Fixed cross beam machine tool with internal constraint structure

Abstract

The invention discloses a fixed cross beam machine tool with an internal constraint structure, which comprises a machine tool main shaft, a rotary table and a machine tool body, at least two guide rails are arranged in the X-axis direction, the Y-axis direction and the Z-axis direction respectively, at least two guide rails in the same axial direction comprise at least one pair of guide rails which are not on the same coordinate plane, and the guide rails form an internal constraint space; the overlapped area of the at least two inner constraint spaces is a motion space, and the motion space is a motion area of a tool nose point of a machine tool spindle in the machining process; and a workpiece on the rotary table coincides with the motion space through the linear displacement of the rotary table. At least two guide rails which are not on the same coordinate plane are arranged in the three axial directions, the layout of the guide rails is optimized, movement of machine tool parts is restrained in the guide rails, a tool nose point is located in a closed space all the time, movement of the tool nose point in the axial directions is effectively restrained, the influence of cutting force is reduced, and the micro-displacement amount is reduced. The machine tool spindle is effectively prevented from being influenced by overturning moment, vibration and deformation are restrained, and machining precision is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of equipment manufacturing, and in particular to a fixed-beam machine tool with an internal constraint structure. Background Art

[0002] As the cornerstone of modern equipment manufacturing, CNC machine tools carry the strategic mission of providing key basic equipment for the manufacturing industry. Among them, fixed-beam machine tools have a relatively simple structure, low manufacturing and assembly costs, and a wide range of applications, with high penetration rates in domestic and foreign markets. In the context of the rapid development of high-end equipment manufacturing, fixed-beam machine tools are in urgent need of breaking through the performance bottleneck of precision manufacturing technology. Especially in high-end manufacturing fields such as aerospace and precision instruments, with the exponential growth of ultra-precision machining demand, the requirements for dynamic stability and machining accuracy of machine tools have approached physical limits. Studies have shown that when machining accuracy enters the sub-micron level, the sensitivity of the machine tool structure to force response will increase nonlinearly, especially during the cutting process of machine tools, the dynamic cutting force borne by the tool system has significant time-varying characteristics and multi-degree-of-freedom coupling characteristics. Under the condition of super-hard tool processing, the instantaneous cutting force peak value generated in the tool-workpiece contact area can reach more than 1,000 Newtons. This high-frequency alternating load will trigger the three-dimensional dynamic response of the machine tool structure. The overturning moment induced by the cutting torque at the joint surface of the spindle-spindle mounting structure (beam, column, etc.) can cause the tool cutting point to produce micro-displacement, resulting in micron-level posture deviation of the tool system. This "butterfly effect" in precision machining not only directly affects the quality of machining, but also causes systematic attenuation of machining accuracy through the error transmission mechanism.

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

[0004] The present invention provides a fixed crossbeam machine tool with an internal constraint structure to solve the above technical problems.

[0005] In order to achieve the above object, the technical solution of the present invention is: A fixed beam machine tool with an internal constraint structure, comprising: a machine tool spindle, a turntable and a bed, and also comprising: 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 arranged in the X-axis direction, the Y-axis direction and the Z-axis direction, and at least one pair of guide rails that are not in the same coordinate plane exists in the same axis direction; Each pair of two X-direction guide rails not in the same coordinate plane, where two XY coordinate planes and two ZX coordinate planes are located, forms an X-direction subspace, and the union of the X-direction subspaces forms an X-direction inward constraint space; Each pair of two XY coordinate planes and two YZ coordinate planes where two Y-direction guide rails are located that are not in the same coordinate plane forms a Y-direction sub-space, and the union of the Y-direction sub-spaces forms a Y-direction inward constraint space; Each pair of two Z-direction guide rails not in the same coordinate plane, where two ZX coordinate planes and two YZ coordinate planes are located, forms a Z-direction sub-space, and the union of the Z-direction sub-spaces forms a Z-direction inward constraint space; The overlapping area of ​​at least two of the X-inward constraint space, the Y-inward constraint space and the Z-inward constraint space is the motion space, and the motion space is the motion area of ​​the tool tip point of the machine tool spindle during machining; The turntable is arranged on the bed through an X-guide rail, and the workpiece on the turntable is made to coincide with the movement space through the linear displacement of the turntable.

[0006] Preferably, the motion space is a region where the X-direction inward constraint space, the Y-direction inward constraint space and the Z-direction inward constraint space overlap.

[0007] Preferably, a first motion plane is formed between a pair of guide rails in the X-axis direction or the Y-axis direction that are not in the same coordinate plane. During machining, the tool tip point of the machine tool spindle can coincide with the first motion plane in at least one axial direction.

[0008] Preferably, at least three guide rails are arranged in at least one axial direction among the X-axis direction, the Y-axis direction and the Z-axis direction.

[0009] Preferably, a prismatic space formed with the guide rails as edges in the direction of at least three guide rails is set as the guide rail constraint space, and the guide rail constraint space replaces the corresponding axial inner constraint space to form the movement space.

[0010] Preferably, it also includes a swing milling head, and a first motion plane is formed between two guide rails on the same axial direction that are not on the same coordinate plane. During the processing, the swing axis of the swing milling head and the first motion plane on at least one axial direction have an intersection, and the tool tip point of the swing milling head coincides with the intersection.

[0011] Preferably, the angular swing milling head is a single-swing angular swing milling head, and during the machining process, the swing axis of the angular swing milling head is located in the first motion plane in at least one axial direction.

[0012] Preferably, the angular swing milling head is a double-swing angular swing milling head, and during the machining process, the swing axis of the angular swing milling head is located in the first motion plane in at least one axial direction.

[0013] Preferably, the swing-angle milling head is a non-orthogonal swing-angle milling head, and the tool tip point of the non-orthogonal swing-angle milling head is located on the swing axis of the non-orthogonal swing-angle milling head.

[0014] Preferably, it also includes a swing milling head, which is arranged on the bed through a Y guide rail and a Z guide rail, and the turntable is arranged on the bed through an X guide rail; the Y guide rail includes at least three guide rails, wherein a second motion plane is formed between a pair of two 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 other Y guide rail; the second motion plane and the third motion plane respectively pass through the mounting end and the tool holding end of the swing milling head / the tool holding end and the mounting end of the swing milling head.

[0015] Preferably, there is an angle between the mounting surface of the swing milling head and the XY coordinate plane.

[0016] Preferably, the bed is fixedly provided with a side wall, and a pair of two X-guide rails which are not in the same coordinate plane are respectively located on the bed and the side wall.

[0017] Preferably, at least three guide rails are arranged in the X-axis direction, wherein a fourth motion plane is formed between two X-guide rails that are not in the same coordinate plane, and the fourth motion plane passes through the workpiece on the turntable.

[0018] Preferably, the bed is fixed with a support column, the X-guide rail is located between the support column and the side wall, a crossbeam is provided at the top of the support column and the side wall, and a pair of two Y-guide rails not in the same coordinate plane are respectively located on the bed and the crossbeam.

[0019] Preferably, it also includes a saddle and a ram, the saddle is arranged on the crossbeam through a Y guide rail, the ram is arranged on the saddle through a Z guide rail, and the swing angle milling head is arranged on the ram.

[0020] Preferably, the Y guide rail located on the bed of the pair of two Y guide rails that are not in the same coordinate plane is arranged below the Y guide rail located on the crossbeam; the two Z guide rails that are not in the same coordinate plane are respectively located on the side of the slide 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 slide away from the crossbeam is arranged below the bottom end of the Z guide rail located on the side of the slide facing the crossbeam; the mounting surface of the swing angle milling head is arranged on the slide, and there is an angle between the mounting surface of the swing angle milling head and the XY coordinate plane, and the angle is greater than 0° and less than 90°, and the distance between the mounting surface and the Y guide rail on the crossbeam gradually increases along the Z-axis direction.

[0021] Preferably, the saddle includes: a first support plate, a second support plate, a third support plate and a top plate, the first support plate is arranged on the cross beam through a Y-guide rail, the second support plate is located on the side of the first support plate away from the cross beam, the third support plate connects the first support plate and the second support plate, the top plate is arranged at the top of the first support plate, the second support plate and the third support plate; the slide pillow is arranged between the first support plate and the second support plate.

[0022] Beneficial effects:

[0023] The present application discloses a fixed-beam machine tool with an internal constraint structure. By arranging at least one pair of guide rails that are not in the same coordinate plane in the X-axis direction, the Y-axis direction and the Z-axis direction, at least two of the X-direction internal constraint space, the Y-direction internal constraint space and the Z-direction internal constraint space respectively formed by the guide rails in the X-axis direction, the Y-axis direction and the Z-axis direction can intersect to form a closed motion space, thereby optimizing the layout of the guide rail structure. The guide rails are used to perform internal constraints on the motion of machine tool components, so that the tool tip point is always located in the closed motion space during the machining process, and effective constraints on the tool tip point in the X-axis direction, the Y-axis direction and the Z-axis direction are achieved, which greatly reduces the influence of the cutting force on the tool tip point, thereby reducing the micro-displacement of the tool tip point; effectively avoiding the influence of the overturning moment on the machine tool spindle during operation, suppressing vibration and deformation, and ensuring the machining accuracy of the machine tool.

[0024] Through the linear displacement of the turntable, it is ensured that the workpiece fixed on the turntable can coincide with the movement space, making loading and unloading convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A schematic diagram of a fixed beam machine tool with an internal constraint structure disclosed in Example 1 of the present invention; Figure 2 It is a structural schematic diagram of a fixed crossbeam machine tool with an internal constraint structure disclosed in Example 1 of the present invention; Figure 3 A front view of a fixed beam machine tool with an internal constraint structure disclosed in Example 1 of the present invention; Figure 4 A side view of a fixed beam machine tool with an internal constraint structure disclosed in Example 1 of the present invention; Figure 5A top view of a fixed beam machine tool with an internal constraint structure disclosed in Example 1 of the present invention; Figure 6 A schematic diagram of the Y-direction inward constraint space of a fixed beam machine tool with an internal constraint structure disclosed in Example 1 of the present invention; Figure 7 A schematic diagram of an X-direction inward constraint space of a fixed beam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention; Figure 8 This is a schematic diagram of the Z-direction inward constraint space of a fixed-beam machine tool with an internal constraint structure disclosed in Example 1 of the present invention.

[0027] In the figure: 1. Bed; 12. Support column; 2. Swing milling head; 21. Mounting end; 22. Tool holding end; 23. Mounting surface; 3. beam; 34. side wall; 4. Sliding saddle; 44. First supporting plate; 45. Second supporting plate; 46. Third supporting plate; 47. Top plate; 5. Sliding ram; 6. Turntable; 71, first X-direction guide rail; 72, second X-direction guide rail; 73, third X-direction guide rail; 81, first Y-direction guide rail; 82, second Y-direction guide rail; 83, third Y-direction guide rail; 91, first Z-direction guide rail; 92, second Z-direction guide rail; 93, third Z-direction guide rail; A1, first motion plane; A2, second motion plane; A3, third motion plane; A4, fourth motion plane; X1, X-direction inward constraint space; Y1, Y-direction inner constraint space; Y11, first Y-direction subspace; Y12, second Y-direction subspace; Z1, Z-direction inner constraint space; Z11, first Z-direction subspace; Z12, second Z-direction subspace; Z13, third Z-direction subspace; N. Sports space. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The accuracy of machine tools is affected by many factors, including the structural design of machine tools, drive systems and control systems, thermal errors, tool wear, and measurement and feedback systems. In order to improve the accuracy of machine tools, we can start from these aspects or take comprehensive measures. Since the structural design of machine tools is the basis of the entire machine tool, if we want to improve the accuracy of machine tools, the first task is to optimize the design of the machine tool structure.

[0030] At present, machine tools are mainly divided 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 forms a cantilever structure for the machine tool spindle; however, the cutting force borne by the tool tip during the machining process mainly acts on the connection between it and the adjacent components, which makes the rigidity of the machine tool directly affect the stress state of the tool tip and the stability of the machining accuracy.

[0031] The existing machine tool structure mainly improves the rigidity of the entire machine tool by enhancing the static rigidity of each component. However, in actual applications, it is found that under the influence of cutting force, gravity, and acceleration, the dynamic rigidity of the machine tool components is insufficient, resulting in irregular tiny displacements of 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 the machining accuracy of the machine tool.

[0032] Machine tools include linear motion axes and rotating axes to achieve the processing of complex parts. This requires that the various components of the machine tool linear axis must be connected and supported by guide rails, so that the guide rails bear the force and ensure the accuracy of movement. During the machine tool processing process, if the dynamic stiffness of the guide rail is insufficient, it will cause the guide rail to deform, which will directly affect the processing accuracy of the machine tool and reduce the processing quality. This means that the dynamic stiffness of the machine tool depends to a large extent on the dynamic stiffness of the guide rail. In other words, the higher the dynamic stiffness of the guide rail, the smaller the impact on the processing accuracy. On the contrary, the lower the dynamic stiffness of the guide rail, the greater the impact on the processing accuracy. However, due to the mechanical properties of the material, the improvement of the dynamic stiffness of the guide rail is limited, which requires us to start from other directions to improve the dynamic stiffness of the guide rail.

[0033] Through research and analysis, it is found that the linear motion of machine tool parts is usually supported by double guide rails. The double guide rails are located in the same plane and are easily affected by the overturning moment during operation, resulting in vibration and deformation, which is not conducive to the precision machining of the entire machine tool. Therefore, this application starts with optimizing the machine tool structure layout and guide rail layout to improve the dynamic stiffness of the guide rail, thereby improving the stiffness of the entire machine tool.

[0034] Embodiment 1:

[0035] A fixed beam machine tool with an internal constraint structure, combined with Figure 1-8 As shown, it includes: a machine tool spindle, a turntable 6 and a bed 1, and also includes: 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 arranged in the X-axis direction, the Y-axis direction and the Z-axis direction, and at least one pair of guide rails that are not in the same coordinate plane exists in the same axis direction; Each pair of two X-direction guide rails not in the same coordinate plane, where two XY coordinate planes and two ZX coordinate planes are located, forms an X-direction sub-space, and the union of the X-direction sub-spaces forms an X-direction inward constraint space X1; Each pair of two XY coordinate planes and two YZ coordinate planes where two Y-direction guide rails are located that are not in the same coordinate plane forms a Y-direction sub-space, and the union of the Y-direction sub-spaces forms a Y-direction inward constraint space Y1; Each pair of two Z-direction guide rails not in the same coordinate plane, where two ZX coordinate planes and two YZ coordinate planes are located, forms a Z-direction sub-space, and the union of the Z-direction sub-spaces forms a Z-direction inward constraint space Z1; The area where at least two of the X-inward constraint space X1, the Y-inward constraint space Y1 and the Z-inward constraint space Z1 overlap is the motion space N, and the motion space N is the motion area of ​​the tool tip point of the machine tool spindle during machining; The turntable 6 is arranged on the bed 1 through an X-guide rail, and the workpiece on the turntable 6 is made to coincide with the movement space N through the linear displacement of the turntable 6 .

[0036] In this embodiment, in order to facilitate the construction of various spaces and planes, the guide rails need to be conceptualized as lines within the space to serve as a reference for the construction of the space and plane; Specifically, when the area of ​​the guide rail used to carry the machine tool component is the guide rail surface of the guide rail itself (with Figure 3 For example, Figure 3 The first Y guide rail 81 in the figure meets this working condition), and the guide rail can be conceptualized as the center line of the guide rail surface; When the area of ​​the guide rail used to carry machine tool components is the edge lines on both sides of the guide rail surface of the guide rail itself (with Figure 3 For example, Figure 3 The third Y pair guide rail 83 in the figure meets this working condition), and the guide rail can be conceptualized as the edge line of the guide rail surface.

[0037] In this embodiment, the coordinate planes include an XY coordinate plane, a YZ coordinate plane, and a ZX coordinate plane; 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, and k is a constant; 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, and k is a constant; 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, and k is a constant.

[0038] For the guide rails in the X-axis direction, the corresponding constant k of each pair of two X-direction guide rails that are not in the same coordinate plane is not equal to the two XY coordinate planes z=k planes; For each pair of two X-guide rails that are not in the same coordinate plane, the corresponding constant k is not equal to the two ZX coordinate planes y=k planes; The X-direction subspace is a quadrangular prism space with open ends surrounded by two XY coordinate planes and two ZX coordinate planes where two pairs of X-direction guide rails that are not in the same coordinate plane are located; When the number of X-direction rails is equal to 2, there is only one pair of X-direction rails that are not in the same coordinate plane, so there is only one X-direction sub-space, and the X-direction inward constraint space X1 is equal to the X-direction sub-space; When the number of X-direction rails is greater than 2, each additional pair of X-direction rails that are not in the same coordinate plane will increase an X-direction subspace accordingly. At this time, the X-direction inward constraint space X1 is equal to the union of multiple X-direction subspaces. For the guide rail in the Y-axis direction, for each pair of two Y-direction guide rails that are not in the same coordinate plane, the corresponding constant k is not equal to the two XY coordinate planes z=k planes where the two Y-direction guide rails are located; For each pair of two Y-directions that are not in the same coordinate plane, the corresponding constant k is not equal to the two YZ coordinate planes x=k planes where the guide rails are located; The Y-direction subspace is a quadrangular prism-shaped space with open ends surrounded by two XY coordinate planes and two YZ coordinate planes where each pair of two Y-direction guide rails that are not in the same coordinate plane are located; When the number of Y-direction guide rails is equal to 2, there is only one pair of Y-direction guide rails that are not in the same coordinate plane, so there is only one Y-direction sub-space, and the Y-direction inward constraint space Y1 is equal to the Y-direction sub-space; When the number of Y-direction guide rails is greater than 2, each additional pair of Y-direction guide rails that are not in the same coordinate plane will correspondingly increase a Y-direction sub-space. At this time, the Y-direction inward constraint space Y1 is equal to the union of multiple Y-direction sub-spaces.

[0039] For the guide rail in the Z-axis direction, the corresponding constant k of each pair of two Z-direction guide rails that are not in the same coordinate plane and the two ZX coordinate planes y=k planes where they are located are not equal; For each pair of two ZY coordinate planes x=k where two Z-guide rails are not in the same coordinate plane, the corresponding constant k is not equal.

[0040] The Z-direction subspace is a quadrangular prism-shaped space with two open ends surrounded by two ZX coordinate planes and two YZ coordinate planes where each pair of two Z-direction guide rails that are not in the same coordinate plane are located; When the number of Z-direction guide rails is equal to 2, there is only one pair of Z-direction guide rails that are not in the same coordinate plane, so there is only one Z-direction sub-space, and the Z-direction inward constraint space Z1 is equal to the Z-direction sub-space; When the number of Z-direction guide rails is greater than 2, each additional pair of Z-direction guide rails that are not in the same coordinate plane will correspondingly increase a Z-direction sub-space. At this time, the Z-direction inward constraint space Z1 is equal to the union of multiple Z-direction sub-spaces.

[0041] The establishment of the motion plane also adopts the aforementioned method of conceptualizing the guide rail as a line in space. On the same axis, the line formed by the conceptualization of two guide rails that are not on the same coordinate plane, the plane on which they share the common position is the motion plane.

[0042] Although the lines formed by the conceptualization of the guide rails are used as the reference for establishing the space, compared with the quadrangular prism-shaped internal constraint space formed by the coordinate plane, the guide rail constraint space in the corresponding direction formed by the constraint surfaces allows the tool tip to be completely located within the encirclement of the guide rail, resulting in a better constraint effect, further reducing the impact of the cutting force on the tool tip and reducing the micro-displacement of the tool tip.

[0043] The tool tip point is the point that the tool tip of the machine tool spindle is to reach.

[0044] The present application arranges at least one pair of guide rails that are not in the same coordinate plane in the X-axis direction, the Y-axis direction and the Z-axis direction, so that at least two of the X-direction inward constraint space, the Y-direction inward constraint space and the Z-direction inward constraint space formed by the guide rails in the X-axis direction, the Y-axis direction and the Z-axis direction respectively can intersect to form a closed motion space N, thereby optimizing the guide rail structural layout, utilizing the guide rails to perform internal constraints on the motion of machine tool components, so that the tool tip point is always located in the closed motion space N during the machining process, and effectively constraining the tool tip point in the X-axis direction, the Y-axis direction and the Z-axis direction, greatly reducing the influence of the cutting force on the tool tip point, thereby reducing the micro-displacement of the tool tip point; effectively avoiding the influence of the overturning moment on the machine tool spindle during operation, suppressing vibration and deformation, and ensuring the machining accuracy of the machine tool.

[0045] Preferably, the motion space N is the overlapping area of ​​the X-inward constraint space X1, the Y-inward constraint space Y1 and the Z-inward constraint space Z1. The closed motion space N is formed by overlapping the X-inward constraint space X1, the Y-inward constraint space Y1 and the Z-inward constraint space Z1, so that the tool tip is always located in the closed space when it moves in three directions during the machining process. During the machining process, the cutting force on the tool tip can be enclosed in the motion space N, and a pair of guide rails on the three axes that are not in the same coordinate plane always maintain the state of supporting the tool tip at both ends, optimizing the force of the guide rails; at the same time, the machine tool parts moving in the three axes can also always maintain support at both ends, which can optimize the force of the guide rails and support and limit the machine tool parts. Finally, through the above-mentioned structural layout, the weak links and areas with insufficient dynamic stiffness are eliminated, thereby improving the overall stiffness of the machine tool, reducing the micro-displacement of the tool tip, avoiding the influence of the overturning moment, and then suppressing vibration and deformation, ensuring the machining stability of the tool tip.

[0046] 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.

[0047] In addition, since the motion space N is formed by the guide rails, the motion space N must be between a pair of guide rails in the three axial directions that are not in the same coordinate plane, which means that the motion area must be located inside the support structure of the machine tool; compared with the support structure of existing machine tools (bed, support columns, saddle and slide, etc.), which can only provide support outside the motion area of ​​the tool tip, the machine tool of the present application can be reduced in size and weight when achieving the same size processing area, which is beneficial to improve the overall rigidity of the machine tool and reduce the cost of the machine tool.

[0048] Preferably, at least three guide rails are provided in at least one of the X-axis direction, the Y-axis direction and the Z-axis direction. At least three guide rails are provided to achieve over-positioning. By adding additional positioning constraints to limit the freedom of the guide rails in multiple directions, the guide rails can withstand greater lateral forces and torsional forces, improve the dynamic stiffness of the guide rails, and thus reduce the positioning error caused by loosening or deformation of the guide rails; and increase the support points of the machine tool components connected to it, and improve the dynamic stiffness of the corresponding machine tool components. At the same time, the consistency of each positioning can be ensured, the accuracy of repeated positioning can be improved, and high-precision processing can be met.

[0049] Preferably, at least three guide rails are provided with a prismatic space formed with the guide rails as edges as the guide rail constraint space, and the guide rail constraint space replaces the inner constraint space in the corresponding axial direction to form the motion space. The prismatic space is a constraint surface formed between two adjacent guide rails, and a plurality of the constraint surfaces are connected to form the guide rail constraint space in the corresponding direction.

[0050] The establishment of the constraint surface also adopts the aforementioned method of conceptualizing the guide rail as a line in space, and at least three guide rails are set, and the line formed by the conceptualization of two adjacent guide rails, and the plane where they are located is the constraint surface; The constraint surfaces are connected to form a guide constraint space in the corresponding direction, which is a polygonal prism space formed by the lines formed by conceptualization as edges; In the same axial direction, the guide rail constraint space is located in the internal constraint space. Although the line formed by the conceptualization of the guide rail is used as the reference for establishing the space, compared with the quadrangular prism-shaped internal constraint space formed by the coordinate plane, the guide rail constraint space in the corresponding direction formed by the constraint planes, the tool tip point can be completely located within the encirclement of the guide rail, and the tool tip point will not form a cantilever structure for the guide rail in this direction, so the constraint effect is better, which further improves the dynamic stiffness of the tool tip point, reduces the influence of the cutting force on the tool tip point, and reduces the micro-displacement of the tool tip point.

[0051] Preferably, it also includes a swing milling head 2, which is a single-swing swing milling head. During the machining process, the swing axis of the swing 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, reducing the influence of the cutting force on the swing axis and the tool tip point, thereby maintaining stable precision during the machining process.

[0052] Preferably, the angular swing milling head 2 is a double-swing angular swing milling head, and during the machining process, the swing axis of the angular swing milling head 2 is located in the first motion plane A1 in at least one axial direction.

[0053] Preferably, the swing angle milling head 2 is a non-orthogonal swing angle milling head, and the tool tip of the non-orthogonal swing angle milling head is located on the swing axis of the non-orthogonal swing angle milling head. Specifically, the non-orthogonal swing angle milling head is a 45° swing angle milling head.

[0054] Preferably, the angular milling head 2 is arranged on the bed 1 through a Y guide rail and a Z guide rail, and the turntable 6 is arranged on the bed 1 through an X guide rail; the Y guide rail includes at least three guide rails, wherein a second motion plane A2 is formed between a pair of two Y guide rails that are not in the same coordinate plane, and a third motion plane A3 is formed between one of the two Y guide rails and any other Y guide rail; 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 angular milling head 2 / the tool clamping end 22 and the mounting end 21 of the angular 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 angular milling head 2, improve the dynamic stiffness of the angular milling head 2, achieve better support for the mounting end 21 and the tool clamping end 22 of the angular milling head 2 during the machining process, reduce the influence of the cutting force on the mounting end 21 and the tool clamping end 22, so as to maintain the stability of the precision during the machining process.

[0055] Preferably, there is an angle between the mounting surface 23 of the swing milling head 2 and the XY coordinate plane, so that the distance from the tool tip to the mounting surface 23 can be shortened, reducing the cantilever length of the tool tip relative to the mounting surface 23, thereby improving the rigidity of the swing milling head.

[0056] Preferably, the bed 1 is fixed with a side wall 34, and a pair of two X-guide rails that are not in the same coordinate plane are respectively located on the bed 1 and the side wall 34. Providing a portion of the X-guide rail on the side wall 34 can provide stable and reliable support for the rail, suppress vibration and deformation, and help ensure the dynamic stiffness of the X-guide rail.

[0057] Preferably, at least three guide rails are arranged in the X-axis direction, wherein a fourth motion plane A4 is formed between two X-guide rails that are not in the same coordinate plane, and 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 the cutting force on the position of the workpiece, and thus can maintain the stability of the precision during the machining process.

[0058] Preferably, the bed 1 is fixed with a support column 12, the X-guide rail is located between the support column 12 and the side wall 34, a crossbeam 3 is provided at the top of the support column 12 and the side wall 34, and a pair of two Y-guide rails 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 rigidity of the side wall 34, the support column 12 and the crossbeam 3 to provide stable support for the Y-guide rail, and at the same time, it can make the turntable 6 pass through the bottom of the crossbeam 3 along the X-axis direction to enter the motion space N, which is conducive to loading and unloading of the machine tool.

[0059] In a specific embodiment, in combination Figure 7As shown, the X-guide rail includes 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 arranged on the side wall of the side wall 34, the third X-guide rail 73 is arranged on the bed 1, the first X-guide rail 71 and the second X-guide rail 72 are located in the same coordinate plane, 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 sub-space, and the X-direction sub-space is the X-direction inward constraint space X1.

[0060] Preferably, it also includes a saddle 4 and a ram 5 , the saddle 4 is arranged on the crossbeam 3 through a Y guide rail, the ram 5 is arranged on the saddle 4 through a Z guide rail, and the swing angle milling head 2 is arranged on the ram 5 .

[0061] Preferably, the Y guide rail located on the bed 1 of the pair of two Y guide rails not in the same coordinate plane is arranged below the Y guide rail located on the beam 3; the two Z guide rails not in the same coordinate plane are respectively located on the side of the ram 5 facing the beam 3 and the side away from the beam 3, and the bottom end of the Z guide rail located on the side of the ram 5 away from the beam 3 is arranged below the bottom end of the Z guide rail located on the side of the ram 5 facing the beam 3; the mounting surface 23 of the swing milling head 2 is arranged 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°, and the distance between the mounting surface 23 and the Y guide rail located on the beam 3 gradually increases along the Z-axis direction. This layout not only enables the second motion plane A2 to support the mounting surface 23 and the tool tip of the swing milling head 2, but also ensures that the tool tip can be lowered to a lower position, ensuring the processing stroke of the tool tip in the Z-axis direction.

[0062] In a specific embodiment, in combination Figure 6 As shown, the Y guide rail includes 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 arranged on the side wall of the beam 3, and the third Y guide rail 83 is arranged on the bed 1; the first Y guide rail 81 and the second Y guide rail 82 are located in the same coordinate plane, and the third Y guide rail 83 and the first Y guide rail 81 and the second Y guide rail 82 are not in the same coordinate plane. 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 forming two Y-direction sub-spaces, namely, the first Y-direction sub-space Y11 and the second Y-direction sub-space Y12. The union of the two Y-direction sub-spaces is the Y-direction inward 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.

[0063] 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 arranged on the cross beam 3 through a Y-guide rail, the second support plate 45 is located on the side of the first support plate 44 away from the cross beam 3, the third support plate 46 connects the first support plate 44 and the second support plate 45, and the top plate 47 is arranged at the top of the first support plate 44, the second support plate 45 and the third support plate 46; the ram 5 is arranged 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 is conducive to improving the dynamic stiffness of the ram 5.

[0064] In a specific embodiment, in combination Figure 8 As shown, 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 arranged on the slide saddle 4. The first Z-guide rail 91 is arranged on the first support plate 44, the second Z-guide rail 92 is arranged on the second support plate 45, and the third Z-guide rail 93 is arranged 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, thereby forming three Z-direction sub-spaces - the first Z-direction sub-space Z11, the second Z-direction sub-space Z12 and the third Z-direction sub-space Z13. The union of the three Z-direction sub-spaces is the Z-direction inner constraint space Z1; the space surrounded by the three constraint surfaces formed by the three Z-guide rails is the guide rail constraint space in the Z-axis direction.

[0065] 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 5, and the swing milling head 2 can be turned to the side of the slide 5 away from the third support plate 46, and then the tool change can be achieved by moving the saddle 4 and cooperating with the tool magazine arranged on the bed 1.

[0066] Embodiment 2:

[0067] The difference between this embodiment and the first embodiment lies in the positional relationship between the tool tip of the machine tool spindle and the first motion plane A1 during the machining process.

[0068] Preferably, combined Figure 1 , Figure 2 and Figure 6As shown, a first motion plane A1 is formed between a pair of guide rails in the X-axis direction or the Y-axis direction that are not in the same coordinate plane. In this embodiment, it is in the X-axis direction. During the machining process, the tool tip of the machine tool spindle can coincide with the first motion plane A1 in at least one axial direction. When the tool tip coincides with the first motion plane A1, the first motion plane A1 supports the tool tip, and the tool tip does not form a cantilever structure relative to the first motion plane A1, thereby ensuring that the tool tip maintains a stable precision during the machining of the plane.

[0069] The tool tip of the swing milling head 2 is the tool tip of the machine tool spindle. During machining, the swing axis of the swing milling head 2 and the first motion plane A1 in at least one axial direction have an intersection, and the tool tip of the swing milling head 2 coincides with the intersection. When the tool tip of the swing milling head coincides with the intersection, the first motion plane A1 supports the tool tip, and the tool tip does not form a cantilever structure relative to the first motion plane A1, reducing the influence of the cutting force on the displacement of the tool tip relative to the swing axis, thereby ensuring that the tool tip maintains a stable precision during machining.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements 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 comprises a spindle, a rotary table (6), a swing milling head (2) and a bed (1), characterized in that it also comprises: 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 arranged in the X-axis direction, the Y-axis direction and the Z-axis direction, and at least one pair of guide rails that are not in the same coordinate plane exists in the same axis direction; Each pair of two X-direction guide rails not in the same coordinate plane, where two XY coordinate planes and two ZX coordinate planes are located, forms an X-direction subspace, and the union of the X-direction subspaces forms an X-direction inward constraint space; Each pair of two XY coordinate planes and two YZ coordinate planes where two Y-direction guide rails are located that are not in the same coordinate plane forms a Y-direction sub-space, and the union of the Y-direction sub-spaces forms a Y-direction inward constraint space; Each pair of two Z-direction guide rails not in the same coordinate plane, where two ZX coordinate planes and two YZ coordinate planes are located, forms a Z-direction sub-space, and the union of the Z-direction sub-spaces forms a Z-direction inward constraint space; The overlapping area of ​​at least two of the X-inward constraint space, the Y-inward constraint space and the Z-inward constraint space is the motion space, and the motion space is the motion area of ​​the tool tip point of the machine tool spindle during machining; The turntable (6) is arranged on the bed (1) via an X-guide rail, and the workpiece on the turntable (6) is made to coincide with the movement space through the linear displacement of the turntable (6); The bed (1) is fixedly provided with a side wall (34), and a pair of two X-direction guide rails not in the same coordinate plane are respectively located on the bed (1) and the side wall (34); The bed (1) is fixedly provided with a support column (12), the X-direction guide rail is located between the support column (12) and the side wall (34), a crossbeam (3) is provided at the top of the support column (12) and the side wall (34), and a pair of two Y-direction guide rails not in the same coordinate plane are respectively located on the bed (1) and the crossbeam (3); It also includes a saddle (4) and a ram (5), wherein the saddle (4) is arranged on the crossbeam (3) via a Y guide rail, the ram (5) is arranged on the saddle (4) via a Z guide rail, and the swing angle milling head (2) is arranged on the ram (5); The Y guide rail located on the bed (1) of the pair of two Y guide rails not in the same coordinate plane is arranged below the Y guide rail located on the beam (3); the two Z guide rails not in the same coordinate plane are respectively located on the side of the ram (5) facing the beam (3) and the side away from the beam (3), and the bottom end of the Z guide rail located on the side of the ram (5) away from the beam (3) is arranged below the bottom end of the Z guide rail located on the side of the ram (5) facing the beam (3); the mounting surface (23) of the swing milling head (2) is arranged on the ram (5), an angle is formed 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°, and the distance between the mounting surface (23) and the Y guide rail on the beam (3) gradually increases along the Z-axis direction; The saddle (4) comprises: 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 arranged on the cross beam (3) through a Y-guide rail; the second support plate (45) is located on the side of the first support plate (44) away from the cross beam (3); the third support plate (46) connects the first support plate (44) and the second support plate (45); the top plate (47) is arranged at the top of the first support plate (44), the second support plate (45) and the third support plate (46); the ram (5) is arranged between the first support plate (44) and the second support plate (45).

2. A 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. The 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 in the X-axis direction or the Y-axis direction that are not in the same coordinate plane. During machining, the tool tip point of the machine tool spindle can coincide with the first motion plane in at least one axial direction.

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

5. A fixed beam machine tool with an internal constraint structure according to claim 4, characterized in that: A prismatic space formed with the guide rails as edges in a direction of at least three guide rails is a guide rail constraint space, and the guide rail constraint space replaces the inner constraint space in the corresponding axial direction 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 comprises a swing milling head (2), wherein a first motion plane is formed between two guide rails on the same axial direction and not on the same coordinate plane, and during machining, a swing axis of the swing milling head (2) and the first motion plane on at least one axial direction have an intersection point, and a tool tip point 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, and during the machining process, the swing axis of the swing angle milling head (2) is located within the first motion plane in at least one axial direction.

8. The 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 swing angle milling head, and 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. The 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 tool tip point of the non-orthogonal swing angle milling head is located on the swing axis of the non-orthogonal swing angle milling head.

10. The fixed beam machine tool with an internal constraint structure according to claim 5, characterized in that: It also includes a swing milling head (2), the swing milling head (2) being arranged on the bed (1) via a Y guide rail and a Z guide rail, and the turntable (6) being arranged on the bed (1) via an X guide rail; the Y guide rail comprises at least three guide rails, wherein a pair of two Y guide rails that are not in the same coordinate plane form a second motion plane, and one of the two Y guide rails forms a third motion plane with any other Y guide rail; the second motion plane and the third motion plane respectively pass through the mounting end (21) and the tool holding end (22) of the swing milling head (2) / the tool holding end (22) and the mounting end (21) of the swing milling head (2).

11. A fixed beam machine tool with an internal constraint structure according to any one of claims 6 to 10, characterized in that: There is an included angle between the mounting surface (23) of the swing angle milling head (2) and 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 arranged in the X-axis direction, wherein a pair of two X-direction guide rails that are not in the same coordinate plane form a fourth motion plane, and the fourth motion plane passes through the workpiece on the turntable (6).

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