DESCRIPTION

Technical Field

This invention relates to a multi-spindle station for robotized cells (or islands).

Background art

The robotized cell (or island) is normally a semi-isolated zone where operations are automatically performed on workpieces to be machined, for example to be deburred, by manipulating one or more programmable robots.

Robotized cells are applied to various sectors, such as cast iron, aluminium, steel, ceramic, wood or plastic and are small automatic workshops, which are highly integrated and made in a few square metres of space.

The workpieces enter and leave the cell using movement means, such as belt feeders, chains or belts or rotary tables, on which an operator has previously manually positioned the workpieces to be processed.

Once the workpieces have entered the cell, they are gripped by a robot and machined with various tools (cutters, discs, grinding wheels, drills...) depending on the dimensions of the workpiece and the machining to be performed.

In this way, the robot (or robots) inside the robotized cell is able to produce workpieces which require a number of different machining operations (cutting, grinding, drilling, milling, tapping, etc.).

The robotized cells, widely used in the assembly, casting, painting and welding sectors, guarantee fast, economical and optimised production processes, allowing the production of better quality machined parts with a parallel reduction in production costs, especially in those processes considered to have high levels of wear and with high risks.

A first problem of this type of robotized cell is due to the fact that in order to perform different types of machining, machine tools are required which are different and separate from each other. The use of two separate machines, as well as problems of overall size, results firstly in production delays since the workpieces must be transferred from one machine to another; this transfer may significantly increase not only the time, but also the labour necessary for the production.

Moreover, the use of these additional machines is added to the production cost, requiring the purchase, operation and maintenance of each apparatus.

Disclosure of the invention

According to the prior art, it is possible to use a single machine tool which allows the robot (or robots) to perform a number of machining operations on the workpiece: the machine is a multi-spindle station with rotary transfer with horizontal and vertical axes of rotation. The spindles support tools which are able to simultaneously perform various machining operations and the change of the spindle/tool units is performed by rotation.

However, these multi-spindle stations have a configuration such as to allow the use of a number of spindles, connected along the circular perimeter of the machine, limited by the dimensions of the machine.

For this reason, in order to be able to insert other spindles/tools it is necessary to widen the perimeter of the machine tool, thereby increasing the overall dimensions.

Moreover, again due to the surrounding environments, machines of this type can mount motors which are relatively small or in any case proportional to the available, limited space, with consequent problems for sizing the multi spindle station.

The aim of the invention is to overcome the above-mentioned drawbacks in known types of multi-spindle stations for robotized cells which allows a greater number of spindles/tools to be mounted - with the same dimensions - compared with the prior art, so as to make robotized cells which are extremely versatile and compact.

In the context of the above-mentioned purpose, an aim of the invention is to provide a multi-spindle station for robotized cells, which allows spindles of any power to be mounted, in such a way as to allow any type of machining. Yet another aim of the invention is to provide a multi-spindle station for robotized cells, with means which are easily available on the market and using materials of common use, in such a way that the device is economically competitive.

This purpose, as well as these and other aims which will become clearer as this description continues, are achieved by a multi-spindle station for robotized cells according to the invention, comprising a column element, extending along a direction of extension, having means for detecting the surface of the workpiece to be machined and means for translating the tool holder spindles, each connected to respective motor means, the tool holder spindles being removably mounted on said column element.

The multi-spindle station therefore comprises a central column structure, with stations designed to house several groups of tools on the basis of the process requirements.

Preferably, the direction of extension is substantially normal to the ground, so that the column is balanced.

Advantageously, the translation means comprise a rectilinear guide for each spindle connected to the column element, which defines a longitudinal direction substantially parallel to the ground. The rectilinear guide is designed to be engaged with a supporting slide for the respective tool holder spindle, to which it is fixed. In this way, the translation of the spindle allows the tool to escape from the dimensions of the column element and allows all the necessary machining to be performed on the workpiece manipulated by the robot.

The slides can house milling spindles, de-burring spindles, cutting discs, grinding wheels, finishing machines and stations for measuring and zeroing the workpiece.

Preferably, the slide is controlled by a piston for its movement along the longitudinal direction. The linear movement for activating and deactivating the units may be performed pneumatically, through a pneumatic cylinder or also electrically by means of electric motors: with a movement by means of an electric motor the motion transmission may occur by means of pinion and rack or by means of belts and pulleys or recirculating ball screws.

Normally, the measuring means comprise a contact member, of essentially known type, mounted on the head of the column element, for measuring the surface to be machined, in such a way as to check the geometrical conformity of the workpiece. The contact member is also designed to engage with the column element, using relative translation means along the longitudinal direction.

Obviously, with the contact member, sensor means of any type, such as a laser pointer, also of essentially known type, may be used which, like the contact member, can check how the workpiece has been gripped by the robot, by measuring some strategic points.

Each operating unit, formed by a tool holder spindle and its respective motor means, comprises the use of an interface plate to be fixed to the central column, as well as the slide which slides on the linear guides.

In order to make the station versatile and to be able to change its configuration quickly and easily, following the machining requirements of the workpiece, whatever it is, the coupling means and the translation means are modular, so that each of the tool holder spindles is designed to be mounted on and removed from any of the slides.

All the stations therefore have the same mechanical interface, so many configurations can be provided.

Advantageously, the slide has at least one rotatable arm for opening outwards relative to the direction of extension of the column element, in such a way that the relative tool holder spindle is moved away from the overall dimensions of the column element to facilitate the machining of very large workpieces.

This embodiment is achieved, for example, by a rotatable guide mounted on the interface plate.

Advantageously, there are means for rotating the column element around the direction of extension. In this way, the multi-spindle station is in fact equipped with a rotary movement which is designed to orient the milling tools in an advantageous position for the machining which the robot must perform.

The rotation of the column element can be controlled directly by the robot (controlled axis): in this case, therefore, the axis of rotation is the seventh axis of the robot.

Alternatively, the rotation may have relative means (fixed rotation); in this case the rotary movement of the platform or the table may occur pneumatically through a lever and a pneumatic cylinder or also electrically through electric motors.

Description of the drawings

Further features and advantages of the invention are more apparent in the detailed description below, with reference to a preferred, non-limiting embodiment of the multi-spindle station for robotized cells, illustrated by way of example and without limiting the scope of the invention, with the aid of the accompanying drawings, in which:

Figure 1 is a perspective view of an embodiment of the multi-spindle station

1 ;

Figure 2 shows the station 1 of Figure 1 in the raised condition;

Figure 3 is a cross-section through line Ill-Ill of Figure 2;

Figure 4 is a perspective view of a second embodiment of the multi-spindle station 102.

Detailed description of the invention

The above-mentioned drawings show a preferred embodiment of a multi spindle station for robotized cells, according to the invention, which is identified in its entirety with the reference numerals 1 and 101 and which comprises the following.

A multi-spindle station 1 or 101 for robotized cells, which comprises a column element 2, extending along a direction of extension 10 substantially at right angles to the ground 9. The station 1 (or 101 ) comprises means 5 for detecting the surface to be machined and translation means for a series of tool holder spindles 3, 3’, 3” and 3’”. Each of these spindles 3, 3’, 3” and 3’” is mounted removably on the column element 2 and is also connected to respective motor means which comprise a piston 4, 4’, 4” and 4’” (in this case, a pneumatic cylinder) driven by the respective motor 19, 19’, 19” and 19”’.

With reference to Figure 3, mounted on the side walls of the column element 2 there is a guide 6 (6’, 6”, 6”’) at the coupling point of the spindle 3 (3’, 3”, 3”’). In this case, the guide 6, like the other guides 6’, 6”, 6”’, consists of a pair of tracks substantially parallel to each other and substantially parallel also to the tracks of the other guides.

Each spindle 3, 3’, 3” and 3”’ therefore defines a longitudinal direction 20 substantially parallel to the ground and to the longitudinal directions 20’, 20” and 20”’, which are all also substantially parallel to each other and to the ground. Along each direction 20, 20’, 20” and 20”’ a relative slide 7, 7’, 7” and 7”’ is engaged for supporting the respective tool holder spindle 3 and connected to the cylinder 4, 4’, 4” and 4”’.

Each operating unit, formed by the tool holder spindle 3, 3’, 3” and 3”’ and its respective motor means (the piston 4, 4’, 4” and 4”’ and the motor 19, 19’, 19” and 19”’), comprises the use of an interface plate 12, 12’, 12” and 12”’ to be fixed to the column element 2 and the slide 7, 7’, 7”, and 7”’ which slides on the guide 6, 6’, 6” and 6”’.

In the preferred embodiment, the scanning measuring contact member 11 , of the known type, which is in practice a measuring rodactivated by an integrated electric motor, is positioned at the head of the column element 2. Obviously, the contact member 11 will also be driven by relative translation means which comprise a motor (not illustrated) which makes it translate on the column element 2 by means of a relative slide 17 for engaging with a relative guide 16 (Figure 2) fixed to the load-bearing frame of the column element 2 by means of a relative plate 18.

There are also covering bellows 15, 15’, 15” and 15”’ for the guides 6, 6’, 6” and 6”’, in such a way as to prevent the falling of chippings in the translation means from adversely affecting the correct operation of the machine.

A second variant embodiment comprises the installation of means for rotating the column-like element 2 (Figure 4), such as a rotary platform or a rotary table 103, of per se known type, mounted at the base of the column like element 2 by means of a supporting platform 104 and equipped with a relative motor 105.

The table 103 is moved by an electric motor 105 which is the seventh axis of the robot, which therefore directly controls the rotation of the column element.

According to another embodiment, the compartment 8 formed inside the column element 2 is used to house a column grinder, thus allowing a very useful accessory to be obtained in the same station and in an extremely compact manner (Figure 3).

In use, the robot receives the workpieces to be machined from the belt feed system by means of known means and, following the command of the operator who sets up the type of workpiece and the type of machining, automatically checks that each workpiece loaded is coherent and therefore - manipulating the workpiece itself - subjects it to the suitable tools 13, 13’, 13” and 13’”, mounted on spindles 3, 3’, 3” and 3’” connected to the column element 2, which are controlled and actuated by the central unit, or by any other data processing unit.

In order for the robot to subject the workpiece to machining, the slide 7 (or 7’, 7” and 7’”), which supports the spindle 3 (or 3’, 3” and 3’”) through the interface plate 12 (or 12’, 12” and 12”’), engages the respective guide 6 (or 6’, 6” and 6”’) in a sliding fashion and allows the translation of the tool 13 (or 13’, 13” and 13”’) outside the area defined by the column element 2.

From the above description it may be seen how the invention achieves the preset purpose and aims and in particular it should be noted that a multi spindle station for robotized cells is made, which allows the assembly of numerous tool holder spindles with the same lateral dimensions, certainly with a greater number than that of the prior art, in such a way as to house larger spindle/motor/tool units and have a solution with a greater number of tools without having significant increases in size.

In particular, since in practice there is no limit in height - apart from that imposed by the ceiling of the building - it will be possible, even with the use of the rotatable arms, to add the number of spindles necessary for organizing any type of machining in a single multi-tool station, with standard dimensions, thus making robotized cells which are extremely versatile and compact.

Another advantage of the above-mentioned station is due to the fact that it has eliminated any problem of lateral dimensions in such a way that it is possible to use tools with higher power ranges.

Another advantage of the invention is due to the fact that the rotation of the column element makes it possible to perform machining operations which would otherwise be impossible by making the robot adopt positions compatible with the geometry of the workpiece and the dimensions of the machine.

Another advantage of the invention is the use of modular translation means interchangeable with each other which, by changing the spindles by activating/deactivating with linear movement, makes it possible to modify the configuration of the station to achieve greater performance levels and make it more convenient with respect to the machining requirements.

Lastly, the use of means which are easily available on the market and the use of common materials makes the device economically competitive.

The invention can be modified and adapted in several ways without thereby departing from the scope of the inventive concept.

Moreover, all the details of the invention may be substituted by other technically equivalent elements.

In practice, the materials used, as well as the dimensions, may be of any type, depending on requirements, provided that they are consistent with their production purposes.