Numerical control planer type milling machine with thermal tilt error compensation

Abstract

A numerical control planer type milling machine with a thermal tilt error compensation function comprises a base, the base is rotationally connected with a lead screw through a bearing seat, the outer surface of the lead screw is in threaded connection with a lead screw nut, the lead screw nut is installed below a workbench, and the lead screw is in transmission connection with a servo motor; a ram is installed on the workbench through a supporting stand column, and a spindle box is slidably installed on the side face of the ram. A first temperature sensor and a second temperature sensor are installed above and below the rear side of the ram respectively, a third temperature sensor is installed on the spindle box body, and the signal output ends of the first temperature sensor, the second temperature sensor and the third temperature sensor are connected with a thermal tilt error compensation module through communication cables. The signal output end of the thermal tilt error compensation module is connected with the controller, and the control end of the controller is connected with the servo motor. According to the utility model, the defects in the prior art are overcome, and the feed amount of the whole workbench in the X-axis direction can be compensated, so that the machining precision of the planer type milling machine in the X-axis direction is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of numerically controlled machine tools, in particular to a numerically controlled gantry milling machine with thermal tilt error compensation. Background Art

[0002] During long-term processing of CNC gantry milling machines, the temperature of the spindle box structure and the ram structure will change due to the temperature rise or drop of the spindle motor and the spindle when they are moving or stopped, which will cause thermal tilt deformation of the spindle box structure and the ram structure, causing thermal displacement errors of the spindle box structure and the ram structure in the X-axis direction of the machine tool, which will seriously reduce the processing accuracy of the machine tool in the X-axis.

[0003] In order to improve the machining accuracy of the existing CNC gantry milling machines in the X-axis, the traditional method is to increase the grating scale and improve the X-axis of the machine tool to a full closed-loop control mode; improve the heat dissipation of the spindle box structure and the ram structure and add an independent cooling device to suppress the X-axis machining error caused by the thermal tilt error of the spindle box structure and the ram structure.

[0004] However, by adding a grating scale, the method of improving the X-axis of the machine tool to a full closed-loop control mode only improves the error of the X-axis transmission system, but has no effect on the thermal tilt error generated by the spindle box structure and the ram structure; and the method of improving the heat dissipation of the spindle box structure and the ram structure and adding an independent cooling device can only be performed locally on the spindle box structure and the ram structure, otherwise it may affect the rigidity and strength of the spindle box structure and the ram structure, which will cause the temperature of the spindle box structure and the ram structure to be uneven. Although this method improves the thermal tilt error of the spindle box structure and the ram structure, it will also cause the spindle box structure and the ram structure to generate new thermal distortion errors due to the uneven temperature at various locations, which in turn creates new error problems. In addition, adding an independent cooling device is difficult to achieve consistent cooling effect all day long because the cooling device has the limitations of low temperature protection and high temperature protection. From the actual effect, the improvement of heat dissipation in the mechanical structure and the addition of an independent cooling device cannot effectively solve the X-axis processing error caused by the thermal tilt deformation of the machine tool spindle box structure and the slide structure, and the effect on improving the X-axis processing accuracy is limited. Utility Model Content

[0005] In view of the deficiencies of the prior art, the utility model provides a CNC gantry milling machine with thermal tilt error compensation, which overcomes the deficiencies of the prior art and has a reasonable design. It can compensate for the feed amount of the entire worktable in the X-axis direction, thereby effectively improving the machining accuracy of the gantry milling machine in the X-axis direction.

[0006] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] A CNC gantry milling machine with thermal tilt error compensation comprises a base, a screw rod is rotatably connected to the base through a bearing seat, a screw rod nut is threadedly connected to the outer surface of the screw rod, and the screw rod nut is fixedly mounted on the lower surface of a workbench, and one end of the screw rod passes through the bearing seat and is drivingly connected to the driving end of a servo motor;

[0008] A supporting column is fixedly installed on the workbench, a sliding block is installed on the side of the supporting column, and a spindle box is slidably installed on the side of the sliding block; a first temperature sensor and a second temperature sensor are respectively installed above and below the rear side of the sliding block, and a third temperature sensor is installed on the spindle box. The signal output ends of the first temperature sensor, the second temperature sensor and the third temperature sensor are connected to a thermal tilt error compensation module through communication cables, and the signal output end of the thermal tilt error compensation module is connected to a controller, and the control end of the controller is connected to a servo motor.

[0009] Preferably, two mutually parallel linear slide rails are fixedly installed on both sides of the upper surface of the base, the axis of the linear slide rail is parallel to the axis of the screw rod, and sliders are installed on both sides of the lower surface of the workbench, and the workbench is slidably connected to the linear slide rails through the sliders.

[0010] Preferably, a plurality of temperature sensors are evenly arranged on the supporting columns, and signal output ends of the temperature sensors are connected to the thermal tilt error compensation module via communication cables.

[0011] The utility model provides a CNC gantry milling machine with thermal tilt error compensation. It has the following beneficial effects: the temperature of the upper surface and the lower surface of the ram and the surface of the spindle box are detected respectively by the first temperature sensor and the second temperature sensor, and the temperature data is converted into the thermal tilt error data of the spindle box and the ram by the thermal tilt error compensation module, and the thermal tilt error data is transmitted to the controller by the thermal tilt error compensation module, and then the controller drives the servo motor to operate, thereby driving the screw rod to rotate, and then driving the screw rod nut to move along the axial direction of the screw rod to drive the entire worktable to move along the X-axis direction, so as to realize the compensation of the feed amount of the entire worktable, and then effectively improve the processing accuracy of the gantry milling machine in the X-axis direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings required for describing the prior art are briefly introduced below.

[0013] Figure 1 A schematic diagram of the structure of the utility model;

[0014] Figure 2 A partial cross-sectional schematic diagram of the base in the utility model;

[0015] Description of the numbers in the figure:

[0016] 1. Base; 2. Bearing seat; 4. Screw; 5. Screw nut; 6. Workbench; 7. Servo motor; 8. Support column; 9. Spindle box; 10. First temperature sensor; 11. Second temperature sensor; 12. Third temperature sensor; 13. Thermal tilt error compensation module; 14. Controller; 15. Linear guide; 16. Slider; 17. Slide; 18. Temperature sensor. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention.

[0018] Embodiment 1, as Figure 1-2 As shown, a CNC gantry milling machine with thermal tilt error compensation includes a base 1, a screw rod 4 is rotatably connected to the base 1 through a bearing seat 2, a screw rod nut 5 is threadedly connected to the outer surface of the screw rod 4, and the screw rod nut 5 is fixedly mounted on the lower surface of a workbench 6, and one end of the screw rod 4 passes through the bearing seat 2 and is drivingly connected to the driving end of a servo motor 7;

[0019] A support column 8 is fixedly installed on the workbench 6, a slide 17 is installed on the side of the support column 8, and a spindle box 9 is slidably installed on the side of the slide 17; a first temperature sensor 10 and a second temperature sensor 11 are respectively installed above and below the rear side of the slide 17, and a third temperature sensor 12 is installed on the spindle box 9. The signal output ends of the first temperature sensor 10, the second temperature sensor 11 and the third temperature sensor 12 are connected to the thermal tilt error compensation module 13 through communication cables, and the signal output end of the thermal tilt error compensation module 13 is connected to the controller 14, and the control end of the controller 14 is connected to the servo motor 7.

[0020] Working principle:

[0021] During normal use, the first temperature sensor 10 and the second temperature sensor 11 are used to detect the temperatures of the upper and lower surfaces of the slide 17 and the surface of the spindle box 9, respectively, and then the detection data is transmitted to the thermal tilt error compensation module 13. The thermal tilt error compensation module 13 converts the temperature data into thermal tilt error data of the spindle box 9 and the slide 17. In this embodiment, the conversion algorithm adopted by the thermal tilt error compensation module 13 can adopt the thermal error compensation system described in the patent number: "202111291001.2" and the patent name: "A method for self-healing of spindle precision of CNC machine tools".

[0022] The thermal tilt error data is then transmitted to the controller 14 through the thermal tilt error compensation module 13, and the controller 14 drives the servo motor 7 to operate, thereby driving the screw 4 to rotate, and then driving the screw nut 5 to move along the axial direction of the screw 4 to drive the entire worktable 6 to move along the X-axis direction, so as to compensate for the feed amount of the entire worktable 6, thereby effectively improving the machining accuracy of the gantry milling machine in the X-axis direction.

[0023] Embodiment 2, as a further preferred solution of embodiment 1, two parallel linear guide rails 15 are fixedly installed on both sides of the upper surface of the base 1, the axis of the linear guide rail 15 is parallel to the axis of the screw rod 4, and sliders 16 are installed on both sides of the lower surface of the workbench 6, and the workbench 6 is slidably connected to the linear guide rails 15 through the sliders 16.

[0024] Therefore, when the servo motor 7 rotates to drive the entire workbench 6 to move along the X-axis direction, the slider 16 on the lower surface of the workbench 6 can be slidably connected to the linear slide rail 15 to ensure the stability of the entire workbench 6 during movement, and can limit the entire workbench 6 in the vertical direction and angle to avoid the workbench 6 from offset, thereby further ensuring the processing accuracy of the gantry milling machine.

[0025] Embodiment 3, as a further preferred solution of embodiment 1, due to the difference in ambient temperature on both sides of the working area of ​​the support column 8 and the combined influence of heat sources such as the spindle motor during long-term processing of the gantry milling machine, the temperature on both sides of the support column 8 changes at different speeds, which causes the support column 8 to produce thermal tilt deformation, causing the support column 8 to produce thermal displacement error in the X-axis direction of the machine tool, and ultimately causing the machining accuracy of the machine tool in the X direction to be seriously reduced. In this embodiment, multiple temperature sensors 18 can be evenly arranged on both sides of the front and rear of the support column 8, and the signal output end of the temperature sensor 18 is connected to the thermal tilt error compensation module 13 through a communication cable. Therefore, the temperatures of the front and rear sides of the support column 8 can be detected respectively by each temperature sensor 18, and the detection data can be transmitted to the thermal tilt error compensation module 13. The thermal tilt error compensation module 13 converts the temperature data into thermal tilt error data of the support column 8, and then drives the servo motor 7 to operate through the controller 14 to drive the entire workbench 6 to move along the X-axis direction, so as to compensate for the feed amount of the entire workbench 6 in the X-axis direction, thereby effectively improving the X-axis processing accuracy.

[0026] 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 the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A CNC gantry milling machine with thermal tilt error compensation, characterized in that: The invention comprises a base (1), a screw rod (4) being rotatably connected to the base (1) via a bearing seat (2), a screw rod nut (5) being connected to the outer surface of the screw rod (4) via a thread, the screw rod nut (5) being fixedly mounted on the lower surface of a workbench (6), one end of the screw rod (4) passing through the bearing seat (2) and being transmission-connected to the driving end of a servo motor (7); A support column (8) is fixedly mounted on the workbench (6), a ram (17) is mounted on the side of the support column (8), and a spindle box (9) is slidably mounted on the side of the ram (17); a first temperature sensor (10) and a second temperature sensor (11) are respectively mounted above and below the rear side of the ram (17), and a third temperature sensor (12) is mounted on the spindle box (9); signal output ends of the first temperature sensor (10), the second temperature sensor (11) and the third temperature sensor (12) are connected to a thermal tilt error compensation module (13) via communication cables, and the signal output end of the thermal tilt error compensation module (13) is connected to a controller (14), and a control end of the controller (14) is connected to a servo motor (7).

2. A CNC gantry milling machine with thermal tilt error compensation according to claim 1, characterized in that: Two mutually parallel linear guide rails (15) are fixedly mounted on both sides of the upper surface of the base (1), the axis of the linear guide rail (15) is parallel to the axis of the screw rod (4), and sliders (16) are mounted on both sides of the lower surface of the workbench (6), and the workbench (6) is slidably connected to the linear guide rails (15) via the sliders (16).

3. A CNC gantry milling machine with thermal tilt error compensation according to claim 1, characterized in that: A plurality of temperature sensors (18) are evenly arranged on the support column (8), and a signal output end of the temperature sensor (18) is connected to a thermal tilt error compensation module (13) via a communication cable.

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