Fixed-beam machine tool having internally constrained structure

Abstract

Disclosed in the present invention is a fixed-beam machine tool having an internally constrained structure. The fixed-beam machine tool comprises: a machine tool spindle, a rotary table and a bed, wherein at least two guide rails are provided in each of an X-axis direction, a Y-axis direction and a Z-axis direction, the at least two guide rails in the same axial direction include at least one pair of guide rails that are not on a same coordinate plane, and these guide rails form internal constraint spaces; the area where at least two internal constraint spaces overlap forms a motion space, and the motion space is a motion area of the tool tip of the machine tool spindle during machining; and a workpiece on the rotary table is made to coincide with the motion space by means of the linear displacement of the rotary table. In the present invention, by means of the provision of at least two guide rails that are not on the same coordinate plane in each of the three axial directions, the guide rail layout is optimized; and the guide rails are used to internally constrain the movement of machine tool components, so that the tool tip is always located in a closed space, and the movement of the tool tip in each axial direction is effectively constrained, thereby reducing the impact of a cutting force, and reducing micro-displacement. The impact of an overturning moment on the machine tool spindle is effectively avoided, thereby suppressing vibration and deformation, and ensuring the machining accuracy.

Description

A fixed beam machine tool with internal constraint structure Technical Field

[0001] This invention relates to the field of equipment manufacturing technology, and in particular to a fixed beam machine tool with an internal constraint structure. Background Technology

[0002] As the cornerstone of modern equipment manufacturing, CNC machine tools bear the strategic mission of providing key basic equipment for the manufacturing industry. Among them, fixed-beam machine tools have a relatively simple structure, lower manufacturing and assembly costs, and a wide range of applications with high market penetration both domestically and internationally. Against the backdrop of the rapid development of high-end equipment manufacturing, fixed-beam machine tools urgently need to overcome the performance bottlenecks of precision manufacturing technology. Especially in high-end manufacturing fields such as aerospace and precision instruments, with the exponential growth in demand for ultra-precision machining, the requirements for machine tool dynamic stability and machining accuracy are approaching physical limits. Research shows that when machining accuracy enters the sub-micron level, the sensitivity of the machine tool structure to force response will increase non-linearly. Particularly during machine tool cutting, the dynamic cutting forces borne by the tool system exhibit significant time-varying characteristics and multi-degree-of-freedom coupling features. Under the conditions of machining with superhard tools, the peak instantaneous cutting force generated in the tool-workpiece contact area can reach over 1,000 Newtons. This high-frequency alternating load will induce a three-dimensional dynamic response of the machine tool structure. The overturning moment induced by the cutting torque at the spindle-spindle mounting structure (beam, column, etc.) joint surface can cause micro-displacement of the tool cutting point, resulting in micron-level positional offset of the tool system. This "butterfly effect" in precision machining not only directly affects the quality of the machining result, but also causes a systematic decay of machining accuracy through the error propagation mechanism.

[0003] Therefore, how to effectively control the impact of cutting force on machine tools in order to improve the machining accuracy of machine tools has become a technical problem that urgently needs to be solved. Summary of the Invention

[0004] This invention provides a fixed beam machine tool with an internal constraint structure to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A fixed-beam machine tool with an internally constrained structure includes: a machine tool spindle, a rotary table, and a bed, and further includes:

[0007] XY coordinate plane, YZ coordinate plane and ZX coordinate plane;

[0008] The XY coordinate plane is a plane perpendicular to the Z-axis direction;

[0009] The YZ coordinate plane is a plane perpendicular to the X-axis direction;

[0010] The ZX coordinate plane is a plane perpendicular to the Y-axis direction;

[0011] At least two guide rails are provided in the X-axis, Y-axis and Z-axis directions, and at least one pair of guide rails that are not in the same coordinate plane exist in the same axis.

[0012] Each pair of X-guides that are not in the same coordinate plane contains two XY coordinate planes and two ZX coordinate planes, which form an X-direction partition space. The union of the X-direction partition spaces forms an X-direction inner constraint space.

[0013] Each pair of Y-guides that are not in the same coordinate plane contains two XY coordinate planes and two YZ coordinate planes, which form a Y-direction partition space. The union of the Y-direction partition spaces forms the Y-direction inner constraint space.

[0014] Each pair of Z-guides that are not in the same coordinate plane contains two ZX coordinate planes and two YZ coordinate planes, which form a Z-direction partition space. The union of the Z-direction partition spaces forms a Z-direction inner constraint space.

[0015] The region in which at least two of the X-direction inward constraint space, Y-direction inward constraint space and Z-direction inward constraint space overlap is the motion space, which is the motion area of ​​the tool tip of the machine tool spindle during the machining process;

[0016] The rotary table is mounted on the bed via an X-axis guide rail, and the workpiece on the rotary table is made to coincide with the motion space by the linear displacement of the rotary table.

[0017] Preferably, the motion space is the region where the X-direction inward constraint space, the Y-direction inward constraint space, and the Z-direction inward constraint space overlap.

[0018] Preferably, a first motion plane is formed between a pair of guide rails that are not in the same coordinate plane in the X-axis or Y-axis direction. During the machining process, the tool tip of the machine tool spindle can coincide with at least one of the first motion planes in the axial direction.

[0019] Preferably, at least three guide rails are provided in at least one of the X-axis, Y-axis and Z-axis directions.

[0020] Preferably, the prism-shaped space formed by the guide rails as edges in the direction of at least three guide rails is the guide rail constraint space, and the guide rail constraint space replaces the inner constraint space in the corresponding axis to form the motion space.

[0021] Preferably, it also includes a tilting milling head, with a first motion plane formed between two guide rails on the same axis but not on the same coordinate plane. During the machining process, the tilting axis of the tilting milling head intersects with at least one of the first motion planes on the same axis, and the tip of the tilting milling head coincides with the intersection point.

[0022] Preferably, the swing angle milling head is a single swing angle milling head, and during the machining process, the swing axis of the swing angle milling head is located in the first motion plane in at least one axial direction.

[0023] Preferably, the oscillating milling head is a double-oscillating oscillating milling head, and during the machining process, the oscillation axis of the oscillating milling head is located in the first motion plane in at least one axial direction.

[0024] Preferably, the oscillating milling head is a non-orthogonal oscillating milling head, and the tip of the non-orthogonal oscillating milling head is located on the oscillation axis of the non-orthogonal oscillating milling head.

[0025] Preferably, the device further includes a tilting milling head, which is mounted on the machine bed via Y-rails and Z-rails, and the rotary table is mounted on the machine bed via X-rails; the Y-rails include at least three rails, wherein a second motion plane is formed between a pair of Y-rails that are not in the same coordinate plane, and a third motion plane is formed between one of the two Y-rails and any of the other Y-rails; the second motion plane and the third motion plane pass through the mounting end and the tool clamping end of the tilting milling head, respectively.

[0026] Preferably, there is an angle between the mounting surface of the tilting milling head and the XY coordinate plane.

[0027] Preferably, the bed is fixedly provided with a side wall, and a pair of X-guide rails that are not in the same coordinate plane are located on the bed and the side wall respectively.

[0028] Preferably, at least three guide rails are provided in the X-axis direction, wherein a fourth motion plane is formed between two X-axis guide rails that are not in the same coordinate plane, and the fourth motion plane passes through the workpiece on the turntable.

[0029] Preferably, the bed is fixedly provided with a support column, the X-guide rail is located between the support column and the side wall, the top of the support column and the side wall is provided with a crossbeam, and a pair of Y-guide rails not in the same coordinate plane are located on the bed and the crossbeam respectively.

[0030] Preferably, it also includes a sliding saddle and a sliding ram, the sliding saddle being mounted on the crossbeam via a Y-guide rail, the sliding ram being mounted on the sliding saddle via a Z-guide rail, and the sway milling head being mounted on the sliding ram.

[0031] Preferably, of the two Y-guide rails not in the same coordinate plane, the Y-guide rail located on the machine bed is positioned below the Y-guide rail located on the crossbeam; the two Z-guide rails not in the same coordinate plane are respectively located on the side of the ram facing the crossbeam and the side away from the crossbeam, and the bottom end of the Z-guide rail located on the side of the ram away from the crossbeam is positioned below the bottom end of the Z-guide rail located on the side of the ram facing the crossbeam; the mounting surface of the tilting milling head is located on the ram, and there is an angle between the mounting surface of the tilting milling head and the XY coordinate plane, with the angle being greater than 0° and less than 90°, and the distance between the mounting surface and the Y-guide rail located on the crossbeam gradually increases along the Z-axis direction.

[0032] Preferably, the slide saddle includes: a first support plate, a second support plate, a third support plate, and a top plate. The first support plate is mounted on the crossbeam via a Y-guide rail. The second support plate is located on the side of the first support plate away from the crossbeam. The third support plate connects the first support plate and the second support plate. The top plate is located at the top of the first support plate, the second support plate, and the third support plate. The slide ram is located between the first support plate and the second support plate. Beneficial effects:

[0033] This application discloses a fixed beam machine tool with an internal constraint structure. By setting at least one pair of guide rails that are not in the same coordinate plane in the X, Y, and Z directions, at least two of the X-direction, Y-direction, and Z-direction internal constraint spaces formed by the guide rails in the X, Y, and Z directions can intersect to form a closed motion space. This optimizes the layout of the guide rail structure and uses the guide rails to internally constrain the movement of the machine tool components. This ensures that the tool tip is always located within the closed motion space during machining, effectively constraining the tool tip in the X, Y, and Z directions. This significantly reduces the impact of cutting forces on the tool tip, thereby reducing the micro-displacement of the tool tip. It also effectively avoids the overturning moment affecting the machine tool spindle during operation, suppresses vibration and deformation, and ensures the machining accuracy of the machine tool.

[0034] The linear displacement of the turntable ensures that the workpiece fixed on the turntable coincides with the motion space, facilitating loading and unloading. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 is a schematic diagram of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0037] Figure 2 is a structural schematic diagram of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0038] Figure 3 is a front view of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0039] Figure 4 is a side view of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0040] Figure 5 is a top view of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0041] Figure 6 is a schematic diagram of the Y-direction internal constraint space of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0042] Figure 7 is a schematic diagram of the X-direction internal constraint space of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0043] Figure 8 is a schematic diagram of the Z-direction internal constraint space of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention.

[0044] In the diagram: 1. Bed; 12. Support column; 2. Swivel milling head; 21. Mounting end; 22. Tool clamping end; 23. Mounting surface; 3. Crossbeam; 34. Side wall; 4. Saddle; 44. First support plate; 45. Second support plate; 46. Third support plate; 47. Top plate; 5. Ram; 6. Turntable; 71. First X-axis guide rail; 72. Second X-axis guide rail; 73. Third X-axis guide rail; 81. First Y-axis guide rail; 82. Second Y-axis guide rail; 83. Third Y-axis guide rail; 91. First Z-axis guide rail; 92. Second Z-axis guide rail; 93. Third Z-axis guide rail; A1. First motion plane; A2. Second motion plane; A3. Third motion plane; A4. Fourth motion plane; X1. X-axis inward constraint space; Y1. Y-axis inward constraint space; Y11. First Y-axis sub-space; Y12. Second Y-axis sub-space; Z1, Z-direction inward constraint space; Z11, first Z-direction subspace; Z12, second Z-direction subspace; Z13, third Z-direction subspace; N, motion space. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Machine tool accuracy is affected by a variety of factors, including its structural design, drive and control systems, thermal errors, tool wear, and measurement and feedback systems. To improve machine tool accuracy, one can address these aspects or take comprehensive measures. Since the structural design of the machine tool is fundamental, optimizing its structure is the primary task for improving accuracy.

[0047] Currently, machine tools are mainly classified into horizontal machine tools, vertical machine tools, and gantry machine tools. The various components of these machine tools are connected in sequence to form an open chain structure, which inevitably leads to the formation of a cantilever structure for the machine tool spindle. However, the cutting force borne by the tool tip during machining is mainly applied to the connection between it and the adjacent components. This means that the rigidity of the machine tool will directly affect the stress state of the tool tip and the stability of machining accuracy.

[0048] Existing machine tool structures mainly improve the overall rigidity of the machine tool by enhancing the static rigidity of each component. However, in practical applications, it has been found that the dynamic rigidity of the machine tool components is insufficient under the influence of cutting force, gravity, and acceleration. This results in irregular micro-displacements at the tool tip, which significantly affects the machining accuracy of the machine tool. This makes us realize that improving the dynamic rigidity of the machine tool is particularly important for improving its machining accuracy.

[0049] Machine tools include linear motion axes and rotary axes to machine complex parts. This necessitates that the components of the linear axes be connected and supported by guide rails, which bear the forces and ensure motion accuracy. During machining, insufficient dynamic stiffness of the guide rails can lead to deformation, directly affecting the machining accuracy and reducing machining quality. This means that the dynamic stiffness of the machine tool largely depends on the dynamic stiffness of the guide rails. In other words, higher dynamic stiffness results in less impact on machining accuracy, while lower dynamic stiffness has a greater impact. However, due to limitations in material mechanics, improvements to guide rail dynamic stiffness are limited. Therefore, we need to address this issue from other angles to enhance guide rail dynamic stiffness.

[0050] Research and analysis revealed that current machine tool components typically employ dual guideways for linear motion support. Since these dual guideways are located in the same plane, they are susceptible to overturning moments during operation, leading to vibration and deformation, which is detrimental to the precision machining of the entire machine tool. Therefore, this application aims to improve the dynamic stiffness of the guideways by optimizing the machine tool's structural layout and guideway arrangement, thereby enhancing the overall rigidity of the machine tool.

[0051] Example 1

[0052] A fixed beam machine tool with an internal constraint structure, as shown in Figures 1-8, includes: a machine tool spindle, a rotary table 6, and a bed 1, and further includes:

[0053] XY coordinate plane, YZ coordinate plane and ZX coordinate plane;

[0054] The XY coordinate plane is a plane perpendicular to the Z-axis direction;

[0055] The YZ coordinate plane is a plane perpendicular to the X-axis direction;

[0056] The ZX coordinate plane is a plane perpendicular to the Y-axis direction;

[0057] At least two guide rails are provided in the X-axis, Y-axis and Z-axis directions, and at least one pair of guide rails that are not in the same coordinate plane exist in the same axis.

[0058] Each pair of X-guides that are not in the same coordinate plane contains two XY coordinate planes and two ZX coordinate planes, which form an X-direction subspace. The union of the X-direction subspaces forms the X-direction inner constraint space X1.

[0059] Each pair of Y-guides that are not in the same coordinate plane contains two XY coordinate planes and two YZ coordinate planes, which form a Y-direction partition space. The union of the Y-direction partition spaces forms the Y-direction inner constraint space Y1.

[0060] Each pair of Z-guides that are not in the same coordinate plane contains two ZX coordinate planes and two YZ coordinate planes, which form a Z-direction partition space. The union of the Z-direction partition spaces forms the Z-direction inner constraint space Z1.

[0061] The region in which at least two of the X-direction inward constraint space X1, Y-direction inward constraint space Y1, and Z-direction inward constraint space Z1 overlap is the motion space N, which is the motion region of the tool tip of the machine tool spindle during the machining process.

[0062] The rotary table 6 is mounted on the bed 1 via an X-axis guide rail. The linear displacement of the rotary table 6 causes the workpiece on the rotary table 6 to coincide with the motion space N.

[0063] In this embodiment, to facilitate the construction of various spaces and planes, the guide rail needs to be conceptualized as a line within the space, serving as a reference for the construction of spaces and planes;

[0064] Specifically, when the area of ​​the guide rail used to support machine tool components is the guide rail surface of the guide rail itself (taking Figure 3 as an example, the first Y guide rail 81 in Figure 3 meets this working condition), the guide rail can be conceptualized as the center line of the guide rail surface;

[0065] When the area of ​​the guide rail used to support machine tool components is the edge line on both sides of the guide rail surface itself (taking Figure 3 as an example, the third Y guide rail 83 in Figure 3 meets this working condition), the guide rail can be conceptualized as the edge line of the guide rail surface.

[0066] In this embodiment, the coordinate planes include the XY coordinate plane, the YZ coordinate plane, and the ZX coordinate plane;

[0067] The XY coordinate plane is a plane parallel to the XY plane, mathematically called the z=k plane, whose normal vector is the same as that of the standard XY plane, where k is a constant;

[0068] The YZ coordinate plane is a plane parallel to the YZ plane, mathematically called the x=k plane, whose normal vector is the same as that of the standard YZ plane, where k is a constant;

[0069] The ZX coordinate plane is a plane parallel to the ZX plane, mathematically called the y=k plane, whose normal vector is the same as that of the standard ZX plane, where k is a constant.

[0070] For the guide rails in the X-axis direction, the constant k corresponding to the two XY coordinate planes z = k planes where the two X guide rails are not in the same coordinate plane are not equal.

[0071] For each pair of X-guides that are not in the same coordinate plane, the two ZX coordinate planes y = k planes where the two X-guides are located have different constants k.

[0072] The X-axis partition space is a quadrangular prism space with open ends, enclosed by two XY coordinate planes and two ZX coordinate planes where each pair of X-axis guides that are not in the same coordinate plane are located.

[0073] When the number of X-guides is equal to 2, there is only one pair of X-guides that are not in the same coordinate plane. Therefore, there is only one X-direction partition space. At this time, the X-direction inner constraint space X1 is equal to the X-direction partition space.

[0074] When the number of X-guide trajectories is greater than 2, each additional pair of X-guide trajectories that are not in the same coordinate plane will add an X-direction subspace. At this time, the X-direction inner constraint space X1 is equal to the union of multiple X-direction subspaces.

[0075] For guide rails in the Y-axis direction, the constant k corresponding to the two XY coordinate planes z = k planes where two Y guide rails are not in the same coordinate plane are not equal.

[0076] For each pair of Y-guides that are not in the same coordinate plane, the two YZ coordinate planes x = k have different constants k.

[0077] The Y-axis partition space is a quadrangular prism space with open ends, enclosed by two XY coordinate planes and two YZ coordinate planes where each pair of Y-guides that are not in the same coordinate plane are located.

[0078] When the number of Y-guides is equal to 2, there is only one pair of Y-guides that are not in the same coordinate plane. Therefore, there is only one Y-direction partition space. At this time, the Y-direction inner constraint space Y1 is equal to the Y-direction partition space.

[0079] When the number of Y-guides is greater than 2, each additional pair of Y-guides that are not in the same coordinate plane will add a corresponding Y-axis subspace. At this time, the Y-axis inner constraint space Y1 is equal to the union of multiple Y-axis subspaces.

[0080] For guide rails in the Z-axis direction, the constant k corresponding to the two ZX coordinate planes y=k planes where the two Z guide rails are located are not in the same coordinate plane.

[0081] For each pair of Z-guides that are not in the same coordinate plane, the two ZY coordinate planes x = k have different constants k.

[0082] The Z-axis partition space is a quadrangular prism space with open ends, enclosed by two ZX coordinate planes and two YZ coordinate planes where each pair of Z-guides that are not in the same coordinate plane are located.

[0083] When the number of Z-guides is equal to 2, there is only one pair of Z-guides that are not in the same coordinate plane. Therefore, there is only one Z-axis partition space. At this time, the Z-axis inner constraint space Z1 is equal to the Z-axis partition space.

[0084] When the number of Z-guides is greater than 2, each additional pair of Z-guides that are not in the same coordinate plane will add a corresponding Z-axis subspace. At this time, the Z-axis inner constraint space Z1 is equal to the union of multiple Z-axis subspaces.

[0085] The motion plane is established by adopting the aforementioned method of conceptualizing the guide rail as a line in space. The line formed by two guide rails conceptualized on the same axis but not on the same coordinate plane, the plane in which they are located is the motion plane.

[0086] Although both use lines formed by the conceptualization of guideways as the reference for establishing space, compared to the inner constraint space of a quadrangular prism formed by coordinate surfaces, the guideway constraint space in the corresponding direction, which is enclosed by the connection of constraint surfaces, allows the tool tip to be completely within the bounded area of ​​the guideway, resulting in a better constraint effect. This further reduces the influence of cutting force on the tool tip and reduces the micro-displacement of the tool tip.

[0087] The tool tip point is the point that the tool tip of the machine tool spindle needs to reach.

[0088] This application optimizes the guide rail structure layout by setting at least one pair of guide rails not in the same coordinate plane in the X, Y, and Z directions. This ensures that at least two of the X-direction, Y-direction, and Z-direction internal constraint spaces formed by the guide rails intersect, forming a closed motion space N. By using the guide rails to internally constrain the movement of machine tool components, the tool tip remains within the closed motion space N during machining. This effectively constrains the tool tip in the X, Y, and Z directions, significantly reducing the impact of cutting forces on the tool tip and thus minimizing its micro-displacement. It also effectively avoids the overturning moment affecting the machine tool spindle during operation, suppressing vibration and deformation, and ensuring the machining accuracy of the machine tool.

[0089] Preferably, the motion space N is the overlapping area of ​​the X-direction inward constraint space X1, the Y-direction inward constraint space Y1, and the Z-direction inward constraint space Z1. By forming a closed motion space N through the overlap of these three spaces, the tool tip remains within this closed space during machining, moving in all three directions. During machining, the cutting force on the tool tip is confined within the motion space N. A pair of guide rails, not lying on the same coordinate plane, on the three axes always maintain end-to-end support for the tool tip, optimizing the force on the guide rails. Simultaneously, the machine tool components moving in the three axes also maintain end-to-end support, optimizing the force on the guide rails and providing support and limitation for the machine tool components. Ultimately, this structural layout eliminates weak points and areas with insufficient dynamic stiffness, thereby improving the overall rigidity of the machine tool, reducing the micro-displacement of the tool tip, avoiding the influence of overturning moments, suppressing vibration and deformation, and ensuring the machining stability of the tool tip.

[0090] At the same time, the improvement of dynamic stiffness can also reduce the wear and aging of machine tools, ensure the machining accuracy of machine tools, and extend the service life of machine tools.

[0091] Furthermore, since the motion space N is formed by the guide rails, the motion space N must be between a pair of guide rails that are not in the same coordinate plane in the three axes. This means that the motion area must be located inside the machine tool's support structure. Compared with the existing machine tool's support structure (bed, support column, slide saddle, and slide ram, etc.), which can only provide support outside the motion area of ​​the tool tip, the machine tool of this application can reduce its volume and weight when achieving the same size machining area, thereby improving the overall rigidity of the machine tool and reducing its cost.

[0092] Preferably, at least three guide rails are provided in at least one of the X-axis, Y-axis, and Z-axis directions. Providing at least three guide rails enables over-positioning, and by adding additional positioning constraints, restricts the degrees of freedom of the guide rails in multiple directions. This allows the guide rails to withstand greater lateral and torsional forces, improving their dynamic stiffness and reducing positioning errors caused by guide rail loosening or deformation. Furthermore, it increases the support points for the connected machine tool components, improving the dynamic stiffness of the corresponding machine tool components. Simultaneously, it ensures consistency in each positioning, improves repeatability, and meets the requirements of high-precision machining.

[0093] Preferably, a prismatic space formed by using the guide rails as edges along the direction of at least three guide rails is designated as the guide rail constraint space. This guide rail constraint space replaces the inner constraint space along the corresponding axis to form the motion space. The prismatic space is formed by constraint surfaces between two adjacent guide rails, and multiple constraint surfaces are connected to enclose the guide rail constraint space in the corresponding direction.

[0094] The constraint surface is established by adopting the aforementioned method of conceptualizing the guide rails as lines in space. At least three guide rails are set in the direction of the lines formed by the conceptualization of two adjacent guide rails. The plane in which they are located is the constraint surface.

[0095] The constraint surfaces are connected to form a guide rail constraint space in the corresponding direction, which is a polygonal prism space formed by lines formed by conceptualization as edges;

[0096] Along the same axis, the guide rail constraint space is located within the inner constraint space. Although both are based on the lines formed by the conceptualization of the guide rail as the reference for establishing the space, compared to the quadrangular prism inner constraint space formed by coordinate surfaces, the guide rail constraint space in the corresponding direction, which is enclosed by the connection of constraint surfaces, allows the tool tip to be completely within the bounded area of ​​the guide rail. The tool tip will not form a cantilever structure with respect to the guide rail in this direction, resulting in a better constraint effect. This further improves the dynamic stiffness of the tool tip, reduces the influence of cutting force on the tool tip, and reduces the micro-displacement of the tool tip.

[0097] Preferably, the milling head 2 is also included. The milling head 2 is a single-swing milling head. During the machining process, the swing axis of the milling head 2 is located in the first motion plane A1 in at least one axial direction, so that the first motion plane A1 supports the swing axis and reduces the influence of cutting force on the swing axis and the tool tip, thereby maintaining stable accuracy during the machining process.

[0098] Preferably, the oscillating milling head 2 is a double oscillating milling head, and during the machining process, the oscillation axis of the oscillating milling head 2 is located within the first motion plane A1 in at least one axial direction.

[0099] Preferably, the oscillating milling head 2 is a non-orthogonal oscillating milling head, and the tip of the non-orthogonal oscillating milling head is located on the oscillation axis of the non-orthogonal oscillating milling head. Specifically, the non-orthogonal oscillating milling head is a 45° oscillating milling head.

[0100] Preferably, the tilting milling head 2 is mounted on the bed 1 via Y-rails and Z-rails, and the rotary table 6 is mounted on the bed 1 via X-rails. The Y-rails include at least three rails, where a second motion plane A2 is formed between two Y-rails not in the same coordinate plane, and a third motion plane A3 is formed between one of the two Y-rails and any one of the remaining Y-rails. The second motion plane A2 and the third motion plane A3 pass through the mounting end 21 and the tool clamping end 22 of the tilting milling head 2, respectively. The second motion plane A2 and the third motion plane A3 support the mounting end 21 and the tool clamping end 22 of the tilting milling head 2, improving the dynamic stiffness of the tilting milling head 2, and providing better support for the mounting end 21 and the tool clamping end 22 during machining, reducing the impact of cutting forces on the mounting end 21 and the tool clamping end 22, thereby maintaining stable accuracy during machining.

[0101] Preferably, the mounting surface 23 of the tilting milling head 2 has an angle with the XY coordinate plane, which reduces the distance from the tip to the mounting surface 23, decreases the cantilever length of the tip relative to the mounting surface 23, and thus improves the rigidity of the tilting milling head.

[0102] Preferably, the bed 1 is fixedly provided with a side wall 34, and a pair of X-guide rails not in the same coordinate plane are located on the bed 1 and the side wall 34 respectively. Setting part of the X-guide rails on the side wall 34 can provide stable and reliable support for the guide rails, suppress vibration and deformation, and help ensure the dynamic stiffness of the X-guide rails.

[0103] Preferably, at least three guide rails are arranged in the X-axis direction, among which a fourth motion plane A4 is formed between two X-axis guide rails that are not in the same coordinate plane. The fourth motion plane A4 passes through the workpiece on the turntable 6. The fourth motion plane A4 supports the workpiece, reduces the influence of cutting force on the workpiece position, and thus maintains stable accuracy during the machining process.

[0104] Preferably, the bed 1 is fixedly provided with a support column 12, the X-axis guide rail is located between the support column 12 and the side wall 34, and the top of the support column 12 and the side wall 34 is provided with a crossbeam 3. A pair of Y-axis guide rails that are not in the same coordinate plane are respectively located on the bed 1 and the crossbeam 3. This layout can make full use of the high static stiffness of the side wall 34, the support column 12 and the crossbeam 3 to provide stable support for the Y-axis guide rails. At the same time, it allows the turntable 6 to pass under the crossbeam 3 along the X-axis direction and enter the motion space N, which is beneficial for loading and unloading the machine tool.

[0105] In a specific embodiment, as shown in Figure 7, the X-guide rails include a first X-guide rail 71, a second X-guide rail 72, and a third X-guide rail 73. The first X-guide rail 71 and the second X-guide rail 72 are disposed on the side wall of the side wall 34, and the third X-guide rail 73 is disposed on the bed 1. The first X-guide rail 71 and the second X-guide rail 72 are located in the same coordinate plane, and the second X-guide rail 72 and the third X-guide rail 73 are located in the same coordinate plane. The first X-guide rail 71 and the third X-guide rail 73 are located in different coordinate planes. The first X-guide rail 71, the second X-guide rail 72, and the third X-guide rail 73 constitute an X-direction subspace, which is an X-direction internal constraint space X1.

[0106] Preferably, the system further includes a sliding saddle 4 and a sliding ram 5. The sliding saddle 4 is mounted on the crossbeam 3 via a Y-guide rail, and the sliding ram 5 is mounted on the sliding saddle 4 via a Z-guide rail. The sway milling head 2 is mounted on the sliding ram 5.

[0107] Preferably, of the two Y-guides not in the same coordinate plane, the Y-guide on the bed 1 is positioned below the Y-guide on the crossbeam 3; the two Z-guides not in the same coordinate plane are respectively located on the side of the ram 5 facing the crossbeam 3 and the side away from the crossbeam 3, with the bottom end of the Z-guide on the side of the ram 5 away from the crossbeam 3 positioned below the bottom end of the Z-guide on the side of the ram 5 facing the crossbeam 3; the mounting surface 23 of the tilting milling head 2 is located on the ram 5, and there is an angle between the mounting surface 23 of the tilting milling head 2 and the XY coordinate plane, with the angle being greater than 0° and less than 90°, and the distance between the mounting surface 23 and the Y-guide on the crossbeam 3 gradually increases along the Z-axis direction. This arrangement not only allows the second motion plane A2 to support the mounting surface 23 of the tilting milling head 2 and the tool tip, but also ensures that the tool tip can be lowered to a lower position, ensuring the machining stroke of the tool tip in the Z-axis direction.

[0108] In a specific embodiment, as shown in Figure 6, the Y-guide rails include a first Y-guide rail 81, a second Y-guide rail 82, and a third Y-guide rail 83. The first Y-guide rail 81 and the second Y-guide rail 82 are disposed on the side wall of the crossbeam 3, and the third Y-guide rail 83 is disposed on the bed 1. The first Y-guide rail 81 and the second Y-guide rail 82 are located in the same coordinate plane, while the third Y-guide rail 83 is not in the same coordinate plane as the first Y-guide rail 81 and the second Y-guide rail 82. The first Y-guide rail 81, the second Y-guide rail 82, and the third Y-guide rail 83 form two pairs of Y-guide rails that are not in the same coordinate plane, thereby constituting two Y-direction subspaces—the first Y-direction subspace Y11 and the second Y-direction subspace Y12. The union of the two Y-direction subspaces is the Y-direction inner constraint space Y1. The space enclosed by the three constraint surfaces formed by the three Y-guide rails is the guide rail constraint space in the Y-axis direction.

[0109] Preferably, the slide saddle 4 includes: a first support plate 44, a second support plate 45, a third support plate 46, and a top plate 47. The first support plate 44 is mounted on the crossbeam 3 via a Y-guide rail. The second support plate 45 is located on the side of the first support plate 44 away from the crossbeam 3. The third support plate 46 connects the first support plate 44 and the second support plate 45. The top plate 47 is located at the top of the first support plate 44, the second support plate 45, and the third support plate 46. The ram 5 is located between the first support plate 44 and the second support plate 45. The first support plate 44, the second support plate 45, the third support plate 46, the top plate 47, and the bed 1 block the ram 5 in five directions, which helps to improve the dynamic stiffness of the ram 5.

[0110] In a specific embodiment, as shown in Figure 8, the Z-guide rails include a first Z-guide rail 91, a second Z-guide rail 92, and a third Z-guide rail 93, all of which are mounted on the slide saddle 4. The first Z-guide rail 91 is mounted on the first support plate 44, the second Z-guide rail 92 is mounted on the second support plate 45, and the third Z-guide rail 93 is mounted on the third support plate 46. Any two of the first Z-guide rail 91, the second Z-guide rail 92, and the third Z-guide rail 93 are not in the same coordinate plane. The first Z-guide rail 91, the second Z-guide rail 92, and the third Z-guide rail 93 form three pairs of Z-guide rails that are not in the same coordinate plane, thus constituting three Z-axis sub-spaces—the first Z-axis sub-space Z11, the second Z-axis sub-space Z12, and the third Z-axis sub-space Z13. The union of the three Z-axis sub-spaces is the Z-axis internal constraint space Z1. The space enclosed by the three constraint surfaces formed by the three Z-guide rails is the guide rail constraint space in the Z-axis direction.

[0111] In a specific embodiment, the third support plate 46 is located on the side of the first support plate 44 and the second support plate 45 facing the side wall 34, that is, the third support plate 46 is located on the side of the slide ram 5. The tilting milling head 2 can turn to the side of the slide ram 5 away from the third support plate 46. Then, by moving the slide saddle 4 and cooperating with the tool magazine set on the bed 1, tool changing can be realized.

[0112] Example 2

[0113] The difference between this embodiment and Embodiment 1 lies in the positional relationship between the tool tip of the machine tool spindle and the first motion plane A1 during the machining process.

[0114] Preferably, as shown in Figures 1, 2, and 6, a first motion plane A1 is formed between a pair of guide rails that are not in the same coordinate plane in the X-axis or Y-axis direction; in this embodiment, it is in the X-axis direction. During machining, the tool tip of the machine tool spindle can coincide with at least one of the first motion planes A1 in the axial direction. When the tool tip coincides with the first motion plane A1, the first motion plane A1 provides support for the tool tip, and the tool tip does not form a cantilever structure relative to the first motion plane A1, thereby ensuring the stability of the tool tip's accuracy during the machining of the plane.

[0115] The tip of the tilting milling head 2 is the same as the tip of the machine tool spindle. During machining, the tilting axis of the tilting milling head 2 intersects with at least one axial first motion plane A1, and the tip of the tilting milling head 2 coincides with the intersection point. When the tip of the tilting milling head coincides with the intersection point, the first motion plane A1 supports the tip, preventing the tip from forming a cantilever structure relative to the first motion plane A1. This reduces the impact of cutting force on the displacement of the tip relative to the tilting axis, thereby ensuring the stability of the tip's accuracy during machining.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fixed beam machine tool with an internal constraint structure, comprising: The machine tool spindle, rotary table (6), tilting milling head (2), and bed (1) are characterized in that they further include: XY coordinate plane, YZ coordinate plane and ZX coordinate plane; The XY coordinate plane is a plane perpendicular to the Z-axis direction; The YZ coordinate plane is a plane perpendicular to the X-axis direction; The ZX coordinate plane is a plane perpendicular to the Y-axis direction; At least two guide rails are provided in the X-axis, Y-axis and Z-axis directions, and at least one pair of guide rails that are not in the same coordinate plane exist in the same axis. Each pair of X-guides that are not in the same coordinate plane contains two XY coordinate planes and two ZX coordinate planes, which form an X-direction subspace. The union of the X-direction subspaces forms an X-direction inner constraint space. Each pair of Y-guides that are not in the same coordinate plane contains two XY coordinate planes and two YZ coordinate planes, which form a Y-direction partition space. The union of the Y-direction partition spaces forms the Y-direction inner constraint space. Each pair of Z-guides that are not in the same coordinate plane contains two ZX coordinate planes and two YZ coordinate planes, which form a Z-direction partition space. The union of the Z-direction partition spaces forms a Z-direction inner constraint space. The region in which at least two of the X-direction inward constraint space, Y-direction inward constraint space and Z-direction inward constraint space overlap is the motion space, which is the motion area of ​​the tool tip of the machine tool spindle during the machining process; The rotary table (6) is mounted on the bed (1) via an X-axis guide rail. The linear displacement of the rotary table (6) causes the workpiece on the rotary table (6) to coincide with the motion space. The bed (1) is fixedly provided with a side wall (34), and a pair of X guide rails that are not in the same coordinate plane are located on the bed (1) and the side wall (34) respectively; The bed (1) is fixedly provided with a support column (12), the X guide rail is located between the support column (12) and the side wall (34), the top of the support column (12) and the side wall (34) is provided with a crossbeam (3), and a pair of Y guide rails not in the same coordinate plane are located on the bed (1) and the crossbeam (3) respectively. It also includes a sliding saddle (4) and a sliding ram (5), the sliding saddle (4) being mounted on the crossbeam (3) via a Y-guide rail, the sliding ram (5) being mounted on the sliding saddle (4) via a Z-guide rail, and the swing angle milling head (2) being mounted on the sliding ram (5); Of the two Y-guide rails not in the same coordinate plane, the Y-guide rail on the bed (1) is located below the Y-guide rail on the crossbeam (3); the two Z-guide rails not in the same coordinate plane are located on the side of the ram (5) facing the crossbeam (3) and the side away from the crossbeam (3), respectively, and the bottom end of the Z-guide rail on the side of the ram (5) away from the crossbeam (3) is located below the bottom end of the Z-guide rail on the side of the ram (5) facing the crossbeam (3); the mounting surface (23) of the swing milling head (2) is located on the ram (5), and there is an angle between the mounting surface (23) of the swing milling head (2) and the XY coordinate plane, and the angle is greater than 0° and less than 90°. The distance between the mounting surface (23) and the Y-guide rail on the crossbeam (3) gradually increases along the Z-axis direction; The sliding saddle (4) includes: a first support plate (44), a second support plate (45), a third support plate (46), and a top plate (47). The first support plate (44) is mounted on the crossbeam (3) via a Y-guide rail. The second support plate (45) is located on the side of the first support plate (44) away from the crossbeam (3). The third support plate (46) connects the first support plate (44) and the second support plate (45). The top plate (47) is located at the top of the first support plate (44), the second support plate (45), and the third support plate (46). The sliding ram (5) is located between the first support plate (44) and the second support plate (45).

2. The fixed beam machine tool with an internal constraint structure according to claim 1, characterized in that, The motion space is the region where the X-direction inward constraint space, the Y-direction inward constraint space, and the Z-direction inward constraint space overlap.

3. A fixed beam machine tool with an internal constraint structure according to claim 1, characterized in that, A first motion plane is formed between a pair of guide rails that are not in the same coordinate plane in the X-axis or Y-axis direction. During the machining process, the tool tip of the machine tool spindle can coincide with at least one of the first motion planes in the axial direction.

4. A fixed beam machine tool with an internal constraint structure according to claim 1, characterized in that, At least three guide rails are provided in at least one of the X-axis, Y-axis and Z-axis directions.

5. A fixed beam machine tool with an internal constraint structure according to claim 4, characterized in that, A prism-shaped space formed by using the guide rails as edges along the direction of at least three guide rails is used as the guide rail constraint space. The guide rail constraint space replaces the inner constraint space in the corresponding axis to form the motion space.

6. A fixed beam machine tool with an internal constraint structure according to claim 2, characterized in that, It also includes a swing milling head (2), where two guide rails on the same axis but not on the same coordinate plane form a first motion plane. During the machining process, the swing axis of the swing milling head (2) intersects with the first motion plane on at least one axis, and the tip of the swing milling head (2) coincides with the intersection point.

7. A fixed beam machine tool with an internal constraint structure according to claim 6, characterized in that, The swing angle milling head (2) is a single swing angle milling head. During the machining process, the swing axis of the swing angle milling head (2) is located in the first motion plane in at least one axial direction.

8. A fixed beam machine tool with an internal constraint structure according to claim 6, characterized in that, The swing angle milling head (2) is a double swing angle milling head. During the machining process, the swing axis of the swing angle milling head (2) is located in the first motion plane in at least one axial direction.

9. A fixed beam machine tool with an internal constraint structure according to claim 6, characterized in that, The swing angle milling head (2) is a non-orthogonal swing angle milling head, and the tip of the non-orthogonal swing angle milling head is located on the swing axis of the non-orthogonal swing angle milling head.

10. A fixed beam machine tool with an internal constraint structure according to claim 5, characterized in that, It also includes a tilting milling head (2), which is mounted on the bed (1) via Y-guide rails and Z-guide rails, and the rotary table (6) is mounted on the bed (1) via X-guide rails; the Y-guide rails include at least three rails, wherein a second motion plane is formed between a pair of Y-guide rails that are not in the same coordinate plane, and a third motion plane is formed between one of the two Y-guide rails and any of the other Y-guide rails; the second motion plane and the third motion plane pass through the mounting end (21) and the tool clamping end (22) of the tilting milling head (2) respectively / the tool clamping end (22) and the mounting end (21) of the tilting milling head (2).

11. A fixed beam machine tool with an internal constraint structure according to any one of claims 6-10, characterized in that, The mounting surface (23) of the tilting milling head (2) has an angle with the XY coordinate plane.

12. A fixed beam machine tool with an internal constraint structure according to claim 10, characterized in that, At least three guide rails are provided in the X-axis direction, among which a fourth motion plane is formed between two X-axis guide rails that are not in the same coordinate plane, and the fourth motion plane passes through the workpiece on the turntable (6).

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