Technically Speaking

When machines for high added-value special products can concretely face international challenges, they are usually interesting solutions.

The U.S.A. call: Caorle, on that market with its dedicated structure, answers from its headquarters in

Marano Vicentino, ready to create a new system, i.e. a development of recent projects, but even more advanced and customized for customers’ specific needs. This is how the latest challenge of Vicenza-based Company has been created, a demanding challenge since the American company specializing in the manufacture of hydraulic cylinders, knew that it could ask for and obtain from the specialist in pipe ends and profiles processing, a very productive solution, lying close to its current and future needs. Customers’ “desires” were indeed ambitious, starting from the need to dispose of a particularly great flexibility. Practically speaking, the possibility of processing both small and big pipes, of course, with an eye to the optimization of cycle times and costs. The starting point, i.e. performing the necessary processing on pipes of different sizes, should in turn be combined with the needs linked to the subsequent use of pipes as hydraulic cylinders, i.e. the precise reception of sliding pistons in them.

The machine almost finished, we were invited to realize the results of our last technological adventure and we have immediately recognized Caorle’s ‘”imprinting” in its classic configuration of end-working machines. The new concept is, however, more elaborate and complete as for tooling and automation.

 

Aim: highest flexibility

As soon as we have entered the workshop and had a look around, company director Alberto Caorle, who we have known for years, reminded us that his company is still moving towards the production of high-end machines, i.e. when it is necessary to dispose of products manufactured with suitable characteristics for qualitative applications, for example, because of the hydraulic components intended for industrial applications. This choice – he assured us – is still rewarding because the company has found its optimal balance between sizes, organization, and ability to innovate. At a first glance, the machine is structurally robust. Plate thickness and the large size of the guides for sliding axes prove a presumable high rigidity.

Mod. CL 152-10 TA Center/5000 machine is composed of two opposing units for processing 300 to 5,000 mm long pipe ends with 50 to 250 mm diameters. The units are mounted on a base with a very strong structure to allow the precise processing even with maximum sizes of pipes. Company director Alberto Caorle says: “The need for highest flexibility in the dimensional field, in terms of lengths and diameters of the pipes according to what is required, has led to a special attention also in the dimensioning of the expected configuration. As a matter of fact, we needed to design structures which had to be both slender to bring cycle time down and not very cumbersome to process even small pieces. At the same time, we needed to design robust and rigid structures to process large pieces. Thanks to our strong know how, we believe we have achieved the best possible optimization”.

 

Automatic alignment as a guarantee of precision

The two work units are identical: the unit on the left is fixed and acts as a “zero-piece” reference; the unit on the right is movable to allow the housing of the different pipe lengths. Each unit consists of a work spindle, HSK A100 tool changer, a floating vice, a 10 station tool warehouse. Each work unit is equipped with two axes, radial U and axial Z; the unit on the right moves axially and determines the nominal length of the pipe. The 5 axes (2 +2 +1) are driven by Fanuc brushless motors on ball screws and roller slippers. When the pipe is automatically loaded on the machine by a special loader unloader positioned in the rear, it is semi-glossed inside. Before expected processing, it has to be subject to alignment. The self-aligning spindle is housed in the tool warehouse, and, as an actual tool, it is taken from the tool changer and mounted on the work spindle in order to avoid alignment errors, for example due to thermal deformation, with reference to the internal diameter of the pipe. The self-aligning piece enters the pipe, with the rear pneumatic command, expands and blocks the pipe from the inside. During this operation, the floating vice holds the “slack” pipe to allow alignment, then it blocks the piece on the outer diameter. The vice is moved by hydraulic motors and trapezoidal screws; the main opening and closing movement is controlled by an encoder for the indirect control of the diameter correctness of the pipe being processed. The floating movements in the transverse plane allow the placement of the pipe on two points in self adaptive way.

The maximum movement and adaptation of the vise is ensured by the oil hydraulic drive through a system with a blow from the inside, to dramatically reduce friction. The discharge of the self-aligning spindle is followed by the load on the work spindle of the d’Andrea head, housed and drawn from the tool warehouse. The aligning phase has assured the perfectly in axis assembly of the pipe on the work spindle: therefore, processing can begin in total safety. The aligning cycle – emphasizes Alberto Caorle – plays an essential role as for precision processing. As a matter of fact, it is fundamental for processing to be strictly in axis with the inner diameter and not with the external one, since the pipes are used to manufacture hydraulic cylinders and thus must house the internal movable piston. The only reference of the outer diameter may induce errors in processing. “Strict alignment is equally fundamentally dependent from the correct structural dimensions, the strength and structural rigidity, in a perfect balance with the required flexibility”.

 

Processing ends

The work cycle expects the following processing on the two ends: the up facing, the outer beveling, the inner beveling, the turning of pre-threading, the execution of a flash ring, chamfer, as well as threading. D’Andrea heads inserted in the spindle take the driving force for the management of the U axis from the motorized U drive device equipped with Fanuc motor, mounted on the main head of the machine. Once processing is over, the vices open and the rear loader unloader discharges the processed pipe and loads the new pipe. In the meanwhile, the tool changer loads the self-aligning spindles on the work spindle and the whole cycle begins again. Everything is managed by a CNC Fanuc 30i with double control panel, with dual-channel in order to allow full flexibility for the independent programming of the two operating units. Alberto Caorle points out that, given the length of the machine, the two interconnected operator panels facilitate the operations in the two work zones. The CNC is of course equipped with all typical CNC Fanuc functions and has been programmed with customer-specific parametric “Part Programs”. In this way, programming is very simple: it is only needed to specify diameter, pipe length, the machine automatically sets the work unit and the right arm in the right position to receive the pipe to be processed.

Concerning the processing to be performed on both ends, it is only needed to specify the variables of the part program step, thread depth and pace, as well as diameter and length of the flash ring with relevant chamfer, to obtain the desired processing. Of course, there is always the possibility of freely programming other processes, through the classic ISO programming. While we took some photos, we discussed on the developed technological solutions and met a smiling Alberto Caorle. Then we realized that one of the important innovations introduced in this machine is the ability of managing D’Andrea heads interchangeably, and not according to the normal processing with fixed heads. As a matter of fact, the two tool warehouses, each of them dedicated to the slaving of the corresponding work unit, are suitable for the housing of heavy tooling and are equipped with three D’Andrea heads, even if they can house other standard tools. . They also house the self-aligning spindles, in the number and type needed by the customers. The following statement provides some points of clarification. “The automatic double-exchange tool for loading and unloading effectively manages the tools, the self-centering items and the whole system, also thanks to the equipment for automatic pipe loading and unloading, it gives the plant a wide operational autonomy of operation on several shifts. It is important to understand that it is a plant characterized by high efficiency, high operability and high flexibility”. The system of chips’ clearance is equipped with blowing and washing devices to keep the work area clean. The machine is equipped with partly-covered safety shrouds and light barriers in the operator’s area. The equipment for automatic pipe loading and unloading at the side of the machine is moved through hydraulic cylinders by pilgrim step. The fixed arm is referred to the position of the fixed unit to the left, and the movable arm operates in correspondence of the right movable unit. The two arms are both equipped with two pairs of “V” devices. Both perform coordinated movements: a workpiece is left on the “V” on the front, machine-side, while the open-vice unloader performs the vertical lifting of the processed pipe, the transverse movement towards the rear part of the machine, and finally the descent on the rear exhaust “V ” device.

 

Behind the corner

While Alberto Caorle was showing us to the exit, we asked him about the future technological developments. Top flexibility seems to be at the center of the Company’s attention; therefore, its future goals include the creation of machines with an even greater number of axes and tool warehouses of various sizes, for ISO 40- ISO 50 – HSK A100 tools. “Our technological development – points out Albert Caorle – already boasts a very high level in the non-standard machine world; and now we would also consolidate our sales efforts to replicate the achievements on bigger markets”.

On the threshold, we made considerations about the plant that really seems to be the state-of-the-art of end machining for high added value productions that require the search for the best balance between contained cycle times, high quality, suitability for subsequent operations, reliability for working on multiple shifts and reduced product costs. Alberto Caorle just smiled and whispered: “This is certainly the most flexible pipe system ever made”.

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Flexibility

The machine can process 300 mm to 5000 mm long pipes with diameters from 50 to 250 mm, and is equipped with head changer to manage multiple D’Andrea heads and self-aligning spindles; the double control panel with double channel allows performing different processing on the two work units.

 

Precision

Thanks to the accurate structural dimensioning and considering the need to work on both small and big size pipes; thanks to the alignment of the pipe referred to the inner diameter.

 

Efficiency

The robust, automated system is designed to continuously work on multiple shifts.

 

Reliability

A careful study of the refrigeration system and chip clearance system; quality components from the well known international manufacturers.

 

Ease of use

Two interconnected operator panels facilitate the operations in the two work zones. The CNC features powerful built-in functionalities and is programmed with customer-specific parametric “Part Programme”: programming is very simple because it is only needed to specify diameter, pipe length; the machine automatically sets the work unit and the right arm in the right position for receiving the pipe to be processed. Concerning the operations performed on the two ends, it is enough to specify the variables of the part program, thread pace and depth as well as the diameter and length of the flesh ring with relevant chamfer, to obtain the desired processing.