Solutions for the most challenging of production tasks
The Pfiffner Group has extensive know-how and wide-reaching competence in systems and turnkey plants. We use these skills to develop innovative, demand-based machine tools. On this basis, we offer you solutions that are perfectly tailored to your requirements and machining processes.
Honing is a precision machining process that can improve the dimensional and shape accuracy of practically all working materials. The best known applications are the piston running surfaces of cylinders for combustion engines and hydraulic construction elements.
The working material is stripped with honing stones that are placed into the honing tool. The diameter can be adjusted. In order to absorb the grinding pressure, the honing tool supports itself with honing shoes on the bore wall. The honing tool moves both longitudinally and with turning movements. This means that a honed surface has characteristic cross-cut markings.
Forming includes all production processes that involve changing the shape of a solid body by means of plastic deformation. The mass and connection of materials are retained. Forming is a chipless production process.
The following are typical uses of rotary transfer machines:
Along with drilling, milling, and grinding, turning is one of the most important machining production processes. Like in all of these processes, chips are removed from a workpiece to create the desired shape. During turning, the turned part rotates around its own axis while the turning tool traces the contour to be created. Turning processes can be categorized in accordance with different aspects:
- Face turning: The production of flat surfaces
- Cylindrical turning: The production of circular shapes
- Thread turning: The production of threads
- Roll turning: The creation of (geared) rolling surfaces
- Profiling: The production of any shapes using profile cutters (containing the shape to be produced as a "negative")
- Form turning: The production of any shapes using a controlled tool movement
Milling is the machining of metals, wood, or artificial materials using a milling tool. Unlike turning, the required cutting movement is generated through the rotation of the cutting tool on a fixed workpiece. The forward movement required for milling is achieved either through the movement of the machine table or by moving the milling tool around the workpiece depending on the design. Depending on the model, forward movements can take place along the X, Y, or Z axis, along the various rotational axes, or a combination thereof. We talk about face milling, hobbing, and 3D milling depending on the movement type of the milling cutter.
Drilling is a machining process. The drill rotates around its own longitudinal axis and is pressed against the workpiece to create a circular hole: The bore. Generally, the drill has two cutting edges on its tip. These strip chips from the workpiece through a rotary motion and axial pressure. The chips are transported out of the bore via spiral flutes.
Grinding is a type of machining that uses a variety of irregularly shaped cutting edges. The cutting edges are the tips and edges of small grindstones made from natural or synthetic abrasives that are firmly incorporated into a tool (the grinding wheel or sanding belt). Machining takes place at a high surface speed (20 – 100 m/s). It generates a large number of small tracks next to each other and on top of each other on the workpiece surface, deforming and removing the working material. Grinding is used if, due to the hardness of the working material, other machining processes such as turning and milling take place and a particularly fine surface or high workpiece precision is subsequently required.
Multispindle units for multi-process machining are used to streamline drilling operations (workpiece-specific drilling patterns) for medium or high batch sizes in series production. With a multispindle head, multiple bores can be machined at the same time. Rigid multispindle units are suitable for drilling, thread cutting, counterboring, reaming, and multispindle milling.
In the case of the pick-up variant, the spindle moves over the workpiece, picks it up, and then moves back to the machining area. Pick-up turning is generally used at the end of the machining process in order to machine the rear of the workpiece. The workpiece is then taken back to the clamping device or to an unloading station.
Recessing slides are tools that enable flexible contour machining through radial cutting edge adjustment. Face turning heads are primarily used for face turning, recessing, and machining contours in large series production on custom machines. The actuation of these slide tools – or the control of the tool holders and cutting edges – takes place using an N/C-controlled cross-feed device. This is located on the spindle drive or on the rear of the tool spindle unit.
Precision drilling creates bores with the best possible hole wall surface finish using drilling alone. Gage accuracy is not always a required condition, since frequently simply a score-free hole wall is required. The procedure is characterized by extremely low chip removal at a very high surface speed. Because of their improved cutting properties, the cutting edges are preferably made from carbide.
In-process measurement control systems are used directly in processing machines. They are used to measure small, medium, or large workpieces in the machine during the production process. The controllers work with high precision, reliability, and repeatability. They check the quality of your components constantly to achieve exclusively high-quality production results.
To ensure process reliability, in-process measurement control systems automatically compensate for tolerance fluctuations. These occur, for example, in cases of tool wear or temperature variations. In such cases, the in-process control systems monitor the measured values in real time. This means that they continuously control the machining process until the target dimensions are reached. This minimizes scrap and rework.
Sawing is machining with the circular or straight cutting motion associated with the tool along with (any) forward movement in a plane perpendicular to the cutting direction. This process cuts or slits workpieces using a multi-toothed tool with a small cutting width. In the case of circular saws, the tool is a circular disk with teeth on its outer side. Sawing using circular saws is the most productive type of sawing.
Pfiffner constructs the following automation systems:
- Vibratory conveyors (with/without optical workpiece detection)
- Lifting conveyors, optionally in combination with a punching unit
- Gravity conveyors with separation and infeed/discharge units
- Gantry loaders with swivel grippers
- Modular feed systems with transport conveyors
A loading system is a system for automatically feeding blank pieces and semi-finished products to machine tools.
- Handling system (linear handling)
- Hydraulic loading cylinder
- Bar feeding magazine
- Industrial robot with gripper system
An unloading system is a system for automatically removing finished parts from machine tools.
- Handling system (linear handling)
- Industrial robot with gripper system
"Deep hole" drilling in metal processing starts at a bore depth of around three times the tool diameter and goes up to 250 times this diameter. The aim here is to minimize the "wandering" of the center of the drill head away from the set axis, since the shaft of the drill no longer has sufficient bending rigidity due to its length. For this reason, a single-fluted gun drill is often used for deep hole drilling. This type of drill cuts off all of the material by removing chips to keep the cutting forces as low as possible. The drill guides itself on the wall of the already drilled hole. Because the drilled material itself absorbs the lateral forces during drilling, a pilot hole or drill bush is required at the start of the drilling process. For some years now, double-edged, extra long twist drills have increasingly been used for deep hole drilling. Unlike in the case of single-fluted deep hole drilling tools, the ratio between the length and diameter is restricted to around 40 in this case. The advantage of this tool type in comparison with the single-fluted gun drill is that the machining speed is several times greater.
Circular milling is face milling/side milling with a circular feed movement of the tool around its longitudinal axis. This can take the form of climb-milling or up-milling. Climb-milling is always preferred due to improved tool wear behavior. This procedure is good for creating bores for which traditional drills cannot be used or if special contours need to be formed. Thread milling is a further usage area. The infeed along the milling axis to the workpiece takes place by the value of the thread pitch per full circle traveled in the bore.
Workpieces can be labeled by means of embossing or pressing. A forming tool (punching unit) is pressed into a workpiece surface at great pressure. The pressure results in deformation that creates a relief.
During needle embossing (also called percussion marking), the material is labeled with a compressed-air-driven oscillating carbide tip (needle) that moves up and down in the X and Y directions.
During engraving, the material is stripped using rotating milling cutters (gravers).