Impact hydraulic multi-step forming process method

Abstract

The invention belongs to the field of forming methods, and discloses an impact hydraulic multi-step forming process method, which comprises the following steps of: placing a plate blank on a die body, enabling the plate blank to be positioned below a concave die, and keeping a first preset distance between the plate blank and the concave die; and a punch arranged in the die body is driven to move towards the plate blank, the forming liquid contained in the die body is extruded through the punch, the forming liquid forms high-speed jet flow, first-time hydraulic impact is conducted on the plate blank, and the plate blank generates local or overall deformation towards the female die. After the first impact is completed, the punch is controlled to return to the initial position, the position of the female die is adjusted, and a second preset distance is formed between the female die and the plate blank. And the second preset interval is smaller than the first preset gap, the forming liquid is more difficult to leak from the edge area of the plate blank, and the liquid pressure of the forming liquid can be increased. And the punch is driven again to move towards the plate blank, the extrusion forming liquid generates second jet flow to impact the plate blank, the plate blank is further subjected to plastic deformation and finally completely attached to the female die molded surface, and final forming of the plate blank is achieved.

Description

Technical Field

[0001] This application belongs to the field of forming method technology, and more specifically, relates to an impact hydraulic multi-step forming process method. Background Technology

[0002] When using traditional quasi-static hydroforming technology to process sheet metal, the sheet metal and mold are usually in a gapless, compressed state. This strong constraint on the sheet metal during forming severely restricts material flow, especially in areas of high deformation, leading to stress concentration and premature sheet metal fracture, thus preventing the forming process from completing smoothly. Furthermore, without an effective sealing structure between the sheet metal and mold, high-pressure fluid can leak from the edges of the sheet metal during loading, failing to establish a stable and uniform hydraulic pressure within the mold cavity. This results in insufficient plastic deformation support for the sheet metal, also causing the part to fail to form the intended shape. Both of these situations limit the feasibility and forming quality of traditional hydroforming technology when processing specific structures or materials. Summary of the Invention

[0003] The purpose of this application is to provide an impact hydraulic multi-step forming process to solve the technical problems of high difficulty and poor forming effect in the prior art.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows: A multi-step impact hydraulic forming process is provided, comprising the following steps: Place the slab on the mold body, below the die cavity; The blank and the die maintain a first preset distance, and the punch in the die body is driven to move toward the blank to squeeze the forming liquid in the die body to generate a jet that impacts the blank for the first time, causing the blank to deform at least partially into the die body. After the punch retracts, the die is moved to maintain a second preset distance from the blank, and the punch is driven to move toward the blank again to extrude the forming liquid to generate a jet that impacts the blank a second time, causing the blank to be pressed against the die and formed.

[0005] As a further improvement to the above technical solution: Optionally, the second preset spacing is smaller than the first preset spacing; Alternatively, the second preset spacing is 0.

[0006] Optionally, before the slab is formed, the preset spacing can be adjusted multiple times, and a jet impact can be generated after each adjustment of the preset spacing to make the slab press against the die to form it; when adjusting the preset spacing, the preset spacing decreases successively.

[0007] Optionally, the punch is electromagnetically driven, and the punch is equipped with a magnetic drive plate. A coil is installed below the magnetic drive plate, and a pulse current is passed through the coil to generate a magnetic field to drive the magnetic drive plate to move.

[0008] Optionally, the first preset spacing is greater than 1 mm; the second preset spacing is less than 1 mm.

[0009] Optionally, the pressure when the punch extrudes the forming fluid for the second time to generate a jet is greater than the pressure when the punch extrudes the forming fluid for the first time to generate a jet.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: The impact hydraulic multi-step forming process provided in this application first places a blank on top of a mold body, positioning it below a die cavity, with a first preset distance maintained between the blank and the die cavity. Then, a punch installed inside the mold body is driven to move towards the blank, squeezing the forming fluid contained within the mold body. This causes the forming fluid to form a high-speed jet and apply a first hydraulic impact to the blank. Under this first hydraulic impact, the blank undergoes localized or overall deformation towards the die cavity. At this time, some of the forming fluid flows out from the edge area of ​​the blank, effectively releasing localized stress, suppressing excessive thinning of the material in the forming area, and preventing the blank from cracking in the early stages of forming. If the forming fluid does not apply a high-speed jet hydraulic impact to the blank, all the forming fluid will leak from the edge area of ​​the blank, making forming impossible.

[0011] After the first impact, the punch is retracted to its initial position, and then the position of the die is adjusted to create a second preset gap between it and the blank. This second preset gap is smaller than the first preset gap, making it less likely for the forming fluid to leak from the edge area of ​​the blank, which is beneficial for increasing the fluid pressure. The punch is then driven towards the blank again, squeezing the forming fluid to generate a second jet impact. This impact causes further plastic deformation of the blank, ultimately resulting in complete and tight contact with the die surface, thus achieving the final precision forming of the blank. Through the coordination of these two impact processes, the shape accuracy and surface quality of the formed part are ensured while preventing sheet metal breakage. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1This is a schematic diagram of the first working state of the impact hydraulic multi-step forming process method of this application; Figure 2 This is a schematic diagram of the second working state of the impact hydraulic multi-step forming process method of this application; Figure 3 This is a schematic diagram of the third working state of the impact hydraulic multi-step forming process method of this application; Figure 4 This is a schematic diagram of the fourth working state of the impact hydraulic multi-step forming process method of this application.

[0014] The following are the labeling elements in the figure: 1. Slab; 2. Mold body; 3. Die; 4. Punch; 5. Forming fluid; 6. Magnetic drive plate; 7. Coil. Detailed Implementation

[0015] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0016] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0017] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0018] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0019] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0020] This application provides a multi-step impact hydraulic forming process, which includes the following steps: like Figures 1 to 4 As shown, the blank 1 is first placed above the mold body 2 and below the die 3, with a first preset distance maintained between the blank 1 and the die 3. Then, the punch 4 inside the mold body 2 is moved towards the blank 1, squeezing the forming fluid 5 contained within the mold body 2 to form a high-speed jet and apply a first hydraulic impact to the blank 1. Under this first hydraulic impact, the blank 1 undergoes partial or overall deformation towards the die 3. At this time, the forming fluid 5 can flow out from the edge area of ​​the blank 1, effectively releasing local stress, suppressing excessive thinning of the material in the forming area, and preventing the blank 1 from cracking in the early stages of forming.

[0021] After the first impact, the punch 4 is retracted to its initial position, and then the position of the die 3 is adjusted to form a second preset gap between it and the blank 1. Next, the punch 4 is driven to move towards the blank 1 again, and the extruded forming fluid 5 generates a second jet impact on the blank 1. This impact causes the blank 1 to undergo further plastic deformation and finally completely adhere to and tightly fit against the surface of the die 3, thereby achieving the final precision forming of the blank 1. Through the coordination of the above two impact processes, the shape accuracy and surface quality of the formed part are ensured while avoiding sheet metal breakage.

[0022] In one specific embodiment of this application, during the two hydraulic impact forming processes, the value of the second preset distance between the blank 1 and the die 3 is less than the value of the first preset distance; wherein, the second preset distance can also be set to zero, that is, the blank 1 and the die 3 achieve a sealed contact fit at this stage.

[0023] In one specific embodiment of this application, the final forming of the blank 1 can be achieved gradually through multiple jet impact processes. Specifically, before the blank 1 is fully pressed into the die 3, a cyclical process of multiple spacing adjustments and jet impacts can be performed: that is, after each time the punch 4 drives the molding fluid 5 to generate a jet impact on the blank 1, causing it to deform to a certain extent, the preset spacing between the die 3 and the blank 1 is adjusted once, and then the next jet impact is performed. During this process, the value of the preset spacing shows a gradually decreasing trend, so that the blank 1 undergoes plastic deformation in stages and gradually under the action of progressively increasing hydraulic pressure, and finally completely fits and is precisely formed in the cavity of the die 3. This multi-step progressive forming method is conducive to the reasonable distribution of material strain, further reducing the risk of sheet metal breakage, and is especially suitable for parts with large forming depth or complex shapes.

[0024] In one specific embodiment of this application, the punch 4 is electromagnetically driven to achieve its high-speed movement. Specifically, the punch 4 is connected to a magnetic drive plate 6, and a coil 7 is installed below the magnetic drive plate 6. When a transient high-intensity pulse current is passed into the coil 7, a corresponding transient high-intensity pulse magnetic field is induced around the coil 7. This magnetic field interacts with the magnetic drive plate 6, thereby generating a sufficiently large electromagnetic force that drives the magnetic drive plate 6 and drives the punch 4 connected to it to perform rapid linear motion within the mold body 2 to complete the extrusion operation of the molding liquid 5.

[0025] In one specific embodiment of this application, the first preset spacing is greater than 1 mm; the second preset spacing is less than 1 mm. The first preset spacing is required to allow the forming fluid to flow out from the edge of the blank 1 during the first impact to release stress, while preventing excessive spacing from causing uncontrolled initial deformation of the blank 1. The second preset spacing is smaller than the first preset spacing to reduce forming fluid leakage during the second impact and ensure stable hydraulic pressure. When the second preset spacing is 0, the blank and the die are sealed and fitted together, suitable for high-precision forming requirements. In one specific embodiment of this application, the hydraulic pressure during the two jet impact processes is differentially controlled. Specifically, when the driving punch 4 moves towards the blank 1 in the second impact, the process parameters of the driving punch 4 (such as energy level and impact speed) are adjusted so that the jet impact pressure generated by the extrusion forming liquid 5 is significantly higher than the pressure applied during the first impact. This staged increasing pressure control strategy allows the blank 1 to achieve sufficient plastic deformation through the second impact with higher pressure, based on the initial pre-forming achieved in the first impact. This ensures that the blank 1 can ultimately be accurately fitted and formed on the surface of the die 3, effectively improving the forming accuracy and quality of the part.

[0026] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for impact hydraulic multi-step forming process, characterized in that, Includes the following steps: Place the blank (1) on the mold body (2) and below the cavity mold (3); The blank (1) and the die (3) maintain a first preset distance, and drive the punch (4) in the mold body (2) to move toward the blank (1) so as to squeeze the forming liquid (5) in the mold body (2) to generate a jet that impacts the blank (1) for the first time, so that the blank (1) deforms at least partially into the die (3); After the punch (4) retracts, the die (3) is moved to maintain a second preset distance from the blank (1), and the punch (4) is driven to move toward the blank (1) again to extrude the forming liquid (5) to generate a jet that impacts the blank (1) a second time, so that the blank (1) is pressed against the die (3) and formed.

2. The impact hydraulic multi-step forming process method as described in claim 1, characterized in that, The second preset spacing is smaller than the first preset spacing; Alternatively, the second preset spacing is 0.

3. The impact hydraulic multi-step forming process method as described in claim 1, characterized in that, Before the blank (1) is formed, the preset spacing can be adjusted multiple times, and a jet impact is generated after each adjustment of the preset spacing to make the blank (1) press against the die (3) one after another to form the blank; When adjusting the preset spacing, the preset spacing decreases gradually.

4. The impact hydraulic multi-step forming process method as described in claim 1, characterized in that, The punch (4) is electromagnetically driven and is equipped with a magnetic drive plate (6). A coil (7) is installed below the magnetic drive plate (6). A pulse current is passed through the coil (7) to generate a magnetic field to drive the magnetic drive plate (6) to move.

5. The impact hydraulic multi-step forming process method as described in claim 1, characterized in that, The first preset spacing is greater than 1 mm; the second preset spacing is less than 1 mm.

6. The impact hydraulic multi-step forming process method as described in claim 1, characterized in that, The pressure of the punch (4) when it extrudes the molding liquid (5) for the second time to generate a jet is greater than the pressure of the punch (4) when it extrudes the molding liquid (5) for the first time to generate a jet.

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