CNC machining center

Abstract

A CNC machining center is described, for machining a workpiece using a tool, comprising or consisting of a supporting frame, a vertical workpiece-holding member and a machine tool that is provided with at least one tool and movable with respect to the frame, within a maneuvering space contained in said empty space, along three mutually orthogonal axes so as to bring the tool into contact with the workpiece.

Description

[0001] CNC MACHINING CENTER

[0002] The present invention relates to a CNC machining center.

[0003] CNC machining centers are well-known for the processing of workpieces. There are those - very complex and expensive - with several work stations, each of which can accommodate a workpiece. The workpiece is advanced gradually, so that the workpieces pass sequentially through the work stations until they are completely machined. Or there are CNC machining centers with a single workpiece-holding member, wherein for example the workpiece is machined on various sides. To reach the various points of the workpiece with the tool, it is necessary to mount the tool on an articulated robot, which is cumbersome and very expensive.

[0004] The main object of the invention is to improve the current state of the art.

[0005] These and other objects are achieved by what is reported in the attached claims; and advantageous technical features are defined in the dependent claims.

[0006] A CNC machining center is proposed, for processing a workpiece by means of a tool, comprising or consisting of:

[0007] • a supporting frame,

[0008] • a vertical workpiece-holding member that extends mainly along a longitudinal axis to have elongated shape and major dimension along such longitudinal axis, is mounted on the frame with the longitudinal axis vertical, and is configured for

[0009] - blocking the workpiece on itself,

[0010] - suspending the workpiece thus blocked inside the frame with an empty space surrounding the workpiece, and

[0011] - rotating about a vertical axis, coinciding or not with its longitudinal axis, relative to the frame for rotating the workpiece with respect to the frame,

[0012] • a machine tool.

[0013] Here, and in the following, the machine tool is defined as

[0014] - equipped with at least one tool, and

[0015] - movable with respect to the frame, within a maneuvering space contained in said empty space, along three orthogonal axes so as to bring the tool into contact with the workpiece.

[0016] This construction allows efficient machining of the workpiece despite the relative complexity of the machine. Even by reducing the complexity of the movements, excellent efficiency is achieved, and the machine tool can be movable with respect to the frame even only along said three axes.

[0017] To reduce cycle time, the machining center may also integrate more than one machine tool.

[0018] In a preferred variant, the frame comprises one or more parallel linear vertical columns on which one or more machine tools are mounted linearly movable.

[0019] In a first preferred variant, the frame comprises: two pairs of parallel linear vertical columns, on each pair at least one machine tool being mounted linearly movable; or a single pair of linear vertical columns, on the single pair at least two machine tools being mounted linearly movable.

[0020] In this variant, preferably the machine tools are at least two and up to four, a number that experimentally has given the best efficiency / complexity ratio. In the case of two pairs of columns, the machine tools are distributed uniformly among the columns.

[0021] More preferably, the machine tools are mounted on the respective pair of parallel linear vertical columns by respective skids which are slidably connected to such column, and aligned with respect to each other, so that one machine tool cannot overtake the other along the linear vertical column (but the construction is still economical and above all efficient).

[0022] In particular, each pair of vertical columns supports two or more horizontal arms which have the ends linearly movable along such pair of columns (vertically), one or more machine tools being mounted respectively on each of the horizontal arms.

[0023] More preferably, for compactness, the horizontal arms are slidably connected to the pair of vertical columns, and, for simplicity, even more preferably the arms are aligned with respect to each other, so that one horizontal arm cannot overtake the other along the pair of vertical columns (but the construction is still economical and above all efficient and compact).

[0024] Preferably, each machine tool is mounted on its respective horizontal arm so that it can move relative to the horizontal arm along two horizontal and mutually orthogonal axes.

[0025] In another preferred variant, structurally simpler, the frame comprises a single vertical column on which one or each of the machine tools, especially one or two, are mounted horizontally movable. Having only one column increases the maneuvering space for the machine tools.

[0026] In particular, on the single vertical column there is, or there are mounted, cantilevered one or two horizontal arms linearly movable along the column (vertically), on the only horizontal arm, or on each of the horizontal arms, at least one machine tool being mounted respectively. The cantilevered arms advantageously reduce the maneuvering space for the machine tools only slightly.

[0027] More preferably, for greater compactness without sacrificing machining efficiency, on the single vertical column there are mounted cantilevered two horizontal arms linearly movable along the column (vertically), with only one machine tool being mounted on each of the horizontal arms.

[0028] More preferably, the horizontal arms slidingly connected to the single vertical column are aligned with each other, so that one horizontal arm cannot overtake the other along the single vertical column (but the construction is still economical, and above all efficient and compact).

[0029] Preferably, each machine tool is mounted on its respective horizontal arm so that it can move with respect to the horizontal arm along two horizontal, mutually orthogonal axes.

[0030] In a preferred variant, which surprisingly turns out to be very efficient nonetheless, one or each machine tool comprises a spindle to drive the tool, wherein the spindle is integral with the displacement along the three axes allowed to the machine tool and has only such displacement as degrees of freedom (that is, the rotation axis of the spindle is movable only along said three axes and only as an effect of the displacement of the entire machine tool; except for the rotation that it imparts to the tool, the spindle is namely devoid of degrees of freedom with respect to the rest of the machine tool).

[0031] To optimize space and maximize maneuvering space, in a preferred variant the workpiece-holding member is placed on one side of the frame and the or each machine tool is placed on the opposite side of the frame, so as to delimit said maneuvering space between the workpiece-holding member and the or each machine tool.

[0032] To optimize space and maximize maneuvering space, in a preferred variant the workpiece-holding member is placed on one side of the frame and the or each vertical column is placed on the opposite side of the frame, so as to delimit said maneuvering space between the workpiece-holding member and the or each vertical column.

[0033] In a preferred variant, one or each of said horizontal arms comprises a horizontal section that extends cantilevered from the single or respective vertical column along a) a horizontal direction oriented towards the workpiece-holding member or b) a horizontal direction that is orthogonal to a horizontal direction oriented toward the workpiece-holding member, and the machine tool is mounted movable with respect to said section along a horizontal axis orthogonal to the longitudinal axis of said section and along a horizontal axis parallel to the longitudinal axis of said section.

[0034] In particular, one or each of said horizontal arms comprises a first linear section and a second linear section, both horizontal and orthogonal to each other, wherein one end of the first linear section is translatably connected to the single or respective vertical column and movably supports the second linear section, on which one of the machine tools is mounted respectively, and the first linear section

[0035] - is translatable vertically along the single or respective vertical column,

[0036] - has a horizontal longitudinal axis oriented towards the workpiece-holding member and

[0037] - comprises a guide for relatively moving the second linear section linearly along such longitudinal axis, and the second linear section

[0038] - is mounted on the guide of the first linear section, and

[0039] - comprises a guide on which one of the machine tools is mounted linearly translatable, which machine tool can translate in the direction of the length of the second linear section.

[0040] In a preferred variant, the frame comprises two horizontal, parallel guides on which the single or each pair of linear vertical columns is slidably mounted.

[0041] To minimize the number of drives without penalizing the machining efficiency, in a preferred variant the single vertical column is fixed with respect to the rest of the frame, and / or the rotation axis of the workpiece-holding member is fixed (immovable) with respect to the frame.

[0042] In a preferred variant, the frame comprises two horizontal parallel crosspieces on which two opposite ends of the workpiece-holding member are respectively mounted (rotatably), wherein said horizontal crosspieces are immovable with respect to the rest of the frame.

[0043] In a preferred variant the workpiece-holding member is composed of

[0044] - an elongated central body having two opposite ends, and

[0045] - two heads mounted on one of said ends respectively (and preferably the central body is rotatably mounted about a vertical axis with respect to the heads).

[0046] Or the central body is integral with the heads and the heads are rotatably mounted about a vertical axis with respect to said horizontal crosspieces.

[0047] In a preferred variant, the workpiece-holding member comprises means for gripping and holding the workpiece (e.g., clamps or suction cups or grippers or claws).

[0048] In a preferred variant, the frame is a box-shaped or parallelepiped framework.

[0049] In particular, the framework delimits within itself said maneuvering space and preferably the framework is composed of rigid beams which constitute support ribs.

[0050] In particular, the framework delimits a space within which the workpiece-holding member and each of the machine tools are installed, for compactness.

[0051] In particular, the framework delimits a space within which the workpiece-holding member and each of the vertical columns are installed.

[0052] In a preferred variant, the machining center comprises a protective casing to enclose the frame and said maneuvering space.

[0053] In a preferred variant, the machining center comprises a robot, e.g. anthropomorphic, configured and / or programmed to load and unload the workpiece from the workpieceholding member. In a preferred variant, the robot is placed outside the frame.

[0054] In a preferred variant, to speed up the machining operations the machining center comprises, for each machine tool, a tool storage unit for a rapid tool change, so as to allow different machining operations in sequence by taking the tool from the tool storage unit. Preferably the tool storage unit is mounted on one said vertical column, to minimize the tool change time by shortening the trajectory of the machine tool during the tool change.

[0055] The vertical columns, the machine tools and the workpiece-holding member are moved by corresponding drives.

[0056] Further advantages will become clear from the following description, which refers to an example of a preferred embodiment of a machine in which:

[0057] - figure 1 shows a diagram of a first variant of a machining center;

[0058] - Figure 2 shows a diagram of a second variant of the machining center.

[0059] - Figure 3 shows a diagram of a third variant of the machining center,

[0060] - Figure 4 shows a detailed embodiment of the third variant of the machining center.

[0061] Equal numbers in figures indicate equal or substantially equal parts; to avoid crowding the drawings, equal elements are sometimes not numbered.

[0062] The machining center 10 (fig. 1 ) comprises a box-shaped supporting frame 12 (shown in dotted lines), inside which a workpiece-holding member 20 and two machine tools 50, 70 are mounted.

[0063] The workpiece-holding member 20 is an elongated support, e.g. a table, provided with means 84 for blocking a workpiece P to be machined onto it. The workpiece-holding member 20 has a major dimension that extends along a longitudinal axis, and is mounted on the frame 12 so that it can rotate relative to the frame 12 about a vertical axis Y substantially coinciding with its own longitudinal axis. Thus the workpiece P blocked onto the workpiece-holding member 20 can not only be rotated relative to the frame 12 and the machine tools 50, 70, but can also remain suspended and blocked inside the frame 12 surrounded by an empty space, giving the tools 98 full access to the parts of the workpiece P.

[0064] The two machine tools 50, 70 are in fact equipped with at least one tool 98, to machine the workpiece P, and are movable with respect to the frame 12 within a maneuvering space provided between the workpiece-holding member 20 and two vertical columns 30 which are horizontally translatable (see arrow X1 ) on horizontal guides 32 of the frame 12. The machine tools 50, 70 are mounted on a respective horizontal arm 34 which is connected to the vertical columns 30 in a linearly movable manner vertically (parallel to the Y-axis, see direction Y1 ).

[0065] In turn, the machine tools 50, 70 are translatable linearly along the respective horizontal arm 34 (direction X2).

[0066] Fig. 2 shows a diagram of a second variant of machining center 100, with simplified mechanisms, which comprises a box-shaped supporting frame 12 (shown in dotted lines), inside which is mounted a workpiece-holding member 120 (analogous to the workpieceholding member 20) and two machine tools 150, 170 (analogous to the machine tools 50, 70).

[0067] The two machine tools 150, 170 are movable with respect to the frame 12 within a maneuvering space located between the workpiece-holding member 120 and a single vertical column 130 which is fixed with respect to the frame 12.

[0068] The machine tools 150, 170 are mounted on a respective horizontal arm 134 which is connected to the vertical column 130 in linearly translatable manner vertically (parallel to the Y-axis, see direction Y1 ).

[0069] In turn, the machine tools 150, 170 are linearly translatable along the respective horizontal arm 34 (direction X2) and also perpendicularly to the length of the arm 134 (direction X1 ).

[0070] Fig. 3 shows a machining center 300, variant for the machining center 200 as to the orientation of the arms on the vertical columns.

[0071] In the machining center 300 the machine tools 150, 170 are movable on a respective horizontal arm 334 connected in cantilevered manner to the vertical column 130 in a linearly translatable manner vertically (parallel to the Y-axis, see direction Y1 ).

[0072] This time the arms 334 comprise a first linear section 336 and a second linear section 338, both horizontal and orthogonal to each other.

[0073] One end of the first linear section 336 is connected translatably to the vertical column 130 and supports the second linear section 338, on which one of the machines 150, 170 is respectively mounted.

[0074] The first linear section 336 is vertically translatable along the vertical column 130 (direction Y1 ), has longitudinal axis horizontal and oriented towards the workpiece-holding member 120 and comprises a guide for relatively moving the second linear section 338 linearly along such longitudinal axis, i.e. away from and towards the workpiece-holding member 120 (direction X1 ).

[0075] The second linear section 338 comprises a guide on which one of the machines 150, 170 is mounted linearly translatable, which machines can then translate in the direction of the length of the second linear section 338, see direction X2.

[0076] Figure 4 shows in detail a machining center 400 that implements the scheme in Fig. 3.

[0077] Advantageously, the cooperation between the displacement along the X1 , X2, Y2 axes of the machine tools 50, 70 and 150, 170, and the rotation about the vertical Y axis of the workpiece-holding member 20, 120 allows the two tools 98 to easily and efficiently reach every part of the workpiece P.

[0078] Overall, the movements along the X1 , X2, Y2 axes allow the machine tools 50, 70 and 150, 170 to be moved along three orthogonal Cartesian axes. Since for simplicity it is preferred that the tool 98 be movable relative to the respective machine tool only by its rotation, also the tool 98 can move in the maneuvering space only along the X1 , X2 and Y2 axes.

[0079] In a preferred variant, the machining center 10, 100, 200, 300 comprises:

[0080] - a robot 200, e.g. anthropomorphic, configured and / or programmed to load and unload the workpiece P from the workpiece-holding member 20, 120. The robot 200 may be placed outside or inside the frame 12; and / or

[0081] - a tool storage unit 94 from which to quickly pick up tools for the machine tools 50, 70 and 150, 170.

[0082] In a preferred variant, the machining center 100, 200, 300 comprises one single arm 34, 134, 334 on which a machine tool 50, 70 or two is / are mounted.

[0083] In a preferred variant, the machine tools 50, 70, 150, 170 comprise a spindle 96 to drive the tool, wherein the spindle 96 is integral with the displacement along the three X1 , X2, X3 axes and has only such displacement as degrees of freedom. In each variant, preferably, for construction simplicity, the rotation axis Y may be fixed (immovable) with respect to the frame 12.

[0084] In a preferred variant, the workpiece-holding member 12, 120 is composed of an elongated central body 80, for supporting the workpiece P, having two opposite ends, and two heads 82 mounted on one of said ends respectively.

[0085] The central body 80 may be rotatably mounted about the Y-axis relative to the heads 82, or the central body 80 is integral with the heads 82 and the heads 82 are rotatably mounted about the Y-axis relative to horizontal crosspieces of the frame 12.

[0086] Preferably, for simplicity of construction, the pair of arms 34, 134 is movable within the same plane. Even if one arm 34, 134 cannot overtake the other, the efficiency of the machining center is not affected.

Claims

CLAIMS1. CNC machining center, for machining a workpiece using a tool, comprising or consisting of:• a suppo / rting frame,• a vertical workpiece-holding member which extends mainly along a longitudinal axis and has major dimension along such longitudinal axis, is mounted on the frame with the longitudinal axis set vertical, is configured for- blocking the workpiece on itself,- keeping the so blocked workpiece suspended inside the frame and surrounded by an empty space, and- rotating about a vertical axis, coinciding or not with its longitudinal axis, relatively to the frame to rotate the workpiece with respect to the frame,• a machine tool that is- provided with at least one tool, and- movable with respect to the frame, within a maneuvering space contained in said empty space, along three mutually orthogonal axes so as to bring the tool into contact with the workpiece.

2. Machining center according to claim 1 , wherein the frame comprises a single vertical column on which one or each of the machine tools, in particular only one or two, are mounted horizontally movable.

3. Machining center according to claim 2, wherein on the single vertical column there is, or are, mounted cantilevered one or two horizontal arms linearly movable along the column vertically, on the only horizontal arm, or on each of the horizontal arms, being mounted at least one machine tool respectively.

4. Machining center according to claim 3, wherein on the single vertical column there are mounted cantilevered two horizontal arms that are linearly movable along the column vertically, on each of the horizontal arms a single machine tool being mounted.

5. Machining center according to claim 3 or 4, wherein the horizontal arms are slidably connected to the single vertical column, and aligned with respect to each other, so that one horizontal arm cannot overtake the other along the single vertical column.

6. Machining center according to claim 3 or 4 or 5, wherein each machine tool is mounted on the respective horizontal arm so as to be able to move with respect to thathorizontal arm along two horizontal and orthogonal axes.

7. Machining center according to any preceding claim, wherein at least one or each machine tool comprises a spindle for operating the tool, wherein the spindle is integral with the displacement along the three axes allowed to the machine tool and has only such displacement as degree of freedom.

8. Machining center according to any claim from 2 to 7, wherein the workpieceholding member is placed on one side of the frame and the at least one or each machine tool is placed on the opposite side of the frame, so as to delimit said maneuvering space between the workpiece-holding member and each machine tool.

9. Machining center according to any claim 2 to 8, wherein the workpiece-holding member is placed on one side of the frame and the vertical column is placed on the opposite side of the frame, so as to delimit said maneuvering space between the workpiece-holding member and the vertical column.

10. Machining center according to any claim 3 to 9, wherein at least one or each of said horizontal arms comprises a horizontal section which extends cantilevered from the single or respective vertical column along a) a first horizontal direction oriented towards the workpiece-holding member or b) a second horizontal direction which is orthogonal to the first direction, and the machine tool is mounted movable with respect to said section along a horizontal axis orthogonal to the longitudinal axis of said section and along a horizontal axis parallel to the longitudinal axis of said section.

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