Details
1. DESCRIPTION AND MECHANICAL DESIGN
1.1 Overview
• Equipment: One Hydraulic Band Press with a rated capacity of 1000 tons ie. (12 X Max 83 Tonne Hydraulic Cylinder for pressing)
• Application: Designed for mounting an annealed copper or gilding metal band into the external circular groove of a hollow steel cylindrical body (positioned vertically on its base).
1.2 Press Structure and Operation
• Pressing Mechanism:
- The press is equipped with 12 hydraulic cylinders and pistons arranged radially in a single horizontal plane around a central pressing station.
- Each cylinder drives a heavy-duty pressing jaw and all 12 cylinders move synchronously to apply a uniform radial force into the groove.
- The cylinders are fabricated in one piece (with no welding) and mounted on a one-piece structural frame using bolt connections for fine alignment. The mounting surfaces are machined to ensure square alignment as per machine tool standards.
• Hydraulic Cylinder Specifications:
- Quantity: 12
- Piston Diameter: Minimum 200 mm
- Piston Rod Diameter: Minimum 110 mm
- Cylinder Wall Thickness: 75 mm
- Stroke: 30–35 mm
- Arrangement: Evenly spaced at 30° intervals around the central pressing station.
• Central Pressing Station:
- Located centrally among the 12 jaws, it moves vertically via a hydraulic (ejector) cylinder with an adjustable stroke of approximately 200 mm (adjustable via HMI).
- The station positions the hollow body’s groove within the pressing zone and then ejects the finished body for manual unloading.
• Cycle Operation:
1. Loading: The hollow cylindrical body with the pre-mounted band is manually loaded onto the central pressing station using an electrical hoist.
2. Positioning: The station moves downward to align the body’s groove with the 12 pressing jaws.
3. Pressing: The 12 jaws concurrently move radially inward to initially grip and then press the band into the groove, applying a predetermined dwell time.
4. Retraction & Indexing: After pressing, the jaws retract. If multiple pressings are required, an automatic indexing mechanism rotates the body (in programmable steps of 15° to 90° for 1 to 11 indexings per cycle) before subsequent pressings.
5. Ejection: The central station then moves upward to present the pressed body for manual unloading.
Production Rate: The system is designed to achieve a minimum output of 20 band-pressed hollow bodies per hour, inclusive of manual loading and unloading (each not exceeding 25 seconds).
2. AUTOMATION, ELECTRICAL CONTROL, AND HYDRAULIC POWER PACK
2.1 Electrical Power System and Panels
• Panels and Enclosures:
- The press is equipped with dedicated Power, Control, and Operator Panels housed in IP54-rated enclosures, fabricated from 14/16 SWG CRCA sheet and powder coated in pebble gray.
- Standard switchgear (e.g., MCCBs for incoming supply and motor feeders, isolators, LED indicators, and panel lighting) are integrated.
• Power Distribution and Protection:
- Power is distributed through copper bus-bars, and a calibrated digital energy meter is included.
- A surge protection device is installed for both the AC and 12/24 V DC control supplies.
- Proper earthing is ensured via copper strips and designated earth terminals.
2.2 Hydraulic Power Pack
• System Overview:
- The press is powered by a complete hydraulic power pack that includes motors, a set of hydraulic pumps, valves, a heat exchanger, and all necessary connecting pipes.
• Key Specifications:
- Pump Type: High-pressure pumps of reciprocating piston/plunger (piston pump) type.
- Installation: Both primary and secondary pressure pumps are mounted externally on the power pack with positive suction.
- Tank Volume: The system contains a minimum of 1500 liters of hydraulic oil, with provisions (power baffle plates and a heat exchanger) to prevent overheating.
- Lubrication: Metered cartridges are provided for piston lubrication along with a separate lubrication pump.
• Performance:
- The power pack is designed to deliver consistent operating pressure (270 kg/cm² working, up to 300 kg/cm² maximum) to all 12 hydraulic cylinders, ensuring uniform force application during pressing.
2.3 Control System and PLC Integration
• PLC-Based Control:
- A PLC (e.g., Siemens S7-300) controls the entire operation, managing horizontal strokes, dwell time, indexing (both number and degree), and job counting.
- The system is provisioned with additional I/O capacity for future expansion.
• Human-Machine Interface (HMI):
- A touch-screen HMI (minimum 10-inch color display) provides graphical visualization of process flows and allows adjustment of key parameters such as ejector stroke, hydraulic pressure, dwell time, and indexing settings.
- The HMI supports recipe functions to save and recall settings and includes password protection for parameter changes.
• Auxiliary Features:
- All electrical motors (including those for indexing) meet IE-3 efficiency standards and have proper MPCB protection.
- Junction boxes for control and power wiring are provided, with cable trays installed for proper cable management.
- An SMPS unit supplies low-voltage power, and the final PLC/HMI program is backed up on removable media. An industrial-grade laptop is provided for diagnostics.
2.4 Safety and Interlock Systems
• Interlocks:
- Hardware limit switches (limit, proximity, and reed types) prevent over-travel and ensure safe operation.
- An emergency stop button is incorporated in the control panel for immediate shutdown if necessary.
• Environmental Monitoring: The system is designed for operation under ambient temperatures up to 50°C, with fault alarms (visual and audible) for abnormal conditions.
• Backup: The system includes provisions for backup and diagnostics, with online PLC access available without password blocking.
3. OPERATING PARAMETERS AND PERFORMANCE
3.1 Force and Hydraulic Performance
• Radial Force: Adjustable from 250 to 1000 tons via digital control on the HMI.
• Operating Pressure: 270 kg/cm² working pressure with a maximum of 300 kg/cm².
• Hydraulic Cylinder Performance: All 12 cylinders operate synchronously with a stroke of 30–35 mm to ensure even force distribution.
• Ejector System: Capacity of 5 to 20 tons upward and 5 tons downward, with an adjustable stroke (up to 200 mm controlled via HMI).
3.2 Cycle Timing and Indexing
• Cycle Time: Total cycle time (including manual loading and unloading, each capped at 25 seconds) is programmed to not exceed 144 seconds.
• Indexing: Programmable indexing in increments of 15° (from 15° to 90° per cycle), with 1 to 11 indexings per pressing cycle.
• Dwell Time: Adjustable dwell time per pressing from 0 to 15 seconds in 1-second increments.
3.3 Power Supply:
• The system operates on a three-phase 415 V ±10%, 50 Hz AC supply.
4. SUMMARY
This technical offer describes a single 1000‐ton Hydraulic Band Press designed for precision mounting of a copper or gilding metal band into the external groove of a hollow steel cylindrical body. Key features include:
• A robust mechanical design with 12 radially arranged hydraulic cylinders ensuring uniform, synchronous force application.
• A central pressing station with adjustable vertical movement for precise positioning and ejection.
• Fully automated cycle control with programmable indexing and dwell times, managed by a PLC and a 12-inch HMI.
• A comprehensive hydraulic power pack delivering reliable high-pressure performance, with a minimum 1500-liter oil capacity, effective heat management, and integrated lubrication.
• An advanced electrical system with dedicated panels, robust power distribution, and safety interlocks to ensure operational reliability and operator safety.
Some modern copper band press machines for ammunition manufacturing also include:
• Rotary indexing tables (for continuous production)
• Pre-heating stations (to slightly expand the copper band thermally before pressing)
• Automatic shell recognition and program selection (via barcode/RFID)
• Data logging for each shell pressed (serial number traceability)