Automatic Scrap Handling for Stamping Dies

1. Research and Application of Automated Scrap Discharge Technology

Stamping dies are critical components in industrial production, and scrap discharge is an essential part of the manufacturing process. Currently, all sheet metal parts of air conditioner outdoor units—such as covers, left/right side panels, and partition plates—generate scrap that must be ejected through scrap discharge mechanisms. However, existing scrap removal systems often fail to efficiently clear waste material from the dies, leading to scrap accumulation and production defects.

These issues necessitate frequent die modifications, including adjustments to punches and dies, which increase machining costs and prolong die development cycles. To reduce rework frequency, lower manufacturing costs, and enhance competitiveness in the die market, targeted research on scrap discharge optimization is imperative.

Objectives:

（1）Reduce die manufacturing costs

（2）Shorten the development cycles

（3）Improve production efficiency

2. Analysis of key die technology examples

Simulate and analyze the product blanking process at the early stage of die opening to confirm the fall-off space.

As shown in the figure, the simulation analysis diagram of the partition waste.

3. Analysis of the selection of the die structure

1. Pneumatic Scrap Ejection Die Structure 

Method of selecting parts: Set the size of the conveying guide trough according to the width of the mold pad and the length of the waste, and determine the connection between the cylinder telescopic stroke size and the positioning size type of the limit block. Then, determine the Pneumatic Scrap Ejection Die Structureand quantity (coupling) of each part (transmission component, shaft) according to the sequence.

 Multiple troughs can be used in a mold of the structural body (lower component), and several punching machines can be connected to transport waste together.

Advantages of function introduction: Because it is a conveying guide trough, waste can be prevented from flying. The waste slide cannot guarantee that the slope will cause mold damage due to the stuck waste. This problem can be solved by using the guide.

2. Conveyor-type waste discharge die structure 

Method of selecting parts: When setting up the picsy conveyor, determine the configuration of the main body, conveyor, and the type of shaft (connection or flexibility).

Then, determine the size and quantity (coupling) of each part (conveyor, shaft) according to the order.

1. In the case where the main body (lower component) and the conveyor can be coaxially configured, when using a connecting shaft, please prepare 2 couplings for 1 connecting shaft. 

Since it can correspond to forward rotation and reverse rotation, please confirm the position of the shock absorber of the lower component when connecting, and several units can be connected. About 3 units are arranged for each component of the main body.

2. In the case where the main body (lower component) and the conveyor cannot be coaxially configured, please use a flexible shaft. Since it is a coupling-integrated type, there is no need to prepare a coupling separately. If a flexible shaft is used, please pay attention to the following matters. The part 125mm away from the left and right end faces cannot be bent.

Please specify a length that can ensure R300 or more when connecting.

3. Advantages of function introduction: Using the up and down movement of the punch press to drive the conveyor belt can reduce electricity costs and prevent human negligence from forgetting to turn on the power switch of the compressor and electric conveyor belt. When used abroad, faults such as different voltages will not occur.

3. Knock-Out Bar (K.O. Bar) Scrap Ejection Die Structure

Method of selecting parts: Set the size of the slide plate in combination with the actual waste size of the mold, determine the coupling of the body, transmission configuration, shaft type connection, and the number of accessories.

1. According to the waste slide plate structure in the actual natural state of the mold, the mold height required by the customer is reasonably designed. The waste slide plate in the natural state

Adding connecting blocks and pads to fix the mechanical shaking device at the left and right ends of the mold can realize multi-mode linkage sliding out of waste.

2. Advantages of function introduction: Reduce workload, no compressor, air pipe, or wiring is required when blowing, just install the body and conveyor belt into the mold and punching machine for use. Use a flexible shaft in the connection part, and the conveyor belt has greater flexibility in installation. Even if there is a step difference between the installation position of the body and the conveyor belt, it can be connected. Multiple conveyor belts can be connected to one waste discharge device.

4. Existing research and development conditions and foundations

1. Processing accuracy and testing equipment

All stamping dies of the project are precision dies, which have high requirements for processing accuracy and testing equipment. At present, the processing equipment in the company is advanced imported equipment, CNC finishing equipment is an imported brand Makino, and product testing equipment is an imported German brand CONTURA G2 776 RDS. This equipment can meet the accuracy requirements of precision dies.

2. Existing technical foundation

The company's technical standards inherit and improve the technical accumulation of Gree Factory for nearly 20 years. It has a group of experienced die design technicians and a scientific 3D tool design analysis plan as a basis to ensure that first-class dies that meet customer requirements can be manufactured.

3. Software used in the research process

5. Innovation ofstamping die structure

(1) The waste guide is connected to the fixed die plate through a shaft device, and the corresponding device of the movable die plate is provided with a hitting rod. When the movable die plate and the fixed die plate are closed, the hitting rod controls the vibration of the waste guide plate by hitting the elastic device to accelerate the sliding speed of the waste in the waste guide plate.

This structure is easy to operate and does not require any external device. It solves the problem that the waste cannot slide out smoothly. This stamping die's automatic waste discharge technology can be promoted and applied to new projects later!

6. Refinement and summary of technology and experience

To achieve automatic in-mold changeover, we have summarized relevant design methods and structural standardization. In the design software, we have established factory modularization to improve design efficiency. This will lay the foundation for similar projects in subsequent related management.