A fixed crossbeam machine tool with an internal constraint structure

Abstract

The present invention discloses a fixed crossbeam machine tool with an internal constraint structure, comprising: a machine tool spindle, a turntable and a machine tool bed. At least two guide rails are provided in the X-axis direction, Y-axis direction and Z-axis direction. At least two guide rails in the same axial direction include at least a pair of guide rails not on the same coordinate plane, and these guide rails form an internal constraint space; the overlapping area of at least two internal constraint spaces is a motion space, and the motion space is the motion area of the tip point of the machine tool spindle during the machining process; the workpiece on the turntable is made to coincide with the motion space through the linear displacement of the turntable. By arranging at least two guide rails not on the same coordinate plane in the three axial directions, the present invention optimizes the guide rail layout, uses the guide rails to internally constrain the movement of the machine tool components, makes the tip point always located in a closed space, effectively constrains its movement in each axial direction, reduces the influence of the cutting force, and reduces the micro displacement amount. It effectively avoids the influence of the tipping moment on the machine tool spindle, suppresses vibration and deformation, and ensures the machining accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment manufacturing, and particularly to a fixed crossbeam machine tool with an internal constraint structure. Background Art

[0002] As the cornerstone of modern equipment manufacturing industry, numerical control machine tools carry the strategic mission of providing key basic equipment for the manufacturing industry. Among them, the structure of the fixed crossbeam machine tool is relatively simple, and the manufacturing and assembly costs are relatively low; moreover, it has a wide range of applications and a high penetration rate in the domestic and international markets. In the context of the rapid development of the high-end equipment manufacturing industry, the fixed crossbeam machine tool urgently needs to break 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 requirements, the requirements for the dynamic stability and machining accuracy of machine tools have approached the physical limit. Research shows that when the machining accuracy enters the sub-micron level, the sensitivity of the machine tool structure to force response will increase non-linearly. Especially during the cutting process of the machine tool, the dynamic cutting force borne by the tool system has significant time-varying characteristics and multi-degree-of-freedom coupling characteristics. Under the machining conditions of super-hard tools, the peak value of the instantaneous cutting force generated in the tool-workpiece contact area can reach more than a thousand 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 moment at the joint surface of the spindle-spindle mounting structural parts (such as crossbeam, column, etc.) can cause micro-displacement at the tool cutting point, resulting in a micron-level pose deviation of the tool system. This "butterfly effect" in precision machining not only directly affects the machining forming quality, but also causes systematic attenuation of machining accuracy through the error transfer mechanism.

[0003] Therefore, how to effectively control the influence of cutting force on the machine tool to improve the machining accuracy of the machine tool has become an urgent technical problem to be solved. 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] To achieve the above object, the technical solution of the present invention is:

[0006] A fixed crossbeam machine tool with an internal constraint structure includes: a machine tool spindle, a turntable and a bed body, 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] There are at least two guide rails provided in each of the X-axis direction, Y-axis direction, and Z-axis direction, and there is at least one pair of guide rails on the same axis that are not in the same coordinate plane;

[0012] The two XY coordinate planes and two ZX coordinate planes where each pair of X-direction guide rails that are not in the same coordinate plane are located form an X-direction sub-space, and the union of the X-direction sub-spaces forms an X-direction inner constraint space;

[0013] The two XY coordinate planes and two YZ coordinate planes where each pair of Y-direction guide rails that are not in the same coordinate plane are located form a Y-direction sub-space, and the union of the Y-direction sub-spaces forms a Y-direction inner constraint space;

[0014] The two ZX coordinate planes and two YZ coordinate planes where each pair of Z-direction guide rails that are not in the same coordinate plane are located form a Z-direction sub-space, and the union of the Z-direction sub-spaces forms a Z-direction inner constraint space;

[0015] The overlapping region of at least two of the X-direction inner constraint space, Y-direction inner constraint space, and Z-direction inner constraint space is the motion space, and the motion space is the motion region of the tip point of the machine tool spindle during the machining process;

[0016] The turntable is arranged on the bed through the X-direction guide rail, and the workpiece on the turntable is made to coincide with the motion space through the linear displacement of the turntable.

[0017] Preferably, the motion space is the overlapping region of the X-direction inner constraint space, Y-direction inner constraint space, and Z-direction inner constraint space.

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

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

[0020] Preferably, the prismatic space formed with the guide rails as the edges in the direction where at least three guide rails are provided is 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.

[0021] Preferably, it further includes a swing angle milling head. A first motion plane is formed between two guide rails on the same axis that are not in the same coordinate plane. During the machining process, the swing axis of the swing angle milling head intersects with the first motion plane in at least one axis direction, and the tip point of the swing angle milling head coincides with the intersection point.

[0022] Preferably, the swing angle milling head is a single swing angle milling head. 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 swing angle milling head is a double swing angle milling head. 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.

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

[0025] Preferably, it further includes a swing angle milling head. The swing angle milling head is arranged on the bed body through a Y-direction guide rail and a Z-direction guide rail, and the turntable is arranged on the bed body through an X-direction guide rail; the Y-direction guide rail includes at least three guide rails. A second motion plane is formed between two Y-direction guide rails that are not in the same coordinate plane, and a third motion plane is formed between one of the two Y-direction guide rails and any other Y-direction guide rail; the second motion plane and the third motion plane respectively pass through the mounting end and the tool clamping end of the swing angle milling head / the tool clamping end and the mounting end of the swing angle milling head.

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

[0027] Preferably, the bed body is fixedly provided with side walls, and two X-direction guide rails that are not in the same coordinate plane are respectively located on the bed body and the side walls.

[0028] Preferably, at least three guide rails are arranged in the X-axis direction. A fourth motion plane is formed between two X-direction 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 body is fixedly provided with support columns. The X-direction guide rail is located between the support columns and the side walls. Cross beams are provided at the tops of the support columns and the side walls, and two Y-direction guide rails that are not in the same coordinate plane are respectively located on the bed body and the cross beams.

[0030] Preferably, it further includes a saddle and a ram. The saddle is arranged on the cross beam through a Y-direction guide rail, the ram is arranged on the saddle through a Z-direction guide rail, and the swing angle milling head is arranged on the ram.

[0031] Preferably, among the two Y-direction guide rails that are not in the same coordinate plane, the Y-direction guide rail located on the machine tool bed is arranged below the Y-direction guide rail located on the crossbeam; the two Z-direction guide rails that are not in the same coordinate plane are respectively located on one side of the ram facing the crossbeam and on the side away from the crossbeam, and the bottom end of the Z-direction guide rail located on the side of the ram away from the crossbeam is arranged below the bottom end of the Z-direction guide rail located on the side of the ram facing the crossbeam; the mounting surface of the swing angle milling head is arranged on the ram, 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-direction guide rail located on the crossbeam gradually increases along the Z-axis direction.

[0032] 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 crossbeam through a Y-direction 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 arranged at the tops of the first support plate, the second support plate and the third support plate; the ram is arranged between the first support plate and the second support plate.

[0033] Beneficial effects:

[0034] In the fixed crossbeam machine tool with an internal constraint structure disclosed in this application, by arranging at least a pair of guide rails that are not in the same coordinate plane in the X-axis direction, Y-axis direction and Z-axis direction respectively, at least two of the X-internal constraint space, Y-internal constraint space and Z-internal constraint space formed by the guide rails in the X-axis direction, Y-axis direction and Z-axis direction can intersect to form a closed motion space, thereby realizing the optimization of the guide rail structure layout. Using the guide rails to internally constrain the movement of the machine tool components, the tip point is always located within the closed motion space during the machining process, realizing the effective constraint of the tip point in the X-axis direction, Y-axis direction and Z-axis direction, greatly reducing the influence of the cutting force on the tip point, thereby reducing the micro-displacement of the 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.

[0035] Through the linear displacement of the turntable, it is ensured that the workpiece fixed on the turntable can coincide with the motion space, which is convenient for loading and unloading. Description of the drawings

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1Schematic diagram of a fixed crossbeam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0038] Figure 2 Structural schematic diagram of a fixed crossbeam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0039] Figure 3 Front view of a fixed crossbeam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0040] Figure 4 Side view of a fixed crossbeam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0041] Figure 5 Top view of a fixed crossbeam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0042] Figure 6 Schematic diagram of the Y - direction internal constraint space of a fixed crossbeam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0043] Figure 7 Schematic diagram of the X - direction internal constraint space of a fixed crossbeam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention;

[0044] Figure 8 Schematic diagram of the Z - direction internal constraint space of a fixed crossbeam machine tool with an internal constraint structure disclosed in Embodiment 1 of the present invention.

[0045] In the figure:

[0046] 1. Bed; 12. Support column;

[0047] 2. Swivel milling head; 21. Mounting end; 22. Tool clamping end; 23. Mounting surface;

[0048] 3. Crossbeam; 34. Side wall;

[0049] 4. Saddle; 44. First support plate; 45. Second support plate; 46. Third support plate; 47. Top plate;

[0050] 5. Ram;

[0051] 6. Turntable;

[0052] 71. First X - direction guide rail; 72. Second X - direction guide rail; 73. Third X - direction guide rail;

[0053] 81. First Y - direction guide rail; 82. Second Y - direction guide rail; 83. Third Y - direction guide rail;

[0054] 91. First Z - direction guide rail; 92. Second Z - direction guide rail; 93. Third Z - direction guide rail;

[0055] A1, the first motion plane; A2, the second motion plane; A3, the third motion plane; A4, the fourth motion plane;

[0056] X1, the X-inward constraint space;

[0057] Y1, the Y-inward constraint space; Y11, the first Y-direction sub-space; Y12, the second Y-direction sub-space;

[0058] Z1, the Z-inward constraint space; Z11, the first Z-direction sub-space; Z12, the second Z-direction sub-space; Z13, the third Z-direction sub-space;

[0059] N, the motion space. Detailed implementation manners

[0060] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0061] The accuracy of a machine tool is affected by various factors, including the structural design of the machine tool, the drive system and control system, thermal errors, tool wear, and the measurement and feedback system, etc. To improve the accuracy of the machine tool, efforts can be made from these aspects or comprehensive measures can be taken. Since the structural design of the machine tool is the foundation of the entire machine tool, if we want to improve the accuracy of the machine tool, the primary task is to optimize the structural design of the machine tool.

[0062] Current machine tools are mainly divided into structural types such as 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 results in a cantilever structure of the machine tool spindle; however, the cutting force borne by the tool tip point during the machining process mainly acts on the connection part between it and the adjacent component, which makes the stiffness of the machine tool directly affect the stress state of the tool tip point and the stability of the machining accuracy.

[0063] The existing machine tool structures mainly improve the stiffness of the entire machine tool by enhancing the static stiffness of each component. However, it is found in actual applications that under the influence of cutting force, gravity, and acceleration, etc., the dynamic stiffness of each component of the machine tool is insufficient, resulting in irregular small displacements of the tool tip point, significantly affecting the machining accuracy of the machine tool. This makes us realize that improving the dynamic stiffness of the machine tool is particularly important for improving the machining accuracy of the machine tool.

[0064] The machine tool includes linear motion axes and rotational axes to achieve the machining of complex parts. This requires that the components of the linear axes of the machine tool must be connected and supported through guide rails, enabling the guide rails to bear the acting forces and ensure the motion accuracy. During the machining process of the machine tool, if the dynamic stiffness of the guide rails is insufficient, it will cause deformation of the guide rails, directly affecting the machining accuracy of the machine tool and further reducing the machining quality. This means that the dynamic stiffness of the machine tool largely depends on the dynamic stiffness of the guide rails. That is, the higher the dynamic stiffness of the guide rails, the smaller the impact on the machining accuracy. On the contrary, the lower the dynamic stiffness of the guide rails, the greater the impact on the machining accuracy. However, limited by the mechanical properties of materials, the improvement of the dynamic stiffness of the guide rails is limited, which requires us to start from other directions to enhance the dynamic stiffness of the guide rails.

[0065] Through research and analysis, it is found that currently, the linear motion of machine tool components is usually supported by double guide rails. The double guide rails are located in the same plane and are prone to being 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 from optimizing the structural layout of the machine tool and the layout of the guide rails to improve the dynamic stiffness of the guide rails, thereby enhancing the stiffness of the entire machine tool.

[0066] Embodiment 1:

[0067] A fixed crossbeam machine tool with an internal constraint structure, in combination with Figure 1-8 as shown, includes: a machine tool spindle, a turntable 6, and a bed 1, and further includes:

[0068] The XY coordinate plane, the YZ coordinate plane, and the ZX coordinate plane;

[0069] The XY coordinate plane is a plane perpendicular to the Z-axis direction;

[0070] The YZ coordinate plane is a plane perpendicular to the X-axis direction;

[0071] The ZX coordinate plane is a plane perpendicular to the Y-axis direction;

[0072] At least two guide rails are provided in the X-axis direction, the Y-axis direction, and the Z-axis direction, and at least one pair of guide rails not in the same coordinate plane exists in the same axial direction;

[0073] The two XY coordinate planes and the two ZX coordinate planes where the two X-direction guide rails of each pair not in the same coordinate plane are located form an X-direction sub-space, and the union of the X-direction sub-spaces forms an X-direction internal constraint space X1;

[0074] The two XY coordinate planes and the two YZ coordinate planes where the two Y-direction guide rails of each pair not in the same coordinate plane are located form a Y-direction sub-space, and the union of the Y-direction sub-spaces forms a Y-direction internal constraint space Y1;

[0075] For each pair of two Z-axis guide rails not in the same coordinate plane, the two ZX coordinate planes and the two YZ coordinate planes where they are located form a Z-axis sub-space, and the union of the Z-axis sub-spaces forms an internal Z-axis constraint space Z1;

[0076] The region where at least two of the internal X-axis constraint space X1, internal Y-axis constraint space Y1, and internal Z-axis constraint space Z1 coincide is the motion space N, and the motion space N is the motion region of the tip point of the machine tool spindle during the machining process;

[0077] The turntable 6 is arranged on the machine body 1 through the X-axis guide rail, and the workpiece on the turntable 6 is made to coincide with the motion space N through the linear displacement of the turntable 6.

[0078] In this embodiment, to facilitate the construction of each space and plane, the guide rail needs to be conceptualized as a line in the space to serve as the basis for the construction of the space and plane;

[0079] Specifically, when the region of the guide rail for carrying the machine tool component is the guide rail surface of the guide rail itself (taking Figure 3 as an example, Figure 3 the first Y-axis guide rail 81 in

[0080] meets this condition), the guide rail can be conceptualized as the center line of the guide rail surface; Figure 3 as an example, Figure 3 the third Y-axis guide rail 83 in

[0081] In this embodiment, the coordinate planes include the XY coordinate plane, YZ coordinate plane, and ZX coordinate plane;

[0082] The XY coordinate plane is a plane parallel to the XY plane, which is called the z = k plane in mathematics, and its normal vector is the same as that of the standard XY plane, where k is a constant;

[0083] The YZ coordinate plane is a plane parallel to the YZ plane, which is called the x = k plane in mathematics, and its normal vector is the same as that of the standard YZ plane, where k is a constant;

[0084] The ZX coordinate plane is a plane parallel to the ZX plane, which is called the y = k plane in mathematics, and its normal vector is the same as that of the standard ZX plane, where k is a constant.

[0085] For the guide rails in the X-axis direction, for each pair of two X-axis guide rails not in the same coordinate plane, the two XY coordinate planes z = k planes where they are located have different corresponding constants k;

[0086] For each pair of two X-axis guide rails not in the same coordinate plane, the two ZX coordinate planes y = k planes where they are located have different corresponding constants k;

[0087] The X-direction sub-space is a prism-shaped space with two open ends, enclosed by two XY coordinate planes and two ZX coordinate planes where each pair of X-direction guide rails that are not in the same coordinate plane are located;

[0088] When the number of X-direction guide rails is equal to 2, there is only one pair of X-direction guide rails that are not in the same coordinate plane, so there is only one X-direction sub-space. At this time, the X-direction internal constraint space X1 is equal to the X-direction sub-space;

[0089] When the number of X-direction guide rails is greater than 2, for each additional pair of X-direction guide rails that are not in the same coordinate plane, one more X-direction sub-space will be correspondingly added. At this time, the X-direction internal constraint space X1 is equal to the union of multiple X-direction sub-spaces;

[0090] For the guide rails in the Y-axis direction, for each pair of Y-direction guide rails that are not in the same coordinate plane, the two XY coordinate planes z = k planes where they are located have different corresponding constants k;

[0091] For each pair of Y-direction guide rails that are not in the same coordinate plane, the two YZ coordinate planes x = k planes where they are located have different corresponding constants k;

[0092] The Y-direction sub-space is a prism-shaped space with two open ends, enclosed by two XY coordinate planes and two YZ coordinate planes where each pair of Y-direction guide rails that are not in the same coordinate plane are located;

[0093] 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. At this time, the Y-direction internal constraint space Y1 is equal to the Y-direction sub-space;

[0094] When the number of Y-direction guide rails is greater than 2, for each additional pair of Y-direction guide rails that are not in the same coordinate plane, one more Y-direction sub-space will be correspondingly added. At this time, the Y-direction internal constraint space Y1 is equal to the union of multiple Y-direction sub-spaces.

[0095] For the guide rails in the Z-axis direction, for each pair of Z-direction guide rails that are not in the same coordinate plane, the two ZX coordinate planes y = k planes where they are located have different corresponding constants k;

[0096] For each pair of Z-direction guide rails that are not in the same coordinate plane, the two ZY coordinate planes x = k planes where they are located have different corresponding constants k.

[0097] The Z-direction sub-space is a prism-shaped space with two open ends, enclosed by two ZX coordinate planes and two YZ coordinate planes where each pair of Z-direction guide rails that are not in the same coordinate plane are located;

[0098] When the number of Z-axis guide rails is equal to 2, there is only one pair of Z-axis guide rails not in the same coordinate plane, so there is only one Z-axis sub-space. At this time, the Z-axis inner constraint space Z1 is equal to the Z-axis sub-space.

[0099] When the number of Z-axis guide rails is greater than 2, for each additional pair of Z-axis guide rails not in the same coordinate plane, one more Z-axis sub-space will be correspondingly added. At this time, the Z-axis inner constraint space Z1 is equal to the union of multiple Z-axis sub-spaces.

[0100] The motion plane is established in the same way as the aforementioned method of conceptualizing the guide rail as a line in space. On the same axis, the plane where the lines formed by conceptualizing two guide rails not in the same coordinate plane are located together is the motion plane.

[0101] Although the lines formed by conceptualizing the guide rail are used as the benchmark for space establishment, compared with the inner constraint space in the shape of a quadrangular prism composed of coordinate planes, for the guide rail constraint space in the corresponding direction surrounded by constraint surfaces, the tool tip point can be completely located within the range surrounded by the guide rails, with a better constraint effect, further reducing the influence of the cutting force on the tool tip point and reducing the micro-displacement of the tool tip point.

[0102] The tool tip point is the point that the tool tip of the machine tool spindle needs to reach.

[0103] In this application, by setting at least one pair of guide rails not in the same coordinate plane in the X-axis direction, Y-axis direction, and Z-axis direction respectively, at least two of the X-axis inner constraint space, Y-axis inner constraint space, and Z-axis inner constraint space formed by the guide rails in the X-axis direction, Y-axis direction, and Z-axis direction can intersect to form a closed motion space N, thereby realizing the optimization of the guide rail structure layout. Using the guide rails to perform inner constraints on the movement of the machine tool components, the tool tip point is always located within the closed motion space N during the machining process, achieving effective constraints on the tool tip point in the X-axis direction, Y-axis direction, and Z-axis direction, greatly reducing the influence of the cutting force on the tool tip point, and thus 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.

[0104] Preferably, the motion space N is the overlapping region of the X inward constraint space X1, the Y inward constraint space Y1, and the Z inward constraint space Z1. By overlapping the X inward constraint space X1, the Y inward constraint space Y1, and the Z inward constraint space Z1 to form a closed motion space N, it can ensure that the tip point is always within the closed space when moving in three motion directions during the machining process. During the machining process, the cutting force acting on the tip point can be confined within the motion space N, and a pair of guide rails on the three axes that are not in the same coordinate plane always maintain a two-end support state for the tip point, optimizing the force on the guide rails; at the same time, the machine tool components moving in the three axes can also always be supported at both ends, that is, it can optimize the force on the guide rails and also support and limit the machine tool components. Finally, through the above structural layout, weak links and regions with insufficient dynamic stiffness are eliminated, thereby improving the overall stiffness of the machine tool, reducing the micro-displacement of the tip point, avoiding the influence of the tipping moment, and further suppressing vibration and deformation, ensuring the machining stability of the tip point.

[0105] At the same time, the improvement of dynamic stiffness can also reduce the wear and aging of the machine tool, ensure the machining accuracy of the machine tool, and achieve the effect of extending the service life of the machine tool.

[0106] 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 on the three axes that are not in the same coordinate plane, which makes the motion area necessarily located inside the support structure of the machine tool; compared with the support structures of existing machine tools (such as the bed, support columns, saddle, and ram, etc.) that can only provide support outside the motion area of the tip point, the machine tool of the present application can reduce the volume and weight when achieving the same size machining area, thereby being beneficial to improving the overall stiffness of the machine tool and reducing the cost of the machine tool.

[0107] 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, the degrees of freedom of the guide rails in multiple directions are restricted. The guide rails can withstand greater lateral forces and torsional forces, improving the dynamic stiffness of the guide rails, thereby reducing the positioning errors caused by the loosening or deformation of the guide rails; and increasing the support points for the machine tool components connected to them, improving the dynamic stiffness of the corresponding machine tool components. At the same time, the consistency of each positioning can be ensured, improving the repeat positioning accuracy and meeting high-precision machining requirements.

[0108] Preferably, the prismatic space formed with the guide rails as the edges in the direction where at least three guide rails are provided 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. The prismatic space is a constraint surface formed between two adjacent guide rails, and multiple constraint surfaces are connected to enclose the guide rail constraint space in the corresponding direction.

[0109] The establishment of the constraint surface also adopts the method of conceptualizing the guide rail as a line in space as described above. In the direction where at least three guide rails are set, the plane where the lines formed by the conceptualization of two adjacent guide rails are located together is the constraint surface;

[0110] The constraint surfaces are connected to enclose a guide rail constraint space in the corresponding direction, which is a prism-shaped space formed with the lines formed by conceptualization as the edges;

[0111] In the same axial direction, 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 benchmark for establishing the space, compared with the inner constraint space in the shape of a quadrangular prism composed of coordinate planes, for the guide rail constraint space in the corresponding direction enclosed by the connected constraint surfaces, the tool tip point can be completely located within the enclosed range of the guide rail. The tool tip point will not form a cantilever structure for the guide rail in this direction, and the constraint effect is better. Further, the dynamic stiffness of the tool tip point is improved, the influence of the cutting force on the tool tip point is reduced, and the micro-displacement amount of the tool tip point is reduced.

[0112] Preferably, it further includes a swing angle milling head 2. The swing angle milling head 2 is a single-pendulum swing angle milling head. During the machining process, the swing axis of the swing angle milling head 2 is located within the first motion plane A1 in at least one axial direction, so that the first motion plane A1 plays a supporting role for the swing axis, reducing the influence of the cutting force on the swing axis and the tool tip point, and thus being able to maintain the stability of the accuracy during the machining process.

[0113] Preferably, the swing angle milling head 2 is a double-pendulum swing angle milling head. During the machining process, the swing axis of the swing angle milling head 2 is located within the first motion plane A1 in at least one axial direction.

[0114] Preferably, 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 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.

[0115] Preferably, the swing angle milling head 2 is arranged on the machine tool bed 1 through Y-direction guide rails and Z-direction guide rails, and the turntable 6 is arranged on the machine tool bed 1 through X-direction guide rails; the Y-direction guide rails include at least three guide rails, and a second movement plane A2 is formed between two Y-direction guide rails that are not in the same coordinate plane, and a third movement plane A3 is formed between one of the two Y-direction guide rails and any other Y-direction guide rail; the second movement plane A2 and the third movement plane A3 respectively pass through the mounting end 21 and the tool clamping end 22 of the swing angle milling head 2 / the tool clamping end 22 and the mounting end 21 of the swing angle milling head 2. The second movement plane A2 and the third movement plane A3 support the mounting end 21 and the tool clamping end 22 of the swing angle milling head 2, improve the dynamic stiffness of the swing angle milling head 2, realize better support for the mounting end 21 and the tool clamping end 22 of the swing angle 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, and thus can maintain the stability of the accuracy during the machining process.

[0116] Preferably, there is an angle between the mounting surface 23 of the swing angle milling head 2 and the XY coordinate plane, so that the distance from the tool tip point to the mounting surface 23 can be reduced, the cantilever length of the tool tip point relative to the mounting surface 23 is reduced, and thus the stiffness of the swing angle milling head is improved.

[0117] Preferably, the machine tool bed 1 is fixedly provided with side walls 34, and two X-direction guide rails that are not in the same coordinate plane are respectively located on the machine tool bed 1 and the side walls 34. Arranging part of the X-direction guide rails on the side walls 34 can provide stable and reliable support for the guide rails, suppress vibration and deformation, and is beneficial to ensuring the dynamic stiffness of the X-direction guide rails.

[0118] Preferably, at least three guide rails are arranged in the X-axis direction, and a fourth movement plane A4 is formed between two X-direction guide rails that are not in the same coordinate plane, and the fourth movement plane A4 passes through the workpiece on the turntable 6. The fourth movement 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 accuracy during the machining process.

[0119] Preferably, the machine tool bed 1 is fixedly provided with support columns 12, the X-direction guide rails are located between the support columns 12 and the side walls 34, and cross beams 3 are provided at the tops of the support columns 12 and the side walls 34. Two Y-direction guide rails that are not in the same coordinate plane are respectively located on the machine tool bed 1 and the cross beams 3. This layout can make full use of the high static stiffness of the side walls 34, the support columns 12 and the cross beams 3 to provide stable support for the Y-direction guide rails, and at the same time enable the turntable 6 to enter the movement space N below the cross beam 3 along the X-axis direction, which is beneficial to the loading and unloading of the machine tool.

[0120] In a specific embodiment, in combination with Figure 7As shown, the X-direction guide rail includes a first X-direction guide rail 71, a second X-direction guide rail 72, and a third X-direction guide rail 73. The first X-direction guide rail 71 and the second X-direction guide rail 72 are arranged on the side wall of the side wall 34, and the third X-direction guide rail 73 is arranged on the bed body 1. The first X-direction guide rail 71 and the second X-direction guide rail 72 are located in the same coordinate plane, the second X-direction guide rail 72 and the third X-direction guide rail 73 are located in the same coordinate plane, the first X-direction guide rail 71 and the third X-direction guide rail 73 are not in the same coordinate plane. The first X-direction guide rail 71, the second X-direction guide rail 72, and the third X-direction guide rail 73 form an X-direction sub-space, and the X-direction sub-space is the X-inward constraint space X1.

[0121] Preferably, it further includes a saddle 4 and a ram 5. The saddle 4 is arranged on the cross beam 3 through a Y-direction guide rail, the ram 5 is arranged on the saddle 4 through a Z-direction guide rail, and the swing angle milling head 2 is arranged on the ram 5.

[0122] Preferably, among the two Y-direction guide rails that are not in the same coordinate plane, the Y-direction guide rail located on the bed body 1 is arranged below the Y-direction guide rail located on the cross beam 3; the two Z-direction guide rails that are not in the same coordinate plane are respectively located on one side of the ram 5 facing the cross beam 3 and on the side away from the cross beam 3, and the bottom end of the Z-direction guide rail located on the side of the ram 5 away from the cross beam 3 is arranged below the bottom end of the Z-direction guide rail located on the side of the ram 5 facing the cross beam 3; the mounting surface 23 of the swing angle milling head 2 is arranged on the ram 5, and there is an angle between the mounting surface 23 of the swing angle milling head 2 and the XY coordinate plane, and the angle is greater than 0° and less than 90°. Along the Z-axis direction, the distance between the mounting surface 23 and the Y-direction guide rail located on the cross beam 3 gradually increases. This layout can not only enable the second moving plane A2 to support the mounting surface 23 and the tip point of the swing angle milling head 2, but also ensure that the tip point can reach a lower position and ensure the machining stroke of the tip point in the Z-axis direction.

[0123] In a specific embodiment, in combination with Figure 6 As shown, the Y-direction guide rail includes a first Y-direction guide rail 81, a second Y-direction guide rail 82, and a third Y-direction guide rail 83. The first Y-direction guide rail 81 and the second Y-direction guide rail 82 are arranged on the side wall of the cross beam 3, and the third Y-direction guide rail 83 is arranged on the bed body 1; the first Y-direction guide rail 81 and the second Y-direction guide rail 82 are located in the same coordinate plane, the third Y-direction guide rail 83 is not in the same coordinate plane as the first Y-direction guide rail 81 and the second Y-direction guide rail 82. The first Y-direction guide rail 81, the second Y-direction guide rail 82, and the third Y-direction guide rail 83 form two pairs of Y-direction guide rails that are not in the same coordinate plane, thus forming two Y-direction sub-spaces - a first Y-direction sub-space Y11 and a second Y-direction sub-space Y12. The union of the two Y-direction sub-spaces is the Y-inward constraint space Y1; the space enclosed by the three constraint surfaces formed by the three Y-direction guide rails is the guide rail constraint space in the Y-axis direction.

[0124] Preferably, the 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-direction 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 tops 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 machine body 1 block the ram 5 in five directions, which is beneficial to improving the dynamic stiffness of the ram 5.

[0125] In a specific embodiment, in combination with Figure 8 As shown, the Z-direction guide rails include a first Z-direction guide rail 91, a second Z-direction guide rail 92 and a third Z-direction guide rail 93, and all three are arranged on the saddle 4. The first Z-direction guide rail 91 is arranged on the first support plate 44. The second Z-direction guide rail 92 is arranged on the second support plate 45. The third Z-direction guide rail 93 is arranged on the third support plate 46. Any two of the first Z-direction guide rail 91, the second Z-direction guide rail 92 and the third Z-direction guide rail 93 are not in the same coordinate plane. The first Z-direction guide rail 91, the second Z-direction guide rail 92 and the third Z-direction guide rail 93 form three pairs of Z-direction guide rails not in the same coordinate plane, thus constituting three Z-direction sub-spaces - a first Z-direction sub-space Z11, a second Z-direction sub-space Z12 and a third Z-direction sub-space Z13. The union of the three Z-direction sub-spaces is the Z-direction internal constraint space Z1. The space enclosed by the three constraint surfaces formed by the three Z-direction guide rails is the guide rail constraint space in the Z-axis direction.

[0126] 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 one side of the ram 5. The swing angle milling head 2 can turn to the side of the ram 5 away from the third support plate 46, and then through the movement of the saddle 4 and cooperation with the tool magazine arranged on the machine body 1, tool change can be realized.

[0127] Embodiment 2:

[0128] The difference between this embodiment and Embodiment 1 lies in the positional relationship between the tip point of the machine tool spindle and the first moving plane A1 during the machining process.

[0129] Preferably, in combination with Figure 1 , Figure 2 and Figure 6As shown, a first movement plane A1 is formed between a pair of guide rails that are not in the same coordinate plane in the X-axis direction or the Y-axis direction. In this embodiment, it is in the X-axis direction. During the machining process, the tip point of the machine tool spindle can coincide with the first movement plane A1 in at least one axial direction. After the tip point coincides with the first movement plane A1, the first movement plane A1 plays a supporting role for the tip point, and the tip point does not form a cantilever structure relative to the first movement plane A1, so as to ensure the stability of the accuracy of the tip point during the machining of the plane.

[0130] The tip point of the swing angle milling head 2 is the tip point of the machine tool spindle. During the machining process, the swing axis of the swing angle milling head 2 has an intersection with the first movement plane A1 in at least one axial direction, and the tip point of the swing angle milling head 2 coincides with the intersection. After the tip point of the swing angle milling head coincides with the intersection, the first movement plane A1 plays a supporting role for the tip point, and the tip point does not form a cantilever structure relative to the first movement plane A1, reducing the influence of the cutting force on the displacement of the tip point relative to the swing axis, so as to ensure the stability of the accuracy of the tip point during the machining process.

[0131] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and 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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