Large variable bevel rotary pipe expander

Abstract

The present invention discloses a large variable bevel rotary pipe expander, comprising a machine base, on which a steel pipe input device, a steel pipe hot rolling device and a steel pipe output device are sequentially arranged, the steel pipe hot rolling device comprises at least three hot rolling rollers uniformly arranged in the circumferential direction, a hot rolling core head is rotatably mounted on the machine base, the hot rolling core head is provided with a diameter expansion support section, and the hot rolling roller is provided with a diameter expansion rolling section; the diameter expansion support section comprises a diameter expansion support cone section and a forming support column section, the diameter expansion rolling section comprises a diameter expansion extrusion cone section and a forming stabilizing column section, and a forming buffer cone section is provided on the hot rolling core head between the diameter expansion support cone section and the forming support column section, and the cone vertex angle of the forming buffer cone section is smaller than the cone vertex angle of the diameter expansion support cone section. The present invention can complete high-quality diameter expansion operation at a large diameter change rate through the arrangement of the forming buffer cone section, significantly improve the diameter change rate, and facilitate the one-time hot rolling forming of large-diameter steel pipes.

Description

Technical Field

[0001] The invention relates to the technical field of steel pipe hot rolling equipment, in particular to a large variable beveling type rotary pipe expanding machine. Background Art

[0002] Steel pipe production is divided into hot rolling and cold rolling, among which hot rolling can better refine grains and eliminate defects. The hot rolling process is usually accompanied by changes in pipe diameter. Due to the limitations of the steel pipe's own plasticity and the structure of the roller core head at this stage, the diameter change rate that can be achieved in hot rolling is currently around 30%. A larger diameter change rate is likely to cause the performance of the steel pipe to decline, or even defects. In this way, for large-diameter steel pipes, multiple hot rolling processes are often required to form them, which consumes a lot of energy, has low production efficiency and high production costs. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a large variable bevel cutting rotary pipe expanding machine which can significantly improve the diameter change rate and is beneficial to one-time hot rolling forming of large diameter steel pipes.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a large variable bevel cutting rotary pipe expander, comprising a machine base, on which a steel pipe input device, a steel pipe hot rolling device and a steel pipe output device are sequentially arranged, and a steel pipe heating device is arranged on the machine base at the steel pipe input device, and the steel pipe hot rolling device comprises at least three hot rolling rollers installed on the machine base and uniformly distributed in the circumferential direction, each of the hot rolling rollers is rotatably installed at the same advance angle, and the hot rolling rollers are commonly connected to a hot rolling drive device; a hot rolling core head that can extend to the hot rolling roller is rotatably installed on the machine base, At least one diameter expansion support section is provided on the hot rolling core head, and an expansion rolling section corresponding to the diameter expansion support section is provided on the hot rolling roller; the diameter expansion support section includes an expansion support cone section and a forming support column section arranged in sequence, and the diameter expansion rolling section includes an expansion extrusion cone section corresponding to the diameter expansion support cone section, and a forming stabilizing column section corresponding to the forming support column section; a forming buffer cone section is provided on the hot rolling core head between the diameter expansion support cone section and the forming support column section, and the cone apex angle of the forming buffer cone section is smaller than the cone apex angle of the diameter expansion support cone section.

[0005] As a preferred technical solution, the hot rolling mandrel is provided with two diameter expansion support sections, and the hot rolling roller is provided with two diameter expansion rolling sections corresponding to the two diameter expansion support sections respectively.

[0006] As a preferred technical solution, a guide tube section is provided at one end of the hot rolling mandrel head close to the pipe supply direction.

[0007] Due to the adoption of the above technical scheme, the heated steel pipe of the present invention reaches the steel pipe hot rolling device and first enters between the first diameter expansion extrusion cone section and the diameter expansion support cone section. The hot rolling mandrel mainly plays a supporting role for the steel pipe, and the hot rolling roller mainly plays a role in rolling the steel pipe. After the hot rolling roller rotates, due to the friction force, the hot rolling mandrel rotates in the opposite direction, and due to the setting of the advance angle of the hot rolling roller, the steel pipe can move forward along the hot rolling mandrel. The setting of the forming buffer cone section makes a buffer space with thickened tube wall appear between the hot rolling mandrel and the hot rolling roller. Before the steel pipe enters the forming support column section and the forming stabilizing column section, it will accumulate in the buffer space. Under the extrusion of the steel pipe later, the accumulated steel pipe is squeezed into the space between the forming support column section and the forming stabilizing column section to form a full columnar roll forming. The formed steel pipe has a uniform and tight structure, stable performance, and is not prone to defects. In this way, the present invention can complete high-quality diameter expansion operations at a large diameter change rate through the provision of the forming buffer cone section, significantly improve the diameter change rate, and facilitate one-time hot rolling forming of large-diameter steel pipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The following drawings are intended only to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0009] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0010] Figure 2 1 is an enlarged structural schematic diagram of a hot rolling roller and a hot rolling mandrel head according to an embodiment of the present invention. In order to clearly illustrate the matching structure of each section, the figure is illustrated in a plan view;

[0011] Figure 3 yes Figure 2 A magnified schematic diagram of the structure at position I in the figure.

[0012] In the figure: 1-machine base; 11-steel pipe input device; 12-steel pipe output device; 13-steel pipe heating device; 14-steel pipe hot rolling device; 2-hot rolling core head; 21-expanding support section; 22-expanding support cone section; 23-forming support column section; 24-forming buffer cone section; 25-conduit section; 26-hot rolling core rod; 3-hot rolling roller; 31-expanding roller section; 32-expanding extrusion cone section; 33-forming stabilizing column section; 4-hot rolling drive device. DETAILED DESCRIPTION

[0013] The present invention is further described below in conjunction with the accompanying drawings and examples. In the following detailed description, exemplary embodiments of the present invention are described only by way of illustration. Needless to say, those of ordinary skill in the art will recognize that the described embodiments may be modified in a variety of ways without departing from the spirit and scope of the present invention. Therefore, the drawings and description are illustrative in nature and are not intended to limit the scope of protection of the claims.

[0014] like Figure 1 , Figure 2 and Figure 3 As shown, the large variable bevel cutting rotary pipe expander includes a machine base 1, on which a steel pipe input device 11, a steel pipe hot rolling device 14 and a steel pipe output device 12 are sequentially arranged. The steel pipe input device 11 and the steel pipe output device 12 both adopt a conventional three-roller conveying structure with an advance angle, and the three rollers are driven by a power distribution frame driven by a driving device, and the three output ends on the power distribution frame are respectively universally connected to the three rollers to realize three-roller conveying. This is a prior art known to those skilled in the art and will not be repeated here.

[0015] A steel pipe heating device 13 is provided on the machine base 1 at the steel pipe input device 11. Conventionally, the steel pipe heating device 13 adopts medium frequency heating to heat the steel pipe to a temperature required for hot rolling.

[0016] The steel pipe hot rolling device 14 includes at least three hot rolling rollers 3 installed on the machine base 1 and evenly distributed in the circumferential direction. Each of the hot rolling rollers 3 is installed and rotated at the same advance angle, and the hot rolling rollers 3 are commonly connected to a hot rolling drive device 4. This embodiment shows that there are three hot rolling rollers 3, and their installation and drive are basically the same as the structure of the steel pipe input device 11 and the steel pipe output device 12, which are well known to those skilled in the art and will not be repeated here.

[0017] A hot rolling mandrel head 2 that can extend to the hot rolling roller 3 is rotatably mounted on the machine base 1. Conventionally, there are two ways to rotatably mount the hot rolling mandrel head 2. One is that the machine base 1 clamps the hot rolling mandrel 26 by three rollers, and the end of the hot rolling mandrel 26 is fixedly mounted with the hot rolling mandrel head 2; the other is that a mandrel sports car is arranged on the machine base 1, and the hot rolling mandrel 26 is rotatably mounted on the mandrel sports car, and the end of the hot rolling mandrel 26 is fixedly mounted with the hot rolling mandrel head 2. The above two methods are both existing technologies known to those skilled in the art, and will not be repeated here.

[0018] The hot rolling mandrel 2 is provided with at least one diameter expansion support section 21, and the hot rolling roller 3 is provided with a diameter expansion rolling section 31 corresponding to the diameter expansion support section 21. The diameter expansion support section 21 includes a diameter expansion support cone section 22 and a forming support column section 23 arranged in sequence, which should be arranged in sequence along the advancing direction of the steel pipe. Conventionally, the cross-sectional area of ​​the diameter expansion support cone section 22 is gradually increased along the advancing direction of the steel pipe.

[0019] The expanding rolling section 31 includes an expanding extrusion cone section 32 corresponding to the expanding support cone section 22, and a forming stabilizing column section 33 corresponding to the forming support column section 23. A forming buffer cone section 24 is provided on the hot rolling mandrel 2 between the expanding support cone section 22 and the forming support column section 23, and the cone vertex angle of the forming buffer cone section 24 is smaller than the cone vertex angle of the expanding support cone section 22. In this way, from a cross-sectional perspective, a triangular enlarged area is approximately formed between the forming buffer cone section 24 and the hot rolling roller 3, which allows the steel pipe to be buffered and accumulated here, thereby achieving wall thickness increase.

[0020] The hot rolling mandrel 2 described in this embodiment mainly plays a supporting role for the steel pipe, and the hot rolling roller 3 mainly plays a role in rolling the steel pipe. After the hot rolling roller 3 rotates, there is mainly rolling friction between the hot rolling roller 3 and the steel pipe, and there is mainly static friction between the steel pipe and the hot rolling mandrel 2. Under the joint action of friction, the hot rolling mandrel 2 rotates in the opposite direction. Due to the setting of the advancing angle of the hot rolling roller 3, the steel pipe can move forward along the hot rolling mandrel 2. In the process of moving forward, the inner surface of the steel pipe is formed based on the outer surface of the hot rolling mandrel 2, and the rolling effect of the hot rolling roller 3 can promote the flow of the steel pipe itself at high temperature, promote the uniformity of the steel pipe structure, and eliminate defects.

[0021] When the heated steel pipe in this embodiment reaches the steel pipe hot rolling device 14, it first enters between the expanding extrusion cone section 32 and the expanding support cone section 22. The hot rolling mandrel 2 in this embodiment is provided with a guide tube section 25 at one end close to the incoming pipe direction, which facilitates the steel pipe to be smoothly sleeved on the hot rolling mandrel 2 and smoothly reach between the expanding extrusion cone section 32 and the expanding support cone section 22; conventionally, the guide tube section 25 is of a conical design. During the process of rolling, the steel pipe gradually expands between the expanding extrusion cone section 32 and the expanding support cone section 22. After the expansion, the steel pipe first reaches the forming buffer cone section 24 for buffering, accumulation, wall thickening, and the accumulated steel pipe material can better promote internal welding under the action of high temperature, eliminate defects such as gaps, cracks, and bubbles, and the accumulated steel pipe is squeezed into the space between the forming support column section 23 and the forming stabilizing column section 33 under the action of subsequent steel pipe extrusion and rolling of the hot rolling roller 3, forming a substantial cylindrical roll-formed. In this way, the present embodiment utilizes the setting of the forming buffer cone section 24 to significantly eliminate the original defects of the steel pipe, as well as the cracks, thin walls and other defects in the expansion process. Not only is the structure of the formed steel pipe uniform and tight, and the performance is stable, but the thickness of the steel pipe can also be well controlled. In summary, the present embodiment can complete high-quality expansion operations at a large diameter change rate, significantly improve the diameter change rate, and facilitate the one-time hot rolling forming of large-diameter steel pipes.

[0022] Preferably, the hot rolling mandrel 2 of this embodiment is provided with two expansion support sections 21, and the hot rolling roller 3 is provided with two expansion rolling sections 31 respectively corresponding to the two expansion support sections 21. In this way, the steel pipe of this embodiment can be continuously expanded, buffered and formed twice above the recrystallization temperature to achieve secondary expansion, while ensuring high-quality expansion output, further improving the diameter change rate, so that the diameter change rate can reach 80%, forming a breakthrough technology of large variable diameter expansion, which has extremely high economic value and social value.

[0023] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A large variable bevel cutting rotary pipe expander, comprising a machine base, on which a steel pipe input device, a steel pipe hot rolling device and a steel pipe output device are sequentially arranged, and a steel pipe heating device is arranged on the machine base at the steel pipe input device, characterized in that: The steel pipe hot rolling device comprises at least three hot rolling rollers installed on the machine base and uniformly distributed in the circumferential direction, each of the hot rolling rollers is rotatably installed at the same advance angle, and the hot rolling rollers are commonly connected to a hot rolling drive device; a hot rolling core head which can extend to the hot rolling roller is rotatably installed on the machine base, at least one diameter expansion support section is provided on the hot rolling core head, and an expansion rolling section corresponding to the diameter expansion support section is provided on the hot rolling roller; the diameter expansion support section comprises an expansion support cone section and a forming support column section which are arranged in sequence, the expansion rolling section comprises an expansion extrusion cone section corresponding to the diameter expansion support cone section, and a forming stabilizing column section corresponding to the forming support column section, and a forming buffer cone section is provided on the hot rolling core head between the diameter expansion support cone section and the forming support column section, and the cone vertex angle of the forming buffer cone section is smaller than the cone vertex angle of the diameter expansion support cone section; The hot rolling mandrel is provided with two diameter expansion support sections, and the hot rolling roller is provided with two diameter expansion rolling sections corresponding to the two diameter expansion support sections respectively; The hot rolling mandrel head has a guide tube section at one end close to the pipe supply direction.

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