SU1224072A1 - Cross=wedge rolling mill - Google Patents

Description

The invention relates to metallurgical equipment, and more specifically to the design of mills for cross-helical rolling of tubes, can be used for cross-helical rolling of tubes, during their expansion and reduction in diameter.

The purpose of the invention is the expansion of the technological capabilities of the mill.

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helical rolling of pipes, in particular, the expansion of the range of rolled pipes and increasing the accuracy of their geometric dimensions.

The drawing shows a helical rolling mill, a general view in horizontal section.

The helical rolling mill contains a working stand 1, the rollers 2 of which are connected by spindles with drive 3. A mechanism 4 for axially moving the workpiece 5 is mounted on the inlet side of the mill. On the output side of the mill there is a shaft 6 with a mandrel 7. The bed 8 is connected working stand 1 using the frame 9, on which the centering 10 and the drive rollers 11.

On the bed 8 in horizontal guides 12 a carriage 13 is movable along the rolling axis, in which a stop head 14 is mounted holding rod 6 with a mandrel 7 The carriage 13 has guides 15 located in planes perpendicular to the rolling axis. A thrust head 14 is mounted on these guides, which is connected vertically with a screw (not shown in the drawing) to raise it above the rolling axis.

In the horizontal guides 16, the frame 8 is mounted movable along the rolling axis of the yoke 17, which is associated with the carriage 13 with screws 18 belonging to the carriage movement mechanism 1.

On the frame 8 is fixedly mounted hydraulic cylinder 20, in which the hollow rod 21 is connected to the crosshead 17 by means of a spherical hinge, including spherical washers 22 and 23.

The hydraulic cylinder 20 has a conduit 24 for supplying a constant pressure fluid to the cavity a. The valve 25 is mounted on the housing of the cylinder 20 and supplies the cavity b through the hole 26 with a specified amount of fluid according to the program. At the end of the hollow rod 21, the lever 27 is fixedly fixed to the lever 27 (with its central hinge), with one end of the lever connected to the valve 25, and the second end through the roller 28 is in contact with the profile bar 29.

The mill helical rolling works as follows.

The workpiece 5 (in the form of a hollow sleeve) is placed on the inlet side of the mill and, using the movement mechanism 4, is fed into the working stand at a design speed along the rolling axis. At the same time, rotating from the drive 3, the work rolls 2 can approach each other and be spread symmetrically with respect to the rolling axis or remain in one position and compress the workpiece along a helical trajectory according to a predetermined program. Thus, the surface of the rolled pipe on the outside has a variable or constant diameter along the length of the pipe.

The shape of the inner surface of the pipe is formed by crimping the workpiece 5 on a curved mandrel 7 fixed on the rod 6. Because the mill allows the mandrel 7 to move in the deformation zone along the rolling axis, the inner surface of the rolled pipe has a variable or constant diameter along its length.

During rolling, the rod 6 is held on the rolling axis by the centrifuges 10 and transmits the axial rolling forces to the bearings of the thrust head 14, in which it is fixed with a conical sleeve. At the same time, the rod with the mandrel rotates freely with the speed of rotation of the packing 5.

The design parameters (direction, speed and magnitude) of the axial movement of the mandrel 7 in the deformation zone are defined as the corresponding profile of the ruler 29, which moves synchronously with the axial movement of the rolled pipe (billet 5). During rolling, the ruler 29 presses on the roller 28 and turns the lever 27 around its central hinge, while the second (opposite roller 28) end of the lever presses the valve of the control valve 25 and controls the amount of fluid that the fluid enters through the hole 26

Into the cavity of the hydraulic cylinder 20, through pipe 24, fluid is supplied to the cavity of the hydraulic cylinder 20 under constant pressure directly from the hydroaccumulator. Thus, the hollow rod 21 of the hydraulic cylinder 20 is moved to both sides in the hydraulic cylinder body in strict accordance with the amount of fluid fed into the cavity b through the valve 25.

During rolling, the reciprocating movement of the hollow rod 21 is transmitted through spherical washers 22 and 23 to traverse 17, which moves in the guides 16 of the frame 8 and using two screws 18 communicates the reciprocating movement of the carriage 13 with the stop head 14 installed in it. In this way, reciprocating movement of the mandrel 7 is communicated from the thrust head 14 through the rod 6 in accordance with the profile of the ruler 29.

The initial position of the mandrel 7 relative to the initial position of the rod 21 of the hydraulic cylinder is adjusted by means of the mechanism 19 by rotating the screws 18 by changing the distance between the carriage 13 and the crosshead 1 7- this is done by fine tuning the mill before rolling, by replacing the mandrel or by adjusting the original data .

The proposed design of the mill makes it possible to perform cross-helix rolling of the workpiece 5 also at a stationary (along the axis, rolling.

ki} the position of the mandrel tea fluid pressure

7. In this case in the cavity b

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five

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five

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the hydraulic cylinder is zero, and the fluid pressure in the cavity is a-supported with a normal one. As a result, the piston rod 21 and, respectively, the yoke 17 remain fixed and occupy their extreme position.

After rolling, the resulting pipe with a variable wall thickness is held by the centrifugal 10 and the rod 6 by the mandrel 7 is retracted to the inlet side of the mill through the deformation zone using drive rollers 11. Then the centerers 10 are opened and the tube is removed from the outlet side of the mill (not shown) i

To replace the rod, the stop head 14 rises up the rolling axes in the guides 15 of the carriage 13 by means of a vertical screw (not shown), after which the rod is retracted through the hollow rod 21 beyond the mill with the help of drive rollers 11. In the same way it can be removed rolled pipe with some malfunctioning mechanisms.

The application of the proposed construction of a helical rolling mill makes it possible to expand the range of rolled tubes, as well as to improve the accuracy of their geometrical dimensions. Due to this, with the further use of such pipes there is an economy of metal by about 10-15%.

Claims (1)

CROSS-SCREW ROLLING MILL, comprising a bed with rails mounted on rails with the possibility of moving the carriage with a thrust head and a carriage moving mechanism made in the form of a hydraulic cylinder, characterized in that, in order to expand the range of rolled tubes and improve the accuracy of their geometric dimensions , it is equipped with a traverse installed with the possibility of moving along the guides of the bed and mounted: a screw mechanism on it, while the traverse is installed between the hydraulic cylinder and the carriage with thrust head and pivotally connected to the hydraulic cylinder, and with a carriage with a thrust head - by means of a screw mechanism. SU „„ 1224072>