Standard Structure of Auxiliary Parts for Automotive Stamping Progressive Dies

Design Considerations:
① The pallet should have four lifting holes on both the front and sides. The size of the lifting holes depends on the weight of the pallet (as shown in the diagram above), at least M16. When purchasing new mold materials, the side lifting holes must be machined according to the attached diagram. However, once the position of the side lifting holes is determined, they must not be moved unilaterally (the side lifting holes are mainly for internal processing and flipping).

② For molds using lifting lugs, the size of the lifting lugs or lifting modules must be selected according to the size and weight of the mold. Ensure that the lower mold lifting lugs or lifting modules can lift 1.5 times the weight of the entire mold. To meet the requirements for mold flipping, ensure that two lifting lugs or lifting modules can lift 1.5 times the weight of the entire upper mold. The spacing between the lifting dies should be greater than 2/3 of the pallet length and symmetrical front-to-back and left-to-right.

③ For molds requiring quick release from the pallet, clearance holes should be made on the pallet, with clearances of 5-10mm on each side. Examples include: through holes for screws fixing nitrogen springs to the upper mold base, and through holes for punch screws or inserts requiring quick release from the front.

④ For machines with scrap discharge holes, ensure the scrap discharge hole is 5mm smaller on each side than the hole on the punch press, and that it has an opening bevel.

⑤ Design quick-positioning holes and center slots according to the punch press specifications. Quick-positioning holes should ideally be located outside the mold, in a directly visible position; specific details are determined according to the project specifications. The height of the quick-positioning insert does not need to be precisely measured; it should be 0.5mm lower than the lower surface of the support plate and painted with color 29. Side wall inserts should be precisely measured, and the insert slots should be painted with color 181.

① Distribute the die-binding positions reasonably according to the mold size, see the table on the right.

② The width of the die-binding slot should be 1.0mm larger on each side than the punch press die-binding slot, and the opening should be chamfered at C3.

③ Determine the hydraulic and manual die-binding positions according to the punch press specifications. If a spare punch press is available, add more die-binding positions for the spare punch press and determine the height of the hydraulic die-binding device, ensuring that there is at least 15mm of vertical space between the die-binding device and the mold when it is open.

④ The thickness of the pallet does not need to be precisely measured, but the groove should be machined to a tolerance of ±0.1mm based on the die-cutting position dimensions.

⑤ If the die-cutting position is shorter than the pallet, the groove needs to be adjusted (as shown in the right figure). The groove should be machined into a "V" shape, with a 120° angle at point A to increase the wrench's range of motion during die-cutting. The clearance should ideally be 5mm larger than the die-cutting device on one side.

⑥ If the height of the die plate is more than 5mm higher than the thickness of the pallet, a die plate can be added to adjust its height by adding a groove (depth not exceeding 1/2 pallet thickness) on the pallet. The groove sidewall and the die plate should be at least 3.0mm on each side, and the bottom depth should be ±0.1mm, as shown in the die plate values ​​below (internal customer pallet die standard, such as ZY, Zhongtai's own stamping standard).

⑦ If the die plate needs to be grooved on the pallet, the groove depth should be 3mm. The height L of the die plate can be determined by the customer (according to customer requirements).

① The feet on the same layer should be machined to the same height (including nitrogen gas seats that need to be of the same height). This should be specified when purchasing materials and purchased together with the main plate. There should be at least two M16 lifting teeth on both sides for easy handling and installation. However, if there are fixing screws, lifting teeth are not required separately.

② The feet are fixed with M16 screws. At least two M16 screws should be present on one end of the die plate.

③ When the pads are used for die mounting or positioning, pins must be added for positioning. When using a support plate for die mounting, at least two pads must have pins for positioning. Pin venting and clearance holes are required (as shown in Figure 1). For pads higher than 100mm, make a 30mm wide, waist-shaped clearance hole with a height greater than the pin length. When the pad height is within 100mm, make the pin hole countersunk, with the through hole larger than the pin hole. Pins with support plates must be staggered, ensuring the effective vertical length of the pin is 2.5 times the pin diameter.

④ The pads must be designed with numbers to distinguish the installation sequence and prevent reverse installation. These numbers must be hammered on during processing. The letter height is 30mm.

⑤ According to the strip material process, forming and shaping stations, external limits, and safety zones must have pads for support and stress bearing. Upper and lower pads should correspond as closely as possible, with a maximum distance of 300mm between two pads. Except for die mounting pads, pads must not be placed within the die mounting slots of the punch press.

⑥ Minimize the clearance in the pad. If the clearance exceeds 1/2 of the height, a screw needs to be added in the middle for fixation. If the clearance exceeds 2/3 of the pad height, divide it into two pads. Avoid areas such as drain holes, guide post holes, and nitrogen gas seats as much as possible. When guide post holes cannot be avoided or scrap is on the pad, the bottom of the clearance should be angled at 45° (as shown in Figure 2) to prevent items from falling in and breaking the mold.

⑦ For pads exceeding 500mm in height, reduce weight by leaving 150mm at the top and bottom (as shown in Figure 3). Avoid reducing weight in the forming and stress-bearing areas.

⑧ Pay attention to the width of the die slot. According to the punch press specifications, it should be 1.0mm larger on each side than the die slot on the punch press table.

⑨ When the pad rests on the scrap hole of the die holder (including those with a support plate), the distance from the pad to the edge of the punch press scrap hole should be ≥150mm.

⑩ The pad width is generally 50mm, and the die slot width is 80mm. For larger forming areas, the pad width can also be 80mm.

① The mold base must have four lifting teeth on its side, ensuring each tooth can lift the entire mold (as shown in Figure 1). To meet the mold flipping requirements, the upper mold base must have two lifting teeth capable of lifting 1.5 times its weight. If this is insufficient, lifting lugs or lifting modules should be used. The distance between the lifting teeth must be greater than 2/3 of the mold base's length. When the mold base and support plate are installed together and side-mounted lifting rings would interfere, add lifting teeth to the front, using the side only for individual flipping (as shown in Figure 3).

② The outer guide pillars must have an offset of at least 20mm to prevent reverse rotation, and the distance between the guide pillars at both ends must be greater than 2/3 of the mold base's length. The distance from the guide sleeve hole to the edge of the mold base must be at least 25mm.

③ Structures with lateral forces require at least two guide blocks.

④ To ensure mold base strength, the cavity machining depth on the mold base cannot exceed half the mold base's length.

⑤ To reduce machining costs and difficulty, the scrap material through holes on the mold base must be optimized (as shown in Figure 2), achieving at least R9.

① When selecting external limit posts, prioritize using parts from Zhongtai's inventory.

② The external limit block must have at least 2/3 of its support feet.

③ When connecting the lower external limit block and the storage/transport block with a steel chain, use M8 screws to lock the chain.

④ Add a solder wire groove to the lower external limit block, with dimensions of 12.7mm wide x 1.27mm deep, depending on customer requirements. The height should be flush with the lower mold surface.

⑤ Use screws to prevent reverse rotation for the upper and lower external limit blocks. For those with solder wire grooves, use the lower mold with a height tolerance of +/-0.01mm. Do not allow for gaps; directly attach them.