CN110722220B - Method for numerically-controlled internal thread turning and repairing by changing rotating speed of main shaft - Google Patents

Method for numerically-controlled internal thread turning and repairing by changing rotating speed of main shaft Download PDF

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Publication number
CN110722220B
CN110722220B CN201910992317.0A CN201910992317A CN110722220B CN 110722220 B CN110722220 B CN 110722220B CN 201910992317 A CN201910992317 A CN 201910992317A CN 110722220 B CN110722220 B CN 110722220B
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tool
point
turning
main shaft
internal thread
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CN110722220A (en
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孙凤芝
刘建群
刘珈利
梁好翠
吴志远
王远干
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Beibu Gulf University
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Beibu Gulf University
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23G—THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH
    • B23G1/00—Thread cutting; Automatic machines specially designed therefor
    • B23G1/02—Thread cutting; Automatic machines specially designed therefor on an external or internal cylindrical or conical surface, e.g. on recesses
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23G—THREAD CUTTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTION THEREWITH
    • B23G5/00—Thread-cutting tools; Die-heads
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
    • B23Q17/00—Arrangements for observing, indicating or measuring on machine tools
    • B23Q17/10—Arrangements for observing, indicating or measuring on machine tools for indicating or measuring cutting speed or number of revolutions

Abstract

A method for numerically controlling and repairing internal threads by changing the rotating speed of a main shaft comprises the following steps: on the reference object by the tool start point SAt main shaft speed n1、n2Turning helix T1、T2(ii) a Positioning the tool tip at T1Point A of the middle part1(ii) a Rotating the main shaft to an angle to make the tool tip point to T1(ii) a Positioning the tip at point A2To point to and T1Adjacent T2(ii) a By A1、A2Coordinate calculation of (1) T1、T2Axial or circumferential deviations of (a), eliminating the deviations; unloading the reference workpiece; installing a workpiece to be repaired and rotating the main shaft to the angle position; providing a pair of cutting rulers, and embedding a positioning contact on a vernier of the cutting ruler with a tooth groove of the internal thread to be repaired; positioning the tool tip at the point B and aligning the tool tip with the tool setting groove on the vernier, and removing the tool setting ruler; using point A1And B, calculating the axial offset distance or the circumferential deviation between the tool starting point set by the vehicle repair program and the tool starting point required by the vehicle repair, eliminating the axial offset distance or the circumferential deviation, and executing the adjusted vehicle repair program. The method can achieve the coincidence of the cutting track and the thread track to be repaired under the condition of variable main shaft rotating speed.

Description

Method for numerically-controlled internal thread turning and repairing by changing rotating speed of main shaft
Technical Field
The invention relates to the technical field of thread maintenance, in particular to a method for numerically controlling and repairing internal threads by turning variable spindle rotation speed.
Background
A large number of threads are processed and maintained by petroleum drilling technical service enterprises every year, petroleum pipe thread maintenance service is necessary for controlling equipment cost in the drilling industry, the service life of petroleum pipes can be prolonged through maintenance, and equipment investment is saved. The technical key point of the petroleum pipe thread maintenance lies in that the original spiral line of the thread is turned, but not completely removed and reprocessed.
The special pipe lathe for machining threads is widely used in the industry, and has the advantages of simple structure, strong applicability, obvious defects, high labor intensity of operators, poor working environment condition, and occupational risks of accidental injury, disability and the like. The adoption of the numerical control lathe to carry out the lathe repair on the screw thread can reduce the labor intensity, however, the following problems exist in the numerical control lathe processing and maintaining process of the screw thread:
1. the mounting position information of the existing spiral line of the thread to be repaired is difficult to obtain economically and conveniently: workpieces to be repaired in the petroleum technical service industry are very heavy, and the clamping position on a numerical control lathe can only be random and is irrelevant to the program parameters for successfully finishing the thread machining. The numerical control lathe must correlate the position information of the thread to be repaired with the machining program to enable the cutter to cut along the original thread track, which is also very inefficient repetitive labor.
2. The phenomenon of gear shifting and tooth disorder exists: when the numerical control lathe is used for turning threads, the rotating speed cannot be changed randomly like a common lathe, otherwise, the threads are randomly buckled. When the surface quality of the machined thread does not meet the technical requirements due to the mechanical property of the workpiece material, the operator of the common lathe can change the cutting speed of the cutter by adjusting the rotating speed of the main shaft of the machine tool, but the problem is very difficult due to the variable speed and the tooth disorder characteristic of the numerical control lathe, so that the thread tracks turned at different rotating speeds have deviation.
The document (practical method for adjusting thread machining of a numerical control lathe, Liu & bin, metal machining: cold working, 1 st stage 2014, 36-37, pages 2 in total) provides a practical method for adjusting thread machining of a numerical control lathe, which obtains a pitch difference by calculating the thread pitch of the machined thread and the system response time, and enables the thread cutting point before the rotation speed is changed to coincide with the thread cutting point after the rotation speed is changed by compensating the pitch difference, thereby avoiding thread untwisting. However, this method aims to solve the thread galling phenomenon before and after the rotation speed changes in the process of forming threads, and the starting point of the tool before the rotation speed of the spindle is changed is known; however, in the case of thread maintenance, the maintenance process and the machining process for forming the thread belong to different machining processes, and in the process of thread turning maintenance, the position information of the thread to be repaired is unknown, so that the document is not applicable to the thread maintenance process, and does not provide a method for avoiding thread unscrewing in the thread maintenance process.
In addition, chinese patent application publication No. CN102350548A discloses a tool setting method for thread maintenance of a numerically controlled lathe, which requires that a "plane plate" perpendicular to the main shaft is provided in front of the main shaft or a certain plane perpendicular to the main shaft is adopted in front of the main shaft, then the distance L1 from a point on the thread to the plane needs to be measured, the distance L2 from a corresponding point on the thread to be repaired to the plane needs to be measured, and the difference between L1 and L2 is calculated. However, in practice, this method has the following disadvantages: 1. the distance L1 cannot be directly obtained from the machine tool, and if manual measurement is adopted, the measurement accuracy of L1 is difficult to guarantee, and if an instrument is adopted for measurement, the equipment structure is complex; 2. the method also needs to detect and calculate the 'rotation angle difference', but most of the numerical control lathe systems in the prior art do not have the main shaft phase angle display function, so the application range of the method is limited; when the 'rotation angle difference' is detected, a detection instrument is required to be used, or a machine tool is required to be modified, so that the turning operation of each thread is complicated, the cost investment is increased, and the work efficiency is reduced; furthermore, the introduction of "rotation angle differences" complicates the position calculation. Therefore, the existence of the 'rotation angle difference' in the method causes the operation to be complicated, the efficiency to be low and the equipment cost to be high, and the method for avoiding the thread break-out in the thread maintenance is not provided.
The chinese patent application with publication number CN109799783A discloses a method for repairing a threaded pipe body by a numerical control machine, a control device and a numerical control machine, wherein the method obtains the thread track data of the threaded pipe, compares the thread track data with the program data of the numerical control machine, and calculates the data difference between the program thread and the thread to be repaired, the method belongs to the technology of thread contour scanning detection, and other systems are required to obtain the information mentioned in the method and simulate turning of the thread, which leads to equipment complication; meanwhile, the method needs to acquire the angle quantity of a spindle encoder and a machine tool of the numerical control machine tool, so that the whole tool setting process is complex. Furthermore, it does not give a way to avoid thread breakouts during thread repairs.
3. For the maintenance of the internal thread, because the internal thread is positioned in a workpiece, the relative position of the turning tool and the internal thread is difficult to judge during tool setting, so that the axial coordinate of the tooth socket of the internal thread cannot be accurately marked during tool setting, and the tool setting is difficult.
Disclosure of Invention
The present invention is directed to solve at least one of the above technical problems, and provides a method for numerically controlling turning and repairing internal threads with variable spindle rotation speeds, which can adjust turning tracks of turning tools at different spindle rotation speeds in a machine tool space, achieve coincidence of the turning tracks of the turning tools and the internal thread tracks to be repaired, and facilitate tool setting operation for internal thread maintenance.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a method for numerically controlling and repairing internal threads by turning at variable spindle rotation speed comprises the following steps:
s1, starting with the tool S [ X ]S,ZS]At spindle speed n on the outer surface of a reference workpiece1Turning visible helix T1And at the main shaft rotation speed n2Turning visible helix T2Wherein X isSAs radial coordinate of point S, ZSAs axial coordinate of point S, said helix T1、T2The lead of the screw thread is the same as the lead P of the internal thread to be repaired;
s2, positioning the tool nose of the turning tool at the point A1[XA,ZA1]Wherein X isAIs point A1Radial coordinate of (Z)A1Is point A1Axial coordinate of (Z)A1The tool tip is positioned on the spiral line T1Any position in the middle;
s3, rotating the main shaft to an angle position which makes the knife point to the spiral line T1Marking or identifying the angle position;
s4, keeping the angle position of the main shaft unchanged, moving the knife tip along the main shaft to make the knife tip positioned at the point A2[XA,ZA2]In a direction of and spirally around T1Adjacent spiral lines T2Wherein X isAIs point A2Radial coordinate of (Z)A2Is point A2Axial coordinates of (a);
s5, passing through point A1And point A2Coordinate calculation helix T of1、T2Shaft of roomDeviation in direction r2Z＝ZA2-ZA1Or a circumferential deviation r2C＝360*(ZA2-ZA1) Corrected at main shaft speed n2Thread turning procedure to eliminate the axial deviation r2ZOr the circumferential deviation r2C；
S6, detaching the reference workpiece from the chuck of the numerical control lathe;
s7, mounting the workpiece to be internally modified on the chuck, rotating the main shaft to the angle position, and turning the tool starting point E [ X ] set by the program to be internally modifiedE,ZE]Wherein X isEAs radial coordinate of point E, ZEIs the axial coordinate of point E;
s8, providing a pair of cutting rulers, including a vernier, wherein the vernier is provided with a positioning contact, the vernier is also provided with a tool aligning groove, the tool aligning groove is positioned outside the workpiece with the internal thread to be repaired, the positioning contact is positioned in the workpiece with the internal thread to be repaired, the positioning contact of the vernier is embedded with one of the tooth grooves of the internal thread to be repaired, and the tool aligning groove and the positioning contact have a fixed interval L in the axial direction of the internal thread to be repaired0；
S9, moving the turning tool to make the tool tip of the turning tool locate at the point B [ X ]B,ZB]And is directed to the center of the tool counter groove, wherein XBIs the radial coordinate of point B, ZBRemoving the tool setting rule as the axial coordinate of the point B;
s10, using point A1Calculating the axial offset distance L ' between the tool starting point E set by the vehicle repair program and the tool starting point E ' required by vehicle repair according to the coordinate values of the point B, wherein L ' is ZB-ZA1-L0-ZE+ZS-FIX((ZB-ZA1-L0-ZE+ZS)/P)*P，-P<L'<P, function FIX ((Z)B-ZA1-L0-ZE+ZS) [ P ] represents (Z)B-ZA1-L0-ZE+ZS) Integer part of/P value, or calculating circumferential deviation r of tool starting point E' required for vehicle repair and tool starting point E set by vehicle repair program0C＝360*L'/P；
S11, working on the numerical control latheMoving the cutter starting point E set by the vehicle repair program to the cutter starting point E 'required by the vehicle repair in space to eliminate the axial offset distance L' or adjusting the angular displacement of the cutter starting point E set by the vehicle repair program to eliminate the circumferential deviation r0C；
S12, executing the adjusted program through the numerical control lathe, and sequentially rotating the main shaft at the rotating speed n for the internal thread to be repaired1And main shaft rotation speed n2And (5) carrying out vehicle repair.
Further, the reference workpiece is a workpiece which satisfies a condition that a visual length is not less than 2 times of a lead P spiral line.
Further, in step S11, for the numerically controlled lathe without the macro program function, the axial offset distance L' is eliminated by translating the coordinate system or adding a tool compensation; in a numerical control lathe with a macro program function, an axial offset distance L' or a circumferential offset r is eliminated by adopting a translation coordinate system, adding a tool compensation, adjusting the position or the angular offset of a tool starting point set by a turning program in the turning program, and setting and calling any one of local coordinate systems G54-G590C。
Further, in step S5, the main shaft rotation speed n is controlled2The lower thread turning program segment adds a Q parameter to eliminate the circumferential deviation r2C。
Further, in step S3, after the spindle is rotated to the angular position, marks are made on the headstock and the chuck to mark the angular position, or the relative position characteristics of the headstock and the chuck are recognized.
Furthermore, the pair of cutting rules further comprises a rule body and a fixed rule, the fixed rule is vertically connected with the rule body, and the vernier is in sliding connection with the rule body; the step of enabling the positioning contact of the vernier to be embedded with one tooth groove of the internal thread to be repaired comprises the following steps of: and (3) enabling the ruler body to be vertical to the axis of a main shaft of the numerical control lathe, moving the vernier, enabling a positioning contact of the vernier to be embedded with one tooth groove of the internal thread to be repaired, and clamping the inner surface and the outer surface of the internal thread respectively by utilizing the positioning contact and the fixed ruler.
Furthermore, the vernier comprises a sleeve and a fixing plate connected with the sleeve, the ruler body penetrates through the sleeve and the fixing plate, and the positioning contact and the tool aligning groove are both arranged on the fixing plate and are respectively positioned on two opposite sides of the ruler body.
Furthermore, the positioning contact is convexly arranged on one side of the fixed plate facing the fixed length, and the tool setting groove is concavely arranged on one side of the fixed plate back to the fixed length.
Furthermore, a V-shaped section with an included angle of 60 degrees is formed on a plane where the positioning contact passes through the ruler body and the fixed ruler, and one end, close to the fixed ruler, of the V-shaped section of the positioning contact is an arc end; the tool aligning groove forms a V-shaped section with an included angle of 60 degrees on a plane where the tool aligning groove passes through the tool body and the fixed length, and a symmetry axis of the V-shaped section of the tool aligning groove is parallel to a symmetry axis of the V-shaped section of the positioning contact and is perpendicular to the fixed length.
Furthermore, a positioning groove is concavely arranged on one side of the fixed scale facing the positioning contact, and one end of the positioning groove penetrates through the end part of the fixed scale far away from the scale body; the cross section of the positioning groove is in an inverted equilateral trapezoid shape, and the center of the positioning contact points to the central axis of the positioning groove.
Due to the adoption of the technical scheme, the invention has the following beneficial effects:
1. by adopting the method, the turning track of the turning tool at different main shaft rotating speeds can be adjusted in the space of the machine tool, the purpose that the turning track of the turning tool is coincident with the track of the internal thread to be repaired is achieved, and the technical problem that the turning track of the turning tool is not coincident with the track of the internal thread to be repaired due to deviation between the turning tracks of the turning tool at different rotating speeds caused by the disordered thread buckling of the numerical control lathe when the main shaft rotating speed is changed for thread trimming is solved. After the method is adopted, the cutting speed of the turning tool can be changed by adjusting the rotating speed of the main shaft of the numerical control lathe so as to overcome the problem that the surface quality of the processed thread does not meet the technical requirements, therefore, the method can improve the surface quality of the thread when the thread is maintained, can provide optimized combination selection with higher cost performance for the turning process, and is beneficial to saving the cost of a cutter.
2. The method adopts the tool setting rule to set the tool, and when in use, the vernier is positionedThe contact is embedded with the tooth socket of the internal thread, the tool tip of the movable turning tool is aligned with the tool aligning groove, and the axial coordinate value of the turning tool can be read from the numerical control lathe. The tool aligning groove is positioned outside the workpiece, so that an operator can conveniently observe the position of the turning tool; and the distance L between the tool aligning groove and the positioning contact in the axial direction of the internal thread is fixed0Therefore, the distance L is obtained according to the axial coordinate of the turning tool read from the numerical control lathe0The axial coordinate value of the tooth socket embedded with the positioning contact can be calculated, so that the tooth socket of the internal thread is externally presented, accurate tool setting is realized, and tool setting operation for maintaining the internal thread is facilitated.
3. The method for numerically controlling and lathing the internal thread by changing the rotating speed of the main shaft does not need to modify or refit a numerically controlled lathe, does not need to use any external detecting instrument, has lower cost, is generally applicable to numerically controlled lathes with thread machining functions and various numerically controlled systems, and has universal applicability.
4. The method for numerically controlled lathe repairing of the internal thread with the variable spindle rotating speed does not need to find or mark the zero position of the spindle encoder, can accurately set the tool at one time, and is more convenient and faster to repair the thread.
Drawings
Fig. 1 is a schematic front view of a cutting rule according to a preferred embodiment of the present invention.
Fig. 2 is a front view of a pair of rulers according to another embodiment of the present invention.
Fig. 3 is a left side view of the pair of blades shown in fig. 2.
Fig. 4 is a bottom view of the pair of cutting rules shown in fig. 2.
Fig. 5 is a perspective view of the pair of cutting rules shown in fig. 2.
Fig. 6 is a perspective view of the pair of cutting rules shown in fig. 5 from another perspective.
FIG. 7 is a flowchart of a method for numerically controlling the rotational speed of the spindle to trim the internal thread according to the preferred embodiment of the present invention.
Fig. 8 is a schematic diagram of a method for numerically controlling and turning internal threads according to the rotation speed of the main shaft in the preferred embodiment of the present invention, wherein the view angle is a horizontal plane where the main shaft of the numerically controlled lathe is observed from top to bottom.
Fig. 9 is an enlarged view of a portion of the structure of fig. 8.
Fig. 10 is a schematic structural view of a lathe tool tip portion in an embodiment of the present invention.
Fig. 11 is a schematic structural diagram of a maximum internal thread suitable for designing a cutting rule in the embodiment of the present invention.
Fig. 12 is a schematic structural view of a positioning contact of a cutting rule according to an embodiment of the present invention engaged with the female screw shown in fig. 11.
Fig. 13 is a schematic structural view of the positioning contact of the pair of blades in the embodiment of the present invention, which is engaged with the minimum internal thread designed and applied to the pair of blades.
In the attached drawings, 100-pair of cutting rule, 2-rule body, 4-fixed rule, 42-positioning groove, 6-vernier, 62-sleeve, 64-fixing plate, 65-mounting hole, 7-positioning contact, 8-pair of tool groove, 9-locking piece, 10-knob, 200-workpiece with internal thread to be repaired, and 300-machine tool spindle box; 400-chuck; 500-reference object; 600-turning tool.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Referring to fig. 7 to 10, a preferred embodiment of the present invention provides a method for numerically controlling lathing internal threads with variable spindle rotation speed, comprising the following steps:
s1, starting with the tool S [ X ]S,ZS]At spindle speed n on the outer surface of a reference object 5001Turning visible helix T1And at the main shaft rotation speed n2Turning visible helix T2As shown in fig. 8 (a), the spiral line T1、T2The lead of the screw thread is the same as the lead P of the screw thread to be repaired. The starting point S [ X ] of the cutting toolS,ZS]Is set by the turning program, wherein XSAs radial coordinate of point S, ZSIs the axial coordinate of point S.
In step S1, the center of the end of the reference object 500 away from the chuck 400 is preferably taken as the zero point of the coordinate system to facilitate the calculation of the subsequent coordinates. Preferably, the helix T1、T2Are external threads to facilitate positioning of the turning tool 600; the reference workpiece 500 is a workpiece which is required to be turned into a helical line with a visual length not less than 2 times of the lead P, so that subsequent operation is facilitated; the spiral line refers to a track left by the center point of the tool nose of the turning tool 600 on the surface of the workpiece. Wherein n is1For removing residual thread speed, n2The rotating speed for achieving the final size of the thread, improving the quality of the final surface of the thread or meeting other requirements.
S2, positioning the tool nose of the turning tool 600 at the point A1[XA,ZA1]Wherein X isAIs point A1Radial coordinate of (Z)A1Is point A1Axial coordinate of (Z)A1Located in a helix T1Any position in the middle.
Point A1[XA,ZA1]The coordinate values of (2) can be directly obtained from the numerically controlled lathe. Preferably, said point A1Radial coordinate of (X)AThe radial position of the tool nose is larger than the helix T1In A1The large diameter at the point to prevent the lathe tool 600 from colliding with the reference object 500 to damage the lathe tool 600 or the reference object 500.
S3, rotating the main shaft to an angle position which enables the tool nose to point to the spiral line T1And marking or recognizing the angle position.
In step S3, the spindle may be manually rotated to the angular position; after the spindle is rotated to the angular position, the spindle head 300 and the chuck 400 may be marked with a marker pen to mark the angular position. Specifically, a mark F may be marked on the machine tool headstock 300, and a mark G may be marked on the chuck 400, the mark F being located on the same horizontal line as the mark G, as shown in fig. 8 (a); or to learn the relative position characteristics of the headstock 300 and the chuck 400.
S4, keeping the angle position of the main shaft unchanged, moving the knife tip along the main shaft to make the knife tip positioned at the point A2[XA,ZA2]In a direction of and spirally around T1Adjacent spiral lines T2Wherein X isAIs point A2Radial coordinate of (Z)A2Is point A2The axial coordinate of (a). Point A2[XA,ZA2]The coordinate values of (2) can be directly obtained from the numerically controlled lathe.
S5, passing through point A1And point A2Coordinate calculation helix T of1、T2Axial deviation r between2Z＝ZA2-ZA1Or a circumferential deviation r2C＝360*(ZA2-ZA1) Corrected at main shaft speed n2Thread turning procedure to eliminate the axial deviation r2ZOr the circumferential deviation r2C。
In step S5, the main shaft rotation speed n can be controlled2Eliminating the circumferential deviation r by adding Q parameter in the lower thread turning program segment2C. It will be appreciated that elimination of the axial deviation r may be employed2ZOr the circumferential deviation r2CIn such a manner that the main shaft rotates at a speed n2Turning spiral track and main shaft rotating speed n1The lower turning spiral tracks coincide.
S6, the reference workpiece 500 is removed from the chuck 400 of the numerically controlled lathe.
S7, installing the workpiece 200 with the internal thread to be repaired on the chuck 400, as shown in (b) of FIG. 8, and rotating the main spindle to the angle position, wherein the starting point of the tool set by the internal thread to be repaired turning program is E [ X ]E,ZE]Wherein X isEAs radial coordinate of point E, ZEIs the axial coordinate of point E.
In step S7, when the workpiece 200 with the internal thread to be repaired is mounted, the spindle is rotated to change the angular position thereof, so that after the workpiece 200 with the internal thread to be repaired is mounted, the spindle needs to be rotated to make the mark F marked on the headstock 300 of the machine tool and the mark G marked on the chuck 400 be in the same horizontal line again, so as to position the spindle at the angular position. The rotation of the spindle may be performed manually.
Preferably, after the workpiece 200 with the internal thread to be repaired is mounted on the chuck 400, the workpiece 200 with the internal thread to be repaired is preferentially corrected, so that the central axis of the internal thread to be repaired is overlapped with the central axis of the spindle of the numerically controlled lathe, and the precision of thread maintenance is further improved.
S8, referring to fig. 1 together, providing a pair of cutting rules 100, including a cursor 6, a positioning contact 7 is disposed on the cursor 6, a tool aligning groove 8 is further disposed on the cursor 6, the tool aligning groove 8 is located outside the workpiece 200 of the internal thread to be repaired, the positioning contact 7 is located in the workpiece 200 of the internal thread to be repaired, and the positioning contact 7 of the cursor 6 is embedded with one tooth slot of the internal thread to be repaired, the tool aligning groove 8 and the positioning contact 7 have a fixed distance L in the axial direction of the internal thread to be repaired0。
In step S8, the cutting rule 100 may be fixed by hand holding. Referring to fig. 2 to 6, in another embodiment, the pair of cutting rules 100 further includes a rule body 2 and a fixed rule 4. The fixed ruler 4 is vertically connected with the ruler body 2, and the vernier 6 is in sliding connection with the ruler body 2. The step of embedding the positioning contact 7 of the cursor 6 with one of the tooth grooves of the internal thread to be repaired specifically comprises the following steps: the ruler body 2 is perpendicular to the axis of a main shaft of the numerical control lathe, the vernier 6 is moved, the positioning contact 7 of the vernier 6 is embedded with one tooth groove of the internal thread to be repaired, and the positioning contact 7 and the fixed ruler 4 are used for clamping the inner surface and the outer surface of the internal thread respectively. The pair of cutting rules 100 can be clamped on the workpiece 200 through the matching of the positioning contact 7 and the fixed length 4 without hand-held positioning; and the cutting rule 100 can be positioned by matching the vertically connected fixed rule 4 with the rule body 2, so that the accuracy of tool setting is further improved.
In the present embodiment, the blade 2 is substantially in the shape of a long bar; the fixed length 4 is approximately in a long strip plate shape and is vertically connected with the ruler body 2, and the length direction of the fixed length 4 is parallel to the axial direction of the internal thread to be repaired. In the present embodiment, the fixed length 4 is connected to one end of the blade 2. It is understood that in other embodiments, the fixed length 4 may be connected to other portions of the blade 2, and the fixed length 4 may be connected to the blade 2 by welding or the like. A positioning groove 42 is concavely arranged on one side of the fixed ruler 4, one end of the positioning groove 42 penetrates through the end part of the fixed ruler 4 far away from the ruler body 2, and the cross section of the positioning groove 42 is in an inverted equilateral trapezoid shape.
The vernier 6 specifically includes the sleeve 62 and the fixed plate 64 connected with the sleeve 62, and sleeve 62 and fixed plate 64 all overlap on the blade 2, and fixed plate 64 is parallel with scale 4, specifically is: the vernier 6 is provided with a mounting hole 65 in a penetrating manner, the mounting hole 65 extends from the sleeve 62 to the fixing plate 64, and the sleeve 62 and the fixing plate 64 are sleeved on the ruler body 2 through the mounting hole 65. In this embodiment, the cross section of blade 2 is square, and the cross section of mounting hole 65 is the square structure with blade 2 cross section assorted, when blade 2 wore to locate mounting hole 65, through the cooperation of blade 2 and mounting hole 65 that the cross section is square, can prevent that cursor 6 from rotating relative blade 2 when moving cursor 6 to further improve the precision of location. In the present embodiment, the fixing plate 64 is connected to one end of the sleeve 62 near the fixed length 4 and is integrally formed with the sleeve 62, but it is understood that in other embodiments, the fixing plate 64 and the sleeve 62 may be connected together by means of screws or the like.
The positioning contact 7 and the tool aligning groove 8 are both arranged on the fixing plate 64 and are respectively positioned at two opposite sides of the ruler body 2. The positioning contact 7 is convexly arranged on one side of the fixed plate 64 facing the fixed ruler 4 and is positioned on the same side of the ruler body 2 as the fixed ruler 4. The positioning contact 7 forms a V-shaped section with an included angle alpha of 60 degrees on a plane passing through the ruler body 2 and the fixed ruler 4, and the top end of the V-shaped section of the positioning contact 7 close to the fixed ruler 4 is an arc end. The opposite knife groove 8 is concavely arranged on one side of the fixed plate 64 back to the fixed scale 4, a V-shaped section with an included angle beta of 60 degrees is formed on a plane where the opposite knife groove 8 passes through the scale body 2 and the fixed scale 4, and a symmetry axis of the V-shaped section of the opposite knife groove 8 is parallel to a symmetry axis of the V-shaped section of the positioning contact 7 and is vertical to the length direction of the fixed scale 4. In the present embodiment, the positioning contact 7 and the fixed plate 64 are integrally formed, but it is understood that in other embodiments, the positioning contact 7 and the fixed plate 64 may be connected by bonding or the like. The positioning contact 7 is opposed to the positioning groove 42, and the center of the positioning contact 7 is directed toward the center axis of the positioning groove 42.
The pair of cutting rules 100 also comprises a locking piece 9 for locking the vernier 6 on the ruler body 2. In this embodiment, the locking member 9 is a locking screw. The locking screw is screwed to the sleeve 62 of the cursor 6 and is located on the side of the sleeve 62 facing away from the positioning contact 7 to facilitate the operation. One end of the locking screw can extend into the sleeve 62 and abut against the ruler body 2 so as to lock the vernier 6 on the ruler body 2; the other end of the locking screw is located outside the cursor 6 and is fixed with a knob 10 to facilitate the rotation of the locking screw.
When the pair of the cutting rule 100 is used, the rule body 2 can be perpendicular to the axis of a main shaft of a machine tool, the tool setting groove 8 is located outside a workpiece 200, the locking screw is rotated to enable one end of the locking screw to be separated from the contact state with the rule body 2, the cursor 6 is moved towards the direction of the fixed length 4 to enable the positioning contact 7 to be embedded with a certain tooth socket of an internal thread, then the rule body 2 and the fixed length 4 are moved to enable the fixed length 4 to be abutted against the outer wall of the workpiece 200, so that the fixed length 4 and the positioning contact 7 are used for clamping the inner surface and the outer surface of the internal thread, the pair of the cutting rule 100 is fixed on the workpiece 200 with the internal thread to be repaired, at the moment, the outer surface of the workpiece 200 with the internal thread to be repaired is abutted against the groove surface of the positioning groove 42, the internal thread of the. Referring to fig. 11 to 13 together, in the present embodiment, the workpiece 200 is an oil internal threaded pipe, and fig. 11 shows the largest internal thread designed and applied to the cutting rule 100 in the present embodiment, wherein the radius R of the bottom arc of the internal thread is0Fig. 12 shows the fitting of the positioning contact 7 to the female screw shown in fig. 11, when the diameter is 0.965 mm. As can be seen from the figure, the radius R of the circular arc of the root of the internal thread0The upper limit of application to the cutting blade 100 is determined, and as long as the arc radius R1 of the positioning contact 7 with respect to the cutting blade 100 is not less than the root arc radius of the female screw, it is possible to ensure that the positioning contact 7 coincides with the center of symmetry of the female screw socket, and in the present embodiment, the arc radius R1 of the positioning contact 7 is preferably 1.00 mm. Fig. 13 shows the lower limit applicable to the tool setting gauge 100 in the present embodiment,as can be seen from fig. 13, the determination condition is the chord length of the arc end of the positioning contact 7, and as long as the chord length of the arc end of the positioning contact 7 is not greater than the crest interval of the internal thread, the symmetry centers of the positioning contact 7 and the internal thread tooth socket can be ensured to coincide, wherein,
arc end chord length of the positioning contact 7: L-R1 cos [30 ° ]2-1.732 mm; for a national standard straight thread, the crest pitch is 7/8 lead, so the lower limit for the cutting rule 100 is an internally threaded tube with a pitch of 1.732 x 8/7-1.979 x 2.000.
In the present embodiment, the normal usage range of the cutting rule 100 is the upper and lower limits, and this range is designed to cover most of the commonly used petroleum pipe internal threads (the lead range is 11.5-4 threads/inch, i.e. the thread pitch is 2.21-6.35 mm). If the pair of cutting rule 100 needs to be used for internal threads with other screw pitches, the matching with the internal threads with different screw pitches can be realized by replacing the vernier 6, or the positioning contact 7 can be designed to be detachably connected with the fixing plate 64 in a screw mode, an insertion mode and the like, and the matching with the internal threads with different screw pitches can be realized by replacing the positioning contact 7 when needed.
After the vernier 6 is moved to the right position, the locking screw can be rotated, so that one end of the locking screw is tightly abutted to the ruler body 2, and the vernier 6 is prevented from moving relative to the ruler body 2 accidentally in the tool setting process.
S9, moving the turning tool 600 to position the tool tip of the turning tool 600 at the point B [ X ]B,ZB]And is directed to the center of the tool counter groove 8, wherein XBIs the radial coordinate of point B, ZBIs the axial coordinate of point B, XBAnd ZBCan be directly obtained from a numerical control lathe; the cutting rule pair 100 is removed.
Since the counter-knife slot 8 is located outside the workpiece 200, the movement of the turning tool 600 is not affected, and the operator can observe the position of the turning tool 600 conveniently. And the counter knife groove 8 and the positioning contact 7 have a fixed distance L in the direction parallel to the fixed length 40Therefore, the distance L is determined according to the axial coordinate of the turning tool 600 read from the numerical control machine tool0The axial coordinate value of the internal thread tooth socket embedded with the positioning contact 7 can be calculated, so that tool setting operation of internal thread maintenance is facilitated.
In step S9, the step of removing the cutting rule 100 is: the locking piece 9 is released, the fixed ruler 4 is far away from the workpiece 200, the position of the vernier 6 is adjusted to enable the tool aligning groove 8 to be disengaged from the tool tip, the positioning contact 7 is disengaged from the tooth groove of the internal thread, and then the tool aligning ruler 100 can be removed from the workpiece 200 to be repaired.
S10, using point A1Calculating the axial offset distance L ' between the tool starting point E set by the vehicle repair program and the tool starting point E ' required by vehicle repair according to the coordinate values of the point B, wherein L ' is ZB-ZA1-L0-ZE+ZS-FIX((ZB-ZA1-L0-ZE+ZS)/P)*P，-P<L'<P, function FIX ((Z)B-ZA1-L0-ZE+ZS) [ P ] represents (Z)B-ZA1-L0-ZE+ZS) Integer part of/P value, or calculating circumferential deviation r of tool starting point E' required for vehicle repair and tool starting point E set by vehicle repair program0C＝360*L'/P。
S11, moving the cutter starting point E set by the turning program to the cutter starting point E 'required by the turning in the working space of the numerical control lathe to eliminate the axial offset distance L' or adjusting the angular displacement of the cutter starting point E set by the turning program to eliminate the circumferential deviation r0C。
In step S11, the numerical control lathe that does not have the function of the macro program is shifted by the coordinate system or by a method of adding a tool complement to eliminate the axial offset distance L'. For the machine tool having the macro program function, various methods may be employed, for example, a translation coordinate system, an additional tool compensation, an adjustment of the position or angular displacement of the tool start point set by the machining program in the machining program, a setting and calling of any one of the local coordinate systems G54 to G59, and the like, to move the tool start point set by the machining program or adjust the angular displacement of the tool start point set by the machining program. By eliminating axial offset distance L' or circumferential deviation r0CIn any mode, the tool tip track of the turning tool 600 is ensured to be coincident with the track of the internal thread to be repaired.
The thread turning becomes a more difficult problem in the application of the numerical control lathe, mainly because the actual starting point of the thread (relative to the angle of a 'spindle zero position signal') of each internal thread to be turned is different and random after being installed on the numerical control lathe, and the actual starting point is not easy to obtain conveniently and economically, which angular position in 360 degrees of the circumference of the spindle is possible, and the turning cannot be carried out if the starting point cannot be found and is not found accurately, so that technicians apply various advanced technologies and various methods to find the position of the internal thread, for example, the methods of using a CCD camera, magnetic induction, laser ranging, infrared rays, self-made measuring tools, numerical control machine tool reconstruction and the like cause high thread turning cost and complex method. The method has the remarkable difference from other prior art in the thought that: taking a shortcut, bypassing unknown measurement by using comparison with known methods, specifically, determining an angle position (namely, an angle position marked by F-G) of a main shaft, comparing the angle position with a point B on each internal thread to be trimmed to obtain a deviation, and then eliminating the deviation to realize the turning of the turning tool 600 according to the track of the internal thread to be trimmed.
S12, executing the adjusted program through the numerical control lathe, and sequentially rotating the main shaft at the rotating speed n for the internal thread to be repaired1And main shaft rotation speed n2And (5) carrying out vehicle repair.
If the number of the workpieces to be repaired with the internal threads is more than two, the steps S7-S12 are repeated until the internal threads are repaired on all the workpieces.
The method for repairing the external thread by adopting the numerical control lathe under the condition of variable spindle rotating speed has the technical principle that:
in the same space of the numerically controlled lathe, the position of the spiral track of the turning tool is determined by the starting point of the tool, the lead and the rotating speed of the main shaft, and further, the specific point A on the spiral track1Has a fixed axial and radial positional relationship with respect to the tool start point S. Thus, by finding the point A on the internal thread to be repaired1And calculating the deviation of the tool starting point E set by the turning program relative to the tool starting point required by turning according to the point B with similar attributes, eliminating the deviation and turning the turning tool according to the track of the internal thread to be turned.
In the machine tool space, the same tool starting point S, lead P and different spindle rotating speeds n1And n2Two helical tracks T are obtained1、T2(n1For the first-used speed, typically the removal margin speed, n2To achieve final dimensions, to improve final surface quality, or to meet other desired rotational speeds), at a fixed spindle radial position, T1、T2There is a determined axial deviation therebetween; or at a fixed axial position, T1、T2A determined circumferential deviation exists between; by the track T1For reference, the deviation is eliminated so that the turning tool is at the spindle speed n2Push down trajectory T1And (5) turning threads. And in the same way, the rotation speed can be expanded to more rotation speed conditions according to actual requirements.
Based on the above principle, the rotation speed n of the spindle can be adjusted by any method in the machine tool space by means of the tool rule 1002The axial position or the angular displacement of the starting point of the tool set by the lower repairing program achieves the aim that the turning track of the tool nose of the turning tool coincides with the track of the processed or to-be-repaired internal thread.
The method is suitable for turning and lathing the internal thread with the same lead, namely the taper and the tooth form half angle of the internal thread to be repaired are not limited.
To facilitate understanding, the following is a specific example provided by an embodiment of the present invention:
preparation work:
1. take Fanuc numerical control system as an example
2. All thread cutters need to be accurately adjusted, and corresponding cutter compensation is called before use
3. Preparing a tool capable of externally displaying the position of the tooth socket of the internal thread, wherein the tool is provided with a pair of cutting rulers 100, and the center distance L between the center of the positioning contact 7 and the center of the V-shaped notch of the tool setting groove 80＝127mm
4. The reference workpiece 500 is prepared, the diameter is not particularly required, in this example, an oil casing pipe with the diameter of 139.7mm and the length of not less than 200mm is used
5. A visually observable zero-taper spiral T with a lead of 6.35mm is turned at 150 revolutions per minute on the outer surface of the reference piece 5001Length of not less than 100mm, starting point of cutting (139,12.7), and turning another helix T at 200 rpm2
6. Stopping the main shaft and moving the tool tip to A1(141, -50.8), rotating the main shaft until the knife tip points to the spiral line T1Marking the current chuck angle position (marking by a marking pen and identifying the chuck angle position characteristics), and moving the tool tip to point to the T2To A2(141, -50.1), and the reference object 500 is removed
7. Preparing a practical and reliable internal thread machining program with a lead of 6.35, such as NC46, and setting an axial coordinate Z of a tool starting point E set by a thread trimming programE12.7, the rotating speed of a main shaft for turning the thread allowance is n1Calling G54 at the thread turning start section of the program, and canceling G54 calling after the thread turning is finished
8. The original program is at a rotating speed n2Adding Q parameter Q #507 to the thread turning section at 200 rpm "
9. Before all instructions of the original program, writing a calling subprogram instruction M98P 6350; ", and then write the following code into the new program O6350, can be invoked by 6.35-out multiple programs without modification
O6350；
#502 ═ 6.35; (refer to thread lead)
#503 is 12.7; (refer to the thread tool starting point Z coordinate ZS)
#504＝-50.8；(A1Point Z coordinate ZA1)
#505＝-50.1；(A2Point Z coordinate ZA2)
127; (center distance L from the center of the positioning contact 7 of the tool setting ruler to the center of the V-shaped notch of the tool setting groove 80)
#507 is 360000 (#505- #504)/# 502; (calculation of r2C)
#1 ═ 5042; (reading the axial coordinate Z of the current tool setting positionBThe value of system parameter #5042 is passed to parameter #1)
#2 [ #1- #504- #510]/#502] # 502; (calculation of axial offset distance L')
#5222 ═ 2; (setting G54 local translation coordinate system Z-direction offset distance L')
G0U-20; (turning tool X moving 10mm in negative direction, away from V-shaped notch)
W200; (turning tool Z forward direction movement 200mm, far away from the tool setting ruler)
M00; (pause procedure, operator take off cutting rule, then start according to cycle, procedure continue)
M99; (Return to vehicle repair procedure)
The implementation steps are as follows:
1. installing and aligning the female threaded NC46 workpiece to be repaired, rotating the chuck 400 to index positions F-G
2. The cutting rule 100 is installed in the horizontal plane of the axis of the main shaft, so that the positioning contact 7 simultaneously contacts any two adjacent teeth of the internal thread (the contact has no axial movable space), and the side wall of the internal thread is clamped
3. Moving the turning tool 600 to the V-shaped notch of the tool aligning groove 8 of the tool aligning ruler 100 with the center of the tool tip, stopping at the position, and detaching the tool aligning ruler 100
4. Running the internal thread machining program
By adopting the method, the turning track of the turning tool at different main shaft rotating speeds can be adjusted in the space of the machine tool, the purpose that the turning track of the turning tool is coincident with the track of the internal thread to be repaired is achieved, and the technical problem that the turning track of the turning tool is not coincident with the track of the internal thread to be repaired due to deviation between the turning tracks of the turning tool at different rotating speeds caused by the disordered thread buckling of the numerical control lathe when the main shaft rotating speed is changed for thread turning is solved. After the method is adopted, the cutting speed of the turning tool can be changed by adjusting the rotating speed of the main shaft of the numerical control lathe so as to overcome the problem that the surface quality of the processed thread does not meet the technical requirements, therefore, the method can improve the surface quality of the thread when the thread is maintained, can provide optimized combination selection with higher cost performance for the turning process, and is beneficial to saving the cost of a cutter.
The method adopts the cutter set 100, when in use, the positioning contact 7 of the vernier 6 is embedded with the tooth socket of the internal thread, the tool tip of the moving turning tool 600 is aligned with the cutter aligning groove 8, the axial coordinate value of the turning tool 600 can be read from the numerical control machine tool, and the cutter aligning groove 8 and the positioning contact 7 have a fixed interval L in the axial direction of the internal thread0Therefore, the distance L is determined according to the axial coordinate of the turning tool 600 read from the numerical control machine tool0The teeth engaged with the positioning contacts 7 can be calculatedThe axial coordinate value of the groove enables the tooth socket of the internal thread to be externally displayed, so that accurate tool setting is realized, and tool setting operation for maintaining the internal thread is facilitated.
The method for numerically controlling and lathing the internal thread by changing the rotating speed of the main shaft does not need to modify or refit a numerically controlled lathe, does not need to use any external detecting instrument, has lower cost, is generally applicable to numerically controlled lathes with thread machining functions and various numerically controlled systems, and has universal applicability.
The method for numerically controlled lathe repairing of the internal thread with the variable spindle rotating speed does not need to find or mark the zero position of the spindle encoder, can accurately set the tool at one time, and is more convenient and faster to repair the thread.
The pair of cutting rule 100 further comprises a locking piece 9 for locking the vernier 6 on the rule body 2, and after the vernier 6 is moved to a required position, the vernier 6 is locked on the rule body 2 through the locking piece 9, so that the vernier 6 is prevented from moving relative to the rule body 2 accidentally in the tool setting process.
When the pair of rule 100 is used for lathing the internal thread of the cylindrical workpiece 200, two inclined groove surfaces which enclose the equilateral trapezoid can be abutted against the outer circumference of the workpiece 200 and are in line contact with the outer circumference of the workpiece 200. Two contact lines formed by two inclined groove surfaces of an equilateral trapezoid of the positioning groove 42 and the outer wall of the workpiece 200 and a contact point formed by the positioning contact 7 and the inner thread in an embedded mode jointly form a one-point two-line positioning and clamping mode, so that the axis of the workpiece 200 is parallel to the fixed length 4, the positioning precision is improved, and the workpiece 200 can be clamped more stably. In addition, by the two inclined groove surfaces enclosing the equilateral trapezoid abutting against the outer circumference of the workpiece 200, when the outer diameter of the workpiece 200 changes, the position of the workpiece 200 in the positioning groove 42 can be adjusted, and the workpiece 200 is ensured to be in contact with the two inclined groove surfaces of the positioning groove 42, so that the fixed length 4 can be applied to workpieces 200 with different outer diameters.
In the above-mentioned cutting rule 100, the positioning contact 7 forms a V-shaped section with an included angle of 60 degrees on the plane passing through the rule body 2 and the fixed rule 4, and is suitable for various thread profiles with a flank angle equal to 1/2 thread angles, the counter knife groove 8 forms a V-shaped section with an included angle of 60 degrees on the plane passing through the rule body 2 and the fixed rule 4, and the symmetry axis of the V-shaped section of the counter knife groove and the symmetry axis of the V-shaped section of the positioning contact are parallel to each other, and can be used for visually observing the degree of embedding with the tooth angle of the turning tool 600.
Above-mentioned to cutting rule 100, its location contact 7 is located the relative both sides of blade 2 respectively with tool setting 8, can avoid blade 2 to the influence that lathe tool 600 removed, more does benefit to the tool setting operation.
It is understood that the shapes of the cursor 6, the blade 2 and the fixed length 4 are not limited to the embodiment, and can be modified accordingly as required.
It can be understood that the shape of the blade 2 is not limited to the square rod shape of the present embodiment, for example, in other embodiments, the blade 2 may be a round rod shape, the mounting hole 65 is a cylindrical through hole, the blade 2 penetrates through the mounting hole 65, at this time, a guide rail extending along the length direction of the blade 2 may be further provided on the blade 2, and a guide groove slidably fitting with the guide rail is provided on the inner wall enclosing the mounting hole 65, through the fit of the guide groove and the guide rail, the movement of the cursor 6 can be guided, and the cursor 6 can be prevented from rotating relative to the blade 2, so as to further improve the accuracy of tool setting.
It will be appreciated that the locking member 9 is not limited to the locking screw of this embodiment, for example, in other embodiments, after the cursor 6 is moved into position, a clip may be provided at the end of the sleeve 62 remote from the fixing plate 64, the clip being clipped onto the blade 2 to prevent accidental movement of the cursor 6 away from the scale 4.
It can be understood that, in other embodiments, a rubber pad may be laid on the side wall enclosing the positioning groove 42 to increase the friction force on the workpiece 200, and prevent the groove surface enclosing the positioning groove 42 from sliding relative to the outer wall of the workpiece 200 after being pressed into contact, so that the clamping is more stable, and the rubber pad has elasticity, and can elastically deform along with the size of the workpiece 200 to better cooperate with the positioning contact 7 to clamp the workpiece 200.
It is understood that the structure and shape of the fixed length 4 are not limited to this embodiment, for example, in other embodiments, the fixed length 4 may be only a flat plate as long as it can cooperate with the positioning contact 7 to sandwich the inner and outer surfaces of the female screw.
It is to be understood that the work 200 is not limited to the petroleum internally threaded pipe in the present embodiment, and may be another work having an internal thread.
The above description is intended to describe in detail the preferred embodiments of the present invention, but the embodiments are not intended to limit the scope of the claims of the present invention, and all equivalent changes and modifications made within the technical spirit of the present invention should fall within the scope of the claims of the present invention.

Claims (10)

1. A method for numerically controlling and repairing internal threads by turning at variable spindle rotation speed is characterized by comprising the following steps:
s1, starting with the tool S [ X ]S,ZS]At spindle speed n on the outer surface of a reference workpiece1Turning visible helix T1And at the main shaft rotation speed n2Turning visible helix T2Wherein X isSAs radial coordinate of point S, ZSAs axial coordinate of point S, said helix T1、T2The lead of the screw thread is the same as the lead P of the internal thread to be repaired;
s2, positioning the tool nose of the turning tool at the point A1[XA,ZA1]Wherein X isAIs point A1Radial coordinate of (Z)A1Is point A1Axial coordinate of (Z)A1The tool tip is positioned on the spiral line T1Any position in the middle;
s3, rotating the main shaft to an angle position which makes the knife point to the spiral line T1Marking or identifying the angle position;
s4, keeping the angle position of the main shaft unchanged, moving the knife tip along the main shaft to make the knife tip positioned at the point A2[XA,ZA2]In a direction of and spirally around T1Adjacent spiral lines T2Wherein X isAIs point A2Radial coordinate of (Z)A2Is point A2Axial coordinates of (a);
s5, passing through point A1And point A2Coordinate calculation helix T of1、T2Shaft of roomDeviation in direction r2Z＝ZA2-ZA1Or a circumferential deviation r2C＝360*(ZA2-ZA1) Corrected at main shaft speed n2Thread turning procedure to eliminate the axial deviation r2ZOr the circumferential deviation r2C；
S6, detaching the reference workpiece from the chuck of the numerical control lathe;
s7, mounting the workpiece to be internally modified on the chuck, rotating the main shaft to the angle position, and turning the tool starting point E [ X ] set by the program to be internally modifiedE,ZE]Wherein X isEAs radial coordinate of point E, ZEIs the axial coordinate of point E;
s8, providing a pair of cutting rulers, including a vernier, wherein the vernier is provided with a positioning contact, the vernier is also provided with a tool aligning groove, the tool aligning groove is positioned outside the workpiece with the internal thread to be repaired, the positioning contact is positioned in the workpiece with the internal thread to be repaired, the positioning contact of the vernier is embedded with one of the tooth grooves of the internal thread to be repaired, and the tool aligning groove and the positioning contact have a fixed interval L in the axial direction of the internal thread to be repaired0；
S9, moving the turning tool to make the tool tip of the turning tool locate at the point B [ X ]B,ZB]And is directed to the center of the tool counter groove, wherein XBIs the radial coordinate of point B, ZBRemoving the tool setting rule as the axial coordinate of the point B;
s10, using point A1Calculating the axial offset distance L ' between the tool starting point E set by the vehicle repair program and the tool starting point E ' required by vehicle repair according to the coordinate values of the point B, wherein L ' is ZB-ZA1-L0-ZE+ZS-FIX((ZB-ZA1-L0-ZE+ZS)/P)*P，-P<L'<P, function FIX ((Z)B-ZA1-L0-ZE+ZS) [ P ] represents (Z)B-ZA1-L0-ZE+ZS) Integer part of/P value, or calculating circumferential deviation r of tool starting point E' required for vehicle repair and tool starting point E set by vehicle repair program0C＝360*L'/P；
S11, turning the car in the working space of the numerical control latheMoving the cutter starting point E set by the trimming program to the cutter starting point E 'required by the vehicle trimming to eliminate the axial offset distance L' or adjusting the angular displacement of the cutter starting point E set by the vehicle trimming program to eliminate the circumferential deviation r0C；
S12, executing the adjusted program through the numerical control lathe, and sequentially rotating the main shaft at the rotating speed n for the internal thread to be repaired1And main shaft rotation speed n2And (5) carrying out vehicle repair.
2. The variable spindle speed numerically controlled internal thread turning method according to claim 1, wherein said reference workpiece is a workpiece that satisfies a visual length of a thread of not less than 2 times lead Phelix.
3. The method for numerically controlled lathe repairing with variable spindle speed according to claim 1, wherein in step S11, for a numerically controlled lathe without macro-programming function, the axial offset distance L' is eliminated by translating the coordinate system or adding a tool compensation; in a numerical control lathe with a macro program function, an axial offset distance L' or a circumferential offset r is eliminated by adopting a translation coordinate system, adding a tool compensation, adjusting the position or the angular offset of a tool starting point set by a turning program in the turning program, and setting and calling any one of local coordinate systems G54-G590C。
4. The method for numerically controlled trimming of internal threads with variable spindle speed according to claim 1, wherein in step S5, the internal threads are trimmed by applying the spindle speed n2The lower thread turning program segment adds a Q parameter to eliminate the circumferential deviation r2C。
5. The method for numerically controlled lathe repairing of internal thread with variable spindle speed according to claim 1, wherein in step S3, after rotating the spindle to the angular position, marks are made on the headstock and the chuck of the machine tool to mark the angular position or to identify the relative position characteristics of the headstock and the chuck of the machine tool.
6. The method for numerically controlled lathing and repairing internal threads with variable spindle rotation speed according to claim 1, characterized in that: the pair of cutting rules further comprises a rule body and a fixed rule, the fixed rule is vertically connected with the rule body, and the vernier is connected with the rule body in a sliding mode; the step of enabling the positioning contact of the vernier to be embedded with one tooth groove of the internal thread to be repaired comprises the following steps of: and (3) enabling the ruler body to be vertical to the axis of a main shaft of the numerical control lathe, moving the vernier, enabling a positioning contact of the vernier to be embedded with one tooth groove of the internal thread to be repaired, and clamping the inner surface and the outer surface of the internal thread respectively by utilizing the positioning contact and the fixed ruler.
7. The method for numerically controlled lathing and repairing internal threads with variable spindle rotation speed according to claim 6, wherein the method comprises the following steps: the vernier comprises a sleeve and a fixing plate connected with the sleeve, the ruler body penetrates through the sleeve and the fixing plate, and the positioning contact and the tool aligning groove are arranged on the fixing plate and are respectively positioned on two opposite sides of the ruler body.
8. The method for numerically controlled lathing of internal threads with variable spindle speed according to claim 7, wherein: the positioning contact is convexly arranged on one side, facing the fixed length, of the fixing plate, and the tool setting groove is concavely arranged on one side, back to the fixed length, of the fixing plate.
9. The method for numerically controlled lathing of internal threads with variable spindle speed according to claim 8, wherein: the positioning contact forms a V-shaped section with an included angle of 60 degrees on a plane where the positioning contact passes through the ruler body and the fixed ruler, and one end, close to the fixed ruler, of the V-shaped section of the positioning contact is an arc end; the tool aligning groove forms a V-shaped section with an included angle of 60 degrees on a plane where the tool aligning groove passes through the tool body and the fixed length, and a symmetry axis of the V-shaped section of the tool aligning groove is parallel to a symmetry axis of the V-shaped section of the positioning contact and is perpendicular to the fixed length.
10. The method for numerically controlled lathing and repairing internal threads with variable spindle rotation speed according to claim 6, wherein the method comprises the following steps: a positioning groove is further concavely arranged on one side of the fixed ruler, which faces the positioning contact, and one end of the positioning groove penetrates through the end part of the fixed ruler, which is far away from the ruler body; the cross section of the positioning groove is in an inverted equilateral trapezoid shape, and the center of the positioning contact points to the central axis of the positioning groove.
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CN113305374B (en) * 2021-06-23 2023-03-24 四川道勤切削工具有限公司 Grinding type thread machining tool
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CN114101812B (en) * 2021-12-21 2022-08-09 中国航发中传机械有限公司 Method for machining multi-head large-groove-width large-helix-angle high-precision internal rectangular threads
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