CN106964660B - A kind of long core bar device subtracting wall for metal pipe material cold-drawn - Google Patents

Abstract

The utility model relates to a long mandrel device for drawing and reducing walls of metal pipes, which belongs to the technical field of cold drawing of metal pipes. The feature is: the mandrels with pressure holes and oil filling holes at the left and right ends are set in the tubular mandrel jacket, and the left and right end caps with the central hole are respectively connected to the left and right sides of the mandrel jacket through the left and right screw groups. , The right end is connected, the central holes of the left and right end caps are respectively connected with the pressurization hole and the oil filling hole, and are connected with the pressure device interface and the refueling device interface, and the outside of the left end cover is connected with the drawing head. The advantage is to reduce the damage to the end and the inner and outer surfaces of the metal pipe during the stripping process; reduce the weight of the mandrel for large-diameter thin-walled metal pipe wall reduction; reduce the wear of the mandrel surface and prolong the service life of the mandrel; simplify the metal The lubrication process of the inner surface of the pipe reduces lubricant consumption and environmental pollution.

Description

A long mandrel device for cold drawing and wall reduction of metal pipes

technical field

The invention belongs to the technical field of cold drawing of metal pipes, and in particular relates to a long mandrel device for cold drawing and wall reduction of metal pipes.

Background technique

At present, in the production process of metal pipe wall reduction and deformation processing, the mandrels used are all solid mandrels composed of single-layer metal or multi-layer metal. There are two main forms, one is a short mandrel, as shown in Figure 1, which is mainly used in the cold rolling and cold drawing process of metal pipes. The feature is that the length of the mandrel is slightly longer than the length of the deformation zone of the metal pipe. During the deformation process, the mandrel has a fixed position in the deformation zone, and there is relative movement between the mandrel and the metal pipe. The disadvantage is that it is difficult to lubricate the contact surface between the mandrel surface and the metal pipe, which will generate strong sliding friction, which will lead to the deterioration of the inner surface of the metal pipe, and it is easy to form defects such as scratches and bonding, which increases the energy consumption of the deformation process and increases the Breakage rate of large thin-walled tubes during drawing and wall reduction. The other is the long mandrel, which is mainly used in the process of hot rolling, wall reduction and extension of metal pipes. The feature is: the length of the mandrel is greater than or close to the length of the metal pipe. During the deformation process, the mandrel moves in the deformation zone. There may or may not be relative motion between the mandrel and the metal pipe, that is, "floating" Mandrel" and "limited mandrel" production methods. The disadvantage is that it is difficult to remove the rod, and the long mandrel is rarely used in the cold drawing and wall reduction production process of metal pipes, especially the wall reduction deformation processing of large diameter and thin wall metal pipes.

Contents of the invention

The object of the present invention is to provide a long mandrel device for cold drawing and wall reduction of metal pipes, which can effectively overcome the shortcomings of the prior art.

The present invention is achieved like this: as shown in Figure 2: it is characterized in that: the mandrel 6 that left and right two ends are respectively shaped on pressure hole 9 and oil filling hole 10 is worn in the mandrel overcoat 7 of tubular shape, left, right The right end cap 8,8/ is respectively connected with the left and right ends of the mandrel outer cover 7 through the left and right screw groups 16,16/, and the left and right end caps 8,8/ conflict with the left and right ends of the mandrel 6 respectively, and the left , The central hole formed in the center of the right end cover 8, 8/ communicates with the pressure hole 9 and the oil filling hole 10 at the left and right ends of the mandrel 6 respectively, and communicates with the pressure device interface 11 at the left end and the oil device interface 12 at the right end , the outer side of the left end cap 8 is connected with the pulling head 13 .

Advantage of the present invention and positive effect are:

(1) Reduce the damage to the end of the metal pipe and the inner and outer surfaces during the stripping process;

(2) Reduce the weight of mandrels for wall reduction processing of large-diameter thin-walled metal pipes;

(3) Reduce the wear on the surface of the mandrel and prolong the service life of the mandrel;

(4) Simplify the lubrication process of the inner surface of the metal pipe, reduce lubricant consumption and environmental pollution.

Description of drawings

Fig. 1 is the drawing deformation process drawing of short mandrel of metal pipe;

Fig. 2 is a structural sectional view of the present invention;

In the figure: 1—drawing fixed die; 2—metal tube blank; 3—fixed mandrel; 4—short mandrel; 5—pipe head for drawing and clamping; 6—mandrel; 7—mandrel jacket; 8—left end cover; 8 ^/ —right end cover; 9—pressure hole; 10—oil hole; 11—pressurization device interface; 12—oiling device interface; 13—drawing head; 14—drawing roller die; 15— Oil storage chamber; 16—left screw group; 16 ^/ —right screw group.

Detailed ways

Embodiments of the invention are:

As shown in Figure 2: when drawing a steel pipe, first put the metal tube blank 2 on the outside of the mandrel jacket 7, then place the long mandrel device in the drawing roller die 14, and then connect it with the oiling device 12 Add oil to the oil storage chamber 15 through the oil filling hole 10, and then pressurize the oil storage chamber 15 through the pressurization hole 9 through the pressure device interface 11, so that the pressure in the oil storage chamber 15 reaches between 0.63-40Mpa, and then pass The drawing head 13 exerts a pulling force on the long mandrel device, so that the metal tube blank 2 passes through the drawing roller die 14 to reduce the wall to meet the design size requirement. After the wall reduction process is completed, decompression is carried out through the interface 11 of the pressurizing device, and the mandrel jacket 7 is in a retracted state, so that the pressure between the mandrel jacket 7 and the metal tube blank 2 is relaxed and disappeared, and a gap is generated, and the metal capillary is withdrawn. Complete the metal pipe cold drawing process.

Claims (1)

1. A long mandrel device for cold drawing and wall reduction of metal pipes, which is characterized in that the mandrel (6) is fitted with a pressure hole (9) and an oil filling hole (10) at the left and right ends respectively. In the tubular mandrel jacket (7), the left and right end caps (8, 8 ^/ ) are respectively connected to the left and right ends of the mandrel jacket (7) through the left and right screw groups (16, 16 ^/ ). The right end cover (8, 8 ^/ ) conflicts with the left and right ends of the mandrel (6) respectively, and the center hole formed in the center of the left and right end covers (8, 8 ^/ ) is respectively in contact with the left and right ends of the mandrel (6). The pressurizing hole (9) and the oil filling hole (10) are connected, and are connected with the interface of the pressure device at the left end (11) and the interface of the oil device at the right end (12). connect.