Machine tool

Abstract

A machine tool includes: a transverse sliding assembly; a bracket assembly configured to slide along a transverse guide member of the sliding assembly; a machining head support carrying a machining head assembly at its lower end and configured to slide parallel to a vertical axis via a vertical sliding member of the bracket assembly; and a workstation positioned below the sliding assembly. The bracket assembly includes a first bracket and a second bracket spaced apart from each other and separated by the machining head support. Each of the first and second brackets includes: a corresponding at least one transverse sliding member slidably associated with one of the transverse guide members of the sliding assembly; and a corresponding at least one vertical sliding member slidably associated with the machining head support.

Description

Technical Field

[0001] This utility model generally relates to a three-axis or multi-axis machine tool, and more specifically, to a CNC milling machine, which includes a sliding assembly, a bracket assembly configured to slide along the sliding assembly, and a machining head support (also referred to as a "ram"), which can slide vertically along the bracket assembly and carries a machining head assembly at its lower end. Background Technology

[0002] Three-axis machine tools (such as CNC milling machines) are designed to machine materials through controlled movements along three main axes: the X-axis (longitudinal direction), the Y-axis (lateral direction), and the Z-axis (vertical direction). (Reference) Figure 10-12 Known three-axis machine tools typically include a machining head L mounted on the lower end of a machining head support C (ram), which contains a pair of vertical guide members O. The machining head support C is driven by a motor M via a pinion-steering rack or ball screw and can slide parallel to the vertical axis along a so-called carriage R. The carriage R is typically a parallelepiped structure with a centrally narrowed hole H through which the machining head support C slides. The wall of the hole H in the carriage R is equipped with a vertical sliding member S, which is connected to the vertical guide members O of the machining head support C. The carriage R is also capable of moving parallel to the transverse axis along a slide member T. In some configurations of this type of machine tool, the slide member T is formed by a beam parallel to the transverse axis and includes a guide member F, which is connected to a corresponding transverse sliding member K carried by the carriage R. In this way, the machining head L can move in both the transverse and vertical directions. For longitudinal movement, there are two different solutions. In the first solution (roughly by...) Figure 10-12 As shown, the machine tool includes a base B, which, for example, comprises a pair of beams spaced apart from each other and extending parallel to a longitudinal axis. Each beam includes a longitudinal guide member A configured to connect with a pair of longitudinal slide members E of a slider T. The workstation is defined between the longitudinal beams. A second solution is the so-called gantry machine tool, in which the slide members are fixed and supported by a pair of columns at the ends of each beam. The workpiece is carried by a platform, which is typically capable of moving longitudinally along a pair of longitudinal guide members.

[0003] Both configurations of this type of machine tool exhibit common problems related to the sliding connection between the carriage and the machining head support, particularly concerning the effects of thermal expansion of the components. Specifically, the issue of so-called "thermal symmetry" is crucial.

[0004] The connection between the bracket and the machining head support includes a series of components that ensure the precise alignment and controlled movement of the machining head support along the bracket.

[0005] Thermal symmetry issues in machine tools are closely related to thermal deformation that occurs during operation. These deformations, caused by temperature variations in machine tool components, negatively impact machining accuracy and the final quality of produced parts. Heat can originate from various sources. For example, motors and drives generate heat during operation, as do friction in bearings, linear guides, and ball screws. The ambient environment, especially in the presence of significant temperature fluctuations, also has an effect. Furthermore, high-power machining generates heat between the tool and the workpiece, further increasing the temperature. These temperature variations cause expansion and contraction of machine tool components, with the core issue being the asymmetry of this deformation. This asymmetry can lead to torsion or bending, altering the alignment between the machining head and the workpiece. These effects impair machining accuracy, causing dimensional errors in the machined parts and accelerating tool wear.

[0006] For machine tools equipped with a machining head support (slide), the problem of thermal deformation is particularly prominent if the machining head support is supported in a cantilever manner by a bracket and the bracket slides on a slide formed by a single crossbeam.

[0007] To mitigate the problem of thermal symmetry, various solutions have been developed. A primary strategy is to design thermally symmetrical structures where components deform uniformly, maintaining axial alignment. Using materials with low or uniform thermal expansion properties helps reduce the impact of temperature variations. Some machine tools are also equipped with active thermal control systems (such as coolers or heaters) to stabilize the temperature of critical components. Other methods include employing advanced software to compensate for thermal deformation in real time, and thermally insulating the machine to protect it from the external environment.

[0008] Another known currently adopted solution is a machine tool configuration with a "box-in-box" carriage structure. For example... Figure 10-12As shown, the "box-in-box" design, by surrounding the bracket with a double-wall structure, achieves symmetrical load distribution, minimizing asymmetry caused by thermal deformation, thereby providing overall high rigidity and high precision. In this configuration, the machine tool may include, as previously described, a sliding member T formed by a pair of spaced-apart crossbeams, between which a bracket R slides. The bracket R is typically a parallelepiped structure with a centrally narrowed hole H. The machining head support C is slidably connected to the hole H of the bracket R via vertical sliding members S (such as ball or roller guides). These vertical sliding members S are mounted parallel to each other on the inner wall of the hole H of the bracket R to ensure that the machining head support C slides with minimal friction. The movement of the machining head support is typically achieved by a ball screw, which is mounted on a support fixed to the bracket and connected to a motor. The motor transmits motion to the screw, and the rotation of the screw causes the machining head support to slide along the vertical sliding members. The entire system requires precise connections to maintain the correct alignment of the machining head support and ensure its movement along the trajectory set by the bracket. Installing the vertical sliding member S of the machining head support C inside the bracket R is a complex operation, especially since the central hole H of the bracket R is only large enough for the machining head support C to pass through. This hole H presents numerous difficulties during machine tool assembly. Specifically, the limited space inside the bracket R makes the installation and alignment of the vertical sliding member S particularly challenging. The installation of each component must be extremely precise to ensure the proper movement of the machining head support C and the structural integrity of the entire system; however, the limited space of hole H restricts the accessibility of assembly tools and complicates component installation and adjustment. The vertical sliding member S can be fixed within the hole H of the bracket R by creating a through hole in the bracket wall. This method can be complex for several reasons. First, drilling a hole in the outer wall of the bracket R requires extremely high precision, as the hole must be perfectly aligned with the internal sliding member and the threaded housing used for fastening. Any misalignment can compromise system stability and sliding efficiency, causing friction or jamming during the movement of the machining head support C. Furthermore, this operation requires meticulous attention to ensure that each screw is screwed in without tilt and with sufficient insertion length. Even screw torque control can be challenging: over-tightening or under-tightening can alter the alignment of the guide, impairing the smooth and low-friction movement of the machining head support C. Limited space restricts the use of tools for verifying alignment and tightening torque, further complicating the assembly process and necessitating specialized equipment. In such a compact environment, even adjusting precision components can be difficult, often requiring corrective intervention.

[0009] Given the complexity of correctly installing the vertical sliding member S of the machining head support C on the bracket R, there is a pressing need to simplify the assembly process. Therefore, a system is required that reduces the difficulties associated with the limited internal space of the bracket while maintaining the thermal symmetry characteristics of the aforementioned "box-in-box" configuration. Utility Model Content

[0010] The purpose of this invention is to overcome the above-mentioned shortcomings and to provide a thermally symmetrical bracket assembly that simplifies the installation of the machining head support (slide) and sliding components, making assembly faster, more precise, more reliable, and less costly.

[0011] According to the present invention, its main feature is that it includes a bracket assembly comprising a first bracket and a second bracket spaced apart from each other and separated by a processing head support, wherein each bracket includes at least one vertical sliding member for the processing head support and at least one lateral sliding member slidably associated with a lateral guide member of the sliding assembly.

[0012] This solution provides a bracket assembly consisting of two separate, spaced-apart bodies (also referred to as "carriers"), greatly simplifying machine tool assembly. Using the separate bracket assembly, the vertical sliding member of the machining head support can be more easily and readily mounted on the outer wall of the bracket assembly. This solution allows for more precise alignment and fixation of the sliding member before assembling the two bracket bodies. Once the sliding member is mounted on the two brackets, the brackets can be assembled, saving time and improving installation accuracy.

[0013] In one embodiment of the present invention, the machine tool includes a base comprising a first beam and a second beam spaced apart from each other, the first beam and the second beam extending parallel to a longitudinal axis and having corresponding opposing longitudinal walls. Each longitudinal wall includes at least one corresponding longitudinal guide member, and a sliding assembly is configured to slide along the longitudinal guide member. A workstation is defined between the first beam and the second beam.

[0014] In one embodiment, the machine tool according to the present invention includes a gantry formed by a pair of columns supporting a first and second crossbeam of the sliding assembly, and the machine tool includes a platform capable of sliding parallel to a longitudinal axis between the pair of columns. A workstation is defined between the pair of columns.

[0015] In one embodiment of the machine tool according to the present invention, the opposing transverse walls of the sliding assembly are arranged obliquely relative to the vertical transverse plane.

[0016] In one embodiment of the machine tool according to the present invention, the first and second brackets of the bracket assembly extend parallel to a longitudinal axis and are spaced apart from each other. Each bracket includes: an inner longitudinal wall opposite to the longitudinal wall of the other bracket and including at least one vertical sliding member slidably associated with the machining head support; a first transverse sidewall and a second transverse sidewall, the first transverse sidewall including at least one transverse sliding member slidably associated with at least one transverse guide member of the first crossbeam of the sliding assembly, and the second transverse sidewall including at least one transverse sliding member slidably associated with at least one transverse guide member of the second crossbeam of the sliding assembly.

[0017] In one embodiment of the machine tool according to the present invention, the first and second brackets of the bracket assembly extend parallel to a transverse axis and spaced apart from each other. Each bracket includes: an inner transverse wall opposite to the transverse wall of the other bracket and including at least one vertical sliding member slidably associated with the machining head support; and an outer transverse wall, wherein the outer transverse wall of the first bracket includes at least one transverse sliding member slidably associated with at least one transverse guide member of the first crossbeam of the sliding assembly, and the outer transverse wall of the second bracket includes at least one transverse sliding member slidably associated with at least one transverse guide member of the second crossbeam of the sliding assembly.

[0018] In one embodiment of the machine tool according to the present invention, the sliding assembly or the movable platform, the bracket assembly, and the machining head support are driven by a linear motor, a pinion gear rack system, or a ball screw.

[0019] In one embodiment, the machine tool according to the present invention is a CNC milling machine equipped with three or more machining axes. Attached Figure Description

[0020] The present invention will now be described in detail with reference to the accompanying drawings, which are provided by way of non-limiting example only, in which:

[0021] Figure 1 This is a schematic perspective view of the first embodiment of the machine tool according to the present invention.

[0022] Figure 2 This is a top view of the first embodiment of the machine tool according to the present invention.

[0023] Figure 3 This is a schematic exploded perspective view of the first embodiment of the machine tool according to the present invention.

[0024] Figure 4 This is a schematic perspective view of the second embodiment of the machine tool according to the present invention.

[0025] Figure 5 This is a schematic perspective view of the third embodiment of the machine tool according to the present invention.

[0026] Figure 6 This is a top view of the third embodiment of the three-axis machine tool according to the present invention.

[0027] Figure 7 This is a schematic exploded perspective view of the third embodiment of the machine tool according to the present invention.

[0028] Figure 8 This is a schematic perspective view of the fourth embodiment of the machine tool according to the present invention.

[0029] Figure 9 This is a schematic perspective view of the fifth embodiment of the machine tool according to the present invention.

[0030] Figure 10 This is a schematic 3D diagram of a machine tool using existing technology.

[0031] Figure 11 yes Figure 10 The top view of the prior art machine tool shown, and

[0032] Figure 12 yes Figure 10 The diagram shows a schematic exploded perspective view of a prior art machine tool. Detailed Implementation

[0033] First refer to Figure 1 1A represents the first embodiment of the machine tool according to the present invention, which operates on three axes: the longitudinal direction, the transverse direction, and the vertical direction, respectively represented by the X-axis, Y-axis, and Z-axis.

[0034] The machine tool includes a machining head support 30, also referred to as a "ram," which is configured to slide along a bracket assembly 20 parallel to the vertical Z-axis. The bracket assembly 20 is configured to slide along a sliding assembly 10 parallel to the transverse Y-axis. The sliding assembly 10 is configured to slide along a base 19 parallel to the longitudinal X-axis.

[0035] The sliding assembly 10 includes a first crossbeam 3 and a second crossbeam 4, both having rectangular cross sections and arranged spaced apart from each other parallel to the transverse Y-axis, and correspondingly having opposing vertical transverse walls 12. Each transverse wall 12 includes a pair of transverse guide members 11, each transverse guide member being disposed along the length of one edge of the vertical transverse wall 12, as described below.

[0036] The crossbeams 3 and 4 are connected at their respective ends by a pair of sliders 9, each slider comprising a square cross-section body extending parallel to the longitudinal X-axis. The transverse wall 17 of each slider 9 is connected to the corresponding lower end portion of the crossbeams 3 and 4, while the transverse wall 16 of each slider 9 includes a longitudinal sliding member 13 (in... Figure 3 (As can be seen in the exploded diagram shown), which will be described below.

[0037] In a first embodiment of this invention, the sliding assembly 10 is movable in the longitudinal direction, i.e., in the X-axis direction. For this purpose, a first beam 5 and a second beam 6 are provided to form a base 19 of the machine tool 1A, the first beam 5 and the second beam 6 extending parallel and spaced apart along the longitudinal X-axis. Each of these beams 5, 6 includes a pair of parallel longitudinal guide members 7 disposed along the entire length of the edge of the upper longitudinal wall 8. The longitudinal sliding member 13 of the slider 9 of the sliding assembly 10 is slidably associated with the corresponding longitudinal guide member 7, allowing the sliding assembly 10 to slide along the beams 5, 6 of the base 19 (i.e., parallel to the longitudinal X-axis).

[0038] Advantageously, according to the present invention, the bracket assembly 20 is configured to slide along the lateral guide member 11 of the sliding assembly 10, as described below, the bracket assembly 20 is divided into two different, spaced apart and non-adjacent elements: a first bracket 21 and a second bracket 22, which are symmetrical, spaced apart from each other, and separated by the processing head support member 30.

[0039] Figures 1 to 4 and Figure 8 The bracket assembly 20 of the machine tool embodiment shown includes a first bracket 21 and a second bracket 22, which are spaced apart parallel to the longitudinal X-axis.

[0040] Each bracket 21, 22 includes an inner longitudinal wall 23. The inner longitudinal wall 23 of bracket 22 is in Figure 3 As can be seen, it is opposite to the inner longitudinal wall of the bracket 21. Each inner longitudinal wall 23 includes a pair of vertical sliding members 24 for the processing head support 30.

[0041] Each bracket 21, 22 further includes a first transverse sidewall 25 and a second transverse sidewall 26: the first transverse sidewall 25 includes a transverse sliding member 27 slidably connected to a transverse guide member 11 of the transverse wall 12 of the first crossbeam 3 of the sliding assembly 10; the second transverse sidewall 26 includes a transverse sliding member 28 slidably connected to the transverse guide member 11 of the transverse wall 12 of the second crossbeam 4 of the sliding assembly 10. Figure 1As shown, each bracket 21, 22 also includes an upper wall 34, which includes an additional vertical sliding member 29, such as a motor, for the processing head support 30.

[0042] like Figure 3 As shown in more detail, the machining head support 30 includes an elongated parallelepiped body in the vertical direction, comprising opposing elongated longitudinal walls 31 that support a vertical guide member 62. The vertical guide member 62 is connected to vertical sliding members 24 of the inner longitudinal wall 23 of the bracket 22 and the inner longitudinal wall 23 of the bracket 21, respectively, to allow the machining head support 30 to slide parallel to the vertical axis. At its lower end, the machining head support 30 includes a machining head assembly 32 (not shown due to well-known facts) for machining a workpiece located in a workstation 2, which is arranged between the first beam 5 and the second beam 6 of the base 19. The machining head 32 is preferably a vertical milling cutter head or a milling cutter head including one or more axes of rotation, optimized for high-precision milling operations, but not limited thereto, and the machining head 32 can be configured to perform other types of machining, such as drilling, cutting, grinding, etc., or can be configured for measurement operations.

[0043] The first variant of this utility model is... Figure 4 As shown, components that are the same or similar to those previously described are indicated by the same reference numerals and will not be described further. In this second embodiment, the first crossbeam 3 and the second crossbeam 4 of the sliding assembly 10 of the machine tool 1B, having a right-angled triangular cross-section, have corresponding opposing inclined transverse walls 15, which correspond to the hypotenuse of the triangle. In other words, the opposing transverse walls 15 of the sliding assembly 10 are arranged obliquely relative to a vertical transverse plane. Each inclined transverse wall 15 includes a pair of transverse guide members 11, each transverse guide member being disposed along the length of one edge of the transverse wall 15.

[0044] According to the second variation of the machine tool of this utility model Figure 5 and Figure 6 As shown in the image.

[0045] The bracket assembly 40 of the third embodiment of the machine tool 1C includes a first bracket 41 and a second bracket 42 that are spaced apart from each other and extend parallel to the transverse Y-axis.

[0046] Each bracket 41, 42 includes an inner transverse wall 43, which includes a vertical sliding member 44 of the processing head support 35. The inner transverse wall 43 of the first bracket 41 is opposite to the transverse wall 43 of the second bracket 42.

[0047] Each bracket 41, 42 also includes an outer transverse wall 45. The outer transverse wall 45 of the first bracket 41 includes a transverse sliding member 47 slidably associated with the transverse guide member 11 of the first crossbeam 3 of the sliding assembly 10. The outer transverse wall 45 of the second bracket 42 includes a transverse sliding member 47 slidably associated with the transverse guide member 11 of the second crossbeam 4 of the sliding assembly 10.

[0048] like Figure 6 As shown, each bracket 41, 42 also includes an upper wall 48, which includes an additional vertical sliding member 49, such as a motor, for the processing head support 35.

[0049] like Figure 7 As shown in more detail, the machining head support 35 according to the third embodiment of the present invention includes an elongated parallelepiped-shaped body in the vertical direction. This body includes opposing elongated transverse walls 36 that support a vertical guide member 37. The vertical guide member 37 is connected to vertical sliding members 44 of the inner transverse wall 43 of the bracket 41 and the inner transverse wall 43 of the bracket 42, respectively, thereby allowing the machining head support 35 to slide parallel to the vertical axis. Similarly, in this case, the machining head support 35 includes at its lower end a machining head assembly 32 for machining a workpiece located in a workstation 2, which is arranged between the first beam 5 and the second beam 6 of the base 19.

[0050] Figure 8 The third variation of the machine tool according to the present invention is shown, namely the so-called gantry machine tool.

[0051] In the fourth embodiment, the ends of the first crossbeam 3 and the second crossbeam 4 of the machine tool 1D are supported by a gantry structure including a first column 51 and a second column 52, respectively. In this embodiment, the sliding component 10 is fixed, and longitudinal movement parallel to the X-axis of the workpiece is achieved by a platform 53, which can slide along the support member 59 between the columns 51 and 52.

[0052] The support member 59 includes a side surface 55 and a top surface 56. Sliding guides 57 and 58 are disposed on the top surface 56 and are slidably connected to corresponding sliding members formed on the lower surface of the platform 53. These sliding members are known and therefore are not shown in the figure.

[0053] As previously described, the bracket assembly 20 of the fourth embodiment is similar to the bracket assembly 20 of the first embodiment of the machine tool 1A, and includes a first bracket 21 and a second bracket 22 spaced apart parallel to the longitudinal X-axis.

[0054] Figure 9The fourth variation of the machine tool according to the present invention is shown, which is also a gantry machine tool.

[0055] The bracket assembly 40 of the fifth embodiment of machine tool 1E is similar to the bracket assembly 40 of the third embodiment of machine tool 1C, and includes a first bracket 41 and a second bracket 42 that are spaced apart from each other and extend parallel to the transverse Y-axis.

[0056] For the movement of different movable elements of the machine tool (e.g., sliding assembly 10 or platform 53, bracket assemblies 20, 40, and machining head supports 30, 35), linear motors, pinion gear rack systems, or ball screws can be provided. Such motors are well known and within the knowledge of those skilled in the art, and therefore are not shown in the accompanying drawings.

[0057] Of course, structural details and embodiments may vary considerably from what has been described and shown, but will not depart from the scope of the present invention as defined by the following claims.

Claims

1. A machine tool (1A, 1B, 1C, 1D), said machine tool having a longitudinal axis (X), a transverse axis (Y), and a vertical axis (Z), said machine tool comprising: - A sliding assembly (10) comprising a first crossbeam (3) and a second crossbeam (4) spaced apart from each other, the first crossbeam (3) and the second crossbeam (4) extending parallel to the transverse axis (Y) and having corresponding opposing transverse walls (12, 15), each of the transverse walls (12, 15) comprising at least one corresponding transverse guide member (11). - A bracket assembly (20, 40) configured to slide along the lateral guide member (11) of the sliding assembly (10), the bracket assembly (20, 40) including a vertical sliding member (24, 44). - A machining head support (30, 35) that carries a machining head assembly (32) at its lower end. The machining head support (30, 35) is configured to slide parallel to the vertical axis (Z) via the vertical sliding members (24, 44) of the bracket assembly (20, 40). - Workstation (2), which is positioned below the sliding assembly (10), The bracket assembly (20, 40) includes a first bracket (21, 41) and a second bracket (22, 42) spaced apart from each other and separated by the processing head support (30, 35). Each of the first bracket (21, 41) and the second bracket (22, 42) includes: at least one corresponding lateral sliding member (27, 28, 47) slidably associated with one of the lateral guide members (11) of the sliding assembly (10); and at least one vertical sliding member (24, 44) slidably associated with the processing head support (30, 35). The first bracket (21) and the second bracket (22) of the bracket assembly (20) extend parallel to the longitudinal axis (X) and are spaced apart from each other, each bracket comprising: - An inner longitudinal wall (23), which is opposite to the inner longitudinal wall (23) of another bracket (21, 22), and includes at least one of the vertical sliding members (24) slidably associated with the processing head support (30). - First transverse sidewall (25) and second transverse sidewall (26), The first transverse sidewall (25) includes at least one transverse sliding member (27) slidably associated with at least one transverse guide member (11) of the first crossbeam (3) of the sliding assembly (10). The second lateral sidewall (26) includes at least one lateral sliding member (28) slidably associated with at least one lateral guide member (11) of the second beam (4) of the sliding assembly (10).

2. The machine tool (1A, 1B, 1C) according to claim 1, characterized in that, The machine tool includes a first beam (5) and a second beam (6) spaced apart from each other, the first beam and the second beam extending parallel to the longitudinal axis (X) and having corresponding longitudinal walls (8), each of the longitudinal walls (8) including at least one corresponding longitudinal guide member (7), and the sliding assembly (10) is configured to slide along the longitudinal guide member (7), and the workstation (2) is defined between the first beam (5) and the second beam (6).

3. The machine tool (1D) according to claim 1, characterized in that, The machine tool includes a gantry formed by a pair of columns (51, 52) supporting the first crossbeam (3) and the second crossbeam (4) of the sliding assembly (10), and the machine tool includes a sliding platform (53) capable of sliding between the pair of columns (51, 52) parallel to the longitudinal axis (X), and the workstation (2) is defined between the pair of columns (51, 52).

4. The machine tool (1B, 1C, 1D) according to any one of claims 1-3, characterized in that, The opposite transverse wall (15) of the sliding component (10) is arranged obliquely relative to the vertical transverse plane.

5. The machine tool (1A, 1B, 1C, 1D) according to any one of claims 1-3, characterized in that, The sliding assembly (10) or the sliding platform (53), the bracket assembly (20, 40), and the processing head support (30, 35) are driven by a linear motor, a pinion steering rack system, or a ball screw.

6. The machine tool (1A, 1B, 1C, 1D) according to any one of claims 1-3, characterized in that, The machine tool is a CNC milling machine that includes three or more machining axes.

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