4Ways for Deep drawing tooling clearance determination

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Balford has passed ISO9001 in 2017. We has over ten years experience on manufacturing motor housing, solenoid valve housing and sensor housing, focused on auto parts.Now Balford enter into solenoid valve housings and sensor housings industry that are mainly based on difficult deep drawing process.

We employ documented procedures for every step in the manufacturing process from initial program launch through steady-state production in order to ensure consistent performance. We engineer our processes to produce the desired results, monitor those results, and use what we learn to regularly refine our processes as part of our commitment to continuous process and efficiency improvement.

Many of our customers have been with us for 5-8 years or more. Year after year, they experience zero late deliveries and zero returns.

For metal Deep drawing tooling, the size of the blanking parts is close to the size of the concave die during use, and the size of the surface punching parts is close to the size of the edge of the punching die. During measurement and use, the blanking parts are large The weaving size is the benchmark, and the punching part is based on the small end size, that is, the blanking and punching are based on the size of the bright belt. During blanking, the punch will become smaller and smaller, and the concave die will become larger and larger. Considering the above situation, the following principles should be followed when determining the edge size of metal stamping die and its manufacturing tolerance:

1.Deep drawing toolings gap determination

1. When blanking, the size of the workpiece is determined by the size of the die: when punching, the size of the hole is determined by the size of the punch. Therefore, when designing the blanking horizontal, it should be based on the concave die, and the gap should be taken on the convex plate: when designing the punching die, the convex die should be used as the benchmark, and the gap should be implicitly taken on the concave die. In use, with the wear of the mold, the gap between the convex and concave molds will become larger and larger, so in the initial design, the gap between the convex and concave calibration should be the smallest and reasonable.
2. Due to the wear of punch and die during blanking, when designing blanking die, the nominal size of the die should take the smaller size within the tolerance range of the product. When designing the punching die, the nominal size of the punch should be The larger dimension within the tolerance range of the dimensions of the part. In this way, the qualified parts can still be punched out under the condition that the punch and the concave die are subjected to a certain grinding simulation.
3. The manufacturing tolerance of the concave and punch is mainly related to the precision and shape of the obtained parts, generally 2~3 grades higher than the precision of the blanking parts. If the parts are not marked with tolerances, for non-ring parts, according to national standards The IT14 precision processing of “tolerance value of non-matching dimensions” can be processed according to ITIo precision for four-shaped parts.
4. The size of the cutting edge of the blanking die is marked according to the principle of “into the body”, that is, the size deviation of the die edge is marked with a positive value, and the size deviation of the punch edge is marked with a negative value: the face is relative to the hole center distance, and it does not change with the wear of the cutting edge. Variable size, taken as a two-way deviation.

The die used for drawing is called a deep drawing tooling, and a deep drawing tooling is a special tool for batch processing of materials (metal or non-metal) into the desired punching parts.
If there are many types of deep drawing toolings, they can be divided into single-step deep drawing toolings, compound dies and progressive deep drawing toolings.

2.Deep drawing toolings body classification

• Divided by stamping equipment, it can also be divided into deep drawing toolings for single-acting presses, deep drawing toolings for double-acting presses and deep drawing toolings for three-acting presses. blank holder and rigid blank holder).
• The deep drawing tooling can also be divided into the first deep drawing tooling and the subsequent deep drawing tooling. The main difference between them is the difference in the structure and positioning of the blank holder.
• Thinning deep drawing tooling, thinning drawing is very different from general drawing. The characteristic of thinning drawing is that the diameter of the drawn part changes relatively small, the thickness of the bottom end of the workpiece does not change, and the side wall thickness of the workpiece does not change. Thinning in the process of deep drawing, the height of the workpiece increases accordingly. Thinning deep drawing tooling, when the punch is punched down, it passes through the die (two pieces), and the blank is thinned and drawn twice. When the punch rises, the unloading ring block unloads the deep drawing from the punch. Down.

There is also a reverse deep drawing tooling. The working principle of the square deep drawing tooling is to turn the inner wall of the workpiece eversion, and the contact surface between the workpiece and the die is large. Due to the large dynamic resistance of the workpiece material, the pressing ring can be omitted. Since the outer diameter of the die is smaller than the inner diameter of the process part, the tensile coefficient of all reverse stretching should not be too large. If it is too large, the wall thickness of the die will be too thin and the strength will be insufficient.

Our company specializes in metal stamping, Deep drawing tooling, stamping parts processing and so on. Products are widely used in precision connector shrapnel, relay shrapnel, micro motor shrapnel, precision tensile parts, home appliance precision shrapnel, intelligent electronic components, medical shrapnel, and other consumer electronics industries. It can provide micro-hole processing technical support services for industries such as engines, aerospace, medical equipment, microelectronics, precision machinery, etc.