Spinning drawing machining tool for seamless tube with variable wall thickness

Abstract

The utility model relates to the technical field of metal pipe machining, and discloses a spinning and drawing machining tool for a seamless pipe with variable wall thickness, the machining tool comprises a male die, a female die, a lifting gasket and a ball, and the female die is provided with a truncated conical surface. The working molded surface of the female die is changed into the truncated conical surface structure from the traditional cylindrical shape, and the lifting gasket can move upwards or downwards in the spinning and drawing process, so that the contact position of the ball and the female die moves upwards or downwards, and the purpose of variable-wall-thickness machining is achieved; the variable wall thickness machining requirement that the wall thickness of the cylindrical blank piece is in linear, stepped or nonlinear progressive increase change from the thin end to the thick end in the length direction can be met; besides, in the axial moving process of the cylindrical blank piece, the height of the lifting gasket is adjusted in real time according to the design thickness value of each axial position of the variable-wall-thickness seamless pipe, so that the thickness size of each axial position of the variable-wall-thickness seamless pipe machined and formed by the cylindrical blank piece meets the requirement of the design thickness value.

Description

Technical Field

[0001] This utility model relates to the field of metal pipe processing technology, and discloses a spinning and deep drawing tooling for seamless pipes with variable wall thickness. Background Technology

[0002] Seamless tubes with constant inner diameter and variable wall thickness can be used in the manufacture of piping systems and similar components for aerospace vehicles, offering advantages such as light weight, high processing efficiency, and good mechanical properties. Typical applications include... Figure 1 The pitot tube shown is a hollow cantilever structure. The pitot tube is installed at the front of the aircraft fuselage to sense the total atmospheric static pressure. Under constant strength design, the tube shell should be a tube with gradually changing wall thickness. Compared with a constant wall thickness structure, this is beneficial for reducing weight and improving vibration resistance.

[0003] Spinning is a metal plastic forming process that combines the characteristics of forging, extrusion, deep drawing, bending, ring rolling, cross rolling, and roll extrusion, resulting in minimal or no chipping. During spinning, a spinning wheel presses the material from one side of the blank onto a rotating mandrel, causing continuous point-to-point plastic deformation to obtain hollow rotating parts of various generatrice shapes. Spinning deep drawing is a branch of high-strength thinning spinning, also known as ball spinning; for example... Figure 2 As shown, using multiple balls 5 instead of spinning wheels, the cylindrical blank 7 is thinned and formed under the combined action of the balls 5, spinning rod 1, and die 2. This process has been widely used in the production of thin-walled seamless tubes. In addition to the general characteristics of spinning methods, ball spinning also has the following advantages:

[0004] Low surface roughness and high dimensional accuracy of the pipe fittings: Due to the low surface roughness and high dimensional accuracy of the ball bearings used as deformation tools, and the point-by-point deformation mode of the deformation zone with very small elastic deformation, the outer diameter of the pipe fittings after rotation can be controlled within ±0.005mm, the surface roughness can usually reach 0.2μm, and the thinnest pipe wall can reach 0.04mm.

[0005] The mechanical properties of the pipe fittings are improved: the metal pipe fittings are under triaxial compressive stress in the deformation zone. After deformation, the material grains are elongated and the structure is refined, resulting in a continuous fibrous structure, which improves the yield strength and hardness of the metal.

[0006] High deformation efficiency: For metals and alloys with good plasticity, the reduction of area of ​​ball spinning can reach 70-85%, resulting in large deformation. Compared with drawing and cutting processes, it can significantly improve production efficiency.

[0007] It has a material self-inspection effect: During the spinning process, the tube blank is deformed point by point by the ball bearings. The inclusions, interlayers, cracks and other structural defects hidden in the tube blank are easily exposed during the large deformation process, which plays a role in the self-inspection of the tube blank material.

[0008] Due to limitations in process principles and mold structure, the above methods can only process conventional uniform wall thickness seamless cylindrical tubes, and cannot meet the manufacturing requirements of tubes with variable wall thickness. Utility Model Content

[0009] The purpose of this utility model is to provide a spinning and deep drawing tooling for seamless tubes with variable wall thickness, which can meet the processing requirements of variable wall thickness of cylindrical blanks where the wall thickness increases linearly, stepwise or non-linearly from the thin end to the thick end along the length direction. Furthermore, by adjusting the height of the lifting washer during the spinning and deep drawing process, it can be ensured that the thickness of the processed seamless tube at each axial position meets the design thickness requirements.

[0010] To achieve the above-mentioned technical effects, the technical solution adopted by this utility model is as follows:

[0011] A spinning and deep drawing fixture for seamless tubes with variable wall thickness includes:

[0012] Male mold, the male mold including a spinning rod that can be fixed to the inner cavity of the cylindrical blank;

[0013] A female mold, wherein a forming groove is provided on the female mold for a cylindrical blank to pass through the female mold, the working surface of the forming groove is a truncated cone surface, the large diameter end of the truncated cone surface is located on the upper surface of the female mold, and the small diameter end of the truncated cone surface extends into the interior of the female mold or penetrates to the lower surface of the female mold.

[0014] A lifting washer, which is coaxially placed in the forming groove of the female mold;

[0015] The ball bearings are arranged in a plurality of circumferentially spaced apart within the annular gap between the outer wall of the cylindrical blank and the truncated conical surface; the outer wall of the ball bearings contacts the truncated conical surface and the outer wall surface of the cylindrical blank, and the bottom surface of the ball bearings contacts the upper end surface of the lifting washer.

[0016] Furthermore, the diameter of the ball is smaller than the annular gap width between the cylindrical blank and the large-diameter end of the conical surface of the female mold, and the diameter of the ball is greater than or equal to the annular gap width between the minimum outer diameter position of the variable wall thickness seamless tube and the small-diameter end of the conical surface of the female mold.

[0017] Furthermore, the small-diameter end of the truncated cone extends into the interior of the female mold, and the female mold is provided with a cylindrical groove for accommodating the lifting washer at the position corresponding to the lifting washer.

[0018] Furthermore, the inner diameter of the cylindrical groove is greater than or equal to the outer diameter of the lifting washer.

[0019] Furthermore, the spinning rod is a cylindrical structure with the same inner diameter as the cylindrical blank.

[0020] Furthermore, it also includes a driving mechanism, which is coaxially driven and connected to the spinning rod, for driving the spinning rod of the male mold to rotate along the spinning rod axis and moving the spinning rod toward the truncated cone surface of the female mold.

[0021] Furthermore, the driving mechanism is a hydraulic telescopic rod with a self-rotating function.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows: By changing the working surface of the female die from the traditional cylindrical shape to a truncated conical surface structure, the lifting washer can move upward or downward during the spinning and drawing process, so that the contact position between the ball and the female die moves up or down, thereby achieving the purpose of variable wall thickness processing. It can meet the variable wall thickness processing requirements of cylindrical blanks where the wall thickness increases linearly, stepwise or non-linearly from the thin end to the thick end along the length direction. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a typical aircraft pitot tube structure.

[0024] Figure 2 A schematic diagram of the existing tooling structure for machining cylindrical seamless tubes with wall thicknesses such as spinning and deep drawing;

[0025] Figure 3 This is a schematic diagram of the spinning and deep drawing tooling structure for the variable wall thickness seamless tube in the embodiment;

[0026] Among them, 1. spinning rod; 2. female mold; 3. truncated cone surface; 4. lifting washer; 5. ball bearing; 6. cylindrical groove; 7. cylindrical blank; 8. variable wall thickness seamless tube. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0028] Example

[0029] See Figures 1-3 A spinning and deep drawing fixture for seamless tubes with variable wall thickness, comprising:

[0030] Male mold, the male mold includes a spinning rod 1 that can be fixed to the inner cavity of the cylindrical blank 7;

[0031] The female mold 2 is provided with a forming groove through which the cylindrical blank 7 can pass. The working surface of the forming groove is a truncated cone surface 3. The large diameter end of the truncated cone surface 3 is located on the upper surface of the female mold 2, and the small diameter end of the truncated cone surface 3 extends into the interior of the female mold 2 or penetrates to the lower surface of the female mold 2.

[0032] The lifting washer 4 is coaxially placed in the forming groove of the female mold 2;

[0033] There are multiple balls 5, which are circumferentially distributed in the annular gap between the outer wall of the cylindrical blank 7 and the truncated cone surface 3. The outer wall of the balls 5 is in contact with the truncated cone surface 3 and the outer wall surface of the cylindrical blank 7, and the bottom surface of the balls 5 is in contact with the upper end surface of the lifting washer 4.

[0034] In this embodiment, before spinning and drawing the cylindrical blank 7 into the variable wall thickness seamless tube 8, the inner surface of the tube structure of the cylindrical blank is first attached to and coaxially fixed with the spinning rod 1 of the male die. Since the working surface of the female die 2 changes from a cylindrical shape to a truncated conical surface 3 structure, the lifting washer 4 can move up or down during the spinning and drawing process, so that the contact position between the ball 5 and the female die 2 moves up or down, thereby achieving the purpose of variable wall thickness processing. This can meet the variable wall thickness processing requirements of the cylindrical blank 7 where the wall thickness increases linearly, stepwise or nonlinearly from the thin end to the thick end along the length direction.

[0035] The machining process for variable wall thickness seamless tubes using the spinning and deep drawing tooling described in this embodiment is as follows:

[0036] Step 1: Fix the male mold onto the driving mechanism, so that the spinning rod 1 of the male mold is coaxially arranged with the truncated cone surface 3 of the female mold 2, and the spinning rod 1 is located directly above the truncated cone surface 3 of the female mold 2; the driving mechanism is used to drive the spinning rod 1 of the male mold to rotate along the axial direction of the spinning rod 1, and to move the spinning rod 1 toward the truncated cone surface 3 of the female mold 2; in this embodiment, the driving mechanism is a hydraulic telescopic rod with a rotation function;

[0037] Step 2: Coaxially sleeve the cylindrical blank 7 to be processed onto the spinning rod 1, and fix the spinning rod 1 to the cylindrical blank 7. The cylindrical blank 7 is used to process and obtain a seamless tube with variable wall thickness 8.

[0038] Step 3: Start the drive mechanism to make the spinning rod 1 drive the cylindrical blank 7 to rotate and pass through the truncated cone surface 3; wherein, during the axial movement of the cylindrical blank 7, the height of the lifting washer 4 is adjusted in real time according to the design thickness value of each axial position of the variable wall thickness seamless tube 8, so that the thickness dimension of each axial position of the variable wall thickness seamless tube 8 processed by the cylindrical blank 7 meets the design thickness value requirement.

[0039] In this embodiment, the spinning and deep drawing process can be carried out by one or more spinning and deep drawing methods so that the thickness of the variable wall thickness seamless tube 8 formed by the cylindrical blank 7 meets the design thickness requirements at each axial position.

[0040] To ensure that the ball bearing 5 can maintain interaction with the outer wall of the tube during the spinning and drawing process, in this embodiment, the diameter of the ball bearing 5 is smaller than the annular gap width between the cylindrical blank 7 and the large diameter end of the truncated conical surface 3 of the female die 2, and the diameter of the ball bearing 5 is greater than or equal to the annular gap width between the minimum outer diameter position of the finished variable wall thickness seamless tube 8 and the small diameter end of the truncated conical surface 3 of the female die 2.

[0041] In this embodiment, the spinning rod 1 is a cylindrical structure with the same inner diameter as the cylindrical blank 7, which ensures that the inner diameter of the cylindrical blank 7 will not change during the spinning and drawing process, thus ensuring the accuracy and roughness of the inner diameter.

[0042] In this embodiment, the small-diameter end of the truncated cone surface 3 extends into the interior of the female mold 2. The female mold 2 is provided with a cylindrical groove 6 at the position corresponding to the lifting washer 4 to accommodate the lifting washer 4. By ensuring that the inner diameter of the cylindrical groove 6 is greater than or equal to the outer diameter of the lifting washer 4, it is ensured that the cylindrical groove 6 can cooperate with the lifting washer 4 to guide the lifting washer 4. This ensures that the lifting washer 4 moves axially along the cylindrical blank 7 during the lifting process, further guaranteeing the accuracy of the thickness dimensions at each axial position of the processed variable wall thickness seamless tube 8.

[0043] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A spinning and deep drawing tooling for seamless tubes with variable wall thickness, characterized in that, include: Male mold, the male mold including a spinning rod that can be fixed to the inner cavity of the cylindrical blank; A female mold, wherein a forming groove is provided on the female mold for a cylindrical blank to pass through the female mold, the working surface of the forming groove is a truncated cone surface, the large diameter end of the truncated cone surface is located on the upper surface of the female mold, and the small diameter end of the truncated cone surface extends into the interior of the female mold or penetrates to the lower surface of the female mold. A lifting washer, which is coaxially placed in the forming groove of the female mold; The ball bearings are arranged in a plurality of circumferentially spaced apart within the annular gap between the outer wall of the cylindrical blank and the truncated conical surface; the outer wall of the ball bearings contacts the truncated conical surface and the outer wall surface of the cylindrical blank, and the bottom surface of the ball bearings contacts the upper end surface of the lifting washer.

2. The spinning and deep drawing tooling for seamless tubes with variable wall thickness according to claim 1, characterized in that, The diameter of the ball is smaller than the annular gap width between the cylindrical blank and the large-diameter end of the conical surface of the female mold, and the diameter of the ball is greater than or equal to the annular gap width between the minimum outer diameter position of the variable wall thickness seamless tube and the small-diameter end of the conical surface of the female mold.

3. The spinning and deep drawing tooling for seamless tubes with variable wall thickness according to claim 1, characterized in that, The small-diameter end of the truncated cone extends into the interior of the female mold, and the female mold has a cylindrical groove for accommodating the lifting washer at the position corresponding to the lifting washer.

4. The spinning and deep drawing tooling for seamless tubes with variable wall thickness according to claim 3, characterized in that, The inner diameter of the cylindrical groove is greater than or equal to the outer diameter of the lifting washer.

5. The spinning and deep drawing tooling for seamless tubes with variable wall thickness according to claim 1, characterized in that, The spinning rod is a cylindrical structure with the same inner diameter as the cylindrical blank.

6. The spinning and deep drawing tooling for seamless tubes with variable wall thickness according to any one of claims 1-5, characterized in that, It also includes a drive mechanism, which is coaxially connected to the spinning rod and is used to drive the spinning rod of the male mold to rotate along the spinning rod axis and move the spinning rod toward the truncated cone surface of the female mold.

7. The spinning and deep drawing tooling for seamless tubes with variable wall thickness according to claim 6, characterized in that, The drive mechanism is a hydraulic telescopic rod with a self-rotating function.

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