Control system of horizontal numerical control turning and milling composite machine tool

Abstract

The invention provides a control system of a horizontal numerical control turning and milling composite machine tool. The machine tool comprises a machine frame, a workpiece clamping assembly arranged on the machine frame, a tool rest base horizontally arranged on the machine frame in a sliding mode, a sliding frame arranged on the tool rest base in a sliding mode, a tool frame rotationally arranged on the sliding frame and used for installing a tool, and a driving motor driving the tool frame to rotate. The control system comprises a controller, a vibration detection unit arranged on the tool frame and used for detecting the vibration value of the tool frame, and a current detection unit connected with the driving motor and used for detecting the current of the motor. And the controller is configured to calculate a weighted comprehensive wear index based on the motor current detected by the current detection unit and the vibration value detected by the vibration detection unit, and dynamically adjust the cutting speed and the feeding amount based on the weighted comprehensive wear index, so that the machining precision of a product is ensured.

Description

Technical Field

[0001] This invention relates to the field of machine tool processing, and more specifically, to a control system for a horizontal CNC turning and milling composite machine tool. Background Technology

[0002] In CNC machining, tool wear directly affects machining quality and equipment safety. Currently, sensors such as cutting force, vibration, current, and acoustic emission are commonly used for monitoring. However, single sensors are susceptible to interference and cannot fully reflect the tool wear status under complex working conditions. In particular, motor current signals are easily affected by power grid fluctuations and sensor system errors, and cannot accurately capture minute wear changes when the cutting amount is small. As for vibration signals, they are affected by machine tool structure vibration, uneven workpiece material, and signal fluctuations caused by different batches of workpieces, leading to misjudgments of the wear degree. Therefore, accurately judging the degree of tool wear is a problem that urgently needs to be solved by those skilled in the art.

[0003] In existing machining processes, process designers first determine the specific cutting speed and feed rate in advance based on the workpiece material, workpiece structure, and cutting tools. Then, these parameters are input into the machine tool's control system to achieve automatic machining. However, regarding tool wear, the machine tool only issues an alarm to prompt the operator to replace the tool when it reaches severe wear. After the tool enters the stable wear stage, the cutting edge of the tool gradually becomes dull, and the actual cutting parameters of the tool change, thus affecting the machining accuracy. Therefore, when machining batches of workpieces, the difference in tool wear will directly affect the product quality when machining with the same process parameters.

[0004] Therefore, it is necessary to improve the control system of the existing horizontal CNC turning and milling machine tool to improve the machining accuracy of the product. Summary of the Invention

[0005] The main objective of this application is to provide a control system for a horizontal CNC milling and turning machine tool, which can automatically adjust the cutting speed and feed rate according to the wear of the cutting tool, thereby ensuring the machining accuracy of the product.

[0006] To achieve the above objectives, in a first aspect, this application provides a control system for a horizontal CNC milling and turning machine tool, the machine tool including a frame, a workpiece clamping assembly disposed on the frame, a tool holder horizontally slidably disposed on the frame, a sliding frame slidably disposed with respect to the tool holder, a tool holder rotatably disposed on the sliding frame and used for mounting a tool, and a drive motor for driving the tool holder to rotate. The control system includes a controller, a vibration detection unit mounted on the tool holder for detecting its vibration value, and a current detection unit connected to the drive motor for detecting its motor current. The controller is configured to calculate a weighted comprehensive wear index based on the motor current detected by the current detection unit and the vibration value detected by the vibration detection unit, and to dynamically adjust the cutting speed and feed rate based on the weighted comprehensive wear index.

[0007] Optionally, the weighted composite wear index Where I is the current average cutting current, I0 is the standard current value for the new tool, V is the current effective vibration value, and V0 is the standard vibration value for the new tool. as well as All are weighting coefficients.

[0008] Optionally, the cutting speed is adjusted based on the weighted composite wear index. ,in Let K be the adjusted cutting speed at time K. The initial cutting speed, For speed adjustment coefficient, The weighted composite wear index of the cutting tool is the normal threshold. is the weighted comprehensive wear index of the tool at time K.

[0009] Optionally, the feed rate can be adjusted based on the weighted composite wear index. ,in This represents the adjusted feed rate at time k. This is the initial feed rate. This is the feed adjustment factor.

[0010] Optionally, the vibration detection unit is a piezoelectric accelerometer.

[0011] Optionally, the current detection unit is a Hall current sensor.

[0012] Optionally, the system also includes an alarm electrically connected to the controller. When the calculated weighted comprehensive wear index is greater than 0.6, the controller controls the alarm to sound and stops the machine tool.

[0013] Optionally, the workpiece clamping assembly includes a first mounting bracket fixedly mounted on the frame, a multi-jaw chuck rotatably mounted on the first mounting bracket, a first motor driving the multi-jaw chuck to rotate, a movable frame slidably mounted on the frame via a first linear track, and a first drive mechanism driving the movable frame to slide.

[0014] Optionally, the sliding frame is inclined and slidably disposed with respect to the tool holder from top to bottom via a second linear track, and the sliding frame is driven to slide by a second drive mechanism.

[0015] Optionally, the tool holder includes a tool holder body and a plurality of tool mounting molds evenly distributed on the tool holder body with its rotation center as the center, and the tools are fixedly mounted on the tool mounting molds by fasteners.

[0016] The present invention provides a control system for a horizontal CNC milling and turning machine tool. Compared with the prior art, its advantages are as follows: by combining two easily obtainable and highly interference-resistant signal values, namely motor current and vibration value, a weighted comprehensive wear index is calculated, and the current cutting speed and feed rate are dynamically adjusted according to the weighted comprehensive wear index. Thus, when batch processing workpieces, the machine tool control system can automatically and dynamically adjust according to the wear degree of the tool, thereby ensuring the quality of each batch of products, and achieving a high degree of automation. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings: Figure 1 This is a machine tool diagram. Figure 1 ; Figure 2 This is a machine tool diagram. Figure 2 .

[0018] The components include: 1. Frame; 2. Tool holder; 3. Sliding frame; 4. Tool holder; 5. Drive motor; 6. Multi-jaw chuck; 7. Center; 8. Mold mounting. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0022] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0023] In addition, the term "multiple" should mean two or more.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] like Figures 1-2 As shown, a control system for a horizontal CNC milling and turning machine tool is disclosed. The machine tool includes a frame 1, a workpiece clamping assembly disposed on the frame 1, a tool holder 2 horizontally slidably disposed on the frame 1, a sliding frame 3 slidably disposed with respect to the tool holder 2, a tool holder 4 rotatably disposed on the sliding frame 3 and used for mounting tools, and a drive motor 5 for driving the tool holder 4 to rotate. The system also includes an alarm electrically connected to the controller. When the calculated weighted comprehensive wear index is greater than 0.6, the controller activates the alarm and stops the machine tool. The normal threshold weighted comprehensive wear index is ≤0.3, indicating slight tool wear that does not require adjustment. The warning threshold is a weighted comprehensive wear index greater than 0.3 and ≤0.6, indicating stable tool wear that requires fine-tuning of machining parameters. When the critical threshold (weighted comprehensive wear index greater than 0.6) is reached, the tool is approaching severe wear and needs to be replaced. At this point, the alarm sounds, and the controller stops the machine tool, waiting for the operator to replace the tool before restarting, thus ensuring product quality.

[0026] However, the above simple adjustments alone are insufficient for precise control of product quality. This is because, during CNC machine tool operation, the operator is not a process engineer and cannot adjust the control parameters in real time based on the degree of tool wear, i.e., real-time dynamic adjustment is not possible. Therefore, the control system of this invention includes a controller, a vibration detection unit mounted on the tool holder 4 for detecting its vibration value, and a current detection unit connected to the drive motor 5 for detecting its motor current. The controller is configured to calculate a weighted comprehensive wear index based on the motor current detected by the current detection unit and the vibration value detected by the vibration detection unit, and dynamically adjust the cutting speed and feed rate based on the weighted comprehensive wear index. The vibration detection unit is preferably a piezoelectric accelerometer, and the current detection unit is preferably a Hall current sensor.

[0027] Regarding the weighted composite wear index Where I is the current average cutting current, I0 is the standard current value for the new tool, V is the current effective vibration value, and V0 is the standard vibration value for the new tool. as well as All are weighting coefficients, among which, + =1. When machining materials with high hardness, changes in motor current may be more sensitive to tool wear; in this case, the motor current can be appropriately increased. The value, such as =0.6, =0.4; however, for turning softer materials, the vibration signal may have a more significant impact on tool wear, and can be set to... =0.4, =0.6, therefore, in actual operation, the operator can adjust the processing parameters according to the hardness of the workpiece. as well as Adjustments will be made.

[0028] As for I0 and V0, the motor current I0 and vibration value V0 under the stable state of the new tool are used as the reference, where the stable state is the state when the new tool is in normal turning.

[0029] Adjust the cutting speed based on the weighted comprehensive wear index. ,in Let K be the adjusted cutting speed at time K. The initial cutting speed, For speed adjustment coefficient, This is the normal threshold for the weighted comprehensive wear index of the cutting tool, which is any value within ≤0.3. The operator sets it according to the different processing requirements of the workpiece, such as selecting 0.3; The weighted composite wear index of the tool at time K is related to the speed adjustment coefficient. For lathe tools, the thickness is 0.2-0.3, while for milling cutters, which are more sensitive to speed, the thickness is 0.25-0.35.

[0030] Adjust feed rate based on weighted composite wear index ,in This represents the adjusted feed rate at time k. This is the initial feed rate. For the feed adjustment factor, regarding the feed adjustment factor For lathe tools, the feed rate is 0.15~0.25. Since the feed rate of the milling cutter has a greater impact on vibration, it needs to be adjusted conservatively. Therefore, the feed rate of the milling cutter is 0.1~0.2.

[0031] It should also be noted that max(0,·) means that no adjustment is made when WMI does not exceed the threshold (the coefficient is 0).

[0032] Regarding the structure of the machine tool, the workpiece clamping assembly includes a first mounting bracket fixedly mounted on the frame 1, a multi-jaw chuck 6 rotatably mounted on the first mounting bracket, a first motor driving the multi-jaw chuck 6 to rotate, a movable frame slidably mounted on the frame 1 via a first linear track, and a first drive mechanism driving the movable frame to slide. A center 7 is rotatably mounted on the movable frame. The workpiece is positioned by the cooperation of the center 7 and the multi-jaw chuck 6. At the same time, the multi-jaw chuck 6 is driven to rotate by the first motor, thereby causing the workpiece to rotate during the processing. As for the first drive mechanism, it essentially adjusts the distance between the movable frame and the first mounting bracket in order to match workpieces of different lengths and to facilitate the loading and unloading of workpieces.

[0033] Furthermore, the sliding frame 3 is inclined and slidably arranged with respect to the tool holder from top to bottom via a second linear track. The sliding frame 3 is driven to slide by a second drive mechanism. It should be noted that the inclined sliding arrangement allows for a larger tool holder 4, which can accommodate different tools, thus expanding the machining range of the CNC machine tool. In addition, the second drive mechanism is controlled by a controller. When adjusting the feed rate, the controller controls the second drive mechanism to adjust the sliding frame 3 relative to the tool holder, thereby achieving tool feed rate adjustment. The use of linear guide rails provides higher precision, thus ensuring product quality. It should be noted that the specific structure of the first and second drive mechanisms is not the design focus of this invention. In this invention, the movement is achieved by the cooperation of a lead screw and a screw sleeve. Of course, other drive methods can still be used and are also within the protection scope of this invention.

[0034] Preferably, the tool holder 4 includes a tool holder 4 body and a plurality of tool mounting molds 8 evenly distributed on the tool holder 4 body with its rotation center as the center. The tool is fixedly mounted on the tool mounting mold 8 by fasteners. When replacing the tool, it is connected to the mounting mold 8 by fasteners, which is convenient for disassembly and assembly. Moreover, by matching different mounting molds 8 with different tools, the stability after installation is improved, thereby ensuring the accuracy of vibration detection.

[0035] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A control system for a horizontal CNC turning and milling composite machine tool, characterized in that, The machine tool includes a frame, a workpiece clamping assembly mounted on the frame, a tool holder mounted horizontally on the frame, a sliding frame slidably mounted with respect to the tool holder, a tool holder rotatably mounted on the sliding frame and used for mounting tools, and a drive motor for driving the tool holder to rotate. The control system includes a controller, a vibration detection unit mounted on the tool holder for detecting its vibration value, and a current detection unit connected to the drive motor for detecting its motor current. The controller is configured to calculate a weighted comprehensive wear index based on the motor current detected by the current detection unit and the vibration value detected by the vibration detection unit, and to dynamically adjust the cutting speed and feed rate based on the weighted comprehensive wear index.

2. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 1, characterized in that: The weighted comprehensive wear index Where I is the current average cutting current, I0 is the standard current value for the new tool, V is the current effective vibration value, and V0 is the standard vibration value for the new tool. as well as All are weighting coefficients.

3. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 2, characterized in that: Adjust the cutting speed based on the weighted comprehensive wear index. ,in Let K be the adjusted cutting speed at time K. The initial cutting speed, For speed adjustment coefficient, The weighted composite wear index of the cutting tool is the normal threshold. is the weighted comprehensive wear index of the tool at time K.

4. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 3, characterized in that: Adjust feed rate based on weighted composite wear index ,in This represents the adjusted feed rate at time k. This is the initial feed rate. This is the feed adjustment factor.

5. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 1, characterized in that: The vibration detection unit is a piezoelectric accelerometer.

6. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 1, characterized in that: The current detection unit is a Hall current sensor.

7. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 1, characterized in that: It also includes an alarm that is electrically connected to the controller. When the calculated weighted comprehensive wear index is greater than 0.6, the controller controls the alarm to sound and controls the machine tool to stop.

8. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 1, characterized in that: The workpiece clamping assembly includes a first mounting frame fixedly mounted on the frame, a multi-jaw chuck rotatably mounted on the first mounting frame, a first motor driving the multi-jaw chuck to rotate, a movable frame slidably mounted on the frame via a first linear track, and a first driving mechanism driving the movable frame to slide.

9. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 1, characterized in that: The sliding frame is inclined and slidably mounted with respect to the tool holder from top to bottom via a second linear track, and the sliding frame is driven to slide by a second drive mechanism.

10. The control system of a horizontal CNC turning and milling composite machine tool as described in claim 1, characterized in that: The tool holder includes a tool holder body and a plurality of tool mounting molds evenly distributed on the tool holder body with its rotation center as the center. The tools are fixedly mounted on the tool mounting molds by fasteners.

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