Method and apparatus for rounding a workpiece

Abstract

The application discloses a workpiece rounding method and device, wherein the workpiece rounding method comprises the following steps: splicing a plurality of core plates to form a workpiece with a polygonal cross section, sealing an inner cavity of the workpiece, and extruding the workpiece with the polygonal cross section into a cylindrical structure by filling the inner cavity of the workpiece with high-pressure gas or liquid. The application also discloses a workpiece rounding device. On one hand, the application can greatly reduce the complexity of operation, save time and labor, and can be formed into a structure with a circular cross section at one time; on the other hand, the application can effectively ensure the connecting strength between the core layer and the face plate during the forming process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of workpiece rounding, in particular to a workpiece rounding method and device. BACKGROUND

[0002] Most of the existing arc-shaped plate forming is to complete the single-layer panel with solid or hollow by rolling or stamping, and it is less to press the sandwich panel into arc-shaped panel. The inventors of the present application have invented a series of core plate rounding methods before the present application. For example, CN 108080476A discloses an arc-shaped brazing sandwich panel forming method, which specifically provides that a plurality of grooves are pre-set on one of the panels; after brazing the two panels and the sandwich layer, a sandwich panel is formed, and then the sandwich panel is placed on a mold with an arc-shaped structure, and an arc-shaped brazing sandwich panel is formed by heating or pressing.

[0003] With subsequent continuous tests, the inventors found that the above forming method has the following defects: (1) the panel needs to be designed into a groove structure, which greatly increases the complexity of the process, resulting in time-consuming and laborious processing; (2) the sandwich panel can only be first changed into an arc-shaped panel, and then a plurality of deformed arc-shaped panels are welded together to form a circle, on the one hand, it cannot be rounded at one time, but needs multiple processes, thereby increasing the degree of operation complexity; on the other hand, the core panel with a horizontal structure is deformed into an arc-shaped core panel by heating or pressing, and due to the large deformation radius, the connection strength between the core layer and the panel is easily reduced, and even part of the core layer can be separated from the panel. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a workpiece rounding method and device which is simple in process, time-saving and labor-saving, and ensures the connection strength.

[0005] The technical solution of the present application is:

[0006] One of the workpiece rounding methods of the present application adopts a plurality of core panels to splice into a workpiece with a polygonal cross section, seals the inner cavity of the workpiece, and extrudes the workpiece with a polygonal cross section into a cylindrical structure by filling high-pressure gas or liquid into the inner cavity of the workpiece.

[0007] Further, the method specifically includes the following steps:

[0008] S1: Splice a plurality of core panels into a workpiece with a polygonal cross section;

[0009] S2: Perform non-destructive testing on all welds to ensure the quality of the welds;

[0010] S3: Perform air tightness leak detection on the inner cavity of the workpiece;

[0011] S4: filling high-pressure gas or liquid pressure, gradually increasing the pressure according to the preset pressure value, and after the pressure is increased to the target pressure, the workpiece with a polygonal cross section is pressed into a workpiece with a circular cross section;

[0012] The flexible transition section is also deformed along with the rounding process of the workpiece, thereby ensuring the sealed connection between the head and the workpiece.

[0013] S5: pressure relief to standard atmospheric pressure or exhaust all the liquid in the inner cavity of the workpiece.

[0014] Further, when the plurality of core plates are welded into a workpiece with a polygonal cross section, the outer panels between adjacent core plates are welded into one body, the inner panels between adjacent core plates are not welded, and a part of the inner panel of each core plate is extended, and then the inner panels between adjacent core plates are welded after the polygonal cross section workpiece is extruded into a circle.

[0015] The workpiece rounding device comprises a tooling and a workpiece with a polygonal cross section, both ends of the workpiece are provided with a head, and a flexible transition section is arranged between the workpiece and the head.

[0016] Further, the head is an arc structure.

[0017] Further, the head is a semispherical structure.

[0018] Further, the workpiece is placed in the tooling, the tooling comprises a base and a containing part for placing the workpiece, a plurality of supporting legs are arranged between the base and the containing part for supporting; the containing part is an arc structure.

[0019] Further, the head at one end of the workpiece is provided with a water injection pipe and / or a gas injection pipe, the head at the other end of the workpiece is provided with a water discharge pipe and / or a gas discharge pipe, and at least one end of the head is provided with a pressure sensor.

[0020] Further, the flexible transition section is arranged around the end face of the workpiece and has a concave-convex structure; the wall of the workpiece is a core plate structure comprising an outer panel, an inner panel and a core layer arranged between the two, one end face of the flexible transition section is welded to the outer panel of the workpiece, and the other end face is welded to the head.

[0021] Further, the lower part of the head is provided with a supporting wheel.

[0022] Further, the workpiece is formed into an N-sided polygonal cross section structure by splicing a plurality of core plates, and N is greater than or equal to 5.

[0023] The workpiece rounding device has the following advantages:

[0024] (1) by first splicing a plurality of core plates into a workpiece with a polygonal cross section, sealing the inner cavity of the workpiece, and filling high-pressure gas or liquid into the inner cavity of the workpiece, the workpiece with a polygonal cross section is extruded into a cylindrical structure. On the one hand, the face plate of the core plate does not need to be changed, and the core plate with a horizontal structure can be spliced into a polygon directly, greatly reducing the complexity of the operation and saving time and effort. On the other hand, the greater the number of sides of the polygon, the closer to the circle. By filling high-pressure gas or liquid into the inner cavity of the workpiece, the polygon can be gradually pressurized into a circle. Not only is the process simple, but also the deformation radius of the core plate is not large during the process of changing the polygon into a circle, which can effectively ensure the connection strength between the core layer and the face plate.

[0025] (2) By setting the end cover, the workpiece can be sealed, and the inner surface of the end cover is provided with a reinforcing rib, which can increase the strength of the end cover and provide a reverse restraining force during pressing.

[0026] (3) By setting the flexible transition section, the end cover and the workpiece can be perfectly connected, and the flexible structure is designed as a wave-shaped ring, which can reduce the restraining force when the polygonal workpiece is pressed into a circle and increase the strength to prevent rupture during pressing, thereby ensuring the sealing between the end cover and the workpiece.

[0027] (4) When a plurality of core plates are welded into a workpiece with a polygonal cross section, a part of the inner face plate of each core plate is designed to extend without welding. After the polygonal cross section workpiece is extruded into a circle, the inner face plates of adjacent core plates are welded, which can effectively ensure the connection strength between the core layer and the face plate and ensure the smooth deformation of the core plate.

[0028] (5) By setting a supporting wheel at the lower part of the end cover, the end cover can be easily moved during pressing due to the large pressure value at both ends of the end cover, thereby preventing tilting or even falling. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structure schematic view of the workpiece before the embodiment of the present application is formed into a circle;

[0030] Figure 2 is a structure schematic view of the workpiece after the embodiment of the present application is formed into a circle;

[0031] Figure 3 is a front view of the embodiment shown in Figure 1 ;

[0032] Figure 4 is a structure schematic view of the end cover of the embodiment of the present application;

[0033] Figure 5 is a structure schematic view of the flexible transition section of the embodiment of the present application;

[0034] Figure 6 is a structure schematic view of the flexible transition section of the embodiment of the present application; Figure 3I part amplification structure schematic diagram of the embodiment shown;

[0035] Figure 7 is Figure 3 II part amplification structure schematic diagram of the embodiment shown;

[0036] Figure 8 is the structure schematic diagram of the adjacent core plate group welding of the embodiment of the application;

[0037] Figure 9 is the state change schematic diagram of the workpiece water filling and drainage of the embodiment of the application.

[0038] Explanation of figure mark:

[0039] 1. tooling; 2. workpiece; 3. end cap; 4. flexible transition section; 5. core plate; 6. support wheel; 11. base; 12. containing part; 13. leg; 31. reinforcing rib; 32. water injection pipe; 33. exhaust pipe; 34. drainage pipe; 35. pressure sensor; 41. recess; 51. outer panel; 52. inner panel; 53. sandwich layer. DETAILED DESCRIPTION

[0040] The application will be further described in detail below in combination with the drawings and specific embodiments of the specification.

[0041] As Figures 1-3 shown: a workpiece rounding device, comprising tooling 1 and workpiece 2 with a polygonal cross section, the two ends of workpiece 2 are provided with end cap 3, and flexible transition section 4 is arranged between workpiece 2 and end cap 3, and workpiece 2 is placed in tooling 1.

[0042] In this embodiment, workpiece 2 is formed into an N-sided polygonal cross section structure by splicing multiple core plates 5, N≥5, preferably hexagonal or octagonal, and further preferably octagonal, because the octagonal shape is closer to a circular shape, so it is easier to be extruded into a circular shape, and if the number of sides is greater than 8, it will lead to a more complex preparation process. In this embodiment, eight core plates 5 are spliced to form an octagonal cross section structure, and the two ends of each core plate 5 are designed as bevels to facilitate the connection of adjacent core plates 5 at an angle.

[0043] As Figure 4 shown: in this embodiment, in order to fill high-pressure gas or liquid into the inner cavity of workpiece 2, it is necessary to seal the two ends of the workpiece, so end cap 3 is designed at the two ends of the workpiece. Among them, the end cap 3 is preferably hemispherical, and the inner surface of the end cap 3 is provided with reinforcing rib 31, which can increase the strength of the end cap, and at the same time provide a reverse restraining force during the pressing process.

[0044] As Figure 5As shown in the figure: in this embodiment, a flexible transition section 4 is arranged between the workpiece 2 and the head 3, the flexible transition section 4 is arranged along the periphery of the end face of the workpiece, and a plurality of recesses 41 are arranged on the plate body of the flexible transition section 4, thereby forming a wave-shaped ring flexible structure. Since the cross section of the workpiece 2 is polygonal and the cross section of the head 3 is circular, the flexible transition section 4 can be arranged to perfectly connect the head and the workpiece, and the wave-shaped ring flexible structure can reduce the constraint force when the polygonal workpiece is pressed into a circular shape, and can also increase the strength so as not to break when pressed.

[0045] In this embodiment, the tooling 1 includes a base 11 and a containing portion 12 for placing the workpiece, and a plurality of supporting legs 13 are arranged between the base and the containing portion for supporting. The containing portion 12 is in a circular arc structure, the workpiece 2 is placed in the arc-shaped cavity of the containing portion 12, and the flexible transition section 4 and the head 3 are externally arranged and not arranged in the tooling.

[0046] As shown in the figure: Figure 6 and Figure 7 In this embodiment, the core plate 5 includes an outer panel 51, an inner panel 52, and a core layer 53 arranged between the two. The inner panel 52 is the inner wall of the workpiece, and the outer panel 51 is the outer wall of the workpiece. One end surface of the flexible transition section 4 is welded to the outer panel 51 of the workpiece, and the other end surface is welded to the head 3. The head 3 is provided with an inclined surface on the surface connected to the flexible transition section 4, so as to increase the welding area and improve the connection strength.

[0047] In this embodiment, a water injection pipe 32 is arranged on the upper part of the head at one end of the workpiece, and the water injection pipe can be used for water injection and also for gas injection. An exhaust pipe 33 is arranged on the upper part of the head at the other end of the workpiece, and a drain pipe 34 is arranged on the lower part of the head. Pressure sensors 35, such as pressure gauges, are arranged on the heads at both ends of the workpiece for detecting the pressure in the cavity of the workpiece.

[0048] The lower part of the head of this embodiment is provided with supporting wheels 6, such as universal wheels, which are used when pressing. Since the pressure values at both ends of the head are large, the supporting wheels can facilitate the movement of the head and prevent tilting or even overturning.

[0049] The method for rounding the workpiece of this embodiment mainly includes the following steps:

[0050] S101: A plurality of core plates are welded to form a workpiece with an octagonal cross section.

[0051] As shown in the figure: Figure 8Specifically, when assembling, the outer panels of adjacent core plates are welded together, the inner panels are not welded together, and the inner panel of each core plate extends outwards and contacts the inner panel of the adjacent core plate, but is not welded to the adjacent core plate. After the polygonal cross-section workpiece is extruded into a circle, the inner panels of the adjacent core plates are welded together. The inner panels of the adjacent core plates are not welded together, which may cause water to enter, but the water will not affect the forming of the circle. On the contrary, after the water enters, the pressure directly acts on the outer surface, which is more conducive to the forming of the outer surface of the workpiece into a circle, and the inner surface of the workpiece into a circle through the action of the core layer. After the circle is formed, the water is drained and then welded.

[0052] S102: After the workpiece is resistance welded, install a water injection pipe, a drainage pipe, a pressure sensor and an exhaust pipe on the head, and then weld the flexible transition section between the head and the outer panel of the workpiece.

[0053] S103: Perform non-destructive testing on all welds to ensure the quality of the welds.

[0054] S104: Perform airtight leak detection on the inner cavity of the workpiece to ensure the sealing of the inner cavity of the workpiece.

[0055] Specifically, a gas pressure of 0.15 MPa is applied to the inner cavity of the workpiece for 10 minutes, and then the pressure is reduced to 0.1 MPa, and the leak is detected by soap solution.

[0056] S105: Fill high-pressure gas or liquid, gradually increase the pressure to the preset pressure value, and then press the workpiece with a polygonal cross-section into a workpiece with a circular cross-section when the target pressure is reached.

[0057] Specifically, as shown in Figure 9 When the high-pressure gas or liquid is filled through the water injection pipe of the head, the pressure is gradually increased by 0.1 MPa, and when the pressure reaches 0.5 MPa (the pressure value can be adjusted according to the size of the workpiece to be pressed into a circle), the workpiece with a polygonal cross-section is pressed into a workpiece with a circular cross-section. The inner cavity of the workpiece is basically completely filled with gas or liquid, which can be inert gas or air. After the workpiece is pressed into a circle, the part of the inner panel of the core plate that extends out gradually becomes arc-shaped, and after the circle is formed, the inner panels of the adjacent core plates are welded together.

[0058] S106: Open the valve of the exhaust pipe to release the pressure in the inner cavity of the workpiece to standard atmospheric pressure.

[0059] S107: Close the exhaust pipe and open the drainage pipe to drain the water in the inner cavity of the workpiece.

[0060] S108: Remove the workpiece from the tooling and remove the head and flexible transition section.

[0061] The workpiece of the embodiment can be used as a car shell of a vacuum tunnel, a vacuum train, etc., for example, a hanger, a hanger rail and a tunnel seat are installed on the workpiece to form a vacuum tunnel.

[0062] In summary, the present application can greatly reduce the complexity of operation, save time and labor, and can be formed into a circular cross-section structure at one time; on the other hand, the connection strength between the core layer and the panel can be effectively guaranteed during the forming process.

Claims

1. A method of rounding a workpiece, comprising: The wall of the workpiece is a core plate structure, comprising an outer panel, an inner panel and a core layer arranged between the two; a plurality of core plates are spliced to form a workpiece with a polygonal cross section, the inner cavity of the workpiece is sealed, and the workpiece with a polygonal cross section is extruded into a cylindrical structure by filling high-pressure gas or liquid into the inner cavity of the workpiece; when the plurality of core plates are spliced to form a workpiece with a polygonal cross section, the outer panels of adjacent core plates are welded into one body, the inner panels are not welded, and the inner panel of each core plate extends out a portion, and then the inner panels of adjacent core plates are welded after the workpiece with a polygonal cross section is extruded into a circle.

2. The workpiece round method of claim 1, wherein, Specifically, the method comprises the following steps: S1: Splicing a plurality of core plates to form a workpiece with a polygonal cross section; S2: Non-destructive testing of all welds to ensure weld quality; S3: Leak detection of the air tightness of the inner cavity of the workpiece; S4: Filling high-pressure gas or liquid to pressurize, gradually increasing the pressure according to the preset pressure value, and after pressurizing to the target pressure, the workpiece with a polygonal cross section is pressed into a workpiece with a circular cross section; S5: The inner cavity of the workpiece is depressurized to standard atmospheric pressure or all the liquid in the inner cavity is discharged.

3. The workpiece round method of claim 1, wherein, The workpiece rounding device comprises a tooling and a head arranged at both ends of the workpiece, and a flexible transition section is arranged between the workpiece and the head.

4. The workpiece round method of claim 3, wherein, The head is in an arc shape; or the head is in a semispherical shape.

5. The workpiece round method of claim 4, wherein, The workpiece is placed in the tooling, which comprises a base and a containing part for placing the workpiece, and a plurality of supporting legs are arranged between the base and the containing part; the containing part is in an arc shape.

6. The workpiece round method of claim 3, wherein, A water injection pipe and / or a gas injection pipe are arranged on the head at one end of the workpiece, and a water discharge pipe and / or a gas discharge pipe are arranged on the head at the other end of the workpiece, and a pressure sensor is arranged on at least one end of the head.

7. The workpiece round method of claim 3, wherein, The flexible transition section is arranged around the end face of the workpiece and has a concave-convex structure; one end face of the flexible transition section is welded to the outer panel of the workpiece, and the other end face is welded to the head.

8. The workpiece round method of claim 3, wherein, The lower part of the head is provided with a supporting wheel.

9. The workpiece round method of claim 3, wherein, The workpiece is formed by splicing a plurality of core plates to form an N-sided polygonal cross section structure, and N≥5.

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