Multi-axis machining center with tool magazine

Abstract

The machining center includes two independent carriages (14', 14"), which are slidably supported along respective longitudinal translation axes (X', X") by a pair of parallel horizontal rails (16a, 16b) extending along the longitudinal direction and fixed at an elevated position to a support structure (12). Each of the carriages (14', 14") supports a machining head (22', 22") movable along a lateral translation axis (Y', Y") and a vertical translation axis (Z', Z") by guide means (18', 18", 20', 20", 24', 24"). Each of the machining heads (22', 22") supports a tool-holding spindle (28', 28") rotatably about a horizontal rotation axis (Yr', Yr") by rotation support means (26', 26"). A work-holding table (34) is supported at a base (30', 30") of the support structure (12) and is rotatable about a first rotation axis (Xr) extending in the horizontal, longitudinal direction. Two mechanized tool magazines (36', 36") are located at opposite longitudinal ends of the support structure (12) and are accessible by the spindles (28', 28").

Description

[Technical Field]

[0001] The present invention relates to a multi-axis machining center with a mechanized tool magazine. [Background technology]

[0002] As is known, a multi-axis machining center generally comprises a power tool-holding spindle attached to a machining head that is movable along two or more axes relative to a workpiece, allowing the workpiece to undergo different machining operations, such as milling, boring, and tapping, in succession.

[0003] The axis of the spindle may be arranged horizontally or vertically.

[0004] It is also known to provide machining centers of the above type with a mechanized tool magazine from which the spindle, taking advantage of the spatial mobility of the machining head, automatically picks up the tools used in the various machining steps.

[0005] A known type of tool magazine comprises a power tool holding drum, which is particularly appreciated for its reliability. In the case of a spindle with a horizontal axis, the tool holding drum is positioned in front of the spindle with its axis horizontal and perpendicular to the axis of the spindle, and presents the tools to be picked up to the spindle.

[0006] To increase productivity, machining centers may be equipped with multiple parallel spindles attached to a single machining head for machining multiple workpieces simultaneously.

[0007] The above types of machining centers are highly regarded for their machining precision and productivity, as they can perform multiple machining operations on a workpiece with a single positioning operation. However, they have limitations in that they are not particularly suitable for small to medium-sized workpieces, such as small machine parts used in the automotive and industrial fields.

[0008] Currently, large workpieces, such as vehicle chassis or body parts, are machined successively with different machining tools, and the workpiece must be repositioned each time it is transferred from one machining tool to the next, resulting in a significant decrease in productivity and machining accuracy.

[0009] So-called multitasking machines are known, which are capable of performing different machining processes on large workpieces, but which have a single spindle that can move along multiple axes, e.g., five axes, and are therefore limited in terms of productivity.

[0010] Furthermore, known multi-task machines, despite using a single spindle, are quite bulky and difficult to install within a production facility. Summary of the Invention

[0011] Therefore, an object of the present invention is to provide a multi-axis machining center with a mechanized tool magazine that can machine large workpieces such as vehicle chassis or body parts, while having the same machining versatility and size as a machining center designed for small to medium-sized workpieces.

[0012] Within this objective, the present invention aims to provide a multi-axis machining center that has a significantly higher productivity than currently known multi-tasking machines for machining large workpieces.

[0013] This object, as well as other objects that will become more apparent from the following description, is achieved by a machining centre according to claim 1, the dependent claims defining further advantageous features of the invention.

[0014] The invention will now be described in more detail with reference to some preferred, but not exclusive, embodiments thereof, illustrated by way of non-limiting examples in the accompanying drawings, in which: [Brief explanation of the drawings]

[0015] [Figure 1]1 is a schematic plan view of a machining center according to the present invention; [Figure 2] 2 is a schematic side view of the machining center of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0016] Referring to the drawings, a machining center 10 according to the present invention comprises a support structure 12. In the illustrated schematic embodiment, the support structure 12 has a box-like outer shape in which a working area MA is defined.

[0017] The two independent carriages 14', 14" are slidably supported by a pair of parallel horizontal rails 16a, 16b. The horizontal rails 16a, 16b are fixed to the support structure 12 in a raised position, preferably at the upper end, and extend longitudinally.

[0018] Each of the two carriages 14', 14'' is therefore slidable along a respective longitudinal translation axis X', X''.

[0019] Each of the two carriages 14', 14" supports a slider 18', 18", respectively, which is slidable along a horizontal guide 20', 20", respectively. The horizontal guides 20', 20", respectively, are integral with the carriages 14', 14", and extend along lateral translation axes Y', Y", respectively.

[0020] Each of the sliders 18', 18" supports a processing head 22', 22", respectively. The processing heads 22', 22" are slidably supported on vertical guides 24', 24", respectively. The vertical guides 24', 24" are integral with the sliders 18', 18", and extend along vertical translation axes Z', Z", respectively.

[0021] In particular, the machining heads 22', 22" are provided at their lower ends with fork-shaped supports 26', 26" (FIG. 2). The supports 26', 26" support tool-holding spindles 28', 28" which are rotatable about horizontal rotation axes Yr', Yr". Preferably, the fork-shaped supports 28', 28" are rotatable about vertical rotation axes Zr', Zr" which are parallel to or coincident with the respective vertical translation axes Z', Z".

[0022] The spindles 28', 28'' can be fitted with different types of tools for machining operations such as milling, boring, tapping, etc.

[0023] According to a preferred embodiment of the present invention, the support structure 12 has a base with at least one chute, advantageously two chutes 30', 30", leading to a chip discharge area. These two chutes 30', 30" are longitudinally opposite each other and lead to a central chip discharge area 32.

[0024] The bases 30′, 30″ support a rotary tool holding drum 35. The rotary tool holding drum 35 has a rotation axis Xr extending horizontally and vertically. A workpiece holding table 34 is supported on the workpiece holding drum 35. Preferably, the workpiece holding table 34 is rotatable about its own rotation axis Hr, which is perpendicular to the rotation axis of the workpiece holding drum 35.

[0025] In this embodiment, the workholding table 34 is advantageously positioned in a longitudinally centered but laterally offset position (i.e., the axis of the workholding drum 35 is laterally offset relative to the centerline of the machining center), for purposes that will be clarified in more detail later.

[0026] In a manner known per se, a workpiece W (shown diagrammatically in broken lines) to be machined can be fixed to the workpiece-holding table 34 by means of a workpiece-holding fixture E (shown diagrammatically in broken lines).

[0027] The machining center 10 is provided with two mechanized tool magazines 36', 36". The tool magazines 26', 26" are located at opposite longitudinal ends of the support structure 12 so as to be accessible by two spindles 28', 28", respectively.

[0028] In this embodiment, the two tool magazines 36', 36" comprise rotating tool holding drums 38', 38" that circumferentially support a plurality of tools 40', 40". The rotating tool holding drums 38', 38" are arranged so that their axes are horizontal and parallel to the lateral translation axes Y', Y". Within each of the tool magazines 36', 36", the tools 40', 40" are arranged in one row, or two rows, or multiple angularly spaced rows of the respective tool holding drums 38', 38". Such rows extend parallel to the axes of the respective tool holding drums 38', 38".

[0029] The spindles 28', 28" utilize their mobility within the space of their respective machining heads 22', 22" to automatically pick up tools 40', 40" to be used in various machining operations from the mechanized tool magazines 36', 36". Depending on where the tools are located on the tool-holding drums 38', 38", the drums are rotated to present one row or another of tools to the respective spindles 28', 28".

[0030] Advantageously, the tool magazines 36', 36" are provided with shields 42', 42". In this embodiment, the shields 42', 42" are fixed to the tool holding drums 38', 38", respectively. During machining, the tool holding drums 38', 38" are rotated so that the shields 42', 42", respectively, face the working area MA, thereby hiding the tool magazines 36', 36", respectively, and protecting them from machining chips.

[0031] In an alternative embodiment, the shield may be movable independently of each of the drums.

[0032] Of course, all of the above-mentioned moving parts of the machining center are motorized by conventional drive systems, such as electric, hydraulic and / or pneumatic actuators, influenced by a control unit (not shown) in a manner customary in the art.

[0033] An electrical / fluid control unit 44 (shown diagrammatically in dashed lines) is selectively positioned at one of the longitudinal ends of the support structure 12 .

[0034] Naturally, the support structure 12 may be provided with inspection doors and windows (not shown) on one or more sides, in a manner per se conventional in the art.

[0035] In operation, the workpiece W to be machined is secured to the rotary table 34 by a fixture E.

[0036] The workpiece W may be machined simultaneously by both spindles 28', 28'', which allows increasing productivity, possibly even doubling it with respect to known solutions.

[0037] For example, spindles 28', 28" may perform the same operation on two opposite sides of workpiece W, or may perform completely independent and different operations by retrieving different types of tools from tool magazines 36', 36", respectively.

[0038] During machining, the shields 42', 42" protect the tool magazines 36', 36" from machining chips, which fall into the chip collection area 32 via the chutes 30', 30".

[0039] The spindles 28', 28" are movable along three Cartesian axes and are further rotatable about lateral and vertical rotation axes Yr', Yr" and Zr', Zr" respectively. Additional degrees of freedom are provided by the rotation of the workholding table 34 about its own axis and about the axis of the workholding drum 35. Any large workpiece can be machined in virtually any direction and on any side and presented to the working area MA in a single positioning operation.

[0040] In an alternative embodiment, the fork-shaped supports 26', 26" may not be rotatable about the vertical rotation axes Zr', Zr".

[0041] The workpiece holding table 34 may be attached so as to be fixed to the workpiece holding drum 35, rather than being rotatable around the axis Hr.

[0042] As will be appreciated by those skilled in the art, one advantage of the present invention is that the two carriages 14', 14" share the same tracks 16a, 16b for longitudinal translation. In this manner, each of the two spindles 28', 28" can longitudinally "trespass" half of the working area occupied by the other spindle, providing great versatility.

[0043] In this preferred embodiment, the laterally offset position of the rotary table allows the spindles 28', 28" to machine even larger workpieces (approximately twice the size) than the effective stroke of the horizontal guides 20', 20" (horizontal axes Y', Y").

[0044] Although several preferred embodiments of the present invention have been described, it will be appreciated by those skilled in the art that various modifications and variations can be applied within the scope of the claims.

[0045] For example, the workpiece-holding drum 35 may support two workpiece-holding tables, and the two spindles 28', 28" may simultaneously machine two smaller workpieces mounted on each of the workpiece-holding tables. Although the machining center described and illustrated herein is devised for machining larger workpieces, such as chassis or body parts in the automotive, aeronautical, marine, etc. industries, it has been observed that the same principles can in fact be applied to machining centers for machining small and medium-sized workpieces, with certain advantages being achieved.

[0046] Furthermore, it should be understood that the laterally offset position of the workholding table, while advantageous, is not a required feature of the present invention.

[0047] Guiding means allowing the translation or rotation of the various moving elements of the machining center may be provided by techniques well known to those skilled in the art and commonly used in the field, such as rotating or sliding supports, e.g., rolling bearings, low-friction sliders, etc.

[0048] The fork-shaped supports 26', 26" which rotatably support the spindles 28', 28" may of course be replaced by a rotary support means of a different shape, for example a rotary support with a single arm instead of two parallel arms as in the case of a fork.

[0049] Although the above-mentioned type of tool magazine is highly rated for its reliability, one or both tool magazines may of course be of a different type, such as a chain-type tool magazine.

[0050] Finally, the functional order of the translation / rotation axes may, of course, be altered or reversed relative to that described and illustrated.

[0051] The disclosures in Italian Patent Application No. 102021000015131, from which this application claims priority, are incorporated herein by reference.

[0052] Where a reference sign is placed after a technical feature referred to in any claim, the reference sign is included solely for the purpose of improving the clarity of the claim, and therefore, such a reference sign does not have a limiting effect on the interpretation of each element illustrated by such a reference sign.

Claims

1. A machining center with two independent carriages (14', 14"), Both of said carriages are slidably supported along respective longitudinal translation axes (X', X") by a pair of parallel horizontal rails (16a, 16b); The horizontal rail extends along the longitudinal direction and is fixed at an upper position of the support structure (12); each of said carriages (14', 14") supports a respective machining head (22', 22"); the machining head is movable along lateral translation axes (Y', Y") and vertical translation axes (Z', Z") inside the pair of horizontal rails (16a, 16b) by respective guide means (18', 18", 20', 20", 24', 24"), Each of the machining heads (22', 22") supports a tool-holding spindle (28', 28") rotatably about a horizontal rotation axis (Yr', Yr") by means of a rotation support means (26', 26"); The machining center (10) further comprises a workpiece holding table (34) and two mechanized tool magazines (36', 36"); The workpiece holding table is supported on a base (30′, 30″) of the support structure (12) and is rotatable about a first rotation axis (Xr) extending in a horizontal longitudinal direction; The two mechanized tool magazines are supported at opposite longitudinal ends of the support structure (12) so as to be accessible to each of the tool holding spindles (28', 28"). Machining center.

2. A machining center with two independent carriages (14', 14"), Both of said carriages are slidably supported along respective longitudinal translation axes (X', X") by a pair of parallel horizontal rails (16a, 16b); The horizontal rail extends along the longitudinal direction and is fixed at an upper position of the support structure (12); The support structure (12) has a box-like outer shape in which a working area (MA) is defined, each of said carriages (14', 14") supports a respective machining head (22', 22"); the machining heads are movable along respective lateral translation axes (Y', Y") and respective vertical translation axes (Z', Z") by respective guide means (18', 18", 20', 20", 24', 24"), Each of the machining heads (22', 22") supports a tool-holding spindle (28', 28") rotatably about a horizontal rotation axis (Yr', Yr") by means of a rotation support means (26', 26"); The machining center (10) further comprises a workpiece holding table (34) and two mechanized tool magazines (36', 36"); The workpiece holding table is supported on a base (30′, 30″) of the support structure (12) and is rotatable about a first rotation axis (Xr) extending in a horizontal longitudinal direction; the two mechanized tool magazines are supported at opposite longitudinal ends of the support structure (12) so as to be accessible to each of the tool holding spindles (28', 28"); The workpiece holding table (34) is positioned at a longitudinally centered and laterally offset position. Machining center (10).

3. the guiding means comprising, for each of the carriages (14', 14"), a slider (18', 18") that is integral with the carriage (14', 14") and is slidable along a horizontal guide (20', 20") extending laterally, and, for each of the sliders (18', 18"), a vertical guide (24', 24") that is integral with the slider (18', 18") and is slidably engaged by one of the machining heads (22', 22"); 3. A machining center (10) according to claim 1 or 2.

4. The rotary support means comprises fork-shaped supports (26', 26"); A machining center (10) according to any one of claims 1 to 3.

5. The base of the support structure (12) is provided with at least one chute (30', 30") leading into a chip discharge area (32). A machining center (10) according to any one of claims 1 to 4.

6. The base is provided with two longitudinally opposed chutes (30', 30") which lead into a central chip discharge area (32).

6. A machining center (10) according to claim 5.

7. At least one of the tool magazines (36', 36") includes a rotary tool holding drum (38', 38"), the rotary tool holding drum being arranged with its axis horizontal and lateral and circumferentially supporting a plurality of tools (40', 40"). A machining center (10) according to any one of claims 1 to 6.

8. Each of the tool magazines (36', 36") is provided with a shield (42', 42") configured to protect the respective tool magazine (36', 36") from machining chips during machining.

8. A machining center (10) according to claim 7.

9. The shields (42', 42") are fixed to the rotary tool holding drums (38', 38"), respectively.

9. A machining center (10) according to claim 8.

10. each of said rotary support means (26', 26") is rotatable about a vertical rotation axis (Zr', Zr") parallel to or coinciding with said vertical translation axis (Z', Z"); A machining center (10) according to any one of claims 1 to 9.

11. The workpiece holding table (34) is supported rotatably around a second rotation axis (Hr) perpendicular to the first rotation axis (Xr). A machining center (10) according to any one of claims 1 to 10.

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