Multi-tool-bit numerical control machine tool system supporting RTCP function and control method thereof

Abstract

The invention relates to a multi-tool-bit numerical control machine tool system supporting an RTCP function, and the system is configured to store and manage at least two groups of independent RTCP parameter sets, and each group of RTCP parameter sets is associated with an independent tool bit motion unit; according to the machining instruction, RTCP operation is executed for each set of tool bit movement unit so as to generate independent movement control instructions which guarantee that the center point of a tool moves along the programming track; and the motion control instruction is issued to the corresponding tool bit motion unit so as to drive at least two tool bits to perform machining in the RTCP mode at the same time. The invention further relates to an RTCP control method for the multi-tool-bit numerical control machine tool. By the adoption of the multi-tool-bit numerical control machine tool system supporting the RTCP function and the control method of the multi-tool-bit numerical control machine tool system, machining of multiple tool bits in the RTCP mode is achieved, and the machining efficiency is remarkably improved. And a multi-four-axis and multi-five-axis machine tool structure is supported, and certain flexibility is achieved.

Description

Technical Field

[0001] This invention relates to the field of CNC machine tool technology, specifically to a multi-head CNC machine tool system and its control method that supports RTCP function. Background Technology

[0002] Five-axis CNC machine tools are key equipment in high-end manufacturing. Their core technology, RTCP (Rotation Around Tool Center Point), ensures that the tool center point continues to move along the programmed trajectory when the tool direction changes. However, existing RTCP technology is mainly designed for five-axis machine tools with a single tool head and a single coordinate system, and does not yet provide effective support for complex CNC machine tool systems with multiple X-axis, multiple Z-axis, and multiple tool heads.

[0003] Therefore, there is an urgent need for an RTCP implementation scheme suitable for multi-X, multi-Z, and multi-head machining centers to enable simultaneous processing by multiple heads and improve processing efficiency. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-head CNC machine tool system and its control method that supports RTCP function.

[0005] To achieve the above objectives, the multi-head CNC machine tool system and its control method supporting RTCP function of the present invention are as follows: The main feature of this multi-head CNC machine tool system supporting RTCP functionality is that the system is configured as follows: Store and manage at least two independent sets of RTCP parameters, each set of RTCP parameters being associated with an independent tool movement unit; According to the machining instructions, RTCP calculations are performed for each group of tool head motion units to generate their own independent motion control instructions that ensure that the tool center point moves along the programmed trajectory. The motion control command is sent to the corresponding tool head motion unit to drive at least two tool heads to perform machining in RTCP mode simultaneously.

[0006] Preferably, the cutting head motion unit includes linear motion axes along the X, Y, and Z axes and at least one rotary axis, forming a four-axis or five-axis linkage structure.

[0007] Preferably, the system includes two sets of cutter head motion units, corresponding to the first cutter head group and the second cutter head group respectively. Each set of cutter head motion units has independent X-axis, Z-axis and B-axis, and shares the same Y-axis, forming a dual four-axis RTCP system.

[0008] Preferably, the system includes two sets of cutter head motion units, corresponding to the first cutter head group and the second cutter head group respectively. Each set of cutter head motion units has independent X-axis, Z-axis, B-axis and C-axis, and shares the same Y-axis, forming a dual five-axis RTCP system.

[0009] The RTCP control method for multi-head CNC machine tools is characterized by the following steps: Parameter configuration steps: Configure RTCP parameters for at least two independent tool heads in the machine tool; Instruction processing steps: parse the machining instructions and identify the machining trajectory corresponding to each tool head; Independent RTCP calculation steps: For each tool head, RTCP calculation is performed independently based on its corresponding RTCP parameters and machining trajectory to calculate the cooperative motion command of its respective rotary axis and linear axis, so that the tool center point of each tool head moves along its programmed trajectory. Synchronous control steps: The calculated motion commands for each tool head are synchronously sent to the machine tool's drive system to control all tool heads to perform machining simultaneously in RTCP mode.

[0010] Preferably, the independent RTCP operation steps specifically include: Obtain the coordinates of the tool center point of each tool head in the working coordinate system; Calculate the tool axis vector of each tool head based on the RTCP parameters of each tool head and the current programming trajectory; Based on the coordinates of the tool center point, the tool axis vector, and the tool pendulum length, the actual control point coordinates of the corresponding linear and rotary axes of each tool head are solved in reverse.

[0011] Preferably, the machining instructions are G-codes, and the RTCP function mode is enabled for each tool head via the G43.4 instruction.

[0012] The multi-head CNC machine tool system and its control method supporting RTCP functionality of the present invention have the following outstanding advantages compared with traditional RTCP technology: Multi-head RTCP control: Enables multi-head machining in RTCP mode, significantly improving machining efficiency. For example, a dual RTCP system provides double the machining efficiency, a three-set RTCP system provides triple the machining efficiency, and so on.

[0013] Flexibility: Supports multiple four-axis and multiple five-axis machine tool structures. Attached Figure Description

[0014] Figure 1 This is a flowchart of the RTCP control method for multi-head CNC machine tools according to the present invention.

[0015] Figure 2This is a schematic diagram of multi-head RTCP machining using dual five-axis RTCP as an example in a specific embodiment of the present invention. Detailed Implementation

[0016] To more clearly describe the technical content of the present invention, the following description is provided in conjunction with specific embodiments.

[0017] Before describing the embodiments of the present invention in detail, it should be noted that, in the following, the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0018] The core idea of ​​this invention is to build a unified RTCP processing architecture in the CNC system to enable multiple tool heads to work in RTCP mode.

[0019] The overall architecture of this multi-head CNC machine tool system that supports RTCP functionality mainly includes the following modules: 1. Multi-head parameter input module: Each RTCP group can be set with different parameters to serve its respective RTCP axis.

[0020] 2. Multiple RTCP adapter modules: Supports multiple four-axis RTCP (single swing head) and multiple five-axis RTCP (double swing head).

[0021] To achieve the above objectives, the core technical solution adopted by this invention is to support multiple sets of RTCP parameters on the CNC system, and to calculate and issue motion commands for each set of RTCP (X, Y, Z, A or B, C) axes during machining.

[0022] In practical applications, this technical solution is used in the overall processing flow of the Ncstudio CNC system software as follows: Figure 1 As shown: 1. Pre-read RTCP parameters at the start of processing or read RTCP parameters when executing T instructions in G code; 2. Interpolation operation: Generate motion instruction sequence based on G-code; The ability of a cutting tool to move along a straight line or arc is called interpolation. After the toolpath for machining the workpiece is prepared (such as a G-code toolpath file or other forms of toolpath file) and loaded into the CNC system, the CNC system converts it into specific interpolation motion information for subsequent control of the machine tool's machining motion.

[0023] 3. Obtain the coordinates of the tool center point (tool tip to workpiece coordinates) for each RTCP axis. Each of the interpolation movements described above can be considered as a tool movement unit, such as moving from a starting point to a target point. When machining a workpiece, each set of RTCP corresponds to one tool and one workpiece, and the spatial coordinates of the current starting point of the movement relative to the workpiece are the workpiece coordinates.

[0024] 4. Calculate the RTCP tool posture (including the oscillating head axis angle and oscillating length) for each group based on the RTCP parameters for each group. The tool orientation of each tool is mainly determined by two factors: Tool tip point: the center point of the tool tip (tool tip point XYZ workpiece coordinates), which is the reference point for the programmed trajectory.

[0025] Tool axis vector: A vector pointing from the tool tip towards the tool holder. This vector defines the spatial direction of the tool axis, which is controlled by the rotation axis angle during the current machining operation and the RTCP parameters (note that each set of RTCP parameters affects its corresponding tool).

[0026] When machining a workpiece, each RTCP group corresponds to one tool and one workpiece. The parameters of each RTCP group affect the current tool's swing length and the offset of the rotation axis center relative to the XYZ axes.

[0027] Example to understand tool axis vector: When the tool is pointing vertically downwards, the tool axis vector is typically (0, 0, 1) or (0, 0, -1) (depending on the definition of the coordinate system).

[0028] When the tool is tilted at 45 degrees, the tool axis vector may become (0, 0.707, 0.707). This vector value represents the component ratio in the X, Y, and Z directions.

[0029] 5. Calculate and issue motion commands for the coordinates of the RTCP axis control points for each group based on the tool posture and center point coordinates of each group: Based on the known tool swing length, tool posture, and motion start point, the motion is broken down into small control point coordinate steps to achieve fine and smooth motion.

[0030] We already know: Tool pendulum length (i.e., the distance from the center of rotation to the tip of the tool); Tool posture (represented by a unit vector indicating the direction of the tool axis); The starting point of the movement (i.e., the coordinates of the cutting point, which is also the coordinates of the blade tip); Objective: To break down motion into small control points to achieve fine, smooth motion.

[0031] The specific calculation process is implemented by our company's existing algorithm. The difference of this solution is that it supports multiple tools. Each tool can process one workpiece. Each tool corresponds to its XYZ axis and rotary axis. Each set of RTCP parameters participates in the calculation of its corresponding axis.

[0032] 6. The CNC system sequentially issues motion interpolation commands. The aforementioned series of motion commands are then issued and the machine tool is controlled to process the workpieces simultaneously using multiple tools.

[0033] This technical solution has been implemented in our company's CNC engraving software and applied to customers' actual needs.

[0034] The implementation of this technical solution will be further explained below with reference to specific embodiments: Example 1: Dual quadcopter RTCP (X1X2YZ1Z2B1B2) Taking a multi-X-X-Z-RTCP CNC machine tool with two independent cutting heads (cutting head A and cutting head B) as an example, the implementation of the present invention is described as follows: System initialization: Configure the tool parameters for tool head A and tool head B, which are the Z-axis reference, L1, and L2 corresponding to tool head A and tool head B, respectively.

[0035] RTCP Function Enabled: In the machining program, use the T command to change tools and update the RTCP parameters of tool head A and tool head B, and use the command "G43.4" to enable the RTCP function for tool head A and tool head B.

[0036] Example 2: Dual five-axis RTCP (X1X2YZ1Z2B1B2C1C2) Taking a multi-X-X-Z-RTCP CNC machine tool with two independent cutting heads (cutting head A and cutting head B) as an example, the implementation of the present invention is described as follows: System initialization: Configure the tool parameters for tool head A and tool head B, which are the Z-axis reference, L1, L2, L3, and L4 corresponding to tool head A and tool head B, respectively.

[0037] RTCP Function Enabled: In the machining program, use the T command to change tools and update the RTCP parameters of tool head A and tool head B, and use the command "G43.4" to enable the RTCP function for tool head A and tool head B.

[0038] Compared with the prior art, the present invention has the following advantages: 1. Supports simultaneous processing of multiple cutting heads in RTCP mode, significantly improving processing efficiency; 2. Applicable to complex machine tool structures such as multi-four-axis and multi-five-axis machines, offering high flexibility; 3. No need to repeatedly deploy multiple machine tool systems, reducing costs.

[0039] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0040] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution device.

[0041] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0042] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0043] In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0045] The multi-head CNC machine tool system and its control method supporting RTCP function of the present invention realize multi-head machining in RTCP mode, which significantly improves machining efficiency and has a certain degree of flexibility.

[0046] In this specification, the invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations can be made without departing from the spirit and scope of the invention. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

Claims

1. A multi-tool head CNC machine tool system supporting RTCP functions, characterized in that, The system is configured to: store and manage at least two independent RTCP parameter sets, each of which is associated with an independent tool head movement unit; perform RTCP operation for each tool head movement unit according to the machining instructions to generate independent movement control instructions that ensure the tool center point of each tool head moves along the programmed trajectory; issue the movement control instructions to the corresponding tool head movement unit to drive at least two tool heads to simultaneously process in RTCP mode.

2. The multi-tool head CNC machine tool system supporting RTCP function according to claim 1, wherein, The tool head movement unit includes linear motion axes along X, Y, and Z axes and at least one rotary axis, forming a four-axis or five-axis linkage structure.

3. The multi-tool head CNC machine tool system supporting RTCP function according to claim 2, wherein, The system includes two tool head movement units corresponding to the first tool head group and the second tool head group, respectively, each tool head movement unit having independent X, Z, and B axes and sharing the same Y axis, forming a dual four-axis RTCP system.

4. The multi-tool head CNC machine tool system supporting RTCP function according to claim 2, wherein, The system includes two tool head movement units corresponding to the first tool head group and the second tool head group, respectively, each tool head movement unit having independent X, Z, B, and C axes and sharing the same Y axis, forming a dual five-axis RTCP system.

5. A method for RTCP control of a multi-tool CNC machine, characterized in that, The method includes the following steps: parameter configuration step: configuring RTCP parameters for at least two independent tool heads in the machine tool; instruction processing step: parsing the machining instructions to identify the machining trajectories corresponding to each tool head; independent RTCP operation step: for each tool head, performing independent RTCP operation according to its corresponding RTCP parameters and machining trajectory to calculate the coordinated movement instructions of the rotary axis and linear axis of each tool head, so that the tool center point of each tool head moves along its programmed trajectory; synchronous control step: issuing the calculated movement instructions of each tool head to the drive system of the machine tool to control all tool heads to process simultaneously in RTCP mode.

6. The RTCP control method for a multi-tool CNC machine tool according to claim 5, characterized in that, In the parameter configuration step, the RTCP parameters of the currently active tool head are dynamically updated in response to the tool change T instruction.

7. The RTCP control method for a multi-tool CNC machine tool according to claim 5, characterized in that, The independent RTCP operation step specifically includes: obtaining the coordinates of the tool center point of each tool head in the work coordinate system; calculating the tool axis vector of each tool head according to its RTCP parameters and the current programmed trajectory; back-solving the actual control point coordinates of the linear axis and rotary axis of each tool head according to the tool center point coordinates, tool axis vector, and tool runout.

8. The RTCP control method for a multi-tool CNC machine tool according to any one of claims 5 to 7, characterized in that, The machining instructions are G codes, and the RTCP function mode is enabled for each tool head through the G43.4 instruction.

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