Numerical control machining method for thread segmented cutting

Abstract

A thread segmented cutting numerical control machining method comprises the following steps that a machine tool obtains thread parameters; determining a plurality of thread cutting points in the length direction of the thread from the thread starting point to the thread ending point, wherein the thread cutting points divide the thread into a plurality of sections; the cycle number of thread turning of the machine tool turning tool is determined; the machine tool spindle is controlled to drive the workpiece to rotate, the machine tool turning tool is controlled to start turning threads from the starting point of the threads, every time the machine tool turning tool moves to a thread cutting point, the tool is lifted for cutting once, the machine tool turning tool feeds from the thread cutting point, the machine tool turning tool continues turning the next section of threads until the thread end point is reached, the tool is retracted, and the machine tool turning tool finishes turning the threads once; and then the machine tool turning tool repeats the turning action for multiple times until the determined cycle number is reached, and thread machining is completed. Sectional cutting of thread machining can be conveniently and rapidly achieved, the thread machining efficiency is improved, scrap iron is small in length, scrap iron is prevented from winding a machine tool spindle chuck, and iron pins are prevented from scratching the inner circle and the outer circle of a workpiece.

Description

Technical Field

[0001] The invention relates to the technical field of thread numerical control machining, and in particular to a thread segmented cutting numerical control machining method. Background Art

[0002] When using the original ordinary CNC thread machining instructions, the thread cannot be processed in sections and can only be turned continuously from end to end. The iron chips generated are long strips, which can easily cause the iron chips to wrap around the machine tool spindle chuck, resulting in a large amount of accumulated iron chips that are difficult to remove. They will also scratch the inner and outer circles of the workpiece, affecting the quality of the workpiece.

[0003] Chinese invention patent CN2019105728770 discloses a segmented processing method for slender threads, the steps are: S1, slender thread processing planning, according to the total length of the slender thread is reasonably distributed into several segments for processing; S2, processing the first segment of the thread, processing the first segment of the thread by turning, and ensuring that the withdrawal angle is controlled at 115-120° when the first segment of the thread is withdrawn; S3, processing the middle segment of the thread, processing the middle segment of the thread by turning, ensuring that the feed point starts from the integer multiple of the pitch of the previous segment of the thread, and when the middle segment of the thread is withdrawn, the withdrawal angle is controlled at 115-120°; S4, processing the last segment of the thread, processing the last segment of the thread by turning, ensuring that the feed point starts from the integer multiple of the pitch of the previous segment of the thread. The above processing method can prevent the deformation and breakage of the slender thread; the withdrawal angle has a good reserved tooth shape, and there will be no withdrawal groove; the selection of the feed point plays a good role in connection. However, the segmented processing method of the slender thread is to process one segment of thread before processing the next segment of thread. The end of each segment of thread needs to be retracted, the processing steps are complicated, and the retraction of the tool will still produce a retraction groove for the coarse thread, which is not suitable for coarse thread processing. Summary of the invention

[0004] The purpose of the present invention is to address the deficiencies in the prior art and thereby provide a CNC machining method for segmented thread cutting. The present invention can conveniently and quickly realize segmented thread machining and improve thread machining efficiency. The length of iron chips is small, and iron chips are prevented from wrapping around the machine tool spindle chuck. The iron chips are easy to remove, and iron pins are prevented from scratching the inner and outer circles of the workpiece, thereby ensuring the quality of the workpiece.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: a CNC machining method for segmented thread cutting, comprising the following steps: The machine tool obtains thread parameters; Several thread cutting points are determined from the thread starting point to the thread end point in the thread length direction, and the thread cutting points divide the thread into multiple sections; Determine the number of cycles of the machine tool turning thread; The machine tool spindle is controlled to drive the workpiece to rotate, and the machine tool turning tool is controlled to start turning the thread from the starting point of the thread. Whenever the machine tool turning tool runs to a thread breaking point, the tool is lifted and cut once, and the machine tool turning tool then feeds from the thread breaking point, and the machine tool turning tool continues to turn the next section of the thread until the end point of the thread, and then the tool is retracted, and the machine tool turning tool completes turning the thread once; thereafter, the machine tool turning tool repeats the above turning action multiple times until a certain number of cycles is reached, and the thread processing is completed.

[0006] Based on the above, the thread parameters are obtained by calling the G65 program.

[0007] Based on the above, the R value and Z value in the G65 program are called to determine the thread length, R is the thread starting point, and Z is the thread end point; Call the Q value in the G65 program. Q is the depth of cut. Positive values ​​are used for thread cutting, while negative values ​​are used for normal processing. If the Q value in the G65 program is set to a positive number, the machine tool will automatically divide the thread into segments from the thread start point to the thread end point based on Q times the pitch, and automatically determine the thread breaking point.

[0008] Based on the above, the ratio of thread length to Q times the pitch is N, and N is greater than 0; When N is an integer, the number of thread breaking points is N-1, and the thread is divided into N segments; When N is a decimal, the number of thread breaking points is the integer part R of N, and the thread is divided into R+1 sections.

[0009] The present invention has outstanding substantive features and significant progress compared to the prior art. Specifically, the present invention determines a number of thread cutting points in the direction of the thread length from the starting point to the end point of the thread. The thread cutting points divide the thread into multiple sections. Whenever the machine tool turning tool runs to a thread cutting point, the tool is lifted and cut once, and the machine tool turning tool then feeds from the thread cutting point to continue turning the thread, thereby conveniently and quickly realizing segmented thread cutting, improving thread processing efficiency, reducing continuous end-to-end turning, and reducing the length of iron chips to avoid iron chips from wrapping around the machine tool spindle chuck. The iron chips are easy to remove, preventing iron pins from scratching the inner and outer circles of the workpiece, and ensuring the quality of the workpiece. At the same time, the continuous turning length is short, which can increase the service life of the tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a flow chart of the numerical control machining method for segmented thread cutting of the present invention.

[0011] Figure 2 It is a schematic diagram that the thread of the present invention is divided into two sections.

[0012] In the figure: 1. Machine tool turning tool; 2. Workpiece; 3. Thread breaking point. DETAILED DESCRIPTION

[0013] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0014] like Figure 1 and Figure 2 As shown, a CNC machining method for segmented thread cutting comprises the following steps: Step 1: The machine tool obtains thread parameters; Step 2: Determine a number of thread breaking points 3 in the thread length direction from the thread starting point to the thread end point, and the thread breaking points 3 divide the thread into multiple sections; Step 3: Determine the number of cycles of the machine tool turning tool 1 for turning the thread (determined by the thread tooth depth and the depth of the thread turned by the machine tool turning tool 1 each time); Step 4: Control the machine tool spindle to drive the workpiece 2 to rotate, and control the machine tool turning tool 1 to start turning the thread from the starting point of the thread. Whenever the machine tool turning tool 1 runs to a thread breaking point 3, the tool is lifted and cut once, and the machine tool turning tool 1 then feeds from the thread breaking point 3, and the machine tool turning tool 1 continues to turn the next section of the thread until the end point of the thread, and then retracts the tool. The machine tool turning tool 1 completes turning the thread once; thereafter, the machine tool turning tool 1 repeats the above turning action multiple times until a certain number of cycles is reached, and the thread processing is completed.

[0015] The thread parameters are obtained by calling the G65 program, specifically using the G65P8030 A_ B_ C_ I_ D_ E_F_M_ Q_ R_ Z_ program segment call, the interpretation is as follows: #1=(A large diameter) #2=(Trail B) #3=(C groove bottom width) #4=(I blade width) #7=(D tooth top arc radius) #8=(E tooth angle 1 / 2) #9=(F pitch) #17=(Q back cutting depth; positive number is for thread cutting, negative number is for normal processing) #18=(R thread starting point) #26=(Z thread end point).

[0016] The R value and Z value in the G65 program are called to determine the thread length, and the Q value in the G65 program is called. If the Q value in the G65 program is set to a positive number, the machine tool will automatically segment the thread from the thread start point to the thread end point based on Q times the pitch, and automatically determine the thread breaking point 3.

[0017] The ratio of thread length to Q times the pitch is N, and N is greater than 0; When N is an integer, the number of thread breaking points 3 is N-1, and the thread is divided into N segments; When N is a decimal, the number of thread breaking points 3 is the integer part R of N, and the thread is divided into R+1 sections.

[0018] Assuming Q is 4, if the thread length is less than 4 times the pitch, no cutting is performed and the thread is one section; if the thread length is greater than 4 times the pitch and less than 8 times the pitch, there is one thread cutting point 3 and the thread is divided into two sections. Figure 2 As shown; if the thread length is greater than 8 times the pitch and less than 12 times the pitch, there are two thread breaking points 3, and the thread is divided into three sections; and so on, no further details are given.

[0019] The present invention determines a plurality of thread cutting points 3 in the direction of the thread length from the starting point to the end point of the thread. The thread cutting points 3 divide the thread into multiple sections. Whenever the machine tool turning tool 1 runs to a thread cutting point 3, the tool is lifted and cut once, and the machine tool turning tool 1 then feeds from the thread cutting point 3 to continue turning the thread, thereby conveniently and quickly realizing segmented thread cutting, improving thread processing efficiency, reducing continuous end-to-end turning, and reducing the length of iron chips to avoid iron chips from winding around the machine tool spindle chuck. The iron chips are easy to remove, preventing iron pins from scratching the inner and outer circles of the workpiece, and ensuring the quality of the workpiece. At the same time, the continuous turning length is short, which can increase the service life of the tool.

[0020] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A CNC machining method for segmented thread cutting, characterized in that: The following steps are involved: The machine tool obtains thread parameters; Several thread cutting points are determined from the thread starting point to the thread end point in the thread length direction, and the thread cutting points divide the thread into multiple sections; Determine the number of cycles of the machine tool turning thread; The machine tool spindle is controlled to drive the workpiece to rotate, and the machine tool turning tool is controlled to start turning the thread from the starting point of the thread. Whenever the machine tool turning tool runs to a thread breaking point, the tool is lifted and cut once, and the machine tool turning tool then feeds from the thread breaking point, and the machine tool turning tool continues to turn the next section of the thread until the end point of the thread, and then the tool is retracted, and the machine tool turning tool completes turning the thread once; thereafter, the machine tool turning tool repeats the above turning action multiple times until a certain number of cycles is reached, and the thread processing is completed.

2. The CNC machining method for segmented thread cutting according to claim 1, characterized in that: The thread parameters are obtained by calling the G65 program.

3. The CNC machining method for segmented thread cutting according to claim 2, characterized in that: Call the R and Z values ​​in the G65 program to determine the thread length, R is the thread start point, and Z is the thread end point; Call the Q value in the G65 program. Q is the depth of cut. Positive values ​​are used for thread cutting, while negative values ​​are used for normal processing. If the Q value in the G65 program is set to a positive number, the machine tool will automatically divide the thread into segments from the thread start point to the thread end point based on Q times the pitch, and automatically determine the thread breaking point.

4. The CNC machining method for segmented thread cutting according to claim 3 is characterized in that: The ratio of thread length to Q times the pitch is N, and N is greater than 0; When N is an integer, the number of thread breaking points is N-1, and the thread is divided into N segments; When N is a decimal, the number of thread breaking points is the integer part R of N, and the thread is divided into R+1 sections.

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