Double-hoop clamping type steel pipe diameter expanding and reducing machining device

Abstract

A double-hoop clamping type steel pipe expanding and reducing machining device relates to the technical field of steel pipe machining and comprises a base and a die mounted on the base, the die is detachably provided with a core die used for expanding or reducing a steel pipe, and two hoops used for fixing the steel pipe are arranged at one end of the core die at intervals. And the axial leads of the two hoops are aligned with the axial lead of the core mold. The steel pipe is fixed through the two hoops, it is ensured that the axis of the steel pipe is aligned with the axis of the die, the centering precision of the steel pipe and the die is improved, the steel pipe can be smoothly expanded and shrunk so that the roundness of a pipe opening can be adjusted, and waste caused by cutting off a gooseneck bend is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of steel pipe processing, in particular to a double-hoop clamping type steel pipe diameter expansion and reduction processing device. Background Art

[0002] Hot-rolled seamless steel pipes often have a "goose-head bend" at the end. Oil drill pipes are typically made by connecting seamless steel pipes with ferrules. The presence of this bend makes it difficult to accurately machine a complete thread at the end of the pipe, thus affecting the threaded connection between the pipe and the ferrule. A common solution to this problem is to simply remove the bend, which undoubtedly results in significant waste. Utility Model Content

[0003] The purpose of the utility model is to provide a double-hoop clamping steel pipe diameter expansion and reduction processing device, which can be used to accurately center and fix the steel pipe, ensuring that the goose head bend at the end of the steel pipe can be straightened.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solution: a double-hoop clamping steel pipe expansion and reduction processing device, comprising a base and a mold installed on the base, the mold is detachably installed with a core mold for expanding or reducing the steel pipe, and two hoops for fixing the steel pipe are arranged at one end at intervals, and the axial center lines of the two hoops are aligned with the axial center line of the core mold.

[0005] Preferably, the clamp comprises a lower half clamp fixed to the base and an upper half clamp movable up and down, and the upper half clamp can loosen the steel pipe or clamp the steel pipe on the lower half clamp when moving up and down.

[0006] More preferably, the upper hoop half is pushed or pulled by a hydraulic cylinder.

[0007] More preferably, the inner wall surfaces of the upper half hoop and the lower half hoop are both provided with anti-slip pads.

[0008] More preferably, one end of the steel pipe away from the mold is connected to a push-pull mechanism to achieve movement of the steel pipe.

[0009] More preferably, a heat treatment heating coil capable of heating the steel pipe is provided between the two clamps.

[0010] More preferably, it further comprises a cooling mechanism for cooling the processed portion of the steel pipe.

[0011] More preferably, the core mold includes at least one central expansion mold and an outer ring shrinking mold, the outer ring shrinking mold is used for diameter reduction processing of the steel pipe, and the central expansion mold is used for diameter expansion processing of the steel pipe.

[0012] Compared with the existing technology, the utility model fixes the steel pipe by two clamps, ensuring that the axis line of the steel pipe is aligned with the axis line of the mold, and can realize precise centering and fixation of the steel pipe, thereby improving the accuracy of the expansion or reduction processing, ensuring the straightening processing of the goose head bend at the end of the steel pipe, and avoiding the waste caused by cutting off the goose head bend. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure in the embodiment;

[0014] Figure 2 Schematic diagram of the steel pipe expansion process in the embodiment;

[0015] Figure 3 Schematic diagram of reducing the diameter of a steel pipe in an embodiment;

[0016] Figure 4 Schematic diagram of the process of expanding the diameter of a steel pipe in an embodiment;

[0017] Figure 5 Schematic diagram of using a mandrel to reduce and expand the diameter of a steel pipe for straightening in an embodiment.

[0018] In the picture:

[0019] 1——Base 2——Mold 3——Steel Pipe

[0020] 4 - Hoop 4a - Lower half hoop 4b - Upper half hoop

[0021] 4c——anti-slip pad 5——outer mold 6——inner membrane

[0022] 7——heat treatment heating coil 8——center mold expansion 9——outer ring mold reduction. DETAILED DESCRIPTION

[0023] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to embodiments and drawings. The contents mentioned in the embodiments are not intended to limit the present invention.

[0024] It should be noted in advance that, in this utility model, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connected," and "fixed" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances. Furthermore, in this utility model, unless otherwise expressly specified or limited, a first feature "above" or "below" a second feature may include direct contact between the first and second features, or may include contact between the first and second features not being in direct contact but through another feature between them.

[0025] like Figure 1 and Figure 2 As shown, a double-hoop clamping steel pipe expansion and reduction processing device includes a base 1 and a mold 2 installed on the base 1. The mold 2 is detachably installed with a core mold for expanding or reducing the steel pipe 3. Two hoops 4 for fixing the steel pipe 3 are arranged at one end of the core mold at intervals, and the axis lines of the two hoops 4 are aligned with the axis line of the core mold.

[0026] Regarding the specific structure of the clamp 4, the clamp 4 includes a lower half clamp 4a fixed to the base 1 and an upper half clamp 4b that can move up and down. When the upper half clamp 4b moves up and down, it can loosen the steel pipe 3 or clamp the steel pipe 3 on the lower half clamp 4a. This allows the clamp 4 to flexibly clamp steel pipes 3 of different diameters, improving the adaptability and versatility of the device. The upper half clamp 4b is pushed or pulled by the hydraulic cylinder 5 to achieve rapid loosening and clamping of the steel pipe 3, improving processing efficiency and operational convenience. In addition, the inner wall surfaces of the upper half clamp 4a and the lower half clamp 4b are both provided with anti-slip pads 4c, which increase the friction between them and the steel pipe 3, effectively preventing the steel pipe 3 from sliding and shifting during processing, and ensuring processing accuracy and safety.

[0027] In this embodiment, the end of the steel tube 3 away from the mold 2 is connected to a push-pull mechanism to enable movement of the steel tube 3. This allows for precise axial movement of the steel tube 3, facilitates adjustment of the relative position between the steel tube 3 and the mold 2, and ensures centering accuracy during processing. The push-pull mechanism can be provided with a clamping mechanism for securing the steel tube 3. This mechanism can be a common push-pull mechanism in the prior art.

[0028] In addition, a heat treatment heating coil 7 is provided between the two clamps 4 to heat the steel pipe 3. The processed part of the steel pipe 3 can be heated directly to prepare for the subsequent expansion and reduction processes, providing an ideal material plastic state for the subsequent expansion and reduction processes, thereby ensuring processing quality and precision.

[0029] The apparatus also includes a cooling mechanism for cooling the processed portion of the steel pipe 3. This allows for rapid cooling of the processed portion, helping to improve processing efficiency while ensuring dimensional stability and material properties after processing. The cooling mechanism can be a conventional cooling liquid spraying device located on one side of the processed portion of the steel pipe 3.

[0030] The core mold in this embodiment includes at least one center expansion mold 8 and an outer ring shrinking mold 9. The outer ring shrinking mold 9 is used for the diameter reduction processing of the steel pipe 3, and the center expansion mold 8 is used for the diameter expansion processing of the steel pipe 3. In the specific processing process, the steel pipe 3 enters the processing station. Figure 5As shown, during the process of the core mold advancing toward the steel pipe 3, the center expansion mold 8 first extends into the steel pipe 3 (the center expansion mold 8 is not working at this time), and then the outer ring shrinking mold 9 contacts the steel pipe 3 and shrinks its diameter. After the diameter reduction is completed, the core mold begins to retreat. During the retreat process, the outer ring shrinking mold 9 is not working, while the center expansion mold 8 expands the diameter of the reduced diameter portion of the steel pipe 1, thereby achieving the purpose of straightening the pipe mouth. Those skilled in the art should know that the center expansion mold 8 in the mold itself has a certain floating adjustment capability. This design allows the center expansion mold 8 to have a certain radial movement space (for example, there is a movement space of about 3mm upward or downward, which is a common technical means in the prior art to improve the flexibility and adaptability of the core mold), so that it can adaptively adjust its state when encountering an irregular pipe mouth. Therefore, even if a pipe mouth with a goose head bend is encountered, it can be smoothly inserted into the steel pipe 3.

[0031] When the outer ring shrinking die 9 is used to reduce the diameter of the steel pipe, it helps to adjust the shape of the pipe mouth and prepare for diameter expansion. Subsequently, during the demolding process, the central expanding die 8 expands the steel pipe 3 to restore the diameter of the pipe mouth, thereby effectively correcting the goose head bend phenomenon. The design of the combined core mold allows the diameter reduction and expansion operations to be performed in stages. The outer ring shrinking die 9 is responsible for diameter reduction, and the central expanding die 8 is responsible for diameter expansion. This design enables the steel pipe 3 to be straightened and shaped corrected in one processing process, greatly improving the processing efficiency.

[0032] In the structural form of direct connection of steel pipes, after the outer wall surface of the steel pipe mouth is processed with external threads after being straightened and rounded, the other end actually needs to be expanded and processed with internal threads, so as to ensure that the two steel pipes are directly connected. However, by using the device provided by this embodiment, it is only necessary to replace the core mold to directly realize the expansion processing of the other end of the steel pipe. Specifically, after replacing the core mold, first extend the part to be processed of the steel pipe 3 into the heat treatment heating coil 7, and then fix the steel pipe 3 through the outermost clamp 4. After the heat treatment is completed, turn off the heat treatment heating coil 7, and then push the steel pipe 3 forward so that the two clamps 4 clamp the steel pipe 3 at the same time, ensuring that the axis of the steel pipe 3 is aligned with the axis of the mold 2 (such as Figure 2 As shown). At this time, the part to be processed at one end of the steel pipe 3 has a certain temperature, and then the outer mold 5 installed on the mold 2 is pushed toward the steel pipe 3 to reduce the diameter of the part to be processed of the steel pipe 3 (as shown). Figure 3 As shown), after the diameter reduction is completed, the mold is withdrawn and the outer mold 5 is removed, and the inner mold 6 is installed on the mold 2 and pushed toward the steel pipe 3 to expand the diameter of the portion to be processed of the steel pipe 3 (as shown). Figure 4 As shown in the figure, the inner die 6 is advanced within the steel pipe 3 to a distance less than the outer die 5 is advanced on the steel pipe 3, so that a step is formed on the inner wall of the steel pipe 3, so that the portion can provide a limit when the threaded portion is formed on the portion and connected to another section of the steel pipe. After the diameter expansion is completed, the die is withdrawn and the steel pipe 3 is cooled to complete the processing and ensure that the shape and size of the steel pipe 3 are stable.

[0033] The core principle of the double-hoop clamping type steel pipe expansion and reduction processing device of the present invention is to use two hoops that are precisely aligned with the axis of the core mold to fix the steel pipe, ensuring that the axis of the steel pipe is aligned with the mold during the expansion or reduction process, thereby improving the processing accuracy and achieving the straightening and rounding of the goose-head bend of the steel pipe, so that the existing steel pipe does not need to be wasted due to the removal of the goose-head bend. Moreover, through this structure, the device can adapt to steel pipes of different diameters, achieve fast and stable clamping, and provide precise positioning and clamping for the processing of the steel pipe ends. The device significantly improves the processing efficiency and accuracy, reduces the processing errors caused by axis misalignment, and enhances the consistency and reliability of the product. At the same time, its modular design facilitates maintenance and replacement, and the core mold can be switched to perform expansion processing on the other end of the steel pipe to facilitate the subsequent processing of the internal thread, thereby meeting the structural requirements of the direct connection of the steel pipe.

[0034] In order to make it easier for ordinary technicians in this field to understand the improvements of the present invention over the prior art, some drawings and descriptions of the present invention have been simplified, and the above-mentioned embodiments are better implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present technical solution is within the scope of protection of the present invention.

Claims

1. A double-hoop clamping type steel pipe diameter expansion and reduction processing device, comprising a base (1) and a mold (2) mounted on the base (1), characterized in that: The mold (2) is detachably mounted with a core mold for expanding or reducing the diameter of the steel pipe (3), and one end of the core mold is provided with two hoops (4) for fixing the steel pipe (3) at intervals, and the axis center lines of the two hoops (4) are aligned with the axis center line of the core mold.

2. The double-hoop clamping steel pipe diameter expansion and reduction processing device according to claim 1 is characterized in that: The hoop (4) comprises a lower hoop (4a) fixed to the base (1) and an upper hoop (4b) movable up and down, wherein the upper hoop (4b) can loosen the steel pipe (3) or clamp the steel pipe (3) on the lower hoop (4a) when moving up and down.

3. The double-hoop clamping steel pipe diameter expansion and reduction processing device according to claim 2, characterized in that: The upper hoop (4b) is pushed or pulled by a hydraulic cylinder (5).

4. The double-hoop clamping steel pipe diameter expansion and reduction processing device according to claim 3 is characterized in that: The inner wall surfaces of the upper half hoop (4b) and the lower half hoop (4a) are both provided with anti-slip pads (4c).

5. The double-hoop clamping steel pipe diameter expansion and reduction processing device according to claim 1, characterized in that: One end of the steel pipe (3) away from the mold (2) is connected to a push-pull mechanism to achieve movement of the steel pipe (3).

6. The double-hoop clamping steel pipe diameter expansion and reduction processing device according to claim 1, characterized in that: A heat treatment heating coil (7) capable of heating the steel pipe (3) is also provided between the two clamps (4).

7. The double-hoop clamping steel pipe diameter expansion and reduction processing device according to claim 6, characterized in that: It also includes a cooling mechanism for cooling the processed part of the steel pipe (3).

8. The double-hoop clamping steel pipe diameter expansion and reduction processing device according to claim 1, characterized in that: The core mold comprises at least one central expansion mold (8) and an outer ring shrinking mold (9), wherein the outer ring shrinking mold (9) is used for diameter reduction processing of the steel pipe (3), and the central expansion mold (8) is used for diameter expansion processing of the steel pipe (3).

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