Multi-axis machining center provided with a mechanized tool magazine

Abstract

The present application relates to a multi-axis machining center provided with a mechanized tool magazine. The machining center comprises two independent carriages supported by two parallel horizontal rails fixed in raised position to a support structure so that they can slide along respective longitudinal translation axes. The carriages support respective machining heads movable along two corresponding translation axes. The machining heads support respective tool holding spindles arranged with a vertical axis. At least one workpiece holding table is supported at a base of the support structure in a manner rotatable about a first horizontal and transversal rotation axis and about a second rotation axis vertical to the first rotation axis. Two mechanized tool magazines are supported at opposite longitudinal ends of the support structure and are usable by the spindles.

Description

Technical Field

[0001] This invention relates to a multi-axis machining center equipped with a mechanized tool library. Background Technology

[0002] It is known that multi-axis machining centers typically include a motorized tool-holding spindle mounted on a machining head, which can move relative to the workpiece along two or more axes, thereby subjecting the workpiece to different successive machining processes, such as milling, boring, tapping, etc.

[0003] The spindle can be arranged with its axis horizontal or vertical.

[0004] It is also known that a mechanized toolmagazine is provided for the above-mentioned type of machining center, from which the spindle automatically picks up the tools to be used in various machining steps by taking advantage of the mobility in the machining head space.

[0005] Known types of tool libraries, particularly appreciated for their reliability, include motorized tool holding drums. When the spindle has a horizontal axis, the tool holding drum can be arranged so that its horizontal axis faces the spindle and is perpendicular to the spindle's axis, in order to provide the tool to be picked up to the spindle.

[0006] To improve productivity, machining centers can also be equipped with multiple parallel spindles mounted on a single machining head to process multiple workpieces simultaneously.

[0007] Although the aforementioned types of machining centers are highly appreciated for both their machining accuracy and productivity, as they are capable of performing multiple machining operations on a workpiece in a single positioning, their limitation lies in their suitability primarily for machining small to medium-sized workpieces, such as mechanical parts for the automotive industry or other industrial sectors.

[0008] Larger workpieces, such as parts of a vehicle chassis or body, can now undergo continuous machining processes on different machine tools, resulting in a sharp decline in both productivity and machining accuracy, as the workpiece must be repositioned each time it is transferred from one machine tool to the next.

[0009] So-called "multitasking" machines are known to perform different machining processes on large workpieces, but they are also limited in terms of productivity because they are equipped with a single spindle that can move relative to multiple axes (e.g., five axes).

[0010] Furthermore, known multitasking machines, despite using a single spindle, are very bulky and therefore difficult to place in production facilities. Summary of the Invention

[0011] The object of the present invention is to provide a multi-axis machining center with a mechanized tool library, which is capable of machining large workpieces, such as chassis or body parts of vehicles, while having substantially the same machining versatility and size as machining centers designed to machine small and medium-sized workpieces.

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

[0013] This purpose and objective, as well as other objectives, which become more apparent from the following description, are achieved by a processing center having the features described in claim 1, while the dependent claims define other advantageous (though minor) features of the invention. Attached Figure Description

[0014] The invention will now be described in more detail with reference to some preferred but non-exclusive embodiments thereof, which are illustrated by way of non-limiting example in the accompanying drawings, wherein:

[0015] Figure 1 This is a schematic plan view of the machining center according to the present invention;

[0016] Figure 2 yes Figure 1 A schematic side view of the machining center. Detailed Implementation

[0017] refer to Figure 1 and Figure 2 The machining center 10 according to the invention includes a support structure 12, which has a box-shaped profile in the illustrated schematic embodiment and defines a work area MA in the support structure.

[0018] Two independent carriages 14′ and 14″ are slidably supported by a pair of parallel horizontal rails 16a and 16b, which are fixed to the raised position of the support structure 12, preferably at the upper end, and extend in the longitudinal direction.

[0019] Therefore, each of the two carriages 14′ and 14″ can slide along its respective longitudinal translation axis X′ and X″.

[0020] Each of the two carriages 14′ and 14″ supports a corresponding slider 18′ and 18″, which can slide along the corresponding horizontal guides 20′ and 20″. The horizontal guides 20′ and 20″ are integral with the carriages 14′ and 14″ and extend along the corresponding lateral translation axes Y′ and Y″.

[0021] Each slider 18′, 18″ supports its respective processing head 22′, 22″, which in turn is slidably supported on its respective vertical guide 24′, 24″. The vertical guide 24′, 24″ is integral with the slider 18′, 18″ and extends along its respective vertical translation axis Z′, Z″.

[0022] Specifically, the machining heads 22′ and 22″ support the spindles 28′ and 28″ at their lower ends, and the spindles 28′ and 28″ are arranged such that their axes are vertical.

[0023] The 28′ and 28″ spindles can be equipped with different types of tools for machining processes such as milling, boring, and tapping.

[0024] According to a preferred embodiment of the invention, the support structure 12 has a base including at least one groove leading to the chip removal area, and advantageously, the base includes two longitudinally opposing grooves 30′, 30″ leading to the central chip removal area 32.

[0025] The base supports at least one workpiece holding table, and advantageously supports two workpiece holding tables 34′ and 34″, which are in a longitudinally mirror position and preferably arranged along the centerline axis of the machining center 10.

[0026] Each workpiece holding stage 34′, 34″ is supported by rotating workpiece holding rollers 35′, 35″, whose horizontal axes Yr′, Yr″ extend in a horizontal and transverse direction. Furthermore, the workpiece holding stages 34′, 34″ are supported by corresponding workpiece holding rollers 35′, 35″, allowing them to rotate about their own axes of rotation Hr′, Hr″, which are perpendicular to the axes of rotation of the workpiece holding rollers 35′, 35″.

[0027] In a manner known per se, the two workpieces W′ and W″ being processed can be fixed to their respective workpiece holding platforms 34′ and 34″ by their respective workpiece holding and fixing devices E′ and E″.

[0028] The machining center 10 is provided with two mechanized tool libraries 36′ and 36″, which are arranged at opposite longitudinal ends of the support structure 12 so that they can be used by the two spindles 28′ and 28″ respectively.

[0029] In this embodiment, each of the two tool magazines 36′, 36″ includes rotating tool holding rollers 38′, 38″ that peripherally support a plurality of tools 40′, 40″. The rotating tool holding rollers 38′, 38″ are arranged such that their axes are horizontal and parallel to the lateral translation axes Y′, Y″. In each tool magazine 36′, 36″, tools 40′, 40″ are arranged on two angled rows of the corresponding tool holding rollers 38′, 38″, the rows extending parallel to the axes of the corresponding tool holding rollers 38′, 38″.

[0030] Spindles 28′ and 28″ utilize the mobility within the space of their respective machining heads 22′ and 22″ to automatically pick up tools 40′ and 40″ from their respective mechanized tool libraries 36′ and 36″ for use in various machining steps. Depending on the arrangement of the tools on the tool holding rollers 38′ and 38″, the rollers are rotated to provide one row or another row of tools to the corresponding spindle 28′ and 28″.

[0031] Advantageously, each of the tool magazines 36', 36″ is provided with a protective cover 42', 42″, which in this embodiment is fixed to the corresponding tool holding rollers 38', 38″. During machining, the tool holding rollers 38', 38″ rotate to guide the corresponding protective cover 42', 42″ to the work area MA, thereby concealing the corresponding tool magazines 36', 36″ and protecting them from machining debris.

[0032] In an alternative embodiment, the shield can move independently of the respective rollers.

[0033] Of course, all the aforementioned movable parts of the machining center are motorized by conventional types of actuation systems, such as electric actuators, hydraulic actuators and / or pneumatic actuators, which are controlled by a control unit (not shown) in a manner conventional in the art.

[0034] The hydraulic / electric control unit 44 (shown schematically only in dashed lines in the figure) is selectively arranged at one of the two longitudinal ends of the support structure 12 in a spaced-out position to form an operator access passage to the tool magazine.

[0035] Naturally, the support structure 12 may be provided with inspection doors or windows (not shown) on one or more sides, in a manner that is conventional in the art.

[0036] During operation, workpieces W′ and W″ are fixed on the corresponding workpiece holding platforms 34′ and 34″ by the corresponding fixing devices E′ and E″.

[0037] Since carriages 14′ and 14″ share the same tracks 16a and 16b, each workpiece can be machined simultaneously by the two spindles 28′ and 28″, or completely independent spindles 28′ and 28″ can work on their respective workpieces, providing much greater versatility than known solutions.

[0038] During the machining process, the protective covers 42′ and 42″ protect the tool magazines 36′ and 36″ from the influence of machining debris, so the machining debris falls into the chip removal area 32 through the chute 30′ and 30″.

[0039] Spindles 28′ and 28″ can move along three Cartesian axes. Two additional degrees of freedom are provided by the rotation of workpiece holding tables 34′ and 34″ about their own axes and about the axes of the corresponding workpiece holding rollers, so that any workpiece with a single position can be machined in virtually any orientation and on any side pointing toward the work area MA.

[0040] 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 translation in the longitudinal direction. In this way, each of the two spindles 28′, 28″ can “intrude” into the half of the work area occupied by the other spindle in the longitudinal direction, thereby providing high versatility.

[0041] Some preferred embodiments of the invention have been described, but those skilled in the art will of course provide various modifications and variations within the scope of the claims.

[0042] For example, each carriage can support two sliding elements, and each sliding element can support two or more spindles for simultaneously machining multiple relatively small workpieces mounted on a workpiece holding table. In fact, although the machining centers described and illustrated herein have been envisioned for machining large workpieces, such as chassis or body parts in the automotive, aerospace, and marine industries, it has been found in practice that the same principles can be applied to machining centers for machining small and medium-sized workpieces, yielding numerous advantages.

[0043] Guide devices that allow various movable elements of a machining center to translate or rotate can be provided using technologies commonly used in industry, which are well known to those skilled in the art, such as rotary supports or sliding supports using rolling bearings, low-friction slides, etc.

[0044] While the aforementioned types of toolkits are particularly appreciated for their reliability, one or two toolkits can certainly be of different types, such as chain-based toolkits.

Claims

1. A machining center, characterized in that, The machining center includes two independent carriages (14′, 14″), each supported by a pair of parallel horizontal rails (16a, 16b) allowing them to slide along corresponding longitudinal translation axes (X′, X″). The pair of parallel horizontal rails (16a, 16b) extend longitudinally and are fixed to a support structure (12) in an elevated position. Each carriage (14′, 14″) supports a corresponding machining head (22′, 22″), which can be guided along corresponding transverse directions by corresponding guides (18′, 18″, 20′, 20″, 24′, 24″). The machining center (10) moves along translation axes (Y′, Y″) and along corresponding vertical translation axes (Z′, Z″), each of the machining heads (22′, 22″) supporting a corresponding tool-holding spindle (28′, 28″) arranged along a vertical axis. The machining center (10) also includes at least one workpiece holding table (34′, 34″) and two mechanized tool magazines (36′, 36″). The workpiece holding tables (34′, 34″) are supported at the base of the support structure (12) in a manner rotatable about a first rotation axis (Yr′, Yr″) and a second rotation axis (Hr′, Hr″). (Yr′, Yr″) extend horizontally and laterally, and the second axis of rotation (Hr′, Hr″) is perpendicular to the first axis of rotation (Yr′, Yr″). The two mechanized tool libraries (36′, 36″) are supported at opposite longitudinal ends of the support structure (12) so that they can be used by each of the main shafts (28′, 28″). For each of the carriages (14, 14″), the guide device includes a slider (18′, 18″) that is slidable along a corresponding horizontal guide (20′, 20″). The slides (14′, 14″) are integral with each other and extend in the lateral direction. For each of the slides (18′, 18″), the vertical guide (24′, 24″) is integral with the slides (18′, 18″) and slidably engaged by a corresponding one of the processing heads (22′, 22″). Each of the tool magazines (36′, 36″) includes a rotating tool holding roller (38′, 38″) arranged such that its axis is horizontal and lateral, and supports a plurality of tools (40′, 40″) around its perimeter.

2. The machining center (10) according to claim 1, characterized in that, The machining center includes two workpiece holding tables (34′, 34″) in a longitudinally mirror position.

3. The machining center (10) according to claim 1 or 2, characterized in that, The at least one workpiece holding table (34′, 34″) is arranged along the centerline axis of the machining center (10).

4. The machining center (10) according to claim 1 or 2, characterized in that, The base includes at least one groove (30′, 30″) leading to the chip removal area (32).

5. The machining center (10) according to claim 4, characterized in that, The base includes two longitudinally opposing grooves (30′, 30″) that lead to the central chip removal area (32).

6. The machining center (10) according to claim 1, characterized in that, Each of the tool magazines (36′, 36″) is provided with a protective cover (42′, 42″) adapted to protect the corresponding tool magazine (36′, 36″) from machining debris during the machining process.

7. The machining center (10) according to claim 6, characterized in that, The protective covers (42′, 42″) are fixed to the corresponding rotating tool retaining rollers (38′, 38″).

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