Drawing device for forming variable-diameter inner wall steel pipe

Abstract

The invention discloses a drawing device for forming a variable-diameter inner wall steel pipe, which comprises an outer mold and a variable-diameter drawing mechanism, and the variable-diameter drawing mechanism comprises: a fixed part arranged in the outer mold; the adjusting component is in sliding fit with the fixing component; the variable-diameter part is arranged on one side of the fixing part, the variable-diameter part is driven by the adjusting part to achieve variable diameter, the variable-diameter part comprises a core head guide ring, a fixing mandrel and a variable-diameter core head, the core head guide ring is arranged on the fixing mandrel in a sliding mode, and the variable-diameter core head is in sliding fit with the core head guide ring; and the adjusting part drives the core head guide ring to move along the fixed core shaft to change the relative position of the reducing core head and the core head guide ring so as to realize reducing. The diameter of the variable-diameter core head is changed by adjusting the position of the core head guide ring, machining of pipes with the constant outer diameter and the thinned middle section wall thickness can be achieved, meanwhile, the device can adapt to machining of pipes with different pipe wall thicknesses, use is convenient, cost is low, and production is facilitated.

Description

Technical Field

[0001] The invention belongs to the field of drawing equipment, and in particular relates to a drawing device for forming a steel pipe with a variable diameter inner wall. Background Art

[0002] Due to special service conditions, the drill pipe for geological drilling tools is a steel pipe with a constant outer diameter, a small diameter at both ends of the inner wall, and a large diameter in the middle. If the total length of such pipes is short, deep hole boring can be used. However, when the length of the pipe exceeds 3 meters, not only is the boring process not applicable, but it is also limited by the metallographic structure requirements of the workpiece (the deformation streamline is not cut off), and even no cutting method can be used. Therefore, for this type of steel pipe, drawing is the most commonly used and most economical forming process. However, drawn pipes generally require consistent wall thickness, and the expansion drawing process is suitable for the forming of pipes with increased diameters at both ends (or one end) (the wall thickness remains unchanged). For pipes with a constant outer diameter and thinning wall thickness in the middle, the drawing process is difficult to process. Summary of the invention

[0003] The purpose of the present invention is to provide a drawing device for forming a variable diameter inner wall steel pipe, so as to solve the problem that the existing equipment cannot process the pipe with constant outer diameter and thinning wall thickness in the middle section.

[0004] In order to solve the above problems, the present invention discloses a drawing device for forming a variable diameter inner wall steel pipe, comprising an outer die and a variable diameter drawing mechanism, wherein the variable diameter drawing mechanism comprises:

[0005] A fixed component is arranged in the outer mold;

[0006] An adjusting component, slidingly matched with the fixing component;

[0007] The reducing component is arranged on one side of the fixed component, and the reducing component is driven by the adjusting component to achieve the reducing diameter. The reducing component includes a core head guide ring, a fixed core shaft and a reducing core head. The core head guide ring is slidably arranged on the fixed core shaft, and the reducing core head is slidably matched with the core head guide ring. The adjusting component drives the core head guide ring to move along the fixed core shaft to change the relative position of the reducing core head and the core head guide ring to achieve the reducing diameter.

[0008] As a further improvement of the above technical solution:

[0009] The core head guide ring comprises a conical body, guide grooves are formed at both ends of the conical body, guide rails are arranged between the guide grooves, and the diameter-changing core head is slidably matched with the guide rails.

[0010] The variable diameter core head comprises a plurality of independent variable diameter pieces which are petaled together. The independent variable diameter pieces comprise two sliding block bodies which are respectively arranged in adjacent guide rails.

[0011] The fixing component comprises a fixing limit seat and a fixing core head, wherein the fixing core head abuts against one side of the fixing limit seat, and the fixing limit seat is connected to the fixing core shaft through a bolt pin.

[0012] The fixed core shaft is provided with a core shaft end through a fixing nut, and comb teeth are provided on both the fixed core shaft and the core shaft end, and the comb teeth are slidably matched with the guide groove.

[0013] A flat key is arranged between the core shaft end and the fixed core shaft.

[0014] The adjusting component includes a pull rod, a rear retaining ring fixed on the pull rod by a limit nut, and a front retaining ring fixed on the pull rod by a threaded pin. The core head guide ring is arranged between the rear retaining ring and the front retaining ring. The position of the core head guide ring is changed by adjusting the position of the pull rod.

[0015] The limiting nut is a locking nut structure composed of two nuts.

[0016] The present invention also discloses a pipe processing method, using the drawing device for forming a variable diameter inner wall steel pipe, comprising the following steps:

[0017] S1. Fix the outer die and the limit seat on the drawing equipment, and the minimum diameter of the inner hole of the outer die is adapted to the outer diameter of the workpiece;

[0018] S2, adjusting the position of the pull rod through the hydraulic mechanism so that the initial diameter of the variable core head is the same as the diameter of the fixed core head, starting the drawing equipment, moving the workpiece, and drawing the front section of the workpiece with the smallest inner diameter;

[0019] S3, adjust the position of the pull rod through the hydraulic mechanism, drive the core head guide ring to move forward in the drawing direction, drive the variable diameter core head to move radially outward, the closed variable diameter core head expands, the diameter becomes larger, and the middle section of the workpiece with the largest inner diameter is drawn;

[0020] S4. Adjust the position of the pull rod through the hydraulic mechanism to drive the core head guide ring to move in the opposite direction of the drawing direction, drive the variable diameter core head to move radially inward, so that the variable diameter core head returns to the initial diameter, and draw the rear section of the workpiece with the same inner diameter as the front section.

[0021] As a further improvement of the above technical solution:

[0022] The method of adjusting the position of the pull rod by means of a hydraulic mechanism comprises:

[0023] Determine the initial diameter value d1 and the diameter value d2 after diameter reduction;

[0024] Then the required diameter change value ΔD = d2-d1, the required diameter change value ΔD = 2L0×tanα, α is the angle between the center axis of the cone and the cone surface;

[0025] Then the required adjustment position of the pull rod is LO = (d2-d1) / 2tanα.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] Realize variable diameter drawing: Through the design of the variable diameter core head, the inner diameter of the workpiece can be changed during the drawing process to meet the requirements of different wall thicknesses and improve the processing flexibility and adaptability of the workpiece.

[0028] Precise control: The precise coordination between the core guide ring and the reducing core, as well as the precise control of the pull rod by the hydraulic cylinder, ensure the accuracy of the change in the inner diameter of the workpiece during the drawing process.

[0029] Simple structure and easy operation: The axial movement of the pull rod is controlled by the hydraulic cylinder to drive the relevant components to achieve diameter change. It has a simple structure, easy operation, and reduces the difficulty of equipment maintenance.

[0030] Improve production efficiency: The design of the variable diameter core head enables the processing of different inner diameter parts of the workpiece to be completed in one drawing process, reducing the number of mold changes and improving production efficiency.

[0031] Cost saving: Compared with the traditional method of multiple drawing or mold replacement, this equipment can save mold replacement time and cost and reduce production costs.

[0032] Strong adaptability: This equipment can be used for inner diameter reducing drawing of various parts, and has strong versatility and adaptability.

[0033] Good stability: The stability of the core head and the smooth progress of the drawing process are ensured by the limitation of the limit seat and the fixed core shaft assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the main structure of the present invention;

[0035] Figure 2 For the present invention Figure 1 Schematic diagram of the cross-sectional structure at AA in the middle;

[0036] Figure 3 For the present invention Figure 1 Schematic diagram of the cross-sectional structure at the middle BB;

[0037] Figure 4 For the present invention Figure 1 Schematic diagram of the cross-section structure at CC in the middle;

[0038] Figure 5 It is a schematic diagram of the installation structure of the variable diameter core head and the core head guide ring of the present invention;

[0039] Figure 6 This is a schematic diagram of the core head guide ring structure of the present invention;

[0040] Figure 7 This is a schematic diagram of the structure of the variable diameter core head before the diameter is changed;

[0041] Figure 8 This is a schematic diagram of the structure of the variable diameter core head after the diameter is changed;

[0042] Fig. 9 This is a schematic diagram of the installation positions of the front retaining ring and the rear retaining ring of the present invention;

[0043] Fig.10 This is a schematic diagram of the structure of the pipe after processing according to the present invention.

[0044] Figure numerals: 1. Pull rod; 10. Bolt pin; 11. Front retaining ring; 12. Outer mold; 13. Fixed limit seat; 14. Flat key; 15. Threaded pin; 2. Limit nut; 3. Rear retaining ring; 4. Fixed nut; 5. Mandrel end; 6. Core head guide ring; 61. Guide groove; 62. Guide rail; 7. Fixed mandrel; 8. Variable diameter core head; 81. Independent variable diameter piece; 9. Fixed core head. DETAILED DESCRIPTION

[0045] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0046] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] 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.

[0049] like Figures 1 to 9 As shown, the drawing device for forming a variable diameter inner wall steel pipe in this embodiment includes an outer die 12 and a variable diameter drawing mechanism, and the variable diameter drawing mechanism includes:

[0050] The fixed component is arranged in the outer mold 12; the fixed component includes a fixed limit seat 13 and a fixed core head 9, the fixed core head 9 abuts against one side of the fixed limit seat 13, and the fixed limit seat 13 is connected to the fixed core shaft 7 through a bolt pin 10. The fixed core shaft 7 is provided with a core shaft end 5 through a fixing nut 4, and the fixed core shaft 7 and the core shaft end 5 are both provided with comb teeth, and the comb teeth are slidably matched with the guide groove 61. A flat key 14 is provided between the core shaft end 5 and the fixed core shaft 7.

[0051] The adjusting component is slidably matched with the fixing component; the adjusting component includes a pull rod 1, a rear retaining ring 3 fixed to the pull rod 1 by a limit nut 2, and a front retaining ring 11 fixed to the pull rod 1 by a threaded pin 15. The core head guide ring 6 is arranged between the rear retaining ring 3 and the front retaining ring 11. By adjusting the position of the pull rod 1, the position of the core head guide ring 6 is changed. The limit nut 2 is a locking nut structure composed of two nuts. The core head guide ring 6 includes a conical body, and guide grooves 61 are opened at both ends of the conical body. A guide rail 62 is arranged between the guide grooves 61, and the reducing core head 8 is slidably matched with the guide rail 62. The reducing core head 8 includes a plurality of independent reducing plates 81 that are closed, and the independent reducing plates 81 include two slider bodies, and the two slider bodies are respectively arranged in adjacent guide rails 62.

[0052] The reducing component is arranged on one side of the fixed component, and the reducing component is driven by the adjusting component to achieve the reducing diameter. The reducing component includes a core head guide ring 6, a fixed core shaft 7 and a reducing core head 8. The core head guide ring 6 is slidably arranged on the fixed core shaft 7, and the reducing core head 8 is slidably matched with the core head guide ring 6. The adjusting component drives the core head guide ring 6 to move along the fixed core shaft 7 to change the relative position of the reducing core head 8 and the core head guide ring 6 to achieve the reducing diameter.

[0053] This embodiment is used for pipe processing, such as Fig.10 As shown, a method for processing a variable-wall thickness steel pipe with a large inner wall diameter in the middle section and small inner wall diameters in the front section and the rear section is introduced herein, comprising the following steps:

[0054] S1. Fix the outer die 12 and the limit seat 13 on the drawing equipment. The minimum diameter of the inner hole of the outer die 12 is adapted to the outer diameter of the workpiece. The limit seat 13 is used to limit the displacement of the core head 9.

[0055] S2, adjust the position of the pull rod 1 through the hydraulic mechanism so that the initial diameter size of the variable diameter core head 8 is the same as the diameter of the fixed core head 9, and obtain the following Figure 7 At the position shown, the drawing equipment is started to move the workpiece, and the front section of the workpiece with the smallest inner diameter is drawn;

[0056] S3, adjust the position of the pull rod 1 through the hydraulic mechanism, drive the core head guide ring 6 to move forward in the pulling direction, drive the variable diameter core head 8 to move radially outward, and the closed variable diameter core head 8 expands and the diameter becomes larger, so as to obtain the following Figure 8 The position shown is the middle section of the workpiece with the largest inner diameter;

[0057] S4, adjust the position of the pull rod 1 through the hydraulic mechanism, drive the core head guide ring 6 to move in the opposite direction of the pulling direction, drive the diameter reducing core head 8 to move radially inward, so that the diameter reducing core head 8 returns to the initial diameter, and obtains the following Figure 7 In the position shown, the rear section of the workpiece with the same inner diameter as the front section is drawn. Even if the reducing core head 8 may move in the negative direction with the core head guide ring 6, it will still be reset to the limiting position of the core head 9 when subjected to a positive external force.

[0058] The position of the tie rod 1 is adjusted by a hydraulic mechanism, including:

[0059] Determine the initial diameter value d1 and the diameter value d2 after diameter reduction;

[0060] Then the required diameter change value ΔD = d2-d1, the required diameter change value ΔD = 2L0×tanα, α is the angle between the center axis of the cone and the cone surface;

[0061] Then the required adjustment position of the tie rod 1 is LO = (d2-d1) / 2tanα. Here, the front section and the rear section are set to have the same inner diameter. In actual processing, the position of the tie rod 1 can be adjusted according to the diameter change to achieve processing.

[0062] The above is only an embodiment of the present invention, and the common sense such as the known specific structure and characteristics in the scheme is not described in detail here. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

Claims

1. A drawing device for forming a variable diameter inner wall steel pipe, comprising an outer die (12) and a variable diameter drawing mechanism, characterized in that: The variable diameter drawing mechanism comprises: A fixing component is arranged in the outer mold (12); An adjusting component, slidingly matched with the fixing component; The variable diameter component is arranged on one side of the fixed component, and the variable diameter component is driven by the adjusting component to achieve the variable diameter. The variable diameter component comprises a core head guide ring (6), a fixed core shaft (7) and a variable diameter core head (8). The core head guide ring (6) is slidably arranged on the fixed core shaft (7), and the variable diameter core head (8) is slidably matched with the core head guide ring (6). The adjusting component drives the core head guide ring (6) to move along the fixed core shaft (7), and changes the relative position of the variable diameter core head (8) and the core head guide ring (6) to achieve the variable diameter.

2. The drawing device for forming a variable diameter inner wall steel pipe according to claim 1, characterized in that: The core head guide ring (6) comprises a cone, with guide grooves (61) formed at both ends of the cone, a guide slide rail (62) arranged between the guide grooves (61), and the diameter-changing core head (8) slidingly cooperates with the guide slide rail (62).

3. The drawing device for forming a variable diameter inner wall steel pipe according to claim 2, characterized in that: The diameter-changing core head (8) comprises a plurality of independent diameter-changing pieces (81) that are closed together. The independent diameter-changing pieces (81) comprise two sliding block bodies. The two sliding block bodies are respectively arranged in adjacent guide rails (62).

4. The drawing device for forming a steel pipe with a variable diameter inner wall according to any one of claims 1 to 3, characterized in that: The fixing component comprises a fixing limit seat (13) and a fixing core head (9), wherein the fixing core head (9) abuts against one side of the fixing limit seat (13), and the fixing limit seat (13) is connected to the fixing core shaft (7) via a bolt pin (10).

5. The drawing device for forming a variable diameter inner wall steel pipe according to claim 4, characterized in that: The fixed core shaft (7) is provided with a core shaft end (5) via a fixing nut (4), and comb teeth are provided on both the fixed core shaft (7) and the core shaft end (5), and the comb teeth are slidably matched with the guide groove (61).

6. The drawing device for forming a variable diameter inner wall steel pipe according to claim 5, characterized in that: A flat key (14) is provided between the core shaft end (5) and the fixed core shaft (7).

7. The drawing device for forming a steel pipe with a variable diameter inner wall according to claim 6, characterized in that: The adjustment component comprises a pull rod (1), a rear retaining ring (3) fixed to the pull rod (1) via a limit nut (2), and a front retaining ring (11) fixed to the pull rod (1) via a threaded pin (15); the core head guide ring (6) is arranged between the rear retaining ring (3) and the front retaining ring (11); and the position of the core head guide ring (6) is changed by adjusting the position of the pull rod (1).

8. The drawing device for forming a variable diameter inner wall steel pipe according to claim 7, characterized in that: The limiting nut (2) is a locking nut structure composed of two nuts.

9. A method for processing a pipe, using the drawing device for forming a variable diameter inner wall steel pipe as claimed in claim 8, characterized in that: The following steps are involved: S1, fixing the outer die (12) and the limit seat (13) on the drawing device, and the minimum diameter of the inner hole of the outer die (12) is adapted to the outer diameter of the workpiece; S2, adjusting the position of the pull rod (1) through the hydraulic mechanism so that the initial diameter of the variable diameter core head (8) is the same as the diameter of the fixed core head (9), starting the drawing device to move the workpiece, and drawing the front section of the workpiece with the smallest inner diameter; S3, adjusting the position of the pull rod (1) through the hydraulic mechanism, driving the core head guide ring (6) to move in the positive direction of the drawing, driving the variable diameter core head (8) to move radially outward, the closed variable diameter core head (8) expands, the diameter becomes larger, and the middle section of the workpiece with the largest inner diameter is drawn; S4. Adjust the position of the pull rod (1) through the hydraulic mechanism to drive the core head guide ring (6) to move in the opposite direction of the drawing direction, drive the variable diameter core head (8) to move radially inward, so that the variable diameter core head (8) returns to the initial diameter, and draws the rear section of the workpiece with the same inner diameter as the front section.

10. The method for processing a pipe according to claim 9, characterized in that: The method of adjusting the position of the pull rod (1) by means of a hydraulic mechanism comprises: Determine the initial diameter value d1 and the diameter value d2 after diameter reduction; Then the required diameter change value ΔD = d2-d1, the required diameter change value ΔD = 2L0×tanα, α is the angle between the center axis of the cone and the cone surface; Then the required adjustment position of the pull rod (1) is LO = (d2 - d1) / 2tanα.

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