Transfer Machines Information
Transfer machines are metal working machine tools with several stations for performing various machining processes. Workpieces are fed into the machine and automatically indexed from station to station. Each station simultaneously performs a different operation on the workpiece and they exit the machine as a partially or completely finished unit. Standard transfer machine systems consist of multiple, sequential mechanical components, such as machining heads, transfer devices, indexing tables, and work. Workpieces are held by stationary or traveling fixtures and indexed in a circular or linear path. In the course of a cycle, components pass through each work station undergoing specific machining operations. The indexing table turns either vertically or horizontally and supports both continuous and intermittent movement. When combined with an automated transfer line for part feeding, transfer machines amplify production rate.
Uses for transfer machines include mass production of metal parts for a variety of industries, such the automotive and industrial machinery industries. Custom systems exist for manufacturing discrete components..
Transfer machines come in three main types, including:
Rotary: These machines move workpieces between stations in a circular path. Mass manufacturing within a small footprint makes these systems an economical solution. Modern CNC-enabled flexible transfer machines of this type gained popularity in European and North American domestic manufacturing facilities given the lower labor costs.
In-line or linear: Workpieces follow a linear path from one workstation to the other. The number of axes a machine operates on, combined with the number of machining stations, determines the quantity and type of parts and processes the machine can perform.
Trunnion: Parts are indexed around a horizontal shaft, known as the trunnion. The rotary movement of the parts is similar to the motion of a Ferris wheel. Cutting tools engage the parts at respective stations at the same time, allowing each index to deliver a completed part. The number of machining units depends on the size of the machine.
CNC-enabled trunnions with the flexibility to adjust their tooling eliminate the need to perform secondary operations, as well as associated tooling and labor. Newer trunnion transfer devices are capable of axially processing a workpiece at each end. They can be configured using supplementary tooling units, vertical or angular, resulting in a five-sided contact with the part during the machining process.
Transfer machines cover a wide range of applications, including:
- Pneumatic fittings
- Hydraulic fittings
- Cast iron
- High volume manufacturing
- Medium volume manufacturing
With the cost per transfer machine running at $1,000,000 or higher, the expected yield must be analyzed to ensure the expense is justified. Historically, integration of transfer machine tools was considered for production levels of one million parts or more. Today, advanced machining mechanisms incorporate computer aided vision systems, superior material handling technologies and other innovations. These tools are capable of manufacturing much lower quantities, with a minimum of 200,000 units, while controlling the production cost and time.
These systems are not a one-size-fits-all solution; they can be custom engineered for specific applications. In addition they have the capacity to run continuously, improving return on investment over comparable machines or processes. The customization options of a transfer machine are an important consideration.