Deep Drawing Die Design and how to design a deep drawing die for a hydraulic deep drawing press. Price from the manufacturer. Free consultation.
Deep Drawing Die Design
Deep drawing die design is the process of designing a die used for the deep drawing process, which is a metal forming process in which a sheet metal blank is drawn into a forming die by a punch to form a desired shape. The design of the die is critical to achieving the desired shape and minimizing defects such as wrinkling, tearing, and excessive thinning of the material.
The following are some of the key considerations in deep drawing die design:
- Material selection: The material used for the die must be able to withstand the forces and temperatures involved in the deep drawing process. Typically, tool steels or carbide materials are used.
- Die shape: The shape of the die must be designed to allow for the flow of material and minimize stresses and strains. The die must also be designed to allow for easy removal of the finished part.
- Punch shape: The shape of the punch must be designed to match the desired final shape of the part. The punch must also be designed to allow for easy removal of the finished part.
- Die clearance: The clearance between the punch and die is critical to achieving the desired part shape and minimizing defects. Too much clearance can cause wrinkling, while too little clearance can cause tearing or excessive thinning.
- Lubrication: Lubrication is essential to minimizing friction and preventing defects such as galling or scoring. The type and amount of lubricant used must be carefully selected based on the material being formed and the specific die design.
- Cooling: Heat buildup can cause deformation or cracking of the die. Therefore, cooling channels must be designed into the die to dissipate heat and maintain the desired temperature.
- Die maintenance: Regular maintenance of the die is essential to ensure consistent quality and prolong the life of the die. This includes cleaning, lubrication, and repair or replacement of worn or damaged components.
Material selection
Material selection is an important aspect of deep drawing die design. The material chosen for the die should have good wear resistance, toughness, and high temperature strength. The most commonly used materials for deep drawing dies are tool steels, which are known for their high hardness and wear resistance. Some examples of tool steels used in deep drawing dies are D2, A2, and S7. Other materials that can be used include carbides, ceramics, and cermets.
In addition to the material selection, the designer must also consider the workpiece material and its properties. The workpiece material should be easy to deform and have good formability to ensure that it can be successfully deep drawn. The workpiece material should also be compatible with the die material to avoid any adverse reactions, such as galling or seizing.
Furthermore, the thickness of the workpiece material must also be taken into account. The thicker the workpiece, the more force is required to form it, which can lead to die wear and failure. To prevent this, the die designer must carefully choose the die material and design the die geometry to minimize the required force.
Overall, material selection is a critical factor in the success of deep drawing die design, and it requires careful consideration of both the die and workpiece materials.
Die shape
The die shape in deep drawing die design is critical for achieving the desired shape of the final product. The die shape determines the final shape of the drawn part and influences the amount of material flow and the thickness distribution of the part. A well-designed die shape should provide a smooth flow of material during the drawing process, without any wrinkles or tearing.
The die shape can be designed using computer-aided design (CAD) software, which allows designers to create and visualize complex shapes before they are manufactured. The die shape should take into account the material properties, such as the yield strength, ductility, and strain hardening behavior, as well as the type of deep drawing operation being performed, such as single or multiple draw.
The die shape consists of several components, including the blank holder, draw bead, and punch. The blank holder holds the sheet metal in place during the drawing process, preventing it from wrinkling or tearing. The draw bead is a raised feature on the die surface that helps control material flow and prevent wrinkling. The punch is the component that pushes the sheet metal into the die cavity and determines the final shape of the drawn part.
Punch shape
The punch shape in deep drawing die design is crucial to achieving the desired shape of the drawn part. The punch shape should correspond to the shape of the desired final product. In some cases, the punch shape may be more complex than the desired shape to allow for material flow and stretching during the drawing process. The punch shape can also affect the amount of material that is drawn and the amount of springback that occurs after the drawing process is complete. Additionally, the punch shape can impact the forces required to perform the drawing operation and the overall cycle time of the process.
Die clearance
Die clearance is the gap between the punch and die in a deep drawing die. It is an important design parameter that affects the quality and accuracy of the formed part. The clearance allows the material to flow into the die and reduces the friction between the punch and die, which helps to prevent galling and scoring. The correct amount of die clearance depends on a number of factors, including the thickness and properties of the material being formed, the shape of the die and punch, and the desired quality of the finished part. The clearance is typically expressed as a percentage of the material thickness, and can range from 2% to 20% or more depending on the application. Too little clearance can cause the material to wrinkle or tear, while too much clearance can result in a poor surface finish or excessive springback.
Lubrication
Lubrication is an essential factor in deep drawing die design. It reduces friction and wear between the die and the sheet metal, which can lead to tearing and wrinkling. The lubricant should be selected based on the type of material being drawn and the surface finish required on the part. Common lubricants used in deep drawing include oils, greases, and dry lubricants like molybdenum disulfide.
The method of lubrication also plays a significant role in the success of the deep drawing process. Lubrication can be applied as a liquid, a solid, or a gas. The most common method of lubrication is to apply it as a liquid through spraying, brushing, or flooding. Solid lubricants can be applied as a powder or a film, and they are often used in situations where liquid lubricants are not appropriate.
In addition to reducing friction and wear, lubrication also helps to dissipate heat generated during the deep drawing process. This can help to extend the life of the die and improve the surface finish of the drawn part. Proper lubrication can also reduce the likelihood of galling, which is a type of severe adhesive wear that can occur between the die and the sheet metal.
Cooling
Cooling is an important aspect of deep drawing die design. During the deep drawing process, the die and punch generate a significant amount of heat due to friction and deformation. This heat can cause the metal to soften, resulting in tearing or wrinkles in the drawn part. Therefore, it is essential to maintain the proper temperature of the die and the workpiece during the drawing process.
Cooling can be achieved by circulating a coolant, typically water or oil, through the die and punch. The coolant removes heat from the die and workpiece, reducing the temperature and minimizing the risk of deformation or damage. The coolant can be circulated through channels or passages in the die, or through a separate cooling system that is connected to the die.
Proper cooling is critical to maintaining the dimensional accuracy and surface finish of the drawn parts. Inadequate cooling can result in distorted or oversized parts, while excessive cooling can lead to cracking or other defects in the material. Therefore, the cooling system should be carefully designed and monitored to ensure that the die and workpiece are maintained at the optimal temperature throughout the drawing process.
Die maintenance
Die maintenance is an important aspect of deep drawing die design, as it can have a significant impact on the quality of the finished product and the lifespan of the die itself. Some key aspects of die maintenance include:
- Cleaning: Regular cleaning of the die surface can help prevent buildup of dirt and debris that can cause scoring and other damage to the die.
- Polishing: Polishing the die surface can help to reduce friction and wear during the deep drawing process, leading to a longer lifespan for the die.
- Repairing: Any cracks, chips, or other damage to the die should be repaired as soon as possible to prevent further damage and ensure the die continues to produce high-quality parts.
- Lubrication: Proper lubrication of the die surface can help to reduce friction and wear during the deep drawing process, leading to a longer lifespan for the die.
- Storage: When not in use, the die should be stored in a cool, dry place to prevent rust and other types of damage