CN102814511B - Numerical control screw thread repairs the detection adjusting apparatus and method of helical trajectory on lathe spindle - Google Patents

Abstract

The invention provides a device for adjusting the inherent spiral trajectory of the tool tip on the spindle of a CNC thread repairing lathe, which is characterized in that: the device mainly includes a bed, a headstock and a tail table; the head box and the tail table are arranged on the bed, and the bed A spindle that can rotate is installed horizontally in the head box, a spindle encoder with a rotatable shell driven by a servo motor is installed at the rear of the head box, and a front chuck and a rear chuck are respectively installed on the front and rear ends of the spindle. Chuck; on one side of the bed, there are multiple sets of rollers on the bracket; on the end of the tail table facing the head box, a positioning cone device is set, and between the head box and the tail table is a screw phase electronic device. A phase detection sensor that detects positioning. The invention obviously improves the technical level, quality level and economic benefit of drill pipe thread repairing.

Description

Device and method for detecting and adjusting spiral trajectory on spindle of CNC thread repairing lathe

technical field

The patent of the invention is used in the field of metal cutting and processing, and relates to the CNC pipe thread lathe for repairing and turning the old internal and external threads at both ends of long pipe workpieces such as petroleum drill pipes and drill collars, changing the inherent tool on the lathe spindle A device for sharp cutting helical trajectories.

Background technique

In the petroleum and geological drilling industry, the drill bits that are drilled into the ground thousands of meters deep are composed of hundreds of drill pipes and drill collars, which are screwed one by one by the threads at both ends, and connected to the ground drilling rig. The ground drilling rig passes through these The drill pipe and drill collar transmit the torque to the drill bit. These drill pipes and drill collars need to be unloaded one by one after completing the drilling work of a well, recovered, repaired, and used repeatedly. In the maintenance work of drill pipes and drill collars, turning and repairing the inner and outer tapered joint threads at both ends is one of the most important tasks. A large number of tapered tool joint threads require reconditioning turning operations each year.

At present, people are all on mechanical pipe thread lathes to the repair turning processing of tapered drill pipe joint threads at both ends of drill pipe and drill collar, and are manually operated by workers. The reason for implementing the manual operation of the mechanical lathe to repair the turning taper thread is that the manual operation can easily adjust the tip of the tool to the groove of the thread, and then during the spiral movement of the tool relative to the workpiece, the two sides of the original triangular thread One side surface is evenly turned off one layer, and the rust, pitting, glue marks, scratches and stress fatigue layers are turned off to meet the processing requirements for thread repair. The advantages of this kind of mechanical repairing and turning tapered thread are: the radial cutting amount of the thread is small. According to the principle of the taper, the length and dimension of the drill pipe are reduced every time the thread is repaired, and the number of repairs of the drill pipe is increased. Rod life is extended.

In the field of machinery manufacturing, the use of CNC lathes to turn taper threads has obvious technical advantages over mechanical lathes, such as high thread precision, good surface quality, and high processing efficiency. Therefore, CNC lathes have been widely used in the manufacture and processing of new threads. In the turning thread function of the existing CNC lathe, as long as the thread parameters and the tool installation position are determined, the spiral trajectory of the tool tip relative to the spindle of each lathe is fixed and inherent. The inherent helical trajectory of the lathe is different, but the inherent helical trajectory of the tool tip is something that people cannot know only by their senses. It is precisely because of the inherent law of the helical trajectory of the tool tip that for an old workpiece to be repaired that is randomly clamped to the chuck of the lathe spindle and has threads, the helical line of the workpiece does not coincide with the inherent cutting helical trajectory of the tool tip on the machine tool spindle. Moreover, the phase difference between the two helical lines is random, and the tool tip cannot be processed along the groove of the old thread of the workpiece, resulting in chaotic buckling. According to the current technical level of CNC lathes, the method of CNC thread repair is to remove all the old threads from the tooth root to the outside, and re-turn new threads. The disadvantages of CNC repair turning tapered thread at this level of technology are: the radial cutting amount of the thread is large, the length and dimension of the drill pipe after turning are greatly reduced, the number of repairs of the drill pipe is reduced, and the economic benefit is not good. This is the only reason why CNC lathes cannot be directly applied to the field of old thread repair processing at present.

The reason why the inherent helical trajectory of the tool tip on the spindle of the lathe cannot be changed is that during the thread turning process of the lathe, the longitudinal movement of the tool always follows the average and transient law of one revolution of the workpiece—the tool holder moves one lead along with the spindle. For rotary motion, the computer of the CNC system needs to obtain the position signal of the spindle at any time during the process of calculating and controlling this function. People install a rotary encoder on the headstock of the lathe. Its stator shell is fixedly installed on the headstock. Its rotor shaft head and the lathe spindle are driven by a transmission ratio of 1:1. The rotary encoder is called the spindle encoder. device.

When the lathe spindle turns 1 turn, the rotor of the spindle encoder turns 1 turn. The encoder rotor will send out a fixed number of electrical pulse signals every time it rotates. In addition, when the encoder rotor is at a fixed position relative to the stator, it will also send out an electrical pulse signal indicating the "O" position. This "O" The positions are random and fixed. The phase of the inherent spiral trajectory of the tool nose on the spindle is related to the absolute position of the "O" position signal. Therefore, after the numerical control system receives this regular signal, the phase of the inherent spiral trajectory of the tool tip on the spindle controlled by it will inevitably show a random and fixed law.

Contents of the invention

Purpose of the invention: The present invention provides a device and method for changing the inherent helical trajectory of the tool tip on the spindle of a CNC thread repair lathe. The thread chaotic problem caused by the misalignment of the helix of the installed thread to be repaired.

Technical solution: the present invention is achieved through the following technical solutions:

A device for adjusting the inherent spiral trajectory of the tool tip on the spindle of a CNC thread repairing lathe, characterized in that: the device mainly includes a bed, a headstock and a tail table; the head box and the tail table are arranged on the bed, and A spindle that can be rotated is installed horizontally, and a spindle encoder with a rotatable casing driven by a servo motor is installed on the rear side of the bedside box, and a front chuck and a rear chuck are respectively installed on the front and rear ends of the spindle; There are multiple groups of idler rollers on one side of the bed; a positioning cone device is installed on the end of the tail table facing the head box, and a screw phase electronic detection and positioning device is installed between the head box and the tail table. Phase detection sensor.

The tail table is set on the bed which can move back and forth through the guide rails, and the bed is also provided with a hydraulic cylinder to push the tail table to move back and forth.

The positioning cone device is a structure for positioning the workpiece to be repaired axially and radially during use.

The positioning cone device is a positioning cone sleeve structure that can be placed on the external thread to be repaired. The inner diameter of the positioning cone device matches the thread outer diameter of the external thread workpiece to be repaired.

The positioning cone device is a positioning cone shaft structure that can extend into the internal taper thread to be repaired, and the outer diameter of the positioning cone device matches the thread inner diameter of the internal thread workpiece to be repaired.

Phase detection sensors are contact or non-contact sensors.

The ratio of spindle encoder to spindle transmission is 1:1.

The method of moving the inherent spiral trajectory of the tool tip on the CNC thread repair lathe implemented by the above-mentioned adjusting device for the inherent spiral trajectory of the tool tip on the CNC thread repair lathe is characterized in that the steps of the method are as follows: the workpiece to be repaired passes through the main shaft and The rear chuck extends to the front end of the main shaft behind the front chuck, and the tail table moves forward under the push of the hydraulic cylinder, so that the positioning cone device installed at the front end of the tail table matches the old taper thread at the front end of the workpiece, and clamps the rear chuck and the front end of the workpiece successively. The front chuck returns to the tail table. At this time, the axial and radial positions of the old thread of the workpiece to be repaired installed on the main shaft have been determined by the positioning cone device, and the circumferential position is still random. Use the thread phase electronic detection positioning sensor to measure the distance from the high point or low point of the helix on the specific generatrix of the thread to the fixed end face of the thread to determine the thread phase, if the inherent cutting of the lathe spindle has been measured and stored in the phase detection device The distance from a low point of the helical trajectory to the thread end face is L ₀ , and the distance of the workpiece measured this time is L ₁ , then the phase of the thread to be repaired in this clamping to the inherent cutting thread trajectory of the tool tip on the spindle The difference α is:

Among them: T is pitch;

n=0,1;

0≤α＜360°

Let the servo motor drive the spindle encoder housing to rotate an angle of α degrees (even if the absolute position of the encoder "0" position signal rotates an angle of α degrees), at this time, the inherent cutting helical track of the tool nose on the lathe spindle will be clamped to the The helix of the old thread to be repaired on the drill pipe, drill collar workpiece and other threaded workpieces on the lathe spindle chuck coincides, and the workpiece positioning and installation work is completed.

When the thread to be repaired is an external thread, the positioning cone device is a structure that can be sleeved on the periphery of the thread to be repaired, and the inner diameter of the positioning cone device matches the outer diameter of the thread to be repaired.

When the thread to be repaired is an internal thread, the positioning cone device is a structure that can extend into the thread to be repaired, and the outer diameter of the positioning cone device matches the inner diameter of the internal thread to be repaired.

Advantages and effects:

The invention provides a device and method for changing the phase of the inherent spiral track of a tool tip on a spindle on a numerically controlled thread repair lathe, which mainly includes two parts: an encoder transposition device and an electronic phase detection device. The present invention changes the structure of the encoder stator shell originally fixedly installed on the bedside box so that the encoder stator shell can rotate relative to the bedside box, the rotation is driven by a servo motor, and the rotation angle is detected by the numerical control system The thread phase data of the workpiece to be processed is controlled and obtained. The rotation range is within 360 ^° .

When a drill pipe workpiece with old thread to be repaired is determined in the axial position and radial position in the spindle hole of the lathe, the two chucks at the rear and front end are clamped. At this time, the workpiece has been clamped to the spindle. The axial and radial positions of the thread have been determined, but the circumferential phase of the thread to be repaired is still random. At this time, the electronic phase detection device of the present invention is used to measure the phase of the thread of the workpiece to be repaired which is randomly installed on the main shaft. Comparing this detection data with the previously known helical trajectory of the tool nose on the spindle, the phase difference is obtained. The CNC system controls the servo motor to drive the rotation of the spindle encoder shell, and the rotation angle is equal to this phase difference. According to this device and method, the adjustment and change of the inherent spiral trajectory of the tool tip on the spindle are realized, and the inherent cutting of the tool tip on the spindle is realized. The technical requirement that the helical trajectory coincides with the thread line of the old drill pipe to be repaired on the spindle chuck of the lathe, so as to achieve the goal of CNC repairing the turning thread. The invention can realize the CNC repair turning of the old thread to be repaired, which combines the advantages of high thread processing precision, good surface quality and high processing efficiency of the CNC lathe and the small radial cutting amount and small loss of the length of the drill pipe of the mechanical lathe. With advantages integrated, the invention significantly improves the technical level, quality level and economic benefits of drill pipe thread repair.

Description of drawings:

Fig. 1 is a structural schematic diagram of the present invention.

The specific embodiment: the present invention will be further described below in conjunction with accompanying drawing:

As shown in Figure 1 , the present invention provides a device for adjusting the inherent spiral trajectory of the spindle tool tip of a CNC thread repair lathe. The device mainly includes a bed 1, a headstock 8 and a tail table 3; Set on the bed 1, the headstock 8 is horizontally installed with a main shaft 7 capable of rotating, and a front chuck 6 and a rear chuck 9 are respectively installed at the front end and rear end of the main shaft 7; There is also a bracket with multiple sets of rollers 10 on the side; a positioning cone device 4 is provided at the end of the tail table 3 facing the head box 8, and a screw phase electronic device is also provided between the head box 8 and the tail table 3. The phase detection sensor 11 that detects the positioning. On the rear side of the headstock 8, a spindle encoder 12 with a rotatable lower casing driven by a servo motor is provided. The phase detection sensor 11 is a contact or non-contact sensor. The transmission ratio of the main shaft encoder 12 and the main shaft 7 is 1:1.

The tail table 3 is arranged on the bed 1 so as to move back and forth through the guide rails, and the bed 1 is also provided with a hydraulic cylinder 2 for pushing the tail table 3 to move back and forth. The positioning cone device 4 is a structure for positioning the workpiece to be repaired axially and radially during use.

Locating cone device 4 is two kinds, as follows:

The locating cone device 4 is a locating taper sleeve structure that can be sleeved on the external taper thread to be repaired, and the inner diameter of the locating cone device matches the thread outer diameter of the external thread workpiece to be repaired.

The positioning cone device 4 is a positioning cone shaft structure that can extend into the internal taper thread to be repaired, and the outer diameter of the positioning cone device matches the thread internal diameter of the internal thread workpiece to be repaired.

Shown in the accompanying drawing is the situation when the tapered thread to be repaired on the workpiece 5 is an external thread, at this moment the positioning cone device 4 is a plate-shaped inner taper sleeve; if the tapered thread to be repaired on the workpiece 5 is an internal thread, the positioning The cone device 4 is just the positioning shaft, and what the accompanying drawing shows is the state that the workpiece 5 and the positioning sleeve are cooperating.

In addition, the present invention also provides a workpiece positioning method for adjusting the inherent spiral trajectory of the tool tip on the main shaft by detecting the measurement data of the positioning device. After passing through the main shaft 7, the rear chuck 9 and the front chuck 6, the old taper thread part extends to the positioning cone device installed at the front end of the tail table. The tail table 3 moves to the main shaft end under the push of the hydraulic cylinder 2, and the workpiece 5 The old taper thread at the front end is matched with the positioning cone device. When the workpiece thread to be repaired is an external thread, the positioning cone device is a structure that can be set on the periphery of the thread to be repaired, and the inner diameter of the positioning cone device matches the outer diameter of the thread to be repaired; when the thread to be repaired is an internal thread, The positioning cone device is a structure that can extend into the thread to be repaired, and the outer diameter of the positioning cone device matches the inner diameter of the internal thread to be repaired. At this time, the axial, radial and circumferential positions of the old thread of the workpiece relative to the main shaft have been determined, but the circumferential position is random. The rear chuck 9 and the front chuck 6 are clamped successively, and the hydraulic cylinder 2 drives the tail table 3 to retreat to the rear position, completing the clamping process of the workpiece. Use the thread phase electronic detection positioning sensor to measure the distance from the high point or low point of the helix on the specific generatrix of the thread to the fixed end face of the thread to determine the thread phase, if it has been measured before and stored in the phase detection device on the lathe spindle The distance from a certain low point of the inherent cutting helical trajectory of the tip to the thread end face is L ₀ , and the distance of the workpiece measured this time is L ₁ , then the thread to be repaired in this clamping has a significant impact on the cutting thread of the inherent tool tip on the spindle. The phase difference α of the trajectory is:

Among them: T is pitch;

n=0,1;

0≤α＜360°

Let the servo motor drive the spindle encoder housing to rotate an angle of α degrees (even if the absolute position of the encoder "0" position signal rotates an angle of α degrees), at this time, the inherent cutting helical trajectory of the tool nose on the spindle of the lathe will be clamped The helix of the old thread to be repaired on the drill pipe, drill collar workpiece and other threaded workpieces on the spindle chuck of the lathe coincides, and the workpiece positioning and installation work is completed.

This ensures that in the subsequent thread turning process, the tool tip can be aligned with the groove of the old thread, and in the helical relative turning movement between the tool and the workpiece, it is ensured that the two sides of the old triangular thread can be evenly cut off by the tool. , to meet the work requirements of thread repair.

After the application of the device of the present invention is shown in the accompanying drawings, the main components related to the positioning and clamping of the workpiece on the machine tool, the saddle, slide plate, tool rest and other parts on the lathe are not described in detail.

Claims (7)

1. a kind of numerical control screw thread repairs the adjusting apparatus of the intrinsic helical trajectory of point of a knife on lathe spindle, it is characterised in that：The device Mainly include lathe bed (1), headstock (8) with tail platform (3)；(3) (8) headstock is arranged on tail platform on lathe bed (1), in headstock (8) The main shaft (7) that can be rotated is horizontally installed with, and servomotor is provided with rear side of headstock (8) and drives lower casing turn Dynamic spindle encoder (12), is separately installed with front chuck (6) and rear chuck (9) on the front-end and back-end of main shaft (7)；In bed The side of body (1) is additionally provided with the multigroup carrying roller of bracket (10)；The one end of tail platform (3) towards headstock (8) is provided with locating cone dress Put (4), headstock (8) with tail platform (3) between be additionally provided with for screw thread phase place detection of electrons positioning phase detection sensor ⑾；

(4) positioning wimble device is by the structure for axially and radially locating of workpiece to be repaired when using；Concrete form is following two Kind：

Positioning wimble device locating cone nested structure (4) for being enclosed within external screw thread to be repaired, the internal diameter of the positioning wimble device and outer spiral shell The major diameter of thread of stricture of vagina workpiece to be repaired is engaged；

Positioning wimble device is (4) for can put in the locating cone axle construction of inside tapered thread to be repaired, the external diameter of the positioning wimble device and interior spiral shell The bottom diameter of stricture of vagina workpiece to be repaired is engaged.

2. numerical control screw thread according to claim 1 repairs the adjusting apparatus of the intrinsic helical trajectory of point of a knife on lathe spindle, its It is characterised by：(3) tail platform is arranged on lathe bed (1) by what guide rail can be moved forward and backward, on lathe bed (1) is additionally provided with promotion tail The hydraulic jack that (3) platform moves forward and backward is (2).

3. numerical control screw thread according to claim 1 repairs the adjusting apparatus of the intrinsic helical trajectory of point of a knife on lathe spindle, its It is characterised by：(11) phase detection sensor is contact or noncontacting proximity sensor.

4. numerical control screw thread according to claim 1 repairs the adjusting apparatus of the intrinsic helical trajectory of point of a knife on lathe spindle, its It is characterised by：Spindle encoder (12) is 1 with main shaft (7) gear ratio：1.

5. on the numerical control screw thread reparation lathe spindle described in application claim 1, the adjusting apparatus institute of the intrinsic helical trajectory of point of a knife is real The numerical control screw thread that applies repairs the moving method of the intrinsic helical trajectory of point of a knife on lathe, it is characterised in that：The step of the method, is as follows： Workpiece to be repaired (5) is reached front-end of spindle through main shaft (7) and after rear chuck (9) front chuck (6), tail platform (3) is in hydraulic oil Move forward under the promotion of cylinder (2), the positioning wimble device for installing tail platform front end is engaged with the old taper thread in workpiece (5) front end, Rear chuck (9) and front chuck (6) is clamped successively, tail platform (3) is return, now, the workpiece to be repaired (5) that is installed on main shaft (7) The axially and radially position of old thread is determined that circumferential position is still random law by positioning wimble device；Using screw thread phase place Detection of electrons alignment sensor, measures the high point of helix on the specific bus of screw thread or low spot to the fixed end face distance of screw thread Determine screw thread phase place, if the lathe spindle for having measured before and being stored in phase detection device inherently cuts helical trajectory Certain low spot to screw thread end face distance be L₀, and this distance of the workpiece of this measurement is L₁, then this clamping treat Repairing screw thread to the phase contrast α of the intrinsic screw cutting track of point of a knife on main shaft is：

Wherein：T is pitch；

N=0,1；

360 ° of 0≤α ＜

Servomotor drive shaft encoder housing is made to rotate α degree angle, even if the absolute position of encoder " 0 " position signalling rotates α degree angle, now, intrinsic point of a knife cutting helical trajectory on lathe spindle just with the drilling rod being clamped on lathe spindle chuck, The helix that drill collar workpiece has had old thread to be repaired on whorl work piece coincides, and the work of workpiece location and installation is completed.

6. numerical control screw thread according to claim 5 repairs the moving method of the intrinsic helical trajectory of point of a knife on lathe, its feature It is：When screw thread to be repaired is external screw thread, it is to be enclosed within the peripheral structure of two-start screw to be repaired, locating cone to position wimble device The internal diameter of device is engaged with the external diameter of two-start screw to be repaired.

7. numerical control screw thread according to claim 5 repairs the moving method of the intrinsic helical trajectory of point of a knife on lathe, its feature It is：When screw thread to be repaired is female thread, positioning wimble device is to put in the structure in two-start screw to be repaired, and locating cone is filled The external diameter that puts is engaged with the internal diameter of female thread to be repaired.