CN110711908A

CN110711908A - Tool setting rule and method for repairing same-lead internal threads at specific spindle rotating speed

Info

Publication number: CN110711908A
Application number: CN201910994112.6A
Authority: CN
Inventors: 孙凤芝; 刘建群; 刘珈利; 马丹; 乔兴; 张玲; 赵微; 高扬
Original assignee: Beibu Gulf University
Current assignee: Beibu Gulf University
Priority date: 2019-10-18
Filing date: 2019-10-18
Publication date: 2020-01-21

Abstract

The invention provides a tool setting ruler, which comprises a ruler body, a fixed ruler and a vernier, wherein the fixed ruler is vertically connected with the ruler body, the vernier is in sliding connection with the ruler body, and a positioning contact is arranged on the vernier and is used for being embedded with a tooth socket of an internal thread; the vernier is also provided with a tool aligning groove for positioning and maintaining a tool, and the tool aligning groove and the positioning contact have a fixed distance in the direction parallel to the fixed length; under the action of external force, the vernier can move towards the fixed length, so that the positioning contact is matched with the fixed length to clamp the inner surface and the outer surface of the internal thread. The tool setting ruler can assist a maintenance tool to accurately mark the axial coordinate of the thread tooth socket, and facilitates tool setting operation of internal thread maintenance. The invention also provides a method for repairing the same-lead internal thread at a specific spindle rotating speed by adopting the tool setting ruler.

Description

Tool setting rule and method for repairing same-lead internal threads at specific spindle rotating speed

Technical Field

The invention relates to the technical field of thread maintenance, in particular to a tool setting ruler and a method for repairing same-lead internal threads at a specific spindle rotating 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 still exist in the numerical control lathe repair process of the screw thread:

(1) the tool setting problem is highlighted as follows: the installation of each thread to be repaired on the numerically controlled lathe is random, namely the difference between the position and the angle of the currently installed thread compared with the position and the angle of the currently installed thread is large, most of machining position data set in the previous program have no significance to the current machining, the data are completely updated, the labor efficiency of an operator can be greatly reduced, the error probability of the program is increased, and the damage risk of the workpiece thread and the maintenance equipment is increased.

In the prior art, the following method is generally adopted to perform tool setting on a numerical control lathe during thread trimming:

1. manual adjustment technology: usually, in the absence of a simpler solution, the operator can use a dynamic correction method to adjust the tool, as in the literature (gaohland how to repair the thread on a numerically controlled lathe [ J ]. modern educational science: teachers in middle schools, 2011(7): 38-38); the method is called a starting point marking method, namely, the known thread starting point position is found and marked. The methods cannot accurately find the vehicle repair starting point at one time, have low efficiency and are only suitable for individual vehicle repair.

2. The system special function expanding technology comprises the following steps: the earliest data available in China are documents (Wangcao, Tang Zhang Wenzhen, several technical problems in numerical control machining of pipe threads [ J ]. Petroleum machinery, 1998, 26 (11): 42-43), and the general idea is to add measurement and feedback functions on numerical control lathe equipment until the layout of the lathe is completely changed, and the method is not good enough in economy.

3. Thread profile scanning detection type technology: the method for solving the problem, which is the earliest thought by related science and technology personnel, is to obtain the surface information of the workpiece outline by additionally introducing a whole set of workpiece outline scanning system into a numerical control device, so as to realize automatic tool setting, such as documents (dazzling, king starting, king show plum, king soldier, li relay, numerical control repair processing method of petroleum drill rod joint threads [ J ]. Chinese mechanical engineering, 1999(6):41-43+4-5), documents (dazzling, king show plum, king starting citizen, king stand, numerical control repair processing system of petroleum drill rod joint threads [ J ]. academy of armored engineering academy academic, 2001,15(1):37-41), documents (king piston, king tom, CCD camera-based numerical control lathe thread repair method [ J ]. machine tool and hydraulic pressure, 2011,39(8):22-25) and documents (cai, lihao, jun jiang river, CCD-based numerical control thread processing automatic tool setting [ J ]. machine tool manufacturing, 2008,46(4):53-54).

This concept is not widely adopted by related enterprises for the following reasons: the method has the advantages that due to the characteristics of large-load cutting, severe working condition, various workpiece forms and variable thread forms in the petroleum pipe thread turning repair, the processing equipment adopted in the technological process needs to have the use requirements of simple structure, convenient operation, stability, reliability and easiness in maintenance, the equipment structure is complicated due to the fact that the equipment needs to be added, the purchase, use and maintenance costs are high, the probability of damage and failure of the equipment is increased due to position exposure, and the stability, reliability and operation convenience of the numerical control lathe are reduced, so that the method is unacceptable for petroleum enterprises with a large number of thread turning repair requirements.

4. Special system function class technique: the application of the thread repairing function provided by the Siemens 828D, FAGOR and the NUM system is introduced in the literature (Zhang Wu, Junyan, Zhang, Zhao Hai Chi. Siemens 828D in the numerical control pipe threading lathe [ J ] metal working: cold working 2015(2):71-72), the literature (Tang Jun, Yu Yan Ling. numerical control lathe [ J ] manufacturing technology and machine tool 2003 (96-97), the literature (horse Bin, remainder. FAGOR system line repairing function in the pipe threading special machine [ J ] numerical control machine market 2007(12): 108:110) respectively, the relevant position calculation and coordinate system setting work can be completed, partial manual labor is avoided, but the detection capability of the position of the thread to be repaired is not provided, and the characteristic part of each installation of the thread to be repaired is different for thread repairing, therefore, this technique generally requires additional installation of a position detection device on the numerically controlled lathe, resulting in an increase in equipment cost; meanwhile, the system is limited by functions and application range, can only be applied to the numerical control lathe with the corresponding system, is not suitable for the numerical control lathe with other systems, and does not have universal applicability.

5. The technology for marking zero signals: the thread repairing method of the numerical control lathe comprises the following steps of reference (Caiaojiale, Marxihong, numerical control lathe manual thread alignment [ J ]. machine tool and hydraulic pressure, 2004 (177) -, therefore, the calculated starting point is inaccurate and needs to be corrected, which is determined by the thread feeding operation principle of the numerical control machine.

6. Manufacturing special measuring tools: the numerical control machining and repairing technology of pipe threads [ J ] petroleum mine machinery, 2007(06):74-75) designs a grating digital display thread aligning device with a metering instrument, namely, the device can measure and display the position deviation value of the thread form to be repaired, which does not introduce the working principle, and the device has high cost.

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; in addition, the introduction of the 'rotation angle difference' makes the position calculation complicated, the operation complicated, the efficiency low, the cost high and the application range small.

The Chinese patent application with the publication number of CN104148752A discloses an automatic extraction and elimination method of deviation quantity in tool setting and grinding of a numerical control thread grinder, which automatically calculates synchronous following errors of a Z axis and an A axis as the deviation quantity, is equivalent to a trial run method most commonly adopted by thread turning and repairing of a numerical control lathe, depends on an operator to visually observe the distance between a tool and the conventional thread, and then repeatedly adjusts and eliminates the distance for multiple times, and has a complex process; and most of the numerically controlled lathe systems in the prior art do not have continuous multi-point and multi-dimensional data acquisition, recording, storage and calculation functions, so that the application range of the method is limited.

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 spiral line and the spiral line to be repaired, the method belongs to the thread contour scanning detection technology, 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.

(2) 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 invention aims to solve at least one of the technical problems and provides a tool setting ruler which can assist a turning tool to accurately mark the axial coordinate of a thread tooth socket and facilitate tool setting operation of internal thread maintenance.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a tool setting ruler for internal thread maintenance comprises a ruler body, a fixed ruler and a vernier, wherein the fixed ruler is vertically connected with the ruler body, the vernier is in sliding connection with the ruler body, and a positioning contact is arranged on the vernier and is used for being embedded with a tooth socket of an internal thread; the vernier is also provided with a tool aligning groove for positioning and maintaining a tool, and the tool aligning groove and the positioning contact have a fixed distance L in the direction parallel to the fixed length₀(ii) a Under the action of external force, the vernier can move towards the fixed length, so that the positioning contact is matched with the fixed length to clamp the inner surface and the outer surface of the internal thread.

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.

Further, the positioning contact is detachably connected with the fixing plate.

Further, the pair of cutting rules also comprises a locking piece for locking the vernier on the rule body.

Furthermore, a positioning groove is further concavely arranged on one side of the fixed length facing the positioning contact, and one end of the positioning groove penetrates through the end part of the fixed length far away from the ruler body.

Furthermore, 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.

Furthermore, a rubber pad is laid on the groove surface which encloses the positioning groove.

The invention also provides a method for repairing the same-lead internal thread under the rotation speed of the specific spindle, which comprises the following steps:

s1, at the preset spindle speed, using the starting point S [ X ] of the cutter_S,Z_S]Turning a reference spiral on the outer surface of a reference object, wherein X_SAs radial coordinate of point S, Z_SThe axial coordinate of the point S is obtained, and the lead of the reference spiral line is the same as the lead P of the internal thread to be repaired;

s2, turning the toolThe tool tip is positioned at point A [ X ]_A,Z_A]Wherein X is_AIs the radial coordinate of point A, Z_AIs the axial coordinate of point A, Z_AThe tool tip is positioned at any position in the middle of the reference spiral line;

s3, rotating the main shaft to an angle position which makes the knife tip point to the reference spiral line to mark or memorize the angle position;

s4, detaching the reference workpiece from the chuck of the numerical control lathe;

s5, mounting the workpiece with the internal thread to be repaired on the chuck, and rotating the main shaft to the angle position, wherein the starting point of the cutter set by the internal thread to be repaired turning program is E [ X ]_E,Z_E]Wherein X is_EAs radial coordinate of point E, Z_EIs the axial coordinate of point E;

s6, providing the tool setting ruler according to claim 1, enabling the ruler body to be perpendicular to the axis of a main shaft of the numerical control lathe, enabling the tool setting groove to be located outside a workpiece with the internal thread to be repaired, moving a cursor, enabling a positioning contact of the cursor 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 by utilizing the fixed ruler and the positioning contact;

s7, moving the turning tool to make the tool tip of the turning tool locate at the point B [ X ]_B,Z_B]And is directed to the center of the tool counter groove, wherein X_BIs the radial coordinate of point B, Z_BRemoving the tool setting rule as the axial coordinate of the point B;

s8, calculating the axial offset distance L' between the points BA as Z_B-Z_A-L₀-Z_E+Z_S-FIX((Z_B-Z_A-L₀-Z_E+Z_S)/P)*P，-P<L'<P, formula (I), function FIX ((Z)_B-Z_A-L₀-Z_E+Z_S) [ P ] represents (Z)_B-Z_A-L₀-Z_E+Z_S) Integer part of/P value, or calculating circumferential deviation r of tool starting point E' required for turning and repairing and tool starting point E set by the turning and repairing program_0C，r_0C＝360*L'/P；

S9, moving the tool starting point E set by the vehicle repair program to the tool starting point E' required by the vehicle repair in the working space of the numerical control lathe to eliminateRemoving 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 r_0C；

And S10, running the adjusted turning program, and processing the internal thread to be turned according to the tool starting point E' required for turning, the lead P and the preset spindle rotating speed to finish the turning of the internal thread to be turned.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

1. when the tool setting ruler is used, the ruler body can be perpendicular to the axis of a machine tool spindle, the vernier is moved, the positioning contact is embedded with the tooth socket of the internal thread, the inner surface and the outer surface of the internal thread are clamped by the fixed ruler and the positioning contact, the tool nose of the movable maintenance tool is aligned with the tool setting groove, the axial coordinate value of the maintenance tool can be read from a numerical control machine, and the tool setting groove and the positioning contact have a fixed distance L in the direction parallel to the fixed ruler₀According to the axial coordinates of the maintenance tool read from the numerical control machine and said spacing L₀The axial coordinate value of the tooth socket embedded with the positioning contact can be calculated, so that tool setting operation for maintaining the internal thread is facilitated.

2. The vernier is locked on the ruler body through the locking piece after the vernier is moved in place, and the vernier is prevented from moving accidentally relative to the ruler body in the tool setting process.

3. The positioning groove is further formed in the fixed ruler of the knife ruler, the cross section of the positioning groove is in an inverted equilateral trapezoid shape, two contact lines formed by two inclined groove surfaces of the equilateral trapezoid shape of the positioning groove and the outer wall of the workpiece and a contact point formed by the positioning contact and the inner thread in an embedded mode jointly form a one-point and two-line positioning and clamping mode, the axis of the workpiece can be enabled to be parallel to the fixed ruler, positioning accuracy can be improved, and the workpiece can be clamped more stably.

4. The positioning contact of the tool setting ruler forms a V-shaped section with an included angle of 60 degrees on a plane passing through the ruler body and the fixed ruler, the tool setting ruler is suitable for various thread tooth shapes with a tooth flank angle equal to 1/2 tooth form angles, the tool setting groove forms a V-shaped section with an included angle of 60 degrees on a plane passing through the ruler body and the fixed ruler, and a symmetry axis of the V-shaped section of the tool setting groove is parallel to a symmetry axis of the V-shaped section of the positioning contact, so that the tool setting ruler can be used for visually observing the embedding degree of the tool setting ruler and the tool tooth form angle.

5. By adopting the method, the internal threads with the same lead can be repaired at the rotating speed of the specific spindle, the problem of tool setting when the numerical control lathe repairs the internal threads is solved, zero positions of the spindle encoder do not need to be found or marked, the tool can be accurately set at one time, and the maintenance of the internal threads is more convenient.

6. According to the method for repairing the internal threads with the same lead at the rotating speed of the specific spindle, the positions from the point E to the point E 'can be adjusted by the minimum and most saved offset distance by calculating the axial offset distance L', and the internal thread repairing efficiency is further improved.

7. The method for repairing the same-lead internal threads at the specific spindle rotating speed does not need any external detection instrument, does not need any modification and refitting of a numerical control machine tool, is lower in cost, is generally applicable to the numerical control machine tool with the thread machining function, is suitable for various numerical control systems, is suitable for both straight threads and tapered threads, can be mixed, and has general applicability.

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 left side view of the pair of blades shown in fig. 1.

Fig. 3 is a bottom view of the pair of cutting rules shown in fig. 1.

Fig. 4 is a schematic perspective view of a pair of cutting rules according to a preferred embodiment of the present invention.

Fig. 5 is a perspective view of the pair of cutting rules shown in fig. 4 from another perspective.

FIG. 6 is a flow chart of a method for repairing an internal thread with the same lead at a specific spindle speed according to a preferred embodiment of the present invention.

FIG. 7 is a schematic diagram of a method for repairing an internal thread with the same lead at a specific spindle speed according to a preferred embodiment of the present invention, wherein the view angle is from top to bottom to a horizontal plane where the spindle of the numerically controlled lathe is located.

Fig. 8 is an enlarged view of a portion of the structure of fig. 7.

Fig. 9 is a schematic structural view of a tool tip portion of the turning tool in the embodiment of the present invention.

Fig. 10 is a schematic structural diagram of a maximum internal thread suitable for designing a cutting rule in the embodiment of the present invention.

Fig. 11 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. 10.

Fig. 12 is a schematic structural view of the positioning contact of the pair of cutting rules in the embodiment of the present invention, which is engaged with the minimum internal thread designed and applied to the pair of cutting rules.

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. 1 to 5, a preferred embodiment of the invention provides a tool setting ruler 100, which includes a ruler body 2, a fixed ruler 4 and a vernier 6.

In the present embodiment, the blade 2 is substantially in the shape of a long bar; the fixed ruler 4 is roughly in the shape of a long strip plate and is vertically connected with the ruler body 2. 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.

Referring to fig. 7 to 9, the vernier 6 is connected with the ruler body 2 in a sliding manner, a positioning contact 7 is arranged on the vernier 6, and the positioning contact 7 is used for being embedded with a tooth socket of the internal thread; the vernier 6 is further provided with a tool aligning groove 8, and the tool aligning groove 8 is used for positioning a maintenance tool, in this embodiment, the maintenance tool is a turning tool 600. The tool aligning groove 8 and the positioning contact 7 have a fixed distance L in the direction parallel to the fixed length 4₀. In the present embodiment, the direction parallel to the fixed length 4 refers to a direction parallel to the length of the fixed length 4. Under the action of an external force, the cursor 6 can move towards the fixed length 4, so that the positioning contact 7 is matched with the fixed length 4 to clamp the inner surface and the outer surface of the internal thread.

Vernier 6 specifically includes sleeve 62 and the fixed plate 64 of being connected with 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 mounting hole 65 of 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 tool setting ruler 100 is used, the ruler 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 ruler body 2, the cursor 6 is moved towards the fixed ruler 4 direction to enable the positioning contact 7 of the cursor 6 to be embedded with a certain tooth socket of an internal thread, then the ruler body 2 and the fixed ruler 4 are moved to enable the fixed ruler 4 and the positioning contact 7 to clamp the inner surface and the outer surface of the internal thread, the tool setting ruler 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 abuts against the inner wall of the positioning groove 42, and the internal thread of the workpiece. Referring to fig. 10 to 12 together, in the present embodiment, the workpiece 200 is an oil internal threaded pipe, and fig. 10 shows a tool setting in the present embodimentRuler 100 is designed for the largest type internal thread with the radius R of the root arc of the internal thread₀Fig. 11 shows the fitting of the positioning contact 7 to the female screw shown in fig. 10, 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. 12 shows the lower limit applicable to the blade setting gauge 100 in the present embodiment, and as can be seen from fig. 12, 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 pitch of the female thread, the center of symmetry of the positioning contact 7 and the tooth groove of the female thread 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.

Rotating the locking screw to enable one end of the locking screw to be tightly abutted against the ruler body 2; the tip of the moving turning tool 600 is aligned with the tool aligning groove 8, and the axial coordinate value of the turning tool 600 can be read from the numerical control machine. 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 4₀According to reading from a numerically controlled machine toolTaking the axial coordinate of the turning tool 600 and the distance L₀The 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.

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 opposite blade ruler 100, the positioning contact 7 forms a V-shaped section with an included angle of 60 degrees on the plane passing through the ruler body 2 and the fixed ruler 4, and is suitable for various thread profiles with a flank angle equal to 1/2 thread angles, the opposite blade groove 8 forms a V-shaped section with an included angle of 60 degrees on the plane passing through the ruler body 2 and the fixed ruler 4, and the symmetry axis of the V-shaped section of the opposite blade groove 8 and the symmetry axis of the V-shaped section of the positioning contact 7 are parallel to each other, and can be used for visually observing the embedding degree of the opposite blade ruler and 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.

Referring to fig. 1 to 8, the present invention further provides a method for repairing an internal thread with the same lead at a specific spindle rotation speed, including the following steps:

s1, at the preset spindle speed, using the starting point S [ X ] of the cutter_S,Z_S]A reference screw line is lathed on the outer surface of a reference workpiece 500, and as shown in (a) of fig. 7, the lead of the reference screw line is the same as the lead P of the internal thread to be repaired. The starting point S [ X ] of the cutting tool_S,Z_S]Is set by the turning program, wherein X_SAs radial coordinate of point S, Z_SIs 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 reference helix is external 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; the rotating speed of the main shaft is set according to actual requirements.

S2, positioning the tool tip of the turning tool 600 at the point A [ X ]_A,Z_A]Wherein X is_AIs the radial coordinate of point A, Z_AIs the axial coordinate of point A, Z_AThe tool tip is positioned at any position in the middle of the reference spiral line. Point A [ X ]_A,Z_A]The coordinate values of (2) can be directly obtained from the numerically controlled lathe. Preferably, the radial coordinate X of said point A_AThe radial position of the tool nose is made larger than the major diameter of the reference spiral line at the point A, so that the turning tool 600 and the reference workpiece 500 are prevented from colliding to cause damage to the turning tool 600 or the reference workpiece 500.

And S3, rotating the main shaft to an angle position, wherein the angle position enables the tool tip to point to the reference spiral line, and 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. 4 (a); or to learn the relative position characteristics of the headstock 300 and the chuck 400.

S4, the reference workpiece 500 is removed from the chuck 400 of the numerically controlled lathe.

S5, installing the workpiece 200 with the internal thread to be repaired on the chuck 400, as shown in (b) of FIG. 7, 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,Z_E]Wherein X is_EAs radial coordinate of point E, Z_EAnd the axial coordinate of the point E is shown, and the lead of the internal thread to be repaired is P. Point E [ X ]_E,Z_E]The coordinate values of (a) can be directly obtained from the turning procedure of the internal thread to be repaired.

In step S5, 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.

And S6, providing the cutting rule 100, enabling the rule body 2 to be vertical to the axis of the main shaft of the numerical control lathe, enabling the tool aligning groove 8 to be positioned outside the workpiece 200 of the internal thread to be repaired, moving the cursor 6, enabling the positioning contact 7 of the cursor 6 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 by utilizing the fixed length 4 and the positioning contact 7.

S7, moving the turning tool 600 to position the tool tip of the turning tool 600 at the point B [ X ]_B,Z_B]And is directed to the center of the tool counter groove 8, wherein X_BIs the radial coordinate of point B, Z_BIs the axial coordinate of point B, X_BAnd Z_BCan be directly obtained and removed from the numerical control latheTo the cutting rule 100.

In step S7, 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.

S8, calculating the axial offset distance L' between the points BA as Z_B-Z_A-L₀-Z_E+Z_S-FIX((Z_B-Z_A-L₀-Z_E+Z_S)/P)*P，-P<L'<P, formula (I), function FIX ((Z)_B-Z_A-L₀-Z_E+Z_S) [ P ] represents (Z)_B-Z_A-L₀-Z_E+Z_S) Integer part of/P value, or calculating circumferential deviation r of tool starting point E' required for turning and repairing and tool starting point E set by the turning and repairing program_0C，r_0C＝360*L'/P。

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 repaired to obtain a deviation, and then eliminating the deviation to realize tool setting of the numerical control lathe.

S9, 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 r_0C。

In step S9, 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 a position or an angular displacement of the tool start point E 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 E set by the machining program, or an adjustment of an angular displacement of the tool start point E set by the machining program. By eliminating axial offset distance L' or circumferential deviation r_0CIn 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.

And S10, running the adjusted turning program, and processing the internal thread to be turned according to the tool starting point E' required for turning, the lead P and the preset spindle rotating speed to finish the turning of the internal thread to be turned. In step S10, the spindle rotation speed in the internal thread trimming process to be trimmed is the same as the spindle rotation speed in step S1.

If the number of the workpieces to be repaired with the internal threads is more than two, the steps S5-S10 are repeated until the internal threads are repaired on all the workpieces.

The technical principle of the method for repairing the internal threads with the same lead at the specific spindle rotating speed is as follows:

in the machine tool space, a specific lead thread spiral track is determined by a cutter starting point and a spindle rotating speed, and under a certain specific spindle rotating speed, any point on the spiral track has a fixed axial and circumferential position relation relative to the cutter starting point. Therefore, by taking a certain fixed point with a specific position attribute on the known thread as a reference, a point with a similar attribute to the fixed point is found on the internal thread to be repaired by the cutting rule 100, and the tool starting point required by the turning repair of the internal thread to be repaired can be calculated.

Based on the principle, the tool starting point coordinate or the angular displacement set by the vehicle trimming program can be adjusted by any method, so that the aim of coinciding the tool tip track of the turning tool with the internal thread track to be trimmed is fulfilled.

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. The internal thread tool is No. 3, the tool is accurately set, and the tool complement is No. 15

3. Preparing a tool capable of externally displaying the position of the tooth socket of the internal thread, wherein the tool is a 'tool setting ruler', and the distance L from the center of a positioning contact to the center of the tool setting groove is used₀＝127mm

4. Preparing a practical and reliable internal thread processing program with a lead of 6.35, and setting a cutter starting point Z by the turning and repairing program_E12.7, the main shaft rotating speed during the thread turning is 150 revolutions per minute, and M98P9999 is written before all codes of the original program; "

5. The following code is written in the new program O9999

O9999；

#502 ═ 6.35; (thread lead/pitch)

#503 is 12.7; (reference thread axial tool start axial coordinate Z_S)

#504 ═ 50.8; (axial coordinate Z of the point corresponding to the angular position of the chuck mark_A)

127; (Pair of cutting tools L₀＝127mm)

#2601 ═ 0; (eliminating Z-direction offset of workpiece coordinate System of front part)

#1 ═ # 5022; (axial coordinate Z of current position_BTo #1)

#2 [ #1- #504- #510]/#502] # 502; (calculation of axial offset distance L')

#2601 ═ 2; (Z-direction offset of the work coordinate System)

G0U-20; (turning tool X direction away from thread to be repaired)

W300; (turning tool Z-direction far thread to be repaired)

M99; (Return to vehicle repair procedure)

6. A section of reference workpiece is prepared, and the diameter of the reference workpiece has no special requirement. Such as an oil casing of diameter 139.7mm and length 200 mm.

7. Turning a zero-taper spiral line with lead of 6.35mm on the outer surface of the reference workpiece at 150 rpm, observing that the length is not less than 12.7mm, starting the cutter at (139,12.7), stopping the main shaft, moving the cutter point to (141, -50.8)

8. Rotating the main shaft to the point spiral line of the tool nose, marking the current angular position F-G of the chuck (marking F-G can be done by a marking pen, and the current angular position characteristic of the chuck can also be recognized), and unloading the reference workpiece

The implementation steps are as follows:

1. installing and correcting the internal thread to be repaired, rotating the chuck to the marking position F-G

2. A cutting rule is arranged in the horizontal plane of the main shaft, so that the positioning contact contacts any two adjacent teeth of the internal thread (the contact has no axial movable space), and the positioning rule clamps the side wall of the internal thread

3. Calling No. 3 internal thread cutter with No. 15 cutter compensation, moving the turning tool until the center of the cutter point points to the center of the notch of the V-shaped cutter setting groove of the cutter setting ruler, and stopping at the position without moving

4. Remove the rule of cutting edge

5. Running the internal thread machining program

By adopting the method, the internal threads with the same lead can be repaired at the rotating speed of the specific spindle, the tool setting problem of the numerical control lathe for repairing the internal threads is solved, the zero position of a spindle encoder does not need to be searched or marked, the tool can be accurately set at one time, and the maintenance of the internal threads is more convenient; the method is adopted to repair the internal thread without any external detection instrument or any modification and refitting of a numerical control machine tool, and the cost is low; the method is adopted to repair the thread, the cutter can be accurately set at one time, the zero position of the main shaft encoder does not need to be searched or marked, the position of the cutter is adjusted in the space of a machine tool, the original program is not changed, and the maintenance is more convenient; the method is generally applicable to numerical control lathes with thread machining functions, is suitable for various numerical control systems, and has general applicability. For a numerical control system with a macroprogram function, manual recording, data input and calculation are not needed, and the use is more convenient; the method has no influence on the taper thread and has better universality.

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

1. The utility model provides a tool setting chi for internal thread maintenance which characterized in that: the pair of cutting rules comprises a rule body, a fixed rule and a vernier, the fixed rule is vertically connected with the rule body, the vernier is connected with the rule body in a sliding mode, and a positioning contact is arranged on the vernier and is used for being embedded with a tooth socket of an internal thread; the vernier is also provided with a tool aligning groove for positioning and maintaining a tool, and the tool aligning groove and the positioning contact have a fixed distance L in the direction parallel to the fixed length₀(ii) a Under the action of external force, the vernier can move towards the fixed length, so that the positioning contact is matched with the fixed length to clamp the inner surface and the outer surface of the internal thread.

2. The tool setting rule of claim 1, characterized in that: 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.

3. The tool setting rule of claim 2, characterized in that: 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.

4. The cutting rule set forth in claim 3, 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.

5. The tool setting rule of claim 2, characterized in that: the positioning contact is detachably connected with the fixing plate.

6. The tool setting rule of claim 1, characterized in that: the pair of cutting rules further comprises a locking piece for locking the vernier on the rule body.

7. The cutting rule set forth in any one of claims 1 to 6, wherein: one side of the fixed length facing the positioning contact is further concavely provided with a positioning groove, and one end of the positioning groove penetrates through the end part of the fixed length far away from the ruler body.

8. The cutting rule set forth in claim 7, wherein: 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.

9. The cutting rule set forth in claim 7, wherein: and a rubber pad is laid on the groove surface which is enclosed into the positioning groove.

10. A method for repairing same-lead internal threads at a specific spindle rotation speed is characterized by comprising the following steps of:

s2, positioning the tool tip of the turning tool at the point A [ X ]_A,Z_A]Wherein X is_AIs the radial coordinate of point A, Z_AIs the axial coordinate of point A, Z_AThe tool tip is positioned at any position in the middle of the reference spiral line;

S9, 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 r_0C；