Residual stress control device for thin-walled cylinder with variable concentration and temperature based on variable temperature expansion type

Abstract

The present invention discloses a variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion, which relates to the technical field of pipe material processing, including a device body, the top of which is open and has an expansion cavity for accommodating the thin-walled tube to be regulated; at least one side of the device body is provided with a variable temperature device that fits the side wall; a forward push fixing plate is linearly reciprocating in the expansion cavity, and the forward push fixing plate is used to apply axial external force to the thin-walled tube to be regulated and seal against the end of the thin-walled tube to be regulated; locking devices are provided on the inner walls of the device body on both sides along the moving direction of the forward push fixing plate, and the locking devices are used to limit the displacement of the forward push fixing plate after it is completely pressed against the thin-walled tube to be regulated; matching proton exchange membranes are connected to the openings at both ends of the thin-walled tube to be regulated. The device of the present invention changes the concentration difference of the solution inside and outside the thin-walled tube to be regulated, so that the inside of the thin-walled tube is subjected to variable temperature expansion, while the external solution does not freeze, thereby regulating and improving the residual stress distribution of the thin-walled tube.

Description

Technical Field

[0001] The invention relates to the technical field of pipe material processing, and in particular to a variable-concentration and variable-temperature thin-walled tube residual stress control device based on variable-temperature expansion. Background Art

[0002] During the manufacturing process, cylindrical thin-walled components often face problems such as large processing deformation, many surface defects and low local strength due to their characteristics such as large material removal, multiple features, weak rigidity and strict processing tolerances. These problems are largely caused by the release and redistribution of residual stress introduced during the forming and processing process during the semi-finishing or finishing stages, which causes the component to warp or twist and reduce the processing accuracy. Therefore, how to effectively eliminate residual stress has become a difficult problem that equipment manufacturers need to solve urgently, which is of great significance for achieving precise shape control during the processing of weak rigid thin-walled parts.

[0003] At present, mechanical deformation methods (such as pre-stretching and bulging methods, etc.) are mainly used in the blank forming stage. By applying a static load to the blank, it causes overall plastic deformation, thereby eliminating residual stress. For example, when the pre-stretching amount of aluminum alloy plates is 2.2%, the residual stress can be effectively reduced. In addition, some media will undergo a morphological change when the temperature changes, resulting in a change in volume, thereby producing a certain amount of deformation. For example, when water changes from liquid to solid, the volume of ice can become 1.09 times that of water, that is, the length in a single direction can become 1.03 times that of water, resulting in a deformation of about 3%.

[0004] However, the traditional mechanical bulging method is complicated to operate, the equipment is cumbersome, and the bulging process is relatively complicated. Therefore, it is necessary to propose a variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature bulging to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a variable-concentration and variable-temperature thin-walled tube residual stress control device based on variable-temperature expansion type to solve the above-mentioned technical problems existing in the prior art.

[0006] To achieve the above-mentioned purpose, the present invention provides the following scheme: a variable-concentration and variable-temperature thin-walled tube residual stress control device based on variable-temperature expansion, comprising a device body, the device body is a box structure with an open top, and has an expansion cavity for accommodating the thin-walled tube to be regulated; at least one side of the device body is provided with a temperature-changing device that fits with the side wall; a forward push fixing plate is linearly reciprocating in the expansion cavity, and the forward push fixing plate is used to apply axial external force to the thin-walled tube to be regulated and seal against the end of the thin-walled tube to be regulated; locking devices are provided on the inner walls on both sides of the device body along the travel direction of the forward push fixing plate, and the locking device is used to limit its displacement after the forward push fixing plate is completely pressed against the thin-walled tube to be regulated; matching proton exchange membranes are connected to the openings at both ends of the thin-walled tube to be regulated.

[0007] In view of the problems existing in the prior art, the present invention proposes a variable concentration and variable temperature residual stress control device that utilizes the change in solution volume to eliminate the residual stress after processing of a cylindrical thin-walled weak rigid structure. The device fills a composite medium with a high expansion coefficient into the interior of a thin-walled structural part or a mold cavity, and changes the ambient temperature to solidify or solidify the composite medium. At the same time, the solution concentration is adjusted through a proton exchange membrane, and the different characteristics of the freezing points of solutions of different concentrations are utilized to generate a controllable bulging force, causing stress release or stress relaxation in the thin-walled part, thereby achieving the purpose of eliminating residual stress. This method is of great significance for improving the residual stress distribution of thin-walled weak rigid structures through mechanical bulging.

[0008] Optionally, a plurality of empty grooves are formed on the inner walls on both sides of the device body along the travel direction of the forward push fixing plate, and the locking device is elastically connected in the empty grooves.

[0009] Optionally, the locking device includes a locking device body, a spring and a plurality of locking teeth, the spring being fixed between the locking device body and the bottom of the empty slot, the locking teeth being arranged on the side of the locking device body facing away from the empty slot, and being evenly spaced along the moving direction of the forward push fixing plate, and a limiting groove for accommodating the forward push fixing plate to be inserted is formed between two adjacent locking teeth.

[0010] Optionally, at least two springs are provided along the length direction of the locking device body to ensure its stability when being compressed and rebounding.

[0011] Optionally, one side of the locking tooth facing the travel direction of the forward-pushing fixed plate is an inclined surface, and the other side is a straight surface.

[0012] Optionally, the position where the middle of the forward push fixing plate cooperates with the end face of the thin-walled tube to be regulated is a solid flat plate, and the forward push fixing plate is provided with a plurality of water holes near the edge, so that the water holes can facilitate the passage of liquid in the expansion cavity when the plate is moved.

[0013] Optionally, a joystick is fixedly connected to a side of the forward-pushing fixing plate that is away from the thin-walled tube to be regulated, and the joystick passes through the device body and forms a seal at the passing position.

[0014] Optionally, a driving mechanism is connected to a side of the forward-pushing fixing plate that is away from the thin-walled cylinder to be regulated.

[0015] Optionally, an upper cover plate of the expansion cavity is connected to the upper opening of the device body, which is used to reduce the temperature exchange with the outside during the variable temperature expansion process and speed up the variable temperature expansion.

[0016] Compared with the prior art, the present invention at least discloses the following beneficial effects:

[0017] The present invention provides a variable-concentration and variable-temperature thin-walled tube residual stress control device based on variable-temperature expansion. Under low-temperature conditions in the expansion cavity, by changing the difference in solution concentration inside and outside the regulated thin-walled tube, the inside of the thin-walled tube is subjected to variable-temperature expansion, while the external solution does not freeze, thereby controlling and improving the residual stress distribution of the thin-walled tube. The present invention utilizes the volume expansion caused by the change in solution temperature to achieve mechanical expansion, and has the characteristics of simple structure, easy maintenance, convenient operation, and high safety. In the expansion process, the present invention uses water and its solution as the medium, and the raw materials are widely available, which has the advantage of being green and environmentally friendly. In addition, the device has low energy consumption during the expansion process and no obvious waste is generated. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of an embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the structure inside the expansion cavity in an embodiment of the present invention;

[0021] Figure 3 is a schematic structural diagram of a device body in an embodiment of the present invention;

[0022] Figure 4 Schematic diagram of the installation position of the locking device and the device body in an embodiment of the present invention;

[0023] Figure 5 It is a schematic diagram of the connection between the expanded thin-walled cylinder and the matching proton exchange membrane in an embodiment of the present invention;

[0024] Figure 6It is a schematic structural diagram of a bulged thin-walled tube in an embodiment of the present invention;

[0025] Figure 7 It is a structural schematic diagram of a locking device in an embodiment of the present invention;

[0026] Figure 8 A top view of a locking device in an embodiment of the present invention;

[0027] Fig. 9 This is a schematic diagram of the connection between the locking device and the device body in an embodiment of the present invention;

[0028] Fig.10 It is a schematic diagram of the structure of the forward push fixing plate and the joystick in an embodiment of the present invention;

[0029] Fig.11 It is a schematic structural diagram of another embodiment of the present invention.

[0030] In the figure: 1. device body; 11. first side wall; 12. second side wall; 13. third side wall; 14. fourth side wall; 15. joystick guide hole; 16. empty slot; 2. upper cover plate of expansion cavity; 3. temperature changing device; 4. thin-walled cylinder to be regulated; 5. matching proton exchange membrane; 6. locking device; 61. locking device body; 62. locking tooth; 63. spring; 7. joystick; 8. forward push fixing plate; 9. driving mechanism. DETAILED DESCRIPTION

[0031] 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.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Reference Figures 1 to 10As shown, an embodiment of the present invention provides a variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion, including a device body 1, the device body 1 is a box structure, the top is open and connected to the expansion cavity upper cover plate 2, the box includes four side walls and a bottom plate, the four side walls and the bottom plate are integrally formed, and together enclose a expansion cavity for accommodating a thin-walled tube 4 to be regulated, for ease of understanding, the four side walls are defined as a first side wall 11, a second side wall 12, a third side wall 13 and a fourth side wall 14, wherein the first side wall 11 and the third side wall 13 are opposite, and the second side wall 12 and the fourth side wall 14 are opposite. The second side wall 12 is a thin-walled surface, which is convenient for heat conduction. A temperature-changing device 3 is installed outside the second side wall 12, and the temperature-changing device 3 is tightly fitted with the second side wall 12, so that the subsequent temperature-changing device 3 can adjust the temperature of the expansion cavity. A joystick guide hole 15 is provided in the middle of the fourth side wall 14 opposite to the second side wall 12, and a joystick 7 is sealed and slid in the hole. A forward push fixing plate 8 is fixedly connected to one end of the joystick 7 entering the expansion cavity. The forward push fixing plate 8 is used to press against the thin-walled tube 4 to be regulated from the end of the thin-walled tube 4 to be regulated. The forward push fixing plate 8 is responsible for pushing forward to complete the axial application of external force to the thin-walled tube 4 to be regulated after the concentration inside and outside the thin-walled tube 4 is stable, so as to prevent the ice formed by the internal solution from axially squeezing out the thin-walled tube 4 to be regulated during the temperature-variable expansion process, and at the same time complete the isolation and sealing of the tube from the external solution. The movement of the joystick 7 is controlled manually or by connecting a driving mechanism to achieve the position adjustment of the forward push fixing plate 8. In order to position the forward push fixing plate 8 in the expansion cavity after reaching the preset position, a plurality of locking devices 6 are connected to the first side wall 11 and the third side wall 13. The locking devices 6 are attached to the inner wall of the expansion cavity and are used together with the forward push fixing plate 8 to limit the displacement of the forward push fixing plate 8 after the forward push fixing plate 8 has completely squeezed the thin-walled tube 4 to be regulated, so as to prevent the forward push fixing plate 8 from falling back.

[0034] In the above embodiment, a plurality of empty grooves 16 are respectively opened on the first side wall 11 and the third side wall 13, and the locking devices 6 are elastically installed in the empty grooves 16. The plurality of locking devices 6 installed on the first side wall 11 and the third side wall 13 correspond to each other one by one, forming limit stops on both sides of the forward push fixing plate 8, so that the forward push fixing plate 8 can only move forward but not backward.

[0035] In a specific embodiment, Figures 7 to 9As shown, the locking device 6 includes a locking device body 61 that matches the size of the empty slot 16. A spring 63 is fixed to one side of the locking device body 61. The number of springs 63 can be two or three. One end of the spring 63 is fixed to the locking device body 61, and the other end is fixed to the bottom of the empty slot 16, so that the entire locking device 6 can be elastically supported in the empty slot 16. When the locking device body 61 is compressed, the spring 63 contracts, so that the locking device body 61 shrinks into the empty slot 16. When the pressure is released, the spring 63 supports the locking device body 61 to pop out of the empty slot 16. The locking device body 61 is provided with a plurality of locking teeth 62 on one side facing the forward push fixing plate 8 (i.e., the back side on which the spring 63 is installed). The plurality of locking teeth 62 are evenly spaced, and the spacing between two adjacent locking teeth 62 is slightly larger than the thickness of the forward push fixing plate 8, forming a limit groove that can accommodate the forward push fixing plate 8. The locking tooth 62 protrudes from the locking device body 61, and has a straight surface facing the second side wall 12 (i.e., facing the backward direction of the forward push fixing plate 8), and an inclined surface facing the fourth side wall 14 (i.e., facing the forward direction of the forward push fixing plate 8). When the forward push fixing plate 8 moves forward, the two sides of the forward push fixing plate 8 cooperate with the inclined surfaces of the locking tooth 62, and the locking device body 61 is pressed into the empty groove 16 by squeezing the inclined surfaces. When the forward push fixing plate 8 reaches the limiting groove between the two locking teeth 62, the locking device body 61 is ejected from the empty groove 16 by the rebound force of the spring 63. At this time, the straight surface of the locking tooth 62 located behind the forward push fixing plate 8 abuts against the back side of the forward push fixing plate 8 to form a limit, and the inclined surface of the locking tooth 62 located in front of the forward push fixing plate 8 cooperates with the front side of the forward push fixing plate 8, so that the forward push fixing plate 8 can continue to move forward.

[0036] In the locking device 6 of the above structure, in the initial state, the locking teeth 62 are exposed in the empty slot 16, that is, the locking teeth 62 protrude from the inner wall of the expansion cavity, and the two sides of the forward push fixing plate 8 are limited in the limiting grooves between the two adjacent locking teeth 62; when the forward push fixing plate 8 moves forward, the forward push fixing plate 8 squeezes the inclined surface of the locking teeth 62, so that the locking teeth 62 shrink into the empty slot 16, and the forward push fixing plate 8 is released and can be pushed forward.

[0037] In a specific embodiment, Figure 5 and Figure 6 As shown, the thin-walled tube to be expanded is a tubular structure with openings at both ends. The supporting proton exchange membrane 5 is used in conjunction with the thin-walled tube to be expanded, and is covered at the openings at both ends of the thin-walled tube 4 to be regulated. It is responsible for isolating solutions of different concentrations inside and outside the tube, and achieving the effect of different freezing points of the solutions inside and outside due to the temperature difference, and finally achieving the temperature-changing expansion of the tube at the same temperature while the outside remains in a solution state.

[0038] In a specific embodiment, Fig.10As shown, the joystick 7 is fixedly connected to the central position of the back side of the forward push fixing plate 8. The central part of the forward push fixing plate 8 is a solid flat plate, which is used to cooperate with the end face of the thin-walled tube 4 to be regulated to form extrusion on the thin-walled tube 4 to be regulated, and a circle of water holes is provided near the edge of the forward push fixing plate 8 to facilitate the passage of liquid in the expansion cavity when moving.

[0039] In a specific embodiment, the temperature changing device 3 can be a refrigeration device commonly used in the prior art, and its function is to fit with the thin wall surface (second side wall 12) of the device body 1 to maintain a lower temperature in the expansion cavity. The specific structure of the temperature changing device 3 is not specifically limited in the embodiment of the present invention.

[0040] In a specific embodiment, the expansion cavity body is connected to an expansion cavity upper cover plate 2 for reducing temperature exchange with the outside during the variable temperature expansion process and accelerating the speed of the variable temperature expansion.

[0041] The above structure aims to propose a device that uses proton exchange membrane to produce regional post-temperature changes of solutions with different concentrations to generate local solution volume changes to improve the residual stress distribution of cylindrical thin-walled structures after processing. It solves the problem of uneven residual stress distribution introduced by the forming and processing processes of thin-walled weak rigid structures, improves the accuracy of subsequent semi-finishing and finishing of thin-walled parts, and is of great significance to improving the unstable residual stress distribution, processing surface quality and processing deformation of cylindrical thin-walled weak rigid structures.

[0042] It should be understood that in actual applications, the operating lever can be manually controlled or automatically controlled by a drive mechanism, such as Fig.11 As shown, in another embodiment of the present invention, the joystick 7 is a telescopic rod, one end of which is fixedly connected to the forward push fixing plate 8, and the other end is fixedly connected to the driving mechanism 9. The driving mechanism 9 is fixedly connected to the outer side of the fourth side wall 14 of the device body 1 and is sealed with the fourth side wall 14 to prevent liquid leakage.

[0043] It should also be understood that the driving mechanism 9 may be other driving devices or mechanical devices capable of realizing linear motion functions / rotational motion / telescopic motion, and for example, may be a servo motor, a hydraulic cylinder, an electric cylinder, and the like.

[0044] Based on the above structure, the embodiment of the present invention can achieve internal variable temperature expansion and external solution not freezing due to different concentrations of internal and external solutions under low temperature conditions in the expansion cavity by changing the regulated thin-walled tube, thereby regulating and improving the residual stress distribution of the thin-walled tube. The present invention utilizes the volume expansion caused by the temperature change of the solution for mechanical expansion, and has a simple structure, easy maintenance, easy operation of the device, and high safety. The present invention uses water and water solutions for variable temperature expansion, has a wide range of materials, is green and environmentally friendly, has low energy consumption during the expansion process of the device, and does not generate obvious waste.

[0045] The details not described in detail in the present invention are all conventional technical means well known to those skilled in the art.

[0046] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, 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 should not be understood as a limitation on the present invention.

[0047] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion, characterized in that: The device comprises a device body (1), the device body (1) is a box structure with an open top, and has an expansion cavity for accommodating a thin-walled tube (4) to be regulated; at least one side of the device body (1) is provided with a temperature-changing device (3) that fits with the side wall; a forward push fixing plate (8) is provided in the expansion cavity for linear reciprocating motion, the forward push fixing plate (8) is used to apply an axial external force to the thin-walled tube (4) to be regulated and seal against the end of the thin-walled tube (4) to be regulated; locking devices (6) are provided on the inner walls of both sides of the device body (1) along the travel direction of the forward push fixing plate (8), the locking devices (6) are used to limit the displacement of the forward push fixing plate (8) after it is completely pressed against the thin-walled tube (4) to be regulated; the thin-walled tube (4) to be regulated is provided with a temperature-changing device (3) that fits with the side wall; a forward push fixing plate (8) is provided in the expansion cavity for linear reciprocating motion, the forward push fixing plate (8) is used to apply an axial external force to the thin-walled tube (4) to be regulated and seal against the end of the thin-walled tube (4) to be regulated; Matching proton exchange membranes (5) are connected to the openings at both ends; a plurality of slots (16) are formed on the inner walls of the device body (1) on both sides along the travel direction of the forward push fixing plate (8); the locking device (6) is elastically connected in the slots (16); the locking device (6) comprises a locking device body (61), a spring (63) and a plurality of locking teeth (62); the spring (63) is fixed between the locking device body (61) and the bottom of the slots (16); the locking teeth (62) are arranged on a side of the locking device body (61) facing away from the slots (16) and are evenly spaced along the travel direction of the forward push fixing plate (8); and a limit groove for accommodating the forward push fixing plate (8) to be inserted is formed between two adjacent locking teeth (62).

2. The variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion type according to claim 1 is characterized in that: At least two springs (63) are provided along the length direction of the locking device body (61).

3. The variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion type according to claim 1 is characterized in that: The locking tooth (62) has a side facing the travel direction of the forward-pushing fixing plate (8) which is an inclined surface, and the other side which is a straight surface.

4. The variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion type according to claim 1 is characterized in that: The position where the middle of the forward push fixing plate (8) cooperates with the end surface of the thin-walled tube (4) to be regulated is a solid flat plate, and a plurality of water holes are arranged near the edge of the forward push fixing plate (8).

5. The variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion type according to claim 4 is characterized in that: A control rod (7) is fixedly connected to a side of the forward-pushing fixed plate (8) facing away from the thin-walled cylinder (4) to be regulated. The control rod (7) penetrates the device body (1) and forms a seal at the penetration position.

6. The variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion type according to claim 4 is characterized in that: A driving mechanism (9) is connected to a side of the forward-pushing fixing plate (8) that faces away from the thin-walled cylinder (4) to be regulated.

7. The variable concentration and variable temperature thin-walled tube residual stress control device based on variable temperature expansion type according to claim 1 is characterized in that: The upper opening of the device body (1) is connected to an expansion cavity upper cover plate (2).

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