A fully enclosed guide device for a three-roller piercing machine for pipe oblique rolling

Abstract

The invention discloses a fully enclosed guide device for a three-roller piercing machine for cross-rolling of pipes, comprising a frame, on which a closed guide device is installed, the closed guide device comprising a hollow cylinder, on the side wall of which three grooves are provided to match the side walls of three rollers of the three-roller cross-rolling piercing machine, and the cylinder is used to place a pipe blank. The fully enclosed guide device for a three-roller piercing machine for cross-rolling of pipes provided by the invention can prevent the formation of a tail triangle during pipe blank processing, while ensuring uniform pipe wall thickness and a simple equipment structure.

Description

Technical Field

[0001] The invention relates to the technical field of tube oblique rolling three-roller punching, in particular to a fully enclosed guide device for a tube oblique rolling three-roller punching machine. Background Art

[0002] With the development of high-end steel pipe technology, the requirements for steel pipes are more stringent, especially with the increasing demand for alloy pipes and alloy pipes with poor plasticity. Although the three-roll piercing machine is very beneficial for the production and deformation of alloy and poor plasticity steel pipes. However, the three-roll piercing machine is currently only suitable for the production of medium and thick wall pipes, and cannot produce thin wall pipes. Otherwise, it is easy to produce a tail triangle at the tail end of the tube billet, resulting in product accidents and reducing the yield rate (d / s (diameter / wall thickness) ≤ 12, so it is impossible to produce thinner wall finished products). The specification range of the product is extremely restricted (that is, it is impossible to produce thinner wall finished products). The production of the tail triangle restricts the widespread use of the three-roll piercing machine. The three-roll oblique rolling piercing machine is composed of three rollers placed in equal parts and rotating in the same direction. Under the action of the three rollers, the tube billet is pierced from a solid round billet to a hollow rough tube, and a header is set in the tube billet during processing.

[0003] In order to reduce the formation of tail triangles, the industry currently often adopts the following methods:

[0004] Produce thicker walls (d / s≤12); or the three-roll tube mill twists the rolls before the tail of the tube reaches the deformation zone of the rolls to increase the opening of the rolls instantly, allowing the rough tube to pass smoothly. However, it is easy to cause the rear of the tube to be stuck and the wall thickness of the tail of the tube to be inconsistent with the wall thickness of the front of the tube, which brings difficulties to the next process; the three-roll tube mill is equipped with 3 small-diameter rollers at the entrance of the rolls. When the tail of the tube reaches the deformation zone, the rollers are quickly started to limit the formation of the tail triangle.

[0005] Although the pipes produced by the above method can reduce the formation of the tail triangle, they have defects such as thick pipe walls, uneven pipe wall thickness, or complex equipment structure, which cannot meet the technical requirements and increase costs. Summary of the invention

[0006] The purpose of the present invention is to provide a fully enclosed guide device for a three-roller piercing machine for pipe oblique rolling to solve the problems existing in the above-mentioned prior art, so that the tube blank can be processed to avoid the formation of a tail triangle while having a uniform tube wall thickness and a simple equipment structure.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] The present invention provides a fully enclosed guide device for a three-roller oblique rolling piercing machine for pipes, comprising a frame, on which a closed guide device is installed, the closed guide device comprises a hollow cylinder, on the side wall of which three grooves are provided that match the side walls of the three rollers of the three-roller oblique rolling piercing machine, and the cylinder is used for placing pipe blanks.

[0009] Optionally, the three grooves are located in the middle of the cylinder, and the lengths of the three grooves match the length of the rolling roller.

[0010] Optionally, a push rod is passed through one end of the cylinder.

[0011] Optionally, a round hole matching with the top of a three-roller oblique rolling piercing machine is formed at the top of the push rod.

[0012] Optionally, the end of the push rod is connected to a push head, and the push head is connected to a cylinder or a hydraulic cylinder.

[0013] Optionally, the push head is a V-shaped push head.

[0014] Optionally, connecting sleeves are respectively provided at both ends of the frame, and both ends of the cylinder are inserted into the connecting sleeves.

[0015] Optionally, a fastening bolt is provided on the side wall of the connecting sleeve close to one end of the push head.

[0016] Optionally, a flange is arranged around the outer wall of the cylinder away from the end of the push head, and the flange is connected to the connecting sleeve away from the end of the push head by bolts.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] The present invention sets a closed space formed by three rollers and the grooves on the side wall of the hollow cylinder according to different specifications. When the tube blank is radially deformed from a circle to a triangle under the action of the rollers, the circumscribed circle formed by the triangle is larger than the circle of the tube blank and is constrained by the preset closed space. The thinner the tube wall is during perforation, the larger the circumscribed circle is. That is, the formed circumscribed circle is restricted by the closed hole type, ensuring that the tube blank passes smoothly through the throat diameter formed by the three rollers.

[0019] When the tube billet approaches the tail end during rolling, the pusher head applies an axial force to the tube billet to overcome the axial force generated by the head, pushing the tube billet through the throat formed by the three rollers smoothly.

[0020] Since the axial force generated by the plug is the largest in the end perforation of the tube, a round hole matching the plug size is set at the front end of the pusher head to push the tube deeper and ensure that the tube can pass through the throat diameter formed by the three rollers smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 It is a schematic diagram of the structure of an existing pipe oblique rolling three-roller piercing machine;

[0023] Figure 2 It is a side view of an existing pipe oblique rolling three-roller piercing machine;

[0024] Figure 3 It is a schematic structural diagram of a fully enclosed guide device for a three-roller piercing machine for tube oblique rolling according to the present invention;

[0025] Figure 4 It is a side view of the fully enclosed guide device of the three-roller piercing machine for pipe oblique rolling of the present invention;

[0026] Figure 5 It is another side view of the fully enclosed guide device of the three-roller piercing machine for pipe cross-rolling of the present invention;

[0027] Among them, 1 is a roller, 2 is a tube blank, 3 is a rough tube, 4 is a gap, 5 is a top head, 6 is a frame, 7 is a cylinder, 8 is a push rod, 9 is a round hole, 10 is a V-shaped push head, 11 is a cylinder, 12 is a connecting sleeve, 13 is a fastening bolt, and 14 is a flange. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The purpose of the present invention is to provide a fully enclosed guide device for a three-roller piercing machine for pipe oblique rolling, so as to solve the problems existing in the above-mentioned prior art, so that the pipe blank can be pierced to avoid the formation of a tail triangle, while the pipe wall thickness is uniform and the equipment structure is simple.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1 and Figure 2As shown, the three-roller oblique rolling piercing machine includes three equally spaced rollers 1 arranged in a circle and rotating in the same direction. Under the action of the three rollers 1, the tube blank 2 is pierced from a solid round billet into a hollow rough tube 3. Since the three rollers 1 of the three-roller oblique rolling piercing machine cannot form a closed hole in the radial area of ​​the deformation zone, there are a large number of gaps 4. The tube blank 2 in the deformation zone is a process of circle-triangle-circle. Therefore, the tube blank 2 will produce radial deformation during the rolling process. If the reduction (D / S; diameter / wall thickness) is large, since there is no restriction there, the radially deformed metal will flow into the gap between the rollers, causing the tail end of the rough tube 3 to be stuck between the rollers 1. Therefore, it will cause a rolling jam accident during production.

[0032] When the tube 2 is rolled toward the tail end, the contact area at the entrance end of the deformation zone (the cross section is a triangle at this time) gradually decreases, which reduces the axial running power of the tube 2 and is insufficient to overcome the axial force generated by the plug 5 located in the tube. This causes a post-rolling jam in production and easily produces a tail triangle at the tail end of the tube 2.

[0033] Aiming at the shortcomings of the three-roller oblique rolling piercing machine, the present invention provides a fully enclosed guide device for the three-roller oblique rolling piercing machine for pipes, such as Figure 3 , Figure 4 and Figure 5 As shown, it includes a frame 6, on which a closed guide device is installed. The closed guide device includes a hollow cylinder 7. The side wall of the cylinder 7 is provided with three grooves that match the side walls of the three rollers 1 of the three-roller oblique rolling piercing machine, so that the three rollers 1 and the inner wall of the cylinder 7 form a closed space, that is, the inner hollow area of ​​the cylinder 7; the hollow area in the cylinder 7 is used to place the tube blank 2. The three grooves are located in the middle of the cylinder 7, and the lengths of the three grooves are equal to the lengths of the rollers 1. A push rod 8 is penetrated at one end of the cylinder 7, and a round hole 9 that matches the top head 5 of the three-roller oblique rolling piercing machine is provided at the top of the push rod 8. A V-shaped push head 10 is connected to the end of the push rod 8, and the V-shaped push head 10 is connected to a cylinder 11.

[0034] Further preferably, connecting sleeves 12 are respectively provided at both ends of the frame 6, and both ends of the cylinder 7 are inserted into the connecting sleeves 12. A fastening bolt 13 is inserted through the side wall of the connecting sleeve 12 near one end of the V-shaped push head 10. A flange 14 is arranged around the outer wall of the cylinder 7 away from one end of the V-shaped push head 10, and the flange 14 is connected to the connecting sleeve 12 away from one end of the V-shaped push head 10 by bolts.

[0035] When processing the tube blank 2, the tube blank 2 is placed in the cylinder 7, and the V-shaped pusher 10 gradually pushes the tube blank 2 forward under the action of the cylinder 11, while the three rollers 1 roll the tube blank 2. When the tube blank 2 is radially deformed under the action of the rollers 1, from a circle to a triangle, the circumscribed circle formed by the triangle is larger than the circle of the tube blank 2, and will be subject to the pre-set space constraint, that is, the constraint of the inner wall of the cylinder 7 and the rollers 1. The thinner the tube wall during perforation, the larger the circumscribed circle formed. That is, the formed circumscribed circle is limited to ensure that the tube blank 2 passes smoothly through the throat formed by the three rollers 1.

[0036] When the tube 2 is rolled toward the tail end, the V-shaped pusher 10 applies an axial force to the tube 2 to overcome the axial force generated by the plug 5, and pushes the tube 2 to smoothly pass through the throat formed by the three rollers 1.

[0037] Since the axial force generated by the plug 5 is the largest area when the end of the tube is pierced, a circular hole 9 matching the size of the plug 5 is provided on the top surface of the front end of the push rod 8. The plug 5 can enter the circular hole 9 after passing through the end of the tube 2, so that the V-shaped push head 10 can push the tube 2 further forward to ensure that the tube 2 can pass through the throat diameter formed by the three rollers 1 smoothly.

[0038] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A fully enclosed guide device for a three-roller piercing machine for pipe cross-rolling, characterized in that: It comprises a frame, on which a closed guide device is installed, and the closed guide device comprises a hollow cylinder, on the side wall of which three grooves are provided to match the side walls of three rollers of a three-roller oblique rolling and piercing machine, and the cylinder is used to place the tube blank; the three grooves are located in the middle of the cylinder, and the lengths of the three grooves match the lengths of the rollers; a push rod is passed through one end of the cylinder; a circular hole matching the top of the three-roller oblique rolling and piercing machine is provided at the top of the push rod; a push head is connected to the end of the push rod, and the push head is connected to a cylinder or a hydraulic cylinder; the push head is a V-shaped push head; and two ends of the frame are provided with A connecting sleeve, both ends of the cylinder are inserted into the connecting sleeve; a fastening bolt is inserted on the side wall of the connecting sleeve close to one end of the push head; a flange is arranged around the outer wall of the cylinder away from one end of the push head, and the flange is connected to the connecting sleeve away from one end of the push head by bolts; when processing the tube blank, the tube blank is set in the cylinder, and the V-shaped push head gradually pushes the tube blank forward under the action of the cylinder, and at the same time, three rollers roll the tube blank, when the tube blank undergoes radial deformation under the action of the rollers, from a circle to a triangle, the circumscribed circle formed by the triangle is larger than the circle of the tube blank, and will be constrained by the inner wall of the cylinder and the rollers.

Images