Method for removing sharp edge burrs of threads through thread tail withdrawing function

Abstract

The invention provides a method for removing sharp edge burrs of a thread by using a thread withdrawing function, which comprises the following steps: calling a thread machining program, and turning the thread from a starting point (X1, Z1) to a point (X2, Z2) by using a thread turning tool to finish thread machining; calling a thread burr removing cutter; the thread deburring tool is controlled to rapidly move to the (X1, Z3) point from the safe tool changing point, and the set thread back-off parameters are called; a thread burr removing program is called and read, so that a thread removing cutter conducts burr removing machining according to the number of revolutions n and the lead during thread machining; and when the thread burr removing cutter moves to (X3, Z4), the thread burr removing cutter is lifted, and thread burr removing machining is completed. According to the method provided by the invention, the thread burrs are removed by virtue of the thread machining and tail withdrawing functions of the numerical control lathe and a thread machining program, and the method is high in burr removal speed, simple and free of influence on the product quality of parts.

Description

Technical Field

[0001] The invention belongs to the field of thread processing, and in particular relates to a method for removing sharp edge burrs of a thread by utilizing a thread tail removal function. Background Art

[0002] The so-called burrs are the excess materials outside the parts caused by the extrusion of the cutting tip or the sharpness of the cutting tool during the machining process, which are produced between the outer circle and the end face of the part, and between the cutting surface and the outer circle.

[0003] The influence of thread burrs mainly affects the thread screwing accuracy. Since the thread burrs fall off when the thread is screwed, it will cause the thread screwing to jam. In addition, the falling of thread burrs will affect the quality of the parts.

[0004] In the past, there were several methods for removing thread burrs:

[0005] The first method is to use a file on the machine tool after the thread is machined. The problems with this method are: first, the machine spindle is rotating during thread deburring, which increases safety risks; second, using a file to deburr can cause the burr to flanging, preventing the thread ring gauge from passing properly; and third, this method can degrade the surface quality of the part.

[0006] The second method is to remove the burrs after the thread processing is completed by the fitter in the subsequent process. The problems with this removal method are: first, poor efficiency; second, poor surface quality. If the thread and the sealing surface are adjacent, it is easy to hit the sealing surface when removing the burrs; third, the time cost is increased due to the increase in the flow process.

[0007] The third method is to perform directional chamfering after the thread processing is completed to achieve the effect of removing thread burrs. The problems with this removal method are: first, the thread burrs are easy to turn over; second, this removal method will cause sharp edges to form at the thread mouth, which is easy to cause scratches when transporting parts. Summary of the Invention

[0008] The purpose of the present invention is to provide a method for removing burrs on the sharp edges of threads by utilizing the thread backing function, which is mainly used to solve the problems of low efficiency of existing burr removal methods, which easily cause quality problems of the sealing surface of parts, and metal dust that harms the processor.

[0009] The present invention provides a method for removing sharp edge burrs of a thread by utilizing a thread backing function, comprising:

[0010] S1. When the thread cutting tool completes thread processing, the thread cutting tool is controlled to return from the end position (X1, Z1) to the safe tool change point, and the thread cutting tool is switched to a thread deburring tool; Z represents the axial position and X represents the radial position;

[0011] S2, controlling the thread deburring tool to move from the safe tool change point to the tool starting point (X1, Z3), and simultaneously reading pre-programmed thread deburring cutting parameters, wherein the thread deburring cutting parameters include the thread deburring tool starting position (X1, Z3), the end position (X3, Z4), the end-retraction parameter, the axial feed speed V1, and the radial end-retraction speed V2;

[0012] Among them, Z3 is the axial starting position, X1 is the radial starting position; the axial starting position Z3 = Z1 + P*n + PX-R, P is the pitch of the thread, n is a natural number, PX is the distance from the end face of the thread tool to the thread tip, and R is the tip radius of the thread deburring tool; Z4 = Z0-Tm, Z0 is the starting point of workpiece programming, T is the distance between the thread tip and the workpiece programming zero point when the thread chamfer width is tangent to the thread tool cutting edge, and m is the correction value; X3 = X2-d; V1 = P*r, r is the workpiece speed; V2 = [(X1-X2) / 2] / thread tailing coefficient*r; X2 is the thread bottom diameter when the thread cutting tool is machining the thread;

[0013] S3, controlling the thread deburring tool to perform cutting processing at the axial feed speed V1 and radial tail withdrawal speed V2;

[0014] S4. When the deburring tool starts to perform the deburring action from the starting position (X1, Z3) to the ending position (X3, Z4), the deburring cutting action is ended, the deburring tool is lifted, and the tool is returned to the safe tool change point.

[0015] Optionally, the chamfer of the thread for removing burrs is 45 degrees.

[0016] Optionally, the thread turning tool and the thread mouth burr removal tool are arranged on the same cross section of the workpiece axis and on the same side of the workpiece.

[0017] Optionally, the cutting edge width L of the tool for removing burrs from the thread mouth is greater than P / 2+2R+1 / 8P, where P is the thread pitch, R is the tip radius of the thread deburring tool, and 1 / 8P is the crest width of the thread.

[0018] Optionally, the values of PX and P conform to any of the columns in the following table:

[0019] PX 0.5 0.5 0.8 0.8 1.00 P 0.5 0.75 1.00 1.25 1.5 .

[0020] Optionally, the value of n is [2,4] and the value of m is in the range of (0.2,0.4).

[0021] Optionally, the parameters for thread retraction include: number of repeated processing, thread retraction amount, and thread profile angle of the processed thread.

[0022] Optionally, the number of repeated processing is 1, the thread tailing amount is 0.5 pitch, and the thread profile angle of the processed thread is 60 degrees.

[0023] Optionally, the workpiece speed and thread pitch in S3 are the same as those during thread machining.

[0024] The present invention provides a method for removing sharp edge burrs of a thread by utilizing a thread backing function. The method comprises the following steps: switching and calling a thread mouth deburring tool, controlling the thread mouth deburring tool to quickly move from a safe tool change point to a starting position (X1, Z3), moving to (X3, Z4) according to a set thread backing coefficient and a thread mouth deburring procedure, and completing the thread mouth deburring action. The thread mouth deburring method is automatically completed by relying on the thread function and the thread backing function of a lathe, the thread deburring time is fast, the thread mouth deburring effect is good, and no damage is caused to parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the occurrence of thread burrs;

[0026] Figure 2a Schematic diagram of the starting point of the original thread cutting;

[0027] Figure 2b Schematic diagram of the starting point for removing burrs from the thread mouth;

[0028] Figure 2c Schematic diagram of the tool for removing burrs from the thread mouth;

[0029] Figure 3 This is the effect diagram when removing burrs from the thread mouth;

[0030] Figure 4 is the thread angle;

[0031] Figure 5 is the chamfer angle of the thread;

[0032] Figure 6 This is a schematic diagram of the distance from the thread cutter tip to the part end face when the thread cutter cutting edge is tangent to the thread chamfer;

[0033] Figure 7 This is a schematic diagram of the process of removing burrs from threaded ends. DETAILED DESCRIPTION

[0034] In order to make the purpose of the invention, the technical method and the advantages of the method easier to understand, the present invention is further described in detail below with reference to schematic diagrams and implementation examples. It should be understood that the specific implementation examples described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] The method for removing burrs from threaded openings provided by the present invention has the following specific implementation steps:

[0036] (1) When the thread cutting tool is completed, return to the safe tool change point and call the thread mouth deburring tool.

[0037] (2) Control the thread deburring tool to quickly move from the safe tool change point to (X1, Z3), call the thread retraction parameter (G76 P010560), clamp the thread retraction parameter within the 0.5 pitch range, and call the thread deburring parameter (thread deburring program). (The above parameters must be used in combination, so that each application will not affect the effect of thread deburring each time due to different thread retraction parameters) The position parameters of the thread deburring tool specifically include the starting position (X1, Z3) and the ending position (X3, Z4) of the thread deburring tool, the axial feed speed V1 and the radial retraction speed V2, among which:

[0038] The starting positions (X1, Z3) for deburring the threaded end portion include a radial starting position X1 and an axial starting position Z3, wherein:

[0039] The radial starting position X1 is the same as the starting position of the thread cutting tool;

[0040] The axial starting position Z3 = Z1 + P*n + PX - R, where Z1 is the starting point of the original thread cutting tool, P is the pitch of the thread, n is a natural number, PX is the distance from the end face of the thread cutting tool to the thread cutting tip, and R is the tip radius of the thread deburring tool;

[0041] The end position (X3, Z4) of the thread deburring tool specifically includes the axial end position Z4 and the radial end position X3, wherein:

[0042] The axial end position Z4 = Z0 - Tm;

[0043] The radial thread run-off X3 = X2-d;

[0044] The axial feed speed of the thread deburring tool is V1=r*P, where r is the workpiece speed and P is the pitch of the thread;

[0045] The radial deburring speed V2 of the thread deburring tool is [(X1-X2) / 2] / thread deburring coefficient*r;

[0046] The G76 P010560 thread backing parameters, where 01 means that the repeated processing is once, where 05 means that the thread backing amount is 0.5 pitch, where 06 means that the thread profile angle of the processed thread is 60 degrees.

[0047] (3) When the thread deburring tool moves rapidly from the safe tool change point to the starting position (X1, Z3), the thread deburring tool is controlled to radially deburr according to the axial feed speed V1 and radial retraction speed V2 of the thread deburring tool;

[0048] (4) When the thread deburring tool moves from the starting position (X1, Z3) to the ending position (X3, Z4), the program ends and the thread deburring tool is lifted.

[0049] In this case, the width of the thread mouth deburring tool L>P / 2+2R+1 / 8P, and the original thread cutting tools include external cylindrical turning tools and thread cutters.

[0050] The above is only a specific implementation case of the present invention, wherein, after the thread cutting process is completed, there are the following steps before deburring the thread mouth:

[0051] The thread cutting parameters are used to generate the thread cutting parameters for deburring the threaded end.

[0052] According to the cutting parameters of the thread, including the pitch, tooth top height, chamfer size, workpiece rotation speed and other values, the distance between the thread blade and the chamfer is calculated. Through these parameters and the calculated values, the program trajectory for deburring the thread mouth is generated, that is, the starting position, tail retraction position, axial feed speed and radial tail retraction speed of the thread deburring tool.

[0053] After the program is generated, the machine tool's control thread processing program controls the thread turning tool to return to the safe tool change point after completing thread processing, calls the thread mouth deburring tool, and quickly moves the tool from the safe tool change point to the starting point (X1, Z3) of the thread mouth deburring. When the thread mouth deburring program is called to process to the thread tail retraction position (X3, Z4), the thread mouth deburring tool is lifted to complete the operation of removing the thread mouth burr. The entire process of removing the thread mouth burr is automatically controlled by the CNC program.

[0054] This program controls the starting and ending points of the thread deburring tool so that the incomplete thread crest width after deburring is the same as the crest width of the standard thread, achieving the effect of deburring the thread mouth.

[0055] In an embodiment of the present invention, the original thread cutting tool and the thread mouth deburring tool are arranged on the same cross section of the workpiece axis and on the same side of the workpiece.

[0056] In the implementation case of the present invention, Figure 5 As shown in the figure, the chamfer angle of the thread is 45 degrees and the tooth angle of the thread is 60 degrees. Figure 4 .

[0057] The chamfer length of this thread is the same as the cutting depth of the thread.

[0058] Axial length The thread pitch P is 1.5 mm, and the length L tangent to the thread chamfer is 1.75. Converted into the circumferential direction, the angle is 0.95 / 1.75=0.54=195 degrees, that is, thread burrs will be generated within the circumference of 195 degrees.

[0059] Radial direction

[0060] The height from the top of the thread bottom to the top of the tooth is H = 0.95, so radial burrs will be generated within this range. Figure 1 .

[0061] It can be seen that the generation of thread burrs has a certain pattern, which is related to the size of the chamfer of the thread and the height of the thread crest.

[0062] In the case of the present invention, thread turning and thread burr removal are both completed on the same equipment. The solution uses a universal tool to turn the flanging burrs produced by the thread, so that the sharp edge of the thread and the flanging burrs of the thread are removed, forming a plane with a tooth top width of no more than 0.2mm. In this way, the original acute angle of the thread becomes an obtuse angle, which has the effect of removing the burrs at the thread mouth. This is also the basic idea and concept of the invention.

[0063] For easier understanding, the following is a specific implementation case to further illustrate:

[0064] Take the external thread diameter of 24mm as an example to remove the burrs on the thread mouth. The parameters of the thread are: pitch P = 1.5, tooth top height is 0.95mm, the chamfer of the thread is 45 degrees and the same depth as the cutting depth of the thread, the speed of the workpiece is 1200 / min, all tools for thread processing, including external cylindrical tools, thread tools, thread mouth deburring tools, etc., and the cutting points of these tools are on the same section through the workpiece axis and on the same side of the workpiece. When the thread cutting tool with Z0 as the programming origin is completed, the thread deburring tool is called. Calculate the starting position of the thread deburring tool Z3 = 4.8mm (away from the end face of the workpiece), such as Figure 2bThe radial starting position X1 is the same as the starting position X1 for thread turning. The thread deburring coefficient is calculated to be 0.5 pitch, and the thread deburring tool moves at a feed rate of 1.5mm / rev. When the thread deburring tool reaches the axial end position Z4 = 1.7mm (cutting into the part end face) and the radial end position X3 = 1.05mm, the thread deburring tool is lifted and returned to the safe tool change point. All thread deburring operations are completed. The entire thread deburring operation takes less than 2 seconds, which is fast and will not damage the part.

[0065] The above description is merely a specific implementation case of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for removing burrs on the sharp edge of a thread by using a thread backing function, characterized in that: include: S1. When the thread cutting tool completes thread processing, the thread cutting tool is controlled to return from the end position (X1, Z1) to the safe tool change point, and the thread cutting tool is switched to a thread deburring tool; Z represents the axial position and X represents the radial position; S2, controlling the thread deburring tool to move from the safe tool change point to the tool starting point (X1, Z3), and simultaneously reading pre-programmed thread deburring cutting parameters, wherein the thread deburring cutting parameters include the thread deburring tool starting position (X1, Z3), the end position (X3, Z4), the end-retraction parameter, the axial feed speed V1, and the radial end-retraction speed V2; Among them, Z3 is the axial starting position, X1 is the radial starting position; the axial starting position Z3 = Z1 + P*n + PX-R, P is the pitch of the thread, n is a natural number, PX is the distance from the end face of the thread tool to the thread tip, and R is the tip radius of the thread deburring tool; Z4 = Z0-Tm, Z0 is the starting point of workpiece programming, T is the distance between the thread tip and the workpiece programming zero point when the thread chamfer width is tangent to the thread tool cutting edge, and m is the correction value; X3 = X2-d; V1 = P*r, r is the workpiece speed; V2 = [(X1-X2) / 2] / thread tailing coefficient*r; X2 is the thread bottom diameter when the thread cutting tool is machining the thread; S3, controlling the thread deburring tool to perform cutting processing at the axial feed speed V1 and radial tail withdrawal speed V2; S4. When the deburring tool starts to perform the deburring action from the starting position (X1, Z3) to the ending position (X3, Z4), the deburring cutting action is ended, the deburring tool is lifted, and the tool is returned to the safe tool change point.

2. The method for removing burrs from sharp edges of threads according to claim 1, characterized in that: The chamfer angle of the thread for removing burrs is 45 degrees.

3. The method for removing burrs from sharp edges of threads according to claim 1, characterized in that: The thread turning tool and the thread mouth burr removal tool are arranged on the same cross section of the workpiece axis and on the same side of the workpiece.

4. The method for removing burrs from sharp edges of threads according to claim 1, wherein: The cutting edge width L of the tool for removing burrs from the thread mouth is > P / 2+2R+1 / 8P, where P is the thread pitch, R is the tip radius of the thread deburring tool, and 1 / 8P is the crest width of the thread.

5. The method for removing burrs from sharp edges of threads according to claim 4, characterized in that: The values of PX and P conform to any of the columns in the following table: 。 6. The method for removing burrs from sharp edges of threads according to claim 1, characterized in that: The value of n is [2,4], and the value range of m is (0.2,0.4).

7. The method for removing burrs from sharp edges of threads according to claim 1, characterized in that: The parameters of thread backing include: number of repeated processing, thread backing amount and thread profile angle of the processed thread.

8. The method for removing burrs from sharp edges of threads according to claim 7, characterized in that: The number of repeated processing times is 1, the thread tail reduction is 0.5 pitch, and the thread profile angle of the processed thread is 60 degrees.

9. The method for removing burrs from sharp edges of threads according to claim 1, wherein: The workpiece speed and pitch in S3 are the same as those during thread machining.

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