DESCRIPTION

The present patent concerns milling and/or drilling machines, and in particular it concerns an improved machine for performing drilling/ deep drilling and milling operations on a workpiece, particularly but not exclusively on moulds for plastic materials.

The use of machines that perform drilling and deep drilling operations, as well as machines that perform milling operations, is well known in the manufacture of moulds for plastic materials.

Therefore, the equipment for making moulds usually includes milling centres and at least one drilling machine.

The known drilling machines usually consist of a worktable, which can be a rotating and/or tilting element, and an upright or column supporting a sliding element that carries the drilling head.

The drilling head in turn usually comprises a rear part, where the electric motor that transmits the rotary motion to a drill bit is located, and a front part that serves as a guide for the drill bit.

The drill bit is also displaced in the axial direction so that it moves forwards towards the piece to be drilled and backwards once the desired hole depth has been reached.

Drilling machines are known, which are equipped with special lubrication systems which facilitate the discharge of drilling chips even from very deep holes, and with drill bit guide systems that prevent the drill bit from breaking.

Drilling machines are known, which also comprise a milling spindle, which, however, works in alternation with the drilling head.

Let us consider below the three orthogonal axes in which the X-axis and the Y-axis define a horizontal plane, while the Z-axis is vertical. The X-axis is the axis along which the tool moves forwards/backwards to reach/move away from the workpiece.

According to the invention, however, two different sets of three Cartesian coordinates can be assigned if the machine that is the subject of the invention has two separate CNC units.

Milling machines usually comprise a tool head that can be moved on a plurality of axes. Therefore, to perform both drilling/deep drilling and milling operations, the total time necessarily results from the sum of the time needed to perform each individual machining cycle, plus the machine changeover time.

The patent 102018000004266 by the same inventor concerns a machine that can perform, even simultaneously, deep drilling operations on the sides and milling operations on the top of the workpiece, for example on moulds for plastic materials, thus reducing the overall machining time for a single workpiece.

Said machine comprises a translating upright, a first spindle associated with a drilling head, a second spindle associated with a milling head, a sliding element suited to be associated with the drilling head in alternation with the milling head, and a rotary worktable.

The machine that is the subject of the above-mentioned patent can also comprise a translating portal-shaped element supported by two side elements, wherein said portalshaped element supports said second sliding element carrying the milling head.

For example, the second spindle is arranged orthogonally and in a higher position with respect to the first spindle.

The upright rests on a base lying on a plane that defines the X-axis and the Y-axis, and said upright can move on the Y-axis with respect to the base.

Said first sliding element can translate on the Z-axis along the upright, orthogonally to the XY-plane. Said first spindle carrying the drilling head can move with respect to the first sliding element along direction X, which coincides with the main machining axis. So, to sum up, the upright can move along the Y-axis, the first sliding element along the Z-axis and the first spindle along the X-axis.

The drilling head unit consists of two independent rotating bodies, the first associated with the sliding element that carries the head, while the second, which is connected to the first, is associated with the drilling head, so that the drilling head can drill according to two directions of inclination and thus be able to cover all possible inclinations in space.

The second sliding element can be mounted on a portal-shaped element and translate along the Y-axis. In addition, the sliding element can translate along the Z-axis. The milling head mounted on the second spindle, which in turn is mounted on the second sliding element, also rotates on two axes.

Thanks to the special configuration of said machine, it is possible to perform both milling and deep drilling operations on the same workpiece.

When the drilling operation on one side of the workpiece has been completed, the machining cycle stops for a short time, the rotary table rotates the workpiece to position the face that has not yet been machined on the drilling side, and the machining cycle starts again, wherein the drilling head provides for performing the drilling operation on the face positioned in front of it while the milling head continues the milling operation according to the new orientation of the workpiece.

The patent 102018000004269 by the same inventor concerns a machine that is similar to the one described above, wherein, however, a second upright, translating along the Y-axis, is positioned in front of said first upright. The second sliding element is mounted on the second upright so that it can translate along the Z-axis, and the second spindle, carrying the milling head, is mounted on the second sliding element and positioned in front of the first spindle, carrying the drilling head. Both spindles are thus oriented along the X-axis, with the workpiece coupled with the rotary worktable that is interposed between them.

In this way, a workpiece placed on the rotary table can be simultaneously machined on both its faces and, in particular, it is possible to carry out the drilling operation on the face facing the drilling head and the milling operation on the face facing the milling head.

A drawback of the known machines lies in that machining on both of the opposite sides of a workpiece at the same time can lead to serious machining errors, especially when there is an imbalance between the forces applied to one side of the workpiece and the forces applied to the opposite side.

For example, if the workpiece is mounted on the worktable and the drilling head has to machine the top of the workpiece, the thrusting force required to make the drilling bit penetrate the workpiece would push it in the direction contrary to that of the thrusting force and consequently against the opposite tool, that is, the milling tool, which would result in a machining process with serious, if not irreparable defects.

In order to permanently constrain the workpieces, worktables are currently used, in which the workpiece is positioned and constrained on the table either by means of magnetic planes or by means of constraining elements, for example those elements known as “barrells” in technical jargon, mounted on the workpiece bottom, that is, on the surface of the workpiece facing the table.

Vertical fixing systems are also known, in which the workpiece is constrained to vertical uprights, called squares.

Both of these fixing systems are effective when machining is only performed on one of the two larger faces of the workpiece, and in particular on the face opposite that constrained to the fixing means. Conversely, said fixing means do not allow the two larger faces of a workpiece to be machined simultaneously, because one of them is resting on the fixing systems.

Machines specifically suitable for deep drilling are known, equipped with drilling heads capable of inclining the drilling tool in a single direction of inclination, while the second direction of inclination results from the rotation of the workpiece obtained by means of a rotary table.

In addition to the above, due to space limitations caused by the large size of the tool head, drilling machines can incline the tool only to a limited extent, reaching an angle of ±20°. The known machines, therefore, have many operating limitations, and are not versatile though being very expensive.

Furthermore, the known drilling heads are not removable, but are permanently fixed to the machine and thus cannot be replaced with other specific equipment, for example milling heads, in order to completely change the function of the machine. With respect to a Cartesian plane, a hole can have a maximum of two directions of inclination.

A deep-drilling head is a specific piece of equipment designed to allow a specific machine to drill holes in various types of material, usually metals, having various diameters and depths that can even reach and exceed 2,000 mm in the mould sector.

The document JP2004255515A describes a workpiece clamping system in which the workpiece is held in the vertical position by locking means that apply a vertical compression force. This technique has the drawback of not being able to prevent undesired movements of the workpiece from the exactly vertical position, which may occur due to the thrusting force of a tool, for example a tool working on the highest part of the workpiece.

Moreover, said locking means do not form a single body with the workpiece as they rest and press on it, but do not engage with it.

Another drawback of the system described in the above-mentioned document lies in that the fixing means do not move along the axes of the machine, as they have a fixed distance, which limits operating efficiency.

Said technique, therefore, cannot be effectively applied in the case of machining operations requiring a very high degree of precision.

The document EN 2018 0000 4269 Al shows a drilling unit in which the thrusting force along the axis W of the tool is discharged onto the first body of the head, inevitably producing an unwanted rotational motion. One of the objects of the machine that is the subject of the present patent is to avoid said unwanted motion, thus increasing machining accuracy.

The subject of the present invention is a new machine for performing drilling/deep drilling and milling operations on a workpiece, particularly but not exclusively on moulds for plastic materials.

The new machine can, for example, be substantially of the type described in the above- mentioned patents in the name of the same applicant and also include a new workpiece clamping system configured to constrain the workpiece on at least two of its opposing faces, for example on the bottom face, which rests on a worktable, and on the opposite top face, or for example on two opposing vertical side faces, leaving the two largest faces free for machining purposes.

To better explain, let us assume for the sake of simplicity that the workpiece has a substantially parallelepiped shape, where on one face, or first main face, milling is to be predominantly carried out, while on the opposite face, or second main face, drilling/ deep drilling is to be predominantly carried out.

Of the four side faces, one face, or bottom face, is intended to face and possibly rest on a lower plane, while the opposite face, or top face, faces upwards. The remaining two faces are hereinafter simply referred to as side faces.

According to a first solution, said bottom face is constrained to the worktable, while the top face is constrained to an upper clamping unit, integral with the machine.

In this way, the two opposing main faces are clear, and can also be machined simultaneously, one by the milling head and the other by the drilling and deep drilling head.

According to this first solution, said upper clamping unit can be mounted on a portalshaped supporting structure, comprising one pair of side elements provided with linear guides arranged according to direction X, and wherein the clamping unit can translate along said linear guides in order to proceed to the loading/unloading of the workpiece. Said clamping unit can be equipped with anchoring elements suited to constrain the workpiece, wherein it is possible to adjust said anchoring elements by displacing them in direction Z and in direction Y depending on the size/shape of the workpiece. Said anchoring elements can be fixed to the workpiece, for example by means of dedicated screws or automatic coupling elements, for example bayonet elements.

In a second solution, said side faces are both constrained by means of a pair of opposing uprights, arranged to the sides of the workpiece. Also in this case, therefore, the two opposing main faces are clear and can be machined even simultaneously, one by the milling head and the other by the drilling/ deep drilling head.

In this solution, said uprights, which can be in the form of squares, can be mounted on linear guides arranged in direction Y, so that they can move towards or away from each other depending on the size of the workpiece to be constrained.

Said uprights are equipped with anchoring elements, for example retractable pins translating according to direction Z and designed to engage with said side faces of the workpiece.

The new machine is preferably provided with a drilling/deep drilling unit, hereinafter only referred to as drilling unit for the sake of simplicity.

The new unit comprises: a base, hereinafter also referred to as cross table, comprising a lower base provided with guides oriented according to direction Y and an upper base that can slide on said guides of the lower base and is equipped with guides oriented according to direction X; an upright mounted on said upper base and sliding on said guides of the upper base; said upright can thus translate along both the X-axis and the Y-axis; a sliding element mounted on said upright and translating in direction Z with respect to the upright; a drilling head mounted on said sliding element and suited to be rotated around a first axis with respect to said sliding element; a drilling device, in turn comprising a casing containing all the necessary components, including the motor and the drill bit guide, and wherein said drilling device is mounted on said head in such a way that it can be rotated around a second axis lying on a plane that is orthogonal to said first axis.

Said drilling head and/or said drilling device are preferably mounted in a removable manner, and in particular said components are mounted in said casing in a removable manner, in such a way as to allow for interchangeability.

The characteristics of the new drilling unit and the new machine are better clarified in the following description, which makes reference to the drawings that are attached hereto by way of non-limiting example.

Figure 1 shows a schematic three-dimensional view of the new machine (100) according to a first solution, where a specially configured drilling unit (1), as described and claimed below, is installed in the machine.

The drilling unit (1) comprises a cross table (20) supporting an upright (30). This solution is particularly advantageous when combined with a sliding element (40) that is not telescopic but only translates in direction Z.

This figure also shows the side elements (610, 620) supporting the upper clamping unit (500).

Figure 2 shows a schematic three-dimensional view of the angled uprights (521, 522) suited to lock a workpiece laterally, according to a possible solution.

Figure 3 shows a schematic three-dimensional view of an angled upright (521) suited to lock a workpiece laterally, where it is possible to see how the anchoring pins (523) can be moved along the Y-axis and the Z-axis.

Figure 4 shows the same machine (100) as Figure 1, without the portal-shaped elements for the sake of clarity.

Figure 5 shows a schematic view of the new machine (101) according to a second solution.

Figure 6 shows a schematic three-dimensional view of the drilling head (910) and the drilling device (900).

Figure 7 shows an alternative embodiment of the clamping unit (530) for locking a workpiece (P).

Figure 8 shows a further alternative embodiment of the clamping unit (540) for locking a workpiece (P).

The new machine (100) is configured to perform drilling/deep drilling and milling operations on a workpiece (P).

The drawings illustrate a generic piece (P), substantially in the shape of a parallelepiped with six faces: a first main face (Pl), a second main face (P2), a bottom face (P3), a top face (P4), and two opposing side faces (P5, P6).

The machine (100) comprises a drilling unit (1) in turn comprising a first upright (30) translating on a first base or cross table (20). Said cross table (20) comprises a first lower base (21) provided with guides (211) oriented according to direction Y and a second upper base (22) with guides (221) oriented according to direction X.

Said second base (22) can thus translate in direction Y with respect to the first base (21), while said upright (30) can translate in direction X with respect to the first base.

A first sliding element (40) associated with a drilling head (910) with drilling device (900) is mounted on said first upright (30).

Said first sliding element (40) can translate in direction Z with respect to the upright (30).

In the solution shown in Figures 1 and 4, the machine (100) comprises a second unit (F), in this case a milling unit, which in turn comprises a second upright (30') translating on a second base (20').

Said second base (20') can, for example, be a cross table made as described above.

A second sliding element (40') associated with a milling device (920) is mounted on said second upright (30').

Said second sliding element (40') can translate in direction Z with respect to the upright (30').

Said uprights (30, 30') are arranged in front of each other, substantially aligned along direction X, and between them there is a rotary worktable (800), to which the bottom face (P3) of the workpiece (P) to be machined can be constrained.

The machine (100) also comprises an upper clamping unit (500) comprising means for constraining the top face (P4) of the workpiece (P).

As shown in Figure 1, said upper clamping unit (500) is mounted on a portal-shaped supporting structure (600) comprising a pair of side elements (610, 620) provided with linear guides (630) arranged in direction X, and wherein the clamping unit (500) can translate along said linear guides (630).

Said clamping unit (500) comprises one or more anchoring elements (510) that can be adjusted in direction Z and in direction Y according to the size/shape of the workpiece. Said anchoring elements (510) can therefore move towards or away from the workpiece (P), moving upwards and downwards along direction Z, and furthermore can move towards and away from each other, varying the distance between them in direction Y, and furthermore can translate along direction X of the machine axis.

In particular, said anchoring elements (510) are preferably centering elements, that is, are configured in such a way that they can also guarantee the centering of the workpiece position.

In a second solution, shown in Figures 2 and 3, the machine comprises, as an alternative to or in combination with said upper clamping unit, a lateral clamping unit (520), which comprises a pair of angled uprights (521, 522) opposing each other in direction Y and suited to be mounted on linear guides or in any case guides translating in direction Y, so that they can move towards/away from each other according to the size of the workpiece to be constrained.

Said angled uprights (521, 522) are equipped with anchoring elements (523), for example retractable pins translating in direction Z and intended to engage with the side faces (P5, P6) of a workpiece (P).

Figure 7 shows an alternative embodiment of the clamping unit (530) for locking a workpiece (P), wherein said clamping unit (530) is configured to hold the two side faces (P5, P6) of the workpiece (P), thus leaving the two main faces (Pl, P2) of the workpiece (P) accessible. In particular, said clamping unit (530) forms an integrated assembly with the worktable (531) of the machine.

Two opposing uprights (532, 533) with fixed spacing are mounted on said worktable (531). In the solution shown in Figure 7, each of said uprights (532, 533) is provided with anchoring elements (534), for example pins as previously described, whose position can vary along the vertical direction Z and which can be retracted along the horizontal direction Y, depending on the size of the workpiece (P). Said anchoring elements (534) are suited to be anchored to the side faces (P5, P6) of the workpiece (P).

Figure 8 shows a further alternative embodiment of the clamping unit (540) for locking a workpiece (P), wherein said clamping unit (540) is configured to hold the bottom face (P3) and the two side faces (P5, P6) of the workpiece (P), thus leaving the two main faces (Pl, P2) of the workpiece (P) always accessible. In particular, said clamping unit

(540) forms an integrated assembly with the worktable (541) of the machine.

Two opposing uprights (542, 543) with fixed spacing are mounted on said worktable

(541). In the solution shown in Figure 8, each of said uprights (542, 543) is provided with anchoring elements (544), for example pins as previously described, which can be extended in direction Y and whose position can vary along the vertical direction Z, depending on the size of the workpiece (P). Said anchoring elements (544) are suited to be anchored to the side faces (P5, P6) of the workpiece (P).

Analogously, also said worktable (541) comprises one or more of said anchoring elements (545) projecting from the table (541) itself, whose position can vary along direction Y and which can extend in direction Z. Said anchoring elements (545) are suited to be anchored to the bottom face (P3) of the workpiece (P).

Figure 9 shows a detailed schematic three-dimensional view from below of the upper clamping unit (500) including a holding structure (501) supporting and moving said anchoring elements (510).

Inside said structure (501) there are guides (502) oriented in said direction Y to allow the translation of said anchoring elements (510) in said direction Y.

Figure 10 shows a schematic sectional view of a detail of the end (511) of one of said anchoring elements (510). Said end (511) comprises an axial opening (512) housing a gripping element (513) that can be moved and translated in the vertical direction Z. Said gripping element (513) is configured to be engaged with a corresponding coupling pawl (514) mounted in a centering ring (515) made integral with the workpiece (P) to be machined, for example by means of a fixing screw (519).

Said coupling system makes it possible to grip and lock the workpiece (P) without applying pressure in the vertical direction to the latter, as occurs, instead, in the currently known systems.

The clamping unit (500) made as described thus makes it possible to adjust and maintain the correct vertical position of the workpiece (P), without applying pressure and thus without causing unwanted misalignments of the workpiece with respect to the perfectly vertical position.

Figure 11 shows a schematic sectional view of the clamping system (516) for locking the anchoring elements (510). According to the invention, said clamping system (516) can for example be of the type with mechanical jaws (517), for example suited to be translated vertically by means of a hydraulic system (518) on conical surfaces (519) which determine the gripping action on the anchoring element (510).

Figure 12 schematically shows how the clamping system (516') can alternatively be of the hydraulic type and comprise: a clamping sleeve (517') fitted on said anchoring element (510) and moved by means of a hydraulic circuit (518').

What has been described above with reference to the upper clamping unit (500) can be repeated identically for said lateral clamping unit (520). Also in this case, said anchoring pins or elements (523) are configured at their ends as said anchoring element (510) shown in Figure 10 and can be locked by means of a clamping system (516, 516') as shown in Figure 11 or Figure 12.

Figure 1 shows the new machine (100), in which a new type of drilling device (900) is installed.

The drilling unit (1) comprises a removable drilling device (900) with no limitations in terms of inclination, that is, a drilling device (900) which can be automatically removed and remounted on a machine, for example but not exclusively a milling machine, and which can drill deep holes with inclinations of ±90° in both the Y-axis and the Z-axis with respect to the plane orthogonal to the tool axis, which coincides with direction X. More specifically, the drilling unit (1) comprises a first drilling body or head (910) and a second body or casing (901) in which the operating devices are mounted, for example a tool rotation motor, a bit feeding motor, bit guides. These devices can also be removable for the automatic bit change.

Said first body or head (910) is mounted on the corresponding sliding element (40), which in turn is mounted on the upright (30). Said head (910) can rotate with respect to the sliding element (40) around a first axis A whose direction is parallel to direction X. Said second body or casing (901) can rotate with respect to the head (910) around a second axis B whose direction is orthogonal to said first axis A.

Said head (910) is preferably configured as a fork, with two substantially parallel arms (911) between which said casing (901) is hinged, in such a way that the rotation axis A of said first body (910) lies on a plane orthogonal to the plane on which the rotation axis B of said casing (901) lies.

Thanks to said solution, the drilling device (900), which actually consists of two independent bodies (910, 901) that can rotate with respect to each other and with respect to the sliding element (40), can thus be oriented over 360° with respect to the vertical YZ-plane of the machine. Thanks to the new drilling unit (1), it is therefore possible to machine 4/5 faces of a workpiece without changing its position and without incurring problems related to inclinations that cannot be obtained.

The rotation of the two bodies (910, 901) can be transmitted by mechanical transmission and/or by transmission with electric and electromagnetic motors and/or other devices and methods.

For example, encoders suited to periodically detect the position of the two bodies (910, 901) can be used. The position is transmitted to the CNC of the machine, which manages the movement of the bodies (910, 901) themselves.

Therefore, with reference to the above description and the attached tables, the following claims are made.