A numerical control turning method

Abstract

The application discloses a numerical control turning method, which comprises rough machining and finish machining of a part, wherein the specific rough machining mode is that an upper computer controls a lathe spindle to drive the part to rotate; meanwhile, the upper computer controls a rough turning tool to simultaneously axially feed and radially feed along the outer circumferential surface of the part according to a preset rough turning path, and when the axial feeding reaches a preset length, the axial feeding and the radial feeding are stopped; then, the upper computer controls the rough turning tool to radially retreat to the original outer circumferential surface of the part, and then simultaneously axially feed and radially feed along the outer circumferential surface of the part, and the above numerical control steps are repeated until the rough machining of the axial machining length of the part is completed; after the rough machining is completed, the outer wall surface of the part forms a stepped structure; the application adopts the outer circumferential stepped turning mode, which can ensure the continuity of the machining process, improve the machining efficiency, ensure the machining precision and prolong the service life of the tool.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of turning processing, and particularly relates to a numerical control turning method. BACKGROUND

[0002] At present, for super-soft materials and soft metals, there are two common chip breaking methods. One is that the tool is axially turned for a length, then is static relative to the lathe spindle, so that the lathe spindle drives the material to be processed to idle, thereby achieving the purpose of chip breaking. Although this method can achieve the effect of chip breaking, the service life of the tool is shortened, and the non-continuous method reduces the surface quality of the part.

[0003] The other is that the tool is axially turned during rough turning, and the chip breaking effect is achieved by matching the depth of the chip breaking groove of the tool with the tool path parameters during turning. However, when this method is used to turn super-soft materials and soft metals, the material is too soft, and the chip is often in the form of a roll or a lump, which is wound around and accumulated on the workpiece, so that the automatic batch processing process is interrupted, and the accumulated chip needs to be cleaned before the process can continue, resulting in low processing efficiency. Moreover, the lump-shaped chip wound on the machined surface can cause the machined surface to be scratched and roughened, making it difficult to achieve the technical requirements during finish turning. SUMMARY

[0004] Therefore, the application provides a numerical control turning method, which adopts the outer circular stepped turning method, can ensure the continuity of the machining process, improve the machining efficiency, ensure the machining precision, and prolong the service life of the tool.

[0005] The application is implemented by the following technical scheme:

[0006] A numerical control turning method, the steps are as follows:

[0007] Step S1: rough machining is performed on a part with an axial machining length L, and the specific method is that: the host computer controls the lathe spindle to drive the part to rotate; at the same time, the host computer controls the rough turning tool to simultaneously supply axially and radially along the outer circumferential surface of the part according to a preset rough turning path, and stops the axial and radial supply when the axial supply reaches a preset length Z0; Z0 < L;

[0008] Then, the host computer controls the rough turning tool to radially retreat to the original outer circumferential surface of the part, and then simultaneously supplies axially and radially along the outer circumferential surface of the part:

[0009] If 2*Z0 >= L, the axial supply is performed to L, and the rough machining is completed;

[0010] If 2*Z0 < L, the axial supply is performed to 2*Z0, and the axial and radial supply is stopped, and the rough turning tool is controlled to radially retreat to the original outer circumferential surface of the part; then, the host computer controls the rough turning tool to simultaneously supply axially and radially along the outer circumferential surface of the part:

[0011] If 3*Z0 ≥ L, axially feed to L and the rough machining ends;

[0012] If 3*Z0 < L, axially feed to 3*Z0, stop the axial and radial feeds, control the rough turning tool to radially retract back to the original outer circumferential surface of the part; then simultaneously axially feed and radially feed along the outer circumferential surface of the part:

[0013] And so on until the rough machining of the axial machining length of the part ends;

[0014] Step S2: Finish machining the part with an axial machining length of L.

[0015] Furthermore, the method of step S2 is: along the stepped outer contour after rough machining, control the finish turning tool to finish machine the surface of the part through the finish turning path preset by the host computer, making the surface of the part smooth; during the finish machining process, the host computer controls the rotational speed of the part to vary periodically and floatingly with the change of the axial machining length, and each preset length segment corresponds to one cycle.

[0016] Furthermore, the host computer controls the rotational speed of the part to vary periodically and floatingly with the change of the axial machining length, and each preset length segment corresponds to one cycle, specifically:

[0017] Step S21: Preset initial values in the host computer, that is, preset: the machining origin is one end of the part, the initial rotational speed of the lathe spindle driving the part is n0, the change amount of the rotational speed is Δn, the maximum limit value of the rotational speed is n max and the minimum limit value of the rotational speed is n min ;

[0018] Step S22: The host computer controls the finish turning tool to start turning from the opposite end of the end where the part origin is located:

[0019] Step S221, the host computer controls the finish turning tool to axially feed at a constant speed; meanwhile, control the rotational speed of the lathe spindle to change according to the following method: the rotational speed of the lathe spindle is based on the initial rotational speed, uniformly increasing, and every time it increases by Δn, the host computer judges whether the rotational speed exceeds the maximum limit value n max ;

[0020] If it does not exceed the maximum limit value, continue to uniformly increase;

[0021] If it exceeds the maximum limit value, the rotational speed uniformly decreases, and every time it decreases by Δn, the host computer judges whether the rotational speed is less than the minimum limit value n min ;

[0022] If it is not less than the minimum limit value n min , then continue to uniformly decrease;

[0023] When the speed is less than the minimum limit n min When the speed increases again for the second time, until it reaches the initial speed, the finishing tool just completes the processing of the first preset length segment; at this time, the finished length is Z1 = Z0;

[0024] Step S222: The host computer compares the pre-processed length Z2=Z1+Z0 with the axial processing length L of the part.

[0025] If L>Z2, repeat step S221 to complete the second preset length segment; at this time, the axial length that has been finely machined is Z2=Z1+Z0=2*Z0;

[0026] If L≤Z2, the remaining axial processing length is a preset processing section or less than a preset processing section. In this case, the rotating shaft will be operated at a variable speed within the remaining length range, and the finishing process is completed, and the program ends.

[0027] By analogy, the host computer will pre-process the length Z i =Z i-1 +Z0 is compared with the axial processing length L of the part.

[0028] If L>Z i Repeat step S221 to complete the processing of the i-th preset length segment; at this time, the length of the finished processing is Z i =Z i-1 +Z0=i*Z0;

[0029] If L≤Z i , the remaining axial processing length is a preset processing section or is less than a preset processing section. In this remaining length range, the rotating shaft will be operated at a variable speed accordingly, and the finishing process will be completed, and the program will end.

[0030] Until the axial processing length of the part is finely processed.

[0031] Furthermore, each preset length segment corresponds to more than two cycles.

[0032] Furthermore, in step S221 , the rotation speed of the lathe spindle may first decrease from an initial value, then increase, and then decrease back to the initial value.

[0033] Furthermore, in step S1 , when the axial supply reaches a preset length Z0 , the axial supply is stopped. At this time, the radial supply is Y1 ; Y1 = Z0 / 5.

[0034] Furthermore, in step S1, when the axial supply reaches a preset length Z0, the axial supply is stopped. At this time, the radial supply is Y1; Y1 = the taper of the frustum-shaped structure / 15.

[0035] Beneficial effects:

[0036] (1)The present application stops axial feeding after supplying a preset length in the axial direction, controls the rough turning tool to retreat to the outer circumferential surface of the part in the radial direction, so that the axial cutting is discontinuous, and the strip-shaped chips formed by cutting the super-soft material are broken during the process of axial feeding and radial feeding after the rough turning tool retreats to the outer circumferential surface of the part in the radial direction, the broken chips are guided out of the lathe by cooperating with the chip breaking groove on the cutting tool, the strip-shaped chips are prevented from winding around the workpiece, the continuity of the machining process is ensured, and the machining efficiency is improved.

[0037] (2)In the fine machining process, the upper computer controls the speed of the part to periodically fluctuate with the change of the axial machining length, and each preset length section corresponds to a period. Thus, the cutting produced by fine machining can leave the surface of the part under the action of centrifugal force, and the chips are guided out of the lathe by cooperating with the chip breaking groove on the cutting tool, so that continuous fine machining can be realized and the machining accuracy is ensured.

[0038] (3)Each preset length section can also correspond to two or more periods. Under the same preset length, the more the periods, the more frequent the speed change, which further ensures that the broken chips are guided out of the lathe along the chip breaking groove under the action of inertial force, and improves the broken chip efficiency.

[0039] (4)In step S221, the speed of the lathe spindle can first decrease from the initial value, then increase, and then decrease to the initial value, so that during each preset length section, the spindle speed is lower when machining the large diameter section, which can protect the tool, and the spindle speed is higher when machining the small diameter section, which further improves the machining efficiency and prolongs the service life of the tool. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a rough machining schematic diagram of the present application;

[0041] Figure 2 is a fine machining schematic diagram of the present application;

[0042] Figure 3 is a fine machining flow chart of the present application;

[0043] Figure 4 is a curve diagram of the speed of the part with the change of the axial fine machining length;

[0044] Figure 5 is a rough machining schematic diagram of the present application (for variable diameter rotary body);

[0045] Figure 6 is a fine machining schematic diagram of the present application (for variable diameter rotary body). DETAILED DESCRIPTION

[0046] The present application will be described in detail below with reference to the drawings and examples.

[0047] Embodiment 1:

[0048] The embodiment provides a numerical control turning method suitable for turning processing of super-soft materials,

[0049] The super-soft material is a super-plastic metal material, such as pure copper, cold heading steel Ml08Al or the like, or a soft plastic material such as silica gel, rubber, nylon or the like.

[0050] The method comprises the following steps:

[0051] Step S1: rough machining is performed on a part with an axial machining length L, referring to the attached Figure 1 The host computer controls the spindle of the lathe to drive the part to rotate; meanwhile, the host computer controls the rough turning tool to simultaneously perform axial feeding and radial feeding along the outer circumferential surface of the part according to a preset rough turning path, when the axial feeding reaches a preset length Z0 (and Z0 < L), the axial feeding and the radial feeding are stopped, at this time, the radial feeding is Y1;

[0052] Then, the host computer controls the rough turning tool to retreat radially to the original outer circumferential surface of the part, and then simultaneously performs axial feeding and radial feeding along the outer circumferential surface of the part:

[0053] If 2*Z0 >= L, the axial feeding reaches L, and the rough machining is completed;

[0054] If 2*Z0 < L, the axial feeding reaches 2*Z0, and the radial feeding is Y1, then the axial feeding and the radial feeding are stopped, the rough turning tool is controlled to retreat radially to the original outer circumferential surface of the part, and then the host computer controls the rough turning tool to simultaneously perform axial feeding and radial feeding along the outer circumferential surface of the part:

[0055] If 3*Z0 > L, the axial feeding reaches L, and the rough machining is completed;

[0056] If 3*Z0 < L, the axial feeding reaches 3*Z0, and the radial feeding is Y1, then the axial feeding and the radial feeding are stopped, the rough turning tool is controlled to retreat radially to the original outer circumferential surface of the part, and then simultaneously performs axial feeding and radial feeding along the outer circumferential surface of the part:

[0057] In this way, the axial machining length of the part is rough machined until the rough machining is completed; after the rough machining is completed, the outer wall surface of the part forms a stepped structure, and the outer wall surface of each preset length section encloses a frustoconical structure;

[0058] Further, Y1 = Z0 / 5 or Y1 = the taper of the frustoconical structure / 15;

[0059] In specific embodiments, the preset length Z0 = 2 mm, and Y1 = 0.4 mm;

[0060] In this step, after the preset length is axially supplied, the axial supply is stopped, the rough turning tool is controlled to retreat to the outer circumferential surface of the part, so that the axial cutting is discontinuous, and during the process of axial supply and radial supply after the rough turning tool is controlled to retreat to the outer circumferential surface of the part, the strip-shaped chips formed by cutting the super-soft material are broken, the broken chips are matched with the chip breaking grooves on the cutting tool to guide the chips out of the lathe, and the strip-shaped chips are prevented from winding the workpiece too long, so that the continuity of the machining process is ensured and the machining efficiency is improved.

[0061] Step S2: referring to the attached Figure 2 , along the stepped outer contour after rough machining, the fine turning tool is controlled to machine the surface of the part along the fine machining path preset by the upper computer, so that the surface of the part is smooth; during the fine machining process, the speed of the part controlled by the upper computer changes periodically with the change of the axial machining length, and each preset length corresponds to a period; specifically:

[0062] Step S21: preset the initial amount in the upper computer, that is, preset: the machining origin is one end of the part, the initial speed of the part driven by the lathe spindle is n0, the change amount of the speed is Δn, and the maximum limit value of the speed is n max , and the minimum limit value of the speed is n min ;

[0063] Step S22: the upper computer controls the fine turning tool to start turning from the opposite end of the part origin:

[0064] Step S221, the upper computer controls the fine turning tool to supply at a constant speed in the axial direction; at the same time, the speed of the lathe spindle is controlled to change in the following manner: the speed of the lathe spindle takes the initial speed as the base point and increases uniformly, and each time the speed increases by Δn, the upper computer judges whether the speed exceeds the maximum limit value n max ;

[0065] If the maximum limit value is not exceeded, the speed continues to increase uniformly;

[0066] If the maximum limit value is exceeded, the speed decreases uniformly, and each time the speed decreases by Δn, the upper computer judges whether the speed is less than the minimum limit value n min ;

[0067] If the minimum limit value n min is not less than, the speed continues to decrease uniformly;

[0068] When the speed is less than the minimum limit value n min , the speed is increased for the second time, and when the speed increases to the initial speed, the fine turning tool just completes the machining of the first preset length; at this time, the length of the part that has been machined is Z1=Z0;

[0069] Step S222: The host computer compares the pre-processed length Z2=Z1+Z0 with the axial processing length L of the part:

[0070] If L>Z2, repeat step S221 to complete the second preset length segment; at this time, the axial length that has been finely machined is Z2=Z1+Z0=2*Z0;

[0071] If L≤Z2, the remaining axial processing length is a preset processing section or less than a preset processing section. In this case, the rotating shaft will be operated at a variable speed within the remaining length range, and the finishing process is completed, and the program ends.

[0072] By analogy, the host computer will pre-process the length Z i =Z i-1 Compare +Z0 with the axial machining length L of the part:

[0073] If L>Z i Repeat step S221 to complete the processing of the i-th preset length segment; at this time, the length of the finished processing is Z i =Z i-1 +Z0=i*Z0;

[0074] If L≤Z i , the remaining axial processing length is a preset processing section or is less than a preset processing section. In this remaining length range, the rotating shaft will be operated at a variable speed accordingly, and the finishing process will be completed, and the program will end.

[0075] Until the axial processing length of the part is finely processed.

[0076] In the specific embodiment, see the attached Figure 3 and 4 The initial speed of the lathe spindle driving the parts is n = 600r / min, the speed change is Δn = 10r / min, and the maximum speed limit is n max =650r / min, the minimum speed limit is n min =550r / min, the axial processing length of the part L = 300mm.

[0077] In this step, the speed of the part is changed during the finishing process to control its rotation, so that the cuttings produced by the finishing can leave the part surface under the action of centrifugal force. By cooperating with the cutting groove on the cutter, the chips are guided out of the lathe, so that continuous finishing can be achieved and the processing accuracy can be guaranteed.

[0078] Furthermore, the rotation speed of the part controlled by the host computer fluctuates periodically with the change of the axial processing length, and each preset length segment may correspond to more than two cycles.

[0079] Further, in step S221, the rotating speed of the lathe spindle can be first decreased from the initial value, then increased, and then decreased to the initial value, so that in each preset length section, the rotating speed of the spindle is lower when machining the large-diameter section and higher when machining the small-diameter section, further improving the machining efficiency and prolonging the service life of the tool.

[0080] Embodiment 2

[0081] This embodiment is based on Embodiment 1 and provides a numerical control turning method, as shown in FIG. 4. Figure 5 and 6 When the outer circumference of the part has a variable-diameter section, i.e., a machining section smoothly transitioning from a small diameter to a large diameter, the axial feeding and radial feeding of the control rough turning tool along the outer circumferential surface of the part in step S1 are replaced by only axial feeding; due to the change of the outer circumferential diameter of the part, even if no radial feeding is given, the cutting can be disconnected.

[0082] The remaining machining methods are the same as those in Embodiment 1, which will not be described here.

[0083] In conclusion, the above is only a preferred embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A numerical control turning method characterized by, The method steps are as follows: Step S1: rough machining of a part with an axial machining length of , specifically in the following manner: the host computer controls the rotation of the part driven by the spindle of the lathe; at the same time, the host computer controls the simultaneous axial feeding and radial feeding of the rough turning tool along the outer circumferential surface of the part according to a preset rough turning path, and when the axial feeding reaches a preset length , the axial feeding and radial feeding are stopped; the ; Then, the host computer controls the rough turning tool to retreat to the original outer circumferential surface of the part in the radial direction, and then supplies the rough turning tool in the axial direction and in the radial direction along the outer circumferential surface of the part: If , the axial supply to L, rough machining is finished; If , the axial supply to , stop axial supply and radial supply, control rough turning tool to retreat to the original outer circumferential surface of the part; then, the upper computer controls the rough turning tool to supply simultaneously along the outer circumferential surface of the part and the axial supply and radial supply: If , the axial supply to L, rough machining is finished; If , the axial supply to , stop axial supply and radial supply, control rough turning tool to radial retreat to the original outer circumferential surface of the part; along the outer circumferential surface of the part while axial supply and radial supply: By analogy, until the rough machining of the axial machining length of the part is completed; Step S2: finish machining the part with an axial machining length of ; The mode of the step S2 is that the host computer controls the fine turning tool to perform fine machining on the surface of the part along the stepped outer contour after rough machining, so that the surface of the part is smooth; during the fine machining, the host computer controls the rotational speed of the part to periodically fluctuate with the change of the axial machining length, and each preset length section corresponds to a period.

2. The numerical control turning method according to claim 1, wherein The host computer controls the rotational speed of the part to periodically fluctuate with the change of the axial machining length, and each preset length section corresponds to a period, specifically: Step S21: preset initial quantity in host computer, i.e. preset: machining origin is one end of part, initial rotating speed of lathe spindle driving part is , change amount of rotating speed is , maximum limit value of rotating speed is , minimum limit value of rotating speed is ; Step S22: the host computer controls the fine turning tool to start turning from the opposite end of the original point of the part: Step S221, the host computer controls the fine turning tool to be fed along the axial direction at a uniform speed; at the same time, the speed of the lathe spindle is controlled to change in the following manner: the speed of the lathe spindle is uniformly increased with the initial speed as the base point, and the speed is increased by a certain increment every time The host computer judges whether the speed exceeds the maximum limit value ; If the maximum limit is not exceeded, continue to uniformly increase; If the maximum limit is exceeded, the rotational speed is uniformly reduced, each time by The host computer determines whether the rotational speed is less than the minimum limit ; If not less than minimum limit Then continue uniform decrement; When the rotational speed is less than the minimum limit , the rotational speed is increased for the second time until it reaches the initial rotational speed, and the finishing cutter just finishes machining the first preset length section; at this time, the length that has been finished machining is . Step S222, the host computer compares the pre-processed length with the axial machining length of the part performed, If , repeat step S221, and process the second preset length section; at this time, the already finished axial length is ; If If the remaining axial machining length is one preset machining section or less than one preset machining section, the spindle is correspondingly operated at variable speed within the remaining length range, the finishing machining is completed, and the program ends. By analogy, the host computer will pre-process the length with the axial machining length of the part for comparison, If , repeat step S221 to process the first preset length segment; at this time, the length of the already finished processing is . ​ If , the remaining axial machining length is one preset machining section or less than one preset machining section, the spindle is correspondingly operated at variable speed within the remaining length range, the finishing machining is completed, and the program ends. until the fine machining of the axial machining length of the part is completed.

3. The numerical control turning method according to claim 1, wherein Each preset length section corresponds to two or more periods.

4. The numerically controlled turning method according to claim 2, wherein In step S221, the rotational speed of the lathe spindle can first decrease from the initial value, then increase, and then decrease to the initial value.

5. A method of numerically controlled turning according to any one of claims 1 to 4, wherein, In step S1, when the shaft direction supply of the predetermined length is completed , the shaft direction supply is stopped, and at this time, the radial direction supply is ; .

6. A method of numerically controlled turning according to any one of claims 1 to 4, wherein, In step S1, when the shaft direction supply of the predetermined length is completed , the shaft direction supply is stopped, and at this time, the radial direction supply is ; .

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