A system for forming a petroleum drill pipe pin forging
By integrating pre-forging, final forging, and punching stations in a multi-directional die forging press, the problems of high equipment cost, low efficiency, and unstable quality in the processing of oil drill pipe joints have been solved, achieving efficient and low-cost forming of male oil drill pipe joints.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU ZHONGGONG NEW ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-04-02
- Publication Date
- 2026-06-12
AI Technical Summary
The existing forging process for oil drill pipe joints suffers from problems such as high equipment investment costs, low production efficiency, unstable forging quality, and severe equipment wear. In particular, when the length-to-diameter ratio is large, it is difficult to ensure the coaxiality of the inner hole and avoid deformation defects.
The multi-directional die forging press design integrates pre-forging, final forging, and punching processes on a single machine. It uses a unified die structure to form the male part of the oil drill pipe, achieving efficient forming through the cooperation of multi-directional dies.
It improves the processing quality and efficiency of oil drill pipe male connectors, reduces equipment investment and maintenance costs, reduces forging deformation and wear, and enhances the automation level of the production line.
Smart Images
Figure CN224346874U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the processing of male oil drill pipe connectors, specifically to a forging system for male oil drill pipe connectors. Background Technology
[0002] Oil drill pipe joints are widely used in the drilling and development of oil and gas resources such as petroleum and natural gas, and are an important component of the drill string. They connect multiple drill pipes into a single unit, transmitting the power and torque of the drilling rig, enabling the drill bit to perform drilling operations downhole, while simultaneously ensuring the circulation and sealing of drilling fluid, thus ensuring the smooth progress of the drilling process. Oil drill pipe joints consist of male and female connectors, located at both ends of the drill pipe body.
[0003] The manufacturing process of oil drill pipe joints generally includes blanking, heating, forging, heat treatment, machining, and subsequent processing. Depending on the product specifications and equipment, drill pipe joint forgings utilize different forging processes such as multi-pass progressive upsetting of pipe stock, reverse extrusion forming of bar stock, and multi-directional die forging. This process is suitable for forming small-sized drill pipe joints, and in practical applications, they are often integrally formed with the pipe body.
[0004] Bar stock reverse extrusion forming is mainly performed on a vertical press. The forming process is as follows: sawing – heating in an induction furnace – upsetting on a vertical press – pre-forging on a vertical press – final forging on a vertical press – punching on a vertical press (in practice, upsetting / pre-forging / final forging can be completed simultaneously on a single vertical press). This process requires multiple vertical presses to form a production line, and the production efficiency is generally low. Because the entire inner hole of the forging needs to be formed from one end to the other, for products with a total length of 400-600mm, the length-to-diameter ratio of the punching punch reaches 6-9 times. It is difficult to guarantee the coaxiality of the punching punch and the round die. Moreover, the front end of the punch is in contact with the high-temperature billet for a long time and there is intense friction, which raises the temperature to 650-800℃, which is far greater than the tempering temperature of the punch material. This makes it very easy for expansion deformation and bending to occur, resulting in defects such as over-punched inner hole, skewed inner hole, and wall thickness deviation. When the punch is pulled out, the forging may also get stuck on the punching punch and cannot be removed, which seriously affects the quality of the forging product and production efficiency.
[0005] The traditional multi-directional forging process is as follows: sawing – medium-frequency heating – pre-forging on a vertical press – final forging on a multi-directional forging press – punching on a vertical press. This process requires two vertical presses and one multi-directional forging press to form a forging production line, resulting in high equipment investment costs. The distance between equipment is long, forging transfer time is long, and production efficiency is generally low. Each vertical press requires operator intervention, leading to a large workforce on the production line. Automated production requires multiple automated machines due to the long transfer distance, resulting in high investment costs. For ease of positioning, the round bar stock can only be selected to be close to the maximum outer diameter of the pre-forged part. Furthermore, the pre-forged part produced by the vertical press can only be shaped with a larger top and smaller bottom, limiting the shape of the joint pre-forging. The deformation from the round bar stock to the pre-forged part is mainly upsetting deformation, and only shallow recessed holes can be forged at both ends of the pre-forged part. When attempting to produce a pre-forged shape that is small at both ends and large in the middle, some unavoidable slight folding defects on the surface of the forging may occur, necessitating an increase in machining allowance to ensure that subsequent machining can eliminate these defects. Compared to vertical press forging, using a multi-directional die forging press for final forging can shorten the total punch length and improve forging quality. However, since the pre-forged part is almost a solid blank, the punch tip still experiences significant wear for long products. When punching holes with a vertical press, bulging can occur when removing the connecting skin located in the middle of the final forging part because the outer diameter is not protected, causing problems for subsequent processing of the product. Utility Model Content
[0006] In view of the above problems, this utility model proposes a forging system for male oil drill pipe connectors.
[0007] The technical solution of this utility model:
[0008] A forging system for oil drill pipe male connectors includes a forging press; the forging press is a multi-directional die forging press; the forging press has three stations: a pre-forging station, a final forging station, and a punching station; a high-temperature round bar is placed in the pre-forging station and forged into a pre-forging part by the forging press and a pre-forging die; the pre-forging part is placed in the final forging station and forged into a final forging part by the forging press and a final forging die; the final forging part is placed in the punching station and punched into an oil drill pipe male connector by the forging press and a punching die.
[0009] Further refining the above technical solution, the pre-forging die is set at the pre-forging station and consists of an upper pre-forging die, a lower pre-forging die, a left pre-forging punch, and a right pre-forging punch. The upper pre-forging die is fixed on the upper slide plate of the forging press, the lower pre-forging die is fixed on the lower slide plate of the forging press, the left pre-forging punch is connected to the left cylinder of the forging press, and the right pre-forging punch is connected to the right cylinder of the forging press. The final forging die is set at the final forging station and consists of an upper final forging die, a lower final forging die, a left final forging punch, and a right final forging punch. The forging press consists of an upper forging die fixed to the upper slide plate of the forging press, a lower forging die fixed to the lower slide plate of the forging press, a left forging punch connected to the left cylinder of the forging press, and a right forging punch connected to the right cylinder of the forging press. The punching die is located at the punching station and consists of an upper punching die, a lower punching die, and a punching punch. The upper punching die is fixed to the upper slide plate of the forging press, the lower punching die is fixed to the lower slide plate of the forging press, and the punching punch is connected to either the left or right cylinder of the forging press.
[0010] Further refining the above technical solution, the oil drill pipe male connector forging is a cylindrical body, with smaller ends and a larger middle; the pre-forging upper half die, the final forging upper half die, and the punching upper half die have the same structure, as do the pre-forging lower half die, the final forging lower half die, and the punching lower half die. The cavity formed by the molds is divided into three sections: left, middle, and right. The left section is a circular hole with the same diameter as the left end of the oil drill pipe male connector forging; the middle section matches the oil drill pipe male connector forging; and the right end has a circular hole with the same diameter as the right end of the oil drill pipe male connector forging. In this way, the molds are universalized, reducing procurement, manufacturing, and maintenance costs.
[0011] The advantages of this utility model are that it uses a multi-directional die forging press to realize the pre-forging and punching of oil drill pipe male connector forgings, thereby improving the processing quality of oil drill pipe male connector forgings. Furthermore, the multi-directional die forging press is improved to have multiple workstations, enabling the pre-forging, final forging, and punching of oil drill pipe male connector forgings to be completed on one machine, thus improving the processing efficiency of oil drill pipe male connector forgings. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of a forged male connector for oil drill pipe.
[0013] Figure 2 This is a schematic diagram of the distribution of the oil drill pipe male connector forging system.
[0014] Figure 3 This is a schematic diagram of the pre-forging die structure (with high-temperature round bar attached).
[0015] Figure 4 This is a schematic diagram of the final forging die structure (with pre-forging parts attached).
[0016] Figure 5 This is a schematic diagram of the punching die structure (with the final forging attached).
[0017] The diagram shows: 1. Oil drill pipe male forging; 2. Multi-directional forging press; 3. Pre-forging die; 3-1. Pre-forging upper die; 3-2. Pre-forging lower die; 3-3. Pre-forging left punch; 3-4. Pre-forging right punch; 4. Final forging die; 4-1. Final forging upper die; 4-2. Final forging lower die; 4-3. Final forging left punch; 4-4. Final forging right punch; 5. Punching die; 5-1. Punching upper die; 5-2. Punching lower die; 5-3. High-temperature bar stock; 6. Pre-forging part; 7. Final forging part; 8. Detailed Implementation
[0018] like Figure 1-5 As shown,
[0019] The male drill pipe forging 1 is a cylindrical body, with small ends and a large middle;
[0020] A forging system for oil drill pipe male connectors, the forming system includes a multi-directional die forging press 2, the multi-directional die forging press 2 has three stations, which are arranged in sequence as a pre-forging station, a final forging station, and a punching station;
[0021] The pre-forging die 3 consists of an upper pre-forging die 3-1, a lower pre-forging die 3-2, a left pre-forging punch 3-3, and a right pre-forging punch 3-4. The upper pre-forging die 3-1 is fixed on the upper slide plate of the multi-directional forging press 2, the lower pre-forging die 3-2 is fixed on the lower slide plate of the multi-directional forging press 2, the left pre-forging punch 3-3 is connected to the left cylinder of the multi-directional forging press 2, and the right pre-forging punch 3-4 is connected to the right cylinder of the multi-directional forging press 2. The final forging die 4 consists of an upper final forging die 4-1, a lower final forging die 4-2, a left final forging punch 4-3, and a right final forging punch 4-4. The upper final forging die 4-1 is fixed on the upper slide plate of the multi-directional forging press 2, the lower final forging die 4-2 is fixed on the lower slide plate of the multi-directional forging press 2, the left final forging punch 4-3 is connected to the left cylinder of the multi-directional forging press 2, and the right final forging punch 4-4 is connected to the right cylinder of the multi-directional forging press 2. The punching die 5 is connected to the right cylinder of the multi-directional forging press 2. The punching die 5 consists of an upper punching die 5-1, a lower punching die 5-2, and a punching punch 5-3. The upper punching die 5-1 is fixed on the upper slide plate of the multi-directional forging press 2, the lower punching die 5-2 is fixed on the lower slide plate of the multi-directional forging press 2, and the punching punch 5-3 is connected to the left cylinder of the multi-directional forging press 2. The pre-forging upper die 3-1, the final forging upper die 4-1, and the punching upper die 5-1 have the same structure. The pre-forging lower die 3-2, the final forging lower die 4-2, and the punching lower die 5-2 have the same structure. The cavity formed by the mold is divided into three sections: left, middle, and right. The left section is a round hole with the same diameter as the left end of the oil drill pipe male connector forging 1. The middle section matches the oil drill pipe male connector forging 1. The right end is a round hole with the same diameter as the right end of the oil drill pipe male connector forging 1.
[0022] The high-temperature bar stock 6 is transferred to the pre-forging station. At the pre-forging station, the multi-directional forging press 2, in conjunction with the pre-forging die 3, forges the high-temperature round bar 6 into a pre-forged part 7. The pre-forged part 7 is transferred to the final forging station. At the final forging station, the multi-directional forging press 2, in conjunction with the final forging die 4, forges the pre-forged part 7 into a final forged part 8. The final forged part 8 is transferred to the punching station. At the punching station, the multi-directional forging press 2, in conjunction with the punching die 5, punches the final forged part 8 into an oil drill pipe male connector forging 1.
[0023] The above embodiments are only for illustrating the technical concept and features of the utility model, and are intended to enable those skilled in the art to understand the content of the utility model and implement it accordingly. They should not be construed as limiting the scope of protection of the utility model. All equivalent changes or modifications made in accordance with the spirit and essence of the utility model should be covered within the scope of protection of the utility model.
Claims
1. A forging system for male oil drill pipe fittings, the forging system comprising a forging press; the forging press being a multi-directional die forging press; characterized in that, The forging press has three stations: a pre-forging station, a final forging station, and a punching station. A high-temperature round bar is placed in the pre-forging station and forged into a pre-forging part by the forging press and a pre-forging die. The pre-forging part is placed in the final forging station and forged into a final forging part by the forging press and a final forging die. The final forging part is placed in the punching station and punched into a male oil drill pipe connector by the forging press and a punching die. The pre-forging die is set in the pre-forging station and consists of an upper pre-forging die, a lower pre-forging die, a left pre-forging punch, and a right pre-forging punch. The upper pre-forging die is fixed on the upper slide plate of the forging press, the lower pre-forging die is fixed on the lower slide plate of the forging press, the left pre-forging punch is connected to the left cylinder of the forging press, and the right pre-forging punch is connected to the right cylinder of the forging press. The final forging die is set at the final forging station and consists of an upper final forging die, a lower final forging die, a left final forging punch, and a right final forging punch. The upper final forging die is fixed on the upper slide plate of the forging press, the lower final forging die is fixed on the lower slide plate of the forging press, the left final forging punch is connected to the left cylinder of the forging press, and the right final forging punch is connected to the right cylinder of the forging press. The punching die is set at the punching station and consists of an upper punching die, a lower punching die, and a punching punch. The upper punching die is fixed on the upper slide plate of the forging press, the lower punching die is fixed on the lower slide plate of the forging press, and the punching punch is connected to the left or right cylinder of the forging press. The forged male part of the oil drill pipe is a cylindrical body, with smaller ends and a larger middle. The upper half of the pre-forging die, the upper half of the final forging die, and the upper half of the punching die have the same structure. The lower half of the pre-forging die, the lower half of the final forging die, and the lower half of the punching die have the same structure. The cavity formed by the mold is divided into three sections: left, middle, and right. The left section is a round hole with the same diameter as the left end of the forged male part of the oil drill pipe. The middle section matches the diameter of the forged male part of the oil drill pipe. The right end is a round hole with the same diameter as the right end of the forged male part of the oil drill pipe.