Cage Type Shot Blasting Machine for Small Parts

The cage type shot blasting machine for small parts is a specialized surface treatment equipment designed to efficiently clean, derust, strengthen, and polish small-sized workpieces in batches. As the name suggests, its core component is a rotating cage that holds the small parts during the shot blasting process. This type of machine has gained widespread popularity in industries such as automotive manufacturing, hardware processing, aerospace, and fastener production due to its high processing efficiency, uniform treatment effect, and strong adaptability to various small workpieces. In this section, we will delve into the working principle, structural composition, application scope, key advantages, operating procedures, maintenance requirements, and technical parameters of the cage type shot blasting machine for small parts, providing a comprehensive understanding of this essential equipment.

The working principle of the cage type shot blasting machine for small parts is based on the kinetic energy impact of high-speed shot particles on the surface of workpieces. When the machine is in operation, the operator first loads the small parts into the rotating cage. The cage is usually made of high-wear-resistant steel plates with appropriate gaps to allow the shot particles to pass through and contact the workpieces while preventing the workpieces from falling out. Once the loading is completed and the door is closed (equipped with safety interlocks to ensure operational safety), the cage starts to rotate at a predetermined speed driven by a motor and a transmission mechanism. Simultaneously, the shot blasting device (typically one or more impellers) accelerates the shot particles (such as steel shots, stainless steel shots, or aluminum shots) to a high speed (usually 60-100 m/s) and sprays them uniformly onto the surface of the small parts in the rotating cage.

Due to the continuous rotation of the cage, each surface of the small parts can be fully exposed to the high-speed shot flow, ensuring uniform surface treatment. The high-speed shot particles impact the surface of the workpieces, removing rust, oxide scales, oil stains, and other impurities. At the same time, this impact can also form a certain roughness on the surface of the workpieces, which is beneficial for improving the adhesion of subsequent coatings (such as painting, electroplating) and enhancing the fatigue resistance of the workpieces through shot peening strengthening. After the shot blasting process is completed, the shot particles and the cleaned impurities are separated through a separation system. The reusable shot particles are recycled to the shot blasting device for reuse, while the impurities (dust, rust, etc.) are collected by the dust removal system to ensure a clean working environment.

The structural composition of the cage type shot blasting machine for small parts is relatively compact and mainly includes the following core components: rotating cage assembly, shot blasting device, transmission system, shot circulation and separation system, dust removal system, electrical control system, and frame. The rotating cage assembly is the core part that holds the workpieces, and its material selection and structural design directly affect the service life and treatment effect. High-wear-resistant manganese steel or wear-resistant alloy steel is often used for the cage body to withstand the impact of shot particles and the friction of workpieces. The size of the cage can be customized according to the production needs, with a volume ranging from a few liters to hundreds of liters to adapt to different batch processing requirements.

The shot blasting device is the power source for shot particle acceleration, and the impeller is the key component of this device. The impeller is usually driven by a high-power motor, and its speed can be adjusted according to the hardness of the workpieces and the required surface treatment effect. The design of the impeller blade (such as curved blades, straight blades) and the number of blades directly affect the shot flow velocity and the uniformity of the shot spray. Some advanced cage type shot blasting machines are equipped with multiple impellers arranged around the cage to ensure that the shot flow can cover the entire cage uniformly, further improving the treatment effect.

The transmission system is responsible for driving the rotation of the cage, which usually consists of a motor, reducer, chain drive, or gear drive. The transmission system needs to provide stable and adjustable rotational speed to ensure that the workpieces can be fully turned over in the cage. The speed adjustment range is generally 5-30 r/min, which can be adjusted according to the type and size of the workpieces. For example, for fragile small parts, a lower rotational speed is used to avoid collision damage between workpieces, while for workpieces that require thorough cleaning, a higher rotational speed is used to ensure full contact with the shot flow.

The shot circulation and separation system is crucial for ensuring the continuous operation of the machine and reducing production costs. This system includes a shot storage hopper, conveyor (such as screw conveyor, bucket elevator), separator (such as air separator, magnetic separator), and related pipelines. After the shot blasting process, the mixture of shot particles and impurities falls into the bottom of the machine, and is transported to the separator by the conveyor. The separator uses the difference in density and aerodynamic characteristics between shot particles and impurities to separate them. The clean shot particles are sent back to the shot storage hopper and then supplied to the shot blasting device for recycling, while the impurities are discharged to the waste collection device. The separation efficiency of the separator directly affects the quality of the shot particles and the treatment effect of the workpieces. High-efficiency separators can ensure that the purity of the recycled shot particles is above 99%, reducing the consumption of shot particles.

The dust removal system is an essential part to meet environmental protection requirements and ensure the health of operators. The dust generated during the shot blasting process (including rust dust, oxide scale dust, and shot particle dust) is collected by the dust hood installed inside the machine and then transported to the dust remover through the air duct. Common dust removers include bag-type dust removers, cyclone dust removers, and electrostatic dust removers. Bag-type dust removers are widely used due to their high dust removal efficiency (up to 99.9% for fine dust) and stable performance. The dust removal system can effectively reduce the dust concentration in the working environment, ensuring that it meets the national environmental protection standards and protecting the health of operators.

The electrical control system is the "brain" of the cage type shot blasting machine, which controls the operation of the entire machine. It usually consists of a PLC controller, touch screen, frequency converter, contactor, and various sensors (such as position sensors, pressure sensors). The operator can set the processing parameters (such as shot blasting time, cage speed, shot flow rate) through the touch screen, and the PLC controller will automatically control the operation of each component according to the set parameters. The electrical control system also has multiple safety protection functions, such as door interlock protection (the machine cannot start when the door is open), overload protection (the motor stops automatically when overloaded), and fault alarm (an alarm is issued when a fault occurs in any component), ensuring the safe and reliable operation of the machine.

The frame is used to support and fix all components of the machine, ensuring the stability and rigidity of the machine during operation. The frame is usually made of welded steel plates, and after stress relief treatment to avoid deformation during long-term operation. The bottom of the frame is usually equipped with adjustable feet to facilitate the leveling and installation of the machine.

The cage type shot blasting machine for small parts has a wide range of application scenarios, mainly focusing on small-sized workpieces that require batch surface treatment. In the automotive manufacturing industry, it is used to clean and strengthen small auto parts such as bolts, nuts, washers, gears, bearings, and brake pads. For example, after the production of auto bolts, there are oxide scales and burrs on the surface, which need to be removed by shot blasting to improve the surface quality and corrosion resistance. In the hardware processing industry, it is used to treat hardware products such as screws, nails, hinges, locks, and tools. Shot blasting can not only remove the rust and oil stains on the surface of hardware products but also enhance their surface hardness and wear resistance, improving the product quality.

In the aerospace industry, it is used to treat small precision parts such as aerospace fasteners, connectors, and small gears. The surface of these parts has high requirements for cleanliness and roughness, and the cage type shot blasting machine can achieve precise surface treatment to meet the technical requirements of the aerospace industry. In the electronic and electrical industry, it is used to treat small electronic components such as connectors, terminals, and heat sinks. Shot blasting can remove the oxide layer on the surface of the components, improving the conductivity and heat dissipation performance. In addition, it is also used in industries such as motorcycle manufacturing, bicycle manufacturing, and hardware decoration to treat various small parts.

Compared with other types of shot blasting machines, the cage type shot blasting machine for small parts has several key advantages. First, it has high processing efficiency. Due to the rotating cage design, multiple small parts can be processed at one time, and the processing time is short (usually 3-15 minutes per batch), which is suitable for mass production. Second, the treatment effect is uniform. The continuous rotation of the cage ensures that each surface of the workpieces is fully exposed to the shot flow, avoiding uneven treatment caused by partial shielding of the workpieces. Third, it has strong adaptability. It can handle various types of small parts, including metal parts, non-metal parts (such as plastic parts, ceramic parts), and parts of different shapes (such as cylindrical, spherical, irregular shapes). By adjusting the processing parameters (such as shot particle size, shot flow rate, processing time), it can meet different surface treatment requirements (such as cleaning, derusting, strengthening, polishing).

Fourth, it is easy to operate and maintain. The electrical control system with PLC and touch screen makes the operation simple and intuitive, and the operator can master the operation skills after simple training. The structural design is compact, and the key components (such as impellers, cage) are easy to disassemble and replace, reducing the maintenance difficulty and cost. Fifth, it is environmentally friendly and energy-saving. The efficient dust removal system can effectively control dust pollution, and the shot circulation system can recycle the shot particles, reducing the consumption of shot particles and energy. Sixth, it has high safety performance. The multiple safety protection functions (door interlock, overload protection, fault alarm) can ensure the safe operation of the machine and protect the personal safety of operators.

To ensure the normal operation and treatment effect of the cage type shot blasting machine for small parts, correct operating procedures must be followed. The specific operating steps are as follows: first, check the machine before starting, including checking whether the shot particle storage is sufficient, whether the transmission system is normal, whether the dust removal system is unblocked, whether the safety interlock is effective, and whether the electrical components are intact. Second, load the small parts into the rotating cage, ensuring that the loading amount does not exceed the rated capacity (usually 70-80% of the cage volume) to avoid affecting the turning over of the workpieces and the treatment effect. Third, close the machine door, ensuring that the door is tightly closed and the safety interlock is triggered. Fourth, set the processing parameters on the touch screen, such as shot blasting time, cage speed, and shot flow rate, according to the type and surface treatment requirements of the workpieces. Fifth, start the machine in the correct order: first start the dust removal system, then start the shot circulation system, then start the rotating cage, and finally start the shot blasting device. During the operation, pay attention to observing the operation status of the machine, such as whether there is abnormal noise, whether the shot flow is uniform, and whether the dust removal effect is good. Sixth, after the processing is completed, stop the machine in the reverse order: first stop the shot blasting device, then stop the rotating cage, then stop the shot circulation system, and finally stop the dust removal system. Seventh, open the machine door, take out the processed workpieces, and check the surface treatment effect. If the effect is not satisfactory, adjust the parameters and reprocess. Eighth, clean the machine, remove the impurities in the shot circulation system and the dust collection device, and check and maintain the key components.

Regular maintenance of the cage type shot blasting machine for small parts is essential to extend its service life and ensure stable performance. The maintenance work mainly includes the following aspects: daily maintenance: clean the machine surface and internal impurities, check the shot particle storage and supplement in time, check the tightness of the transmission chain or gear, check the operation status of the motor and reducer, and check the dust removal system for blockage. Weekly maintenance: check the wear status of the impeller blade and replace it if the wear is excessive (usually when the wear amount exceeds 10-15% of the original thickness), check the wear status of the cage body and repair or replace the wear-resistant liner if necessary, check the electrical connections for looseness, and lubricate the transmission system (add lubricating oil or grease to the reducer, bearing, etc.). Monthly maintenance: check the separation efficiency of the separator and clean the separator if necessary, check the performance of the dust remover (such as the pressure difference of the filter bag, the dust removal effect) and replace the filter bag if necessary, check the safety protection devices (such as door interlock, overload protector) for effectiveness, and calibrate the electrical control system. Annual maintenance: conduct a comprehensive inspection of the entire machine, including the frame, transmission system, shot blasting device, shot circulation system, dust removal system, and electrical system, repair or replace worn components, and conduct performance testing and adjustment to ensure that the machine meets the original technical indicators.

The technical parameters of the cage type shot blasting machine for small parts vary according to different models and manufacturers, but the main technical parameters include the following: cage volume: usually 5-500 L, which determines the batch processing capacity of the machine. Rated loading capacity: usually 3-300 kg per batch, depending on the density of the workpieces. Cage speed: adjustable range 5-30 r/min. Shot blasting device: number of impellers 1-4, impeller diameter 250-600 mm, motor power 1.5-30 kW. Shot flow rate: 50-500 kg/min, which can be adjusted according to the processing requirements. Shot particle size: 0.2-2.0 mm, suitable for different surface treatment requirements. Processing time: 3-15 minutes per batch, depending on the workpiece material and surface condition. Dust removal efficiency: ≥99.5%, ensuring compliance with environmental protection standards. Overall dimensions: length × width × height, varying according to the model, usually 1500×1200×1800 mm to 4000×2500×3500 mm. Weight: 500-5000 kg, depending on the size and configuration of the machine.

In conclusion, the cage type shot blasting machine for small parts is a high-efficiency, uniform, and versatile surface treatment equipment that plays an important role in various industries requiring batch processing of small parts. Its reasonable structural design, advanced control system, and good environmental protection performance make it an indispensable equipment in modern manufacturing. By understanding its working principle, structural composition, application scope, advantages, operating procedures, maintenance requirements, and technical parameters, users can better select, use, and maintain the equipment, improving production efficiency and product quality.