Rubber hydraulic forming method for corrugated double-curvature thin-wall sheet metal part

Abstract

The invention provides a rubber hydraulic forming method for a corrugated double-curvature thin-wall sheet metal part, and belongs to the technical field of metal pressure machining. The transition process part is placed on the forming face of the profiling die, the part blank is placed on the side, back to the forming die, of the transition process part, and the part is formed for the first time to obtain a preformed plate; and the pre-formed plate subjected to solution treatment is placed on the forming face of the profiling mold, and the part is finally formed. Through the treatment scheme, the part quality is improved while the production cost is saved.

Description

Technical Field

[0001] This application relates to the field of metal pressure processing, and in particular to a rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts. Background Technology

[0002] Rubber forming is a flexible die forming method that uses a rubber bladder as an elastic die or punch and a liquid as a pressure transmission medium to shape a metal sheet along a rigid die or punch. The rubber bladder is the part that shapes the sheet material along the die, while the rigid die is the part that constrains the shaping. Compared to traditional methods, it offers advantages such as producing complex parts, high surface quality and shape accuracy, and short production cycles. It also adapts to the flexible development trend of small-batch, multi-variety aerospace products. However, due to limitations in rubber flowability and difficulties in blank pressing, rubber-formed parts are mainly flanged, shallow-drawn, and indented parts. Generally, deep-drawn sheet metal parts are formed using drop forming or hydroforming with an intermediate die, resulting in parts with poor surface quality, poor process stability, and high manufacturing costs. Summary of the Invention

[0003] In view of this, this application provides a rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts, which solves the problems in the prior art, saves production costs and improves part quality.

[0004] The rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts provided in this application adopts the following technical solution: A method for rubber hydroforming of a corrugated hyperbolic thin-walled sheet metal part includes: Step 1, Preparation of transition parts: Place the forming mold on the worktable of the rubber bladder hydraulic press, place a metal pad with a preset thickness h on the forming surface of the forming mold, covering the forming area; set the pressure of the hydraulic press, the rubber bladder of the hydraulic press applies pressure to the metal pad, the metal pad is pressed against the forming surface of the forming mold by the rubber bladder, so that the sheet material corresponding to the groove area of ​​the forming surface of the metal pad flows into the groove, the depth of the sheet material flowing into the groove is 60-80% of the groove depth, forming a transition part with a groove protrusion structure; Step 2, initial forming of the part: Place the transition part on the forming surface of the forming mold, with the protruding structure on the transition part located in the groove of the forming surface. Place the part blank on the side of the transition part facing away from the forming mold. Set the pre-forming pressure P1 of the hydraulic press. The rubber bladder of the hydraulic press applies pressure to the part, causing the part blank and the transition part to adhere together, forming a pre-formed sheet. The forming amount of the pre-formed sheet is 70%-80% of the final forming amount. Step 3: Perform solution treatment on the preformed sheet material; Step 4: Remove the transition process part from the forming mold, place the solution-treated preformed sheet on the forming surface of the forming mold, the protrusion structure on the preformed sheet is located in the groove of the forming mold, set the final forming pressure P2 of the hydraulic press, the rubber bladder of the hydraulic press applies pressure to the part, so that the part blank and the forming mold part are in contact, remove the part, and trim the shape of the part to obtain a corrugated hyperbolic thin-walled sheet metal part.

[0005] Optionally, in step 2, after placing the part blank on the transition process part, a rubber pad is placed on the surface of the part blank facing away from the forming mold.

[0006] Optionally, the thickness of the rubber pad is 10 mm.

[0007] Optionally, the metal pad is made of aluminum alloy.

[0008] Optionally, the thickness h of the metal pad is ≥ 2t- ; Where t is the thickness of the raw material and H is the forming depth of the part.

[0009] Optionally, the raw material for the parts is aluminum alloy, with material grade 2A12-O and a thickness of 0.5mm.

[0010] Optional, final molding pressure P2 = ;in, Let be the elastic modulus of the rubber bag. Let t be the yield strength of the raw material for the part, t be the thickness of the raw material, and H be the forming depth of the part. The coefficient of friction, The bending radius of the protruding rib in the forming mold; This is the maximum diameter of the mold cavity.

[0011] Optionally, the preforming pressure P1 is 60-70% of the final forming pressure P2.

[0012] In summary, this application includes the following beneficial technical effects: The molding method described in this application has a short production cycle and low manufacturing cost. It achieves the goal of completing the hydraulic forming and inspection of parts with a single hydraulic mold, replacing the function of a set of transition molding molds with a 2.0mm-3.0mm thick aluminum plate, and using a pad for low-pressure pre-forming, followed by solution treatment and final forming. In contrast, traditional drop forming requires a drop mold and an inspection mold, and even when converted to hydraulic forming, a set of transition molding molds is still needed.

[0013] Furthermore, the forming method of this application involves forming and straightening simultaneously, resulting in high production efficiency and good surface quality; the coated parts can be reused, reducing production costs. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the parts in the embodiments of this application; Figure 2 This is a schematic diagram of the preforming process of the part in this application; Figure 3 This is a schematic diagram of the final formed part of this application.

[0016] Explanation of reference numerals in the attached drawings: 1. Molding mold; 2. Transition process component; 3. Part; 4. Bending radius of the protruding rib of the molding mold; 5. Rubber bladder. Detailed Implementation

[0017] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0018] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0020] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The illustrations only show the components related to this application and are not drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0022] This application provides a rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts.

[0023] like Figures 1 to 3 As shown, a rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts includes: Step 1, Preparation of transition part 2: Place the forming mold on the worktable of the rubber bladder hydraulic press, place a metal pad with a preset thickness h on the forming surface of the forming mold, covering the forming area; set the pressure of the hydraulic press, the rubber bladder of the hydraulic press applies pressure to the metal pad, the metal pad is pressed against the forming surface of the forming mold by the rubber bladder, so that the sheet material corresponding to the groove area of ​​the forming surface of the metal pad flows into the groove, the depth of the sheet material flowing into the groove is 60-80% of the groove depth, forming the transition part 2 with the groove protrusion structure; Step 2, perform the first forming of part 3: Place the transition process part 2 on the forming surface of the forming mold, with the protruding structure on the transition process part 2 located in the groove of the forming surface. Place the blank part 3 on the side of the transition process part 2 facing away from the forming mold 1. Set the pre-forming pressure P1 of the hydraulic press, and the rubber bladder 5 of the hydraulic press applies pressure to part 3, so that the blank part 3 and the transition process part 2 are bonded together to form a pre-formed sheet. The forming amount of the pre-formed sheet is 70%-80% of the final forming amount. Step 3: Perform solution treatment on the preformed sheet material; Step 4: Remove the transition process part 2 from the forming mold 1, place the solution-treated preformed sheet on the forming surface of the forming mold, the protruding structure on the preformed sheet is located in the groove of the forming mold, set the final forming pressure P2 of the hydraulic press, the rubber bladder 5 of the hydraulic press applies pressure to the part 3, so that the part 3 blank and the forming mold 1 fit together, take out the part 3, and trim the shape of the part 3 to obtain the corrugated hyperbolic thin-walled sheet metal part 3.

[0024] In this application, the rubber bladder 5 remains in close contact with the part 3 throughout the molding process, and there are no scratches on the surface of the part 3. Furthermore, under high pressure and friction, the plasticity of the material is fully utilized, reducing the springback of the part 3 and ensuring high molding accuracy. At the same time, due to the uniform thickness variation, the damage rate inside the material is greatly reduced.

[0025] In step 1, the metal pad is made of aluminum alloy; the thickness h of the metal pad is ≥ 2t- Where t is the thickness of the raw material of part 3, and H is the forming depth of part 3.

[0026] In this application, during the preforming process, the bending radius of part 3 is increased by the transition process component 2. The addition of the transition process component 2 prevents the blank of part 3 from cracking due to insufficient flow rate under a fixed pressure value caused by the deep forming depth and small bending radius. The design of the metal pad thickness can ensure that the material flow rate meets the requirement that part 3 does not crack. At the same time, the transition process component 2 can also have the beneficial effect of reducing the stretching depth of the sheet.

[0027] In step 2, after placing the blank part 3 on the transition process part 2, a rubber pad is placed on the surface of the blank part 3 facing away from the forming mold 1. The thickness of the rubber pad is 10mm.

[0028] The blank material for part 3 is made of aluminum alloy, with material grade 2A12-O and a thickness of 0.5mm.

[0029] Final molding pressure P2= ;in, Let be the elastic modulus of rubber bladder 5. Let t be the yield strength of the raw material for part 3, t be the thickness of the raw material for part 3, and H be the forming depth of part 3. The coefficient of friction, The bending radius of the protruding rib of the forming mold is 4; This is the maximum diameter of the mold cavity. In the embodiments of this application, The value range is 0.1-0.2. The value range is 1.1-1.3.

[0030] The preforming pressure P1 is 60-70% of the final forming pressure P2.

[0031] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for rubber hydroforming of corrugated hyperbolic thin-walled sheet metal parts, characterized in that, include: Step 1, Preparation of transition parts: Place the forming mold on the worktable of the rubber bladder hydraulic press, place a metal pad with a preset thickness h on the forming surface of the forming mold, covering the forming area; set the pressure of the hydraulic press, the rubber bladder of the hydraulic press applies pressure to the metal pad, the metal pad is pressed against the forming surface of the forming mold by the rubber bladder, so that the sheet material corresponding to the groove area of ​​the forming surface of the metal pad flows into the groove, the depth of the sheet material flowing into the groove is 60-80% of the groove depth, forming a transition part with a groove protrusion structure; Step 2, initial forming of the part: Place the transition part on the forming surface of the forming mold, with the protruding structure on the transition part located in the groove of the forming surface. Place the part blank on the side of the transition part facing away from the forming mold. Set the pre-forming pressure P1 of the hydraulic press. The rubber bladder of the hydraulic press applies pressure to the part, causing the part blank and the transition part to adhere together, forming a pre-formed sheet. The forming amount of the pre-formed sheet is 70%-80% of the final forming amount. Step 3: Perform solution treatment on the preformed sheet material; Step 4: Remove the transition process part from the forming mold, place the solution-treated preformed sheet on the forming surface of the forming mold, the protrusion structure on the preformed sheet is located in the groove of the forming mold, set the final forming pressure P2 of the hydraulic press, the rubber bladder of the hydraulic press applies pressure to the part, so that the part blank and the forming mold part are in contact, remove the part, and trim the shape of the part to obtain a corrugated hyperbolic thin-walled sheet metal part.

2. The rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts according to claim 1, characterized in that, In step 2, after placing the part blank on the transition process part, a rubber pad is placed on the surface of the part blank facing away from the forming mold.

3. The rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts according to claim 2, characterized in that, The thickness of the rubber pad is 10mm.

4. The rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts according to claim 1, characterized in that, The metal pad is made of aluminum alloy.

5. The rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts according to claim 1, characterized in that, The thickness h of the metal pad is ≥ 2t- ; Where t is the thickness of the raw material and H is the forming depth of the part.

6. The rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts according to claim 1, characterized in that, The raw material for the parts is aluminum alloy, with material grade 2A12-O and a thickness of 0.5mm.

7. The rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts according to claim 1, characterized in that, Final molding pressure P2= ;in, Let be the elastic modulus of the rubber bag. Let t be the yield strength of the raw material for the part, t be the thickness of the raw material, and H be the forming depth of the part. The coefficient of friction, The bending radius of the protruding rib in the forming mold; This is the maximum diameter of the mold cavity.

8. The rubber hydroforming method for corrugated hyperbolic thin-walled sheet metal parts according to claim 1, characterized in that, The preforming pressure P1 is 60-70% of the final forming pressure P2.

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