrel increases, the mandrel moves in the direction of rolling, and acts on the plungers of the hydraulic pneumatic mechanisms. The stroke is 0.8-0.9 between two successive calibers. After the rear end of the rolled tube exits the first gauge, the mandrel is moved against the rolling stroke by reducing the axial force of the rolling by the energy stored by the hydropneumatic mechanisms. According to

0

five

The successive calibers reduce the axial force on the mandrel.

When the finished tube leaves the last gauge, the axial force on the mandrel is removed, it is completely released from the tube and returns to its original position.

The energy in the hydropneumatic mechanisms is accumulated by compressing gas in the gas chamber with liquid flowing through the calibrated connecting channels 7 from the hydro chamber 5 under the influence of the plunger 4. The magnitude of the stroke of the plungers and the initial gas pressure in the gas chamber 6 5 necessary to ensure simultaneous rolling and separation of the pipe and mandrels, are installed by moving the adjusting screw 10, which displaces the working fluid from chamber 9 through channel 7 to the gas chamber 6.

The total value of the displacement of the mandrel is determined by the working stroke of the plunger of the hydropneumatic compensator, which must not exceed 0.8-0.9 distances between two successive calibers. With a working stroke of the plunger longer than 0.9

between gauges, a working section corresponding to one gauge may fall into another cage, which will lead to a reduction in the quality of the pipes due to the unevenness of the gap between the mandrel and 5 gauge. The total displacement of the mandrel less than 0.8 distances between two subsequent calibers will reduce the working sections of the mandrel in length, which will significantly increase their wear and premature failure.

Self-regulation of the speed, magnitude and direction of movement of the mandrel depending on the axial force transmitted to the plunger of the hydropneumatic mechanism as the mill gauges fill and release from the metal, ensures complete separation of the mandrel and pipe simultaneously with the end of the rolling process due to the energy accumulated in the hydropneumatic mechanisms. reduced time for auxiliary operations, reduced energy costs.

The proposed method of continuous tube rolling provides an 8-10% increase in productivity by combining the rolling operation, section

0

five

50

55

laziness pipe and mandrel and return the mandrel to its original position.

Self-regulation of the speed and magnitude of the displacement of the mandrel, depending on the axial forces, improves the quality of rolled tubes, and reduces scrap when changing the technological conditions of rolling.

FIG. 2

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FIG. B

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Editor I.Rybchenko

Compiled by L.Maturina

Tehred L. Serdyukova Proofreader M. Maksimishinets

Order 3223/9 Circulation 518 Subscription

VNIIPI USSR State Committee

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

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

Claims (1)

METHOD FOR CONTINUOUS PIPE ROLLING, which includes feeding the sleeve to the gauges through the rear end of the mandrel, deforming the sleeve in a series of sequential roll gauges on the mandrel moved along the course of rolling with a limited speed, and moving the mandrel against the rolling course, characterized in that, in order to increase productivity of the process, before rolling, place the front end of the mandrel in the last gauge, restrict it by the pneumohydraulic mechanism along the rolling during the passage of the front and rear the end of the sleeve through the first gauge by an amount equal to 0.8-0.9 of the distance between the calibers, and move the mandrel against the course of rolling during passage through all calibers of the rear end of the sleeve by the same amount, using the accumulated energy of the pneumohydraulic mechanism. SU, „1237269>