Internal thread pipe forming process

Abstract

The invention discloses an internal thread pipe forming process, relates to the technical field of internal thread pipe machining, and aims to solve the problems of low intelligent control level and poor adjustment precision in the prior art. The technical scheme is that the internal thread pipe forming process comprises the five steps of pipe blank preparation, preliminary forming, spinning adjustment, spinning tooth forming and subsequent treatment; a servo motor is controlled through a servo system, the servo motor drives a hollow rotating table, then a movable plug is driven to adjust the position of a core head, and in the drawing process, an operator can manually input the position of the core head according to the surface condition of a product or automatically adjust the position by setting a time interval; a servo control system of the process is utilized to realize a new process breakthrough of continuous micro adjustment of the position of the core head in the pipe drawing process; due to the uniformity of spinning at the position of the core head, the quality of the outer surface of the product is remarkably improved, and the gram weight per meter, the ellipticity and the wall thickness deviation of the product can be more accurately controlled.

Description

Technical Field

[0001] The invention relates to the technical field of internal thread pipe processing, in particular to an internal thread pipe forming process. Background Art

[0002] Chinese patent CN117463850B discloses a special device for forming internally threaded pipes. The technical solution adopted is that it includes a core rod assembly, a spinning assembly and an ultrasonic rolling assembly. The present invention uses a first motor to drive an adjusting nut, thereby driving a moving plug to accurately adjust the relative position of the core rod assembly and the spinning assembly, thereby achieving the spinning position adjustment of the thread core head and the spinning ring.

[0003] Although the device in the above technical solution can complete the processing and production of the internal thread of the pipe, it uses a motor to directly drive the adjustment nut to rotate to change the spinning position of the thread core head and the spinning ring. It has the problems of low intelligent control level and poor adjustment accuracy, and it is easy to cause uneven use of the core head, affecting its service life. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide an internal thread pipe forming process, which can effectively solve the problems in the background technology.

[0005] In order to achieve the above object, the present invention discloses a process for forming an internally threaded pipe, the technical solution of which comprises the following steps: Step 1: Prepare the tube blank. Place the threaded core rod and threaded core head into the tube blank and inject an appropriate amount of stretching endofilm oil. The operator uses the head making machine to make the tube blank into a head so that the tube blank can enter the high-speed motor smoothly and the equipment can be started easily. Step 2: Preliminary forming: The pre-treated tube is placed on the threaded core head of the core rod assembly. The servo system drives the movable plug to move, thereby adjusting the relative position of the core rod assembly and the spinning assembly. The tube is preliminarily stretched and reduced in diameter by using the movable stretching die and the movable core head. Step 3: Spinning adjustment: Control the rotation of the servo motor in the servo system, and drive the rotation of the adjusting nut through the deceleration of the hollow turntable. The rotary motion is converted into linear motion through the threaded connection between the adjusting nut and the movable plug, driving the displacement of the movable die sleeve and the movable stretching die, thereby adjusting the relative position of the core rod body and the spinning assembly, and realizing the spinning position adjustment of the threaded core head and the spinning ring; The servo system controls the servo motor, which drives the hollow turntable, which in turn drives the moving plug to adjust the core head position. During the drawing process, the operator can manually adjust the core head position according to the surface condition of the product, or automatically adjust it by setting the time interval; Step 4: Spinning into teeth: Start the second motor to drive the spinning assembly to work. By adjusting the gear ring, multiple threaded rods are synchronously driven. The position of the wedge block is adjusted to determine the spinning amount. The first spinning ring, the second spinning ring and the steel ball are used to spin the preliminarily formed tube blank to form a threaded tooth profile on the inner surface of the tube blank. Step five, subsequent processing, is to roll up the pipe that has been spun into teeth, and finally obtain the finished product of the internal thread pipe.

[0006] As a preferred technical solution of the present invention, the hollow turntable in the step three is provided with a driving cavity and a rotating cavity, and the driving cavity and the rotating cavity are communicated, a driving shaft is rotatably connected to the driving cavity through a bearing, a support sleeve is provided in the rotating cavity, and a connecting sleeve is rotatably connected to the support sleeve.

[0007] As a preferred technical solution of the present invention, the drive shaft includes a support part and drive teeth. The support part is rotatably connected to the hollow turntable through a bearing. The support part corresponds to the position of the servo motor and is connected to the output shaft of the servo motor. The drive shaft is also provided with a retaining ring for positioning with the hollow turntable. The drive teeth are arranged at one end of the drive shaft close to the rotating cavity and are used for meshing transmission with the connecting sleeve, thereby improving the utilization efficiency and service life of the core head and ensuring the uniform use of the core head during the adjustment process.

[0008] As a preferred technical solution of the present invention, one end of the connecting sleeve is connected to the adjusting nut via a bolt, and a transmission tooth groove that engages with the driving shaft for transmission is provided on the side wall of the connecting sleeve.

[0009] As a preferred technical solution of the present invention, the inner wall of the connecting sleeve is rotatably connected to the supporting sleeve, and a sealing ring is further provided between the outer wall of the connecting sleeve and the hollow turntable.

[0010] As a preferred technical solution of the present invention, in step 1, the diameter deviation of the tube blank does not exceed ±0.05 mm, and the wall thickness deviation does not exceed ±0.03 mm.

[0011] As a preferred technical solution of the present invention, in the step 2, during the initial stretching and diameter-changing process, the stretching speed is 5-10 m / min.

[0012] As a preferred technical solution of the present invention, in step 4, during the spinning process, the rotation speed of the spinning component is 19000-26000 r / min.

[0013] As a preferred technical solution of the present invention, in step six, the sizing treatment uses a sizing die, and the diameter deviation of the pipe after sizing does not exceed ±0.02 mm.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention controls the servo motor through the servo system, the servo motor drives the hollow turntable, and then drives the movable plug to adjust the core head position. During the drawing process, the operator can manually input the adjustment of the core head position according to the surface condition of the product, or automatically adjust it by setting a time interval; and by utilizing the servo control system of this process, a new technological breakthrough of continuous micro-adjustment of the core head position during the pipe drawing process is achieved.

[0015] This process significantly improves the level of intelligent control, increases the efficiency and life of the core head, and ensures the uniform use of the core head during the adjustment process; due to the uniformity of the core head position spinning, the outer surface quality of the product is significantly improved, so that the product's meter weight, ovality and wall thickness deviation can be more accurately controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 Schematic diagram of the servo system of the present invention; Figure 3 An exploded view of the servo system of the present invention; Figure 4 Partial cross-section of the servo system of the present invention Figure 1 ; Figure 5 Partial cross-section of the servo system of the present invention Figure 2 ; Figure 6 This is a schematic diagram of the hollow turntable structure of the present invention; Figure 7 This is a schematic diagram of the drive shaft structure of the present invention; Figure 8 This is a schematic diagram of the connecting sleeve structure of the present invention; Figure 9 The electrical schematic diagram for adjusting the core head of the molding machine of the present invention; Figure 10 This is a diagram of the display screen operation interface of the present invention.

[0017] In the figure: 1. Servo motor; 2. Hollow turntable; 3. Moving plug; 4. Adjusting nut; 5. Connecting sleeve; 6. Drive shaft; 7. Bearing; 8. Sealing ring; 21. Driving chamber; 22. Rotating chamber; 23. Support sleeve; 51. Transmission tooth groove; 61. Support part; 62. Driving teeth; 63. Retaining ring. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example 1

[0019] like Figures 1 to 10 As shown, the present invention discloses a process for forming an internally threaded pipe, the technical solution adopted is to include the following steps: Step 1: Prepare the tube blank. Place the threaded core rod and threaded core head into the tube blank and inject an appropriate amount of stretching endofilm oil. The operator uses the head making machine to make the tube blank into a head so that the tube blank can enter the high-speed motor smoothly and the equipment can be started easily. The diameter deviation of the pipe blank does not exceed ±0.05mm, and the wall thickness deviation does not exceed ±0.03mm; Step 2: Preliminary forming: The pre-treated tube is placed on the threaded core head of the core rod assembly. The servo system drives the movable plug 3 to move, thereby adjusting the relative position of the core rod assembly and the spinning assembly. The tube is preliminarily stretched and reduced in diameter by the cooperation of the movable stretching die and the movable core head. During the initial stretching and diameter reduction process, the stretching speed is 7m / min; Step 3: Spinning adjustment: Control the servo motor 1 in the servo system to rotate, and the hollow turntable 2 drives the adjustment nut 4 to rotate through the deceleration. The threaded connection between the adjustment nut 4 and the movable plug 3 converts the rotary motion into linear motion, driving the displacement of the movable die sleeve and the movable stretching die, thereby adjusting the relative position of the core rod body and the spinning assembly, and realizing the spinning position adjustment of the threaded core head and the spinning ring; The hollow turntable 2 in step 3 is provided with a driving chamber 21 and a rotating chamber 22, and the driving chamber 21 and the rotating chamber 22 are connected. The driving chamber 21 is rotatably connected to the driving shaft 6 through the bearing 7. The rotating chamber 22 is provided with a support sleeve 23, and the support sleeve 23 is rotatably connected to the connecting sleeve 5. One end of the connecting sleeve 5 is connected to the adjusting nut 4 by a bolt, and a transmission tooth groove 51 is formed on the side wall of the connecting sleeve 5 to engage with the driving shaft 6 for transmission; The inner wall of the connecting sleeve 5 is rotatably connected to the supporting sleeve 23, and a sealing ring 8 is provided between the outer wall of the connecting sleeve 5 and the hollow turntable 2; The drive shaft 6 includes a support portion 61 and a drive tooth 62. The support portion 61 is rotatably connected to the hollow turntable 2 via a bearing 7. The support portion 61 corresponds to the position of the servo motor 1 and is connected to the output shaft of the servo motor 1. The drive shaft 6 is also provided with a retaining ring 63 for positioning with the hollow turntable 2. The drive tooth 62 is provided at one end of the drive shaft 6 close to the rotating chamber 22 for meshing transmission with the connecting sleeve 5. Through the meshing transmission between the transmission tooth groove 51 and the driving teeth 62, the servo motor 1 drives the adjusting nut 4 more accurately, thereby improving the use efficiency and life of the core head and ensuring the uniform use of the core head during the adjustment process; Step 4: Spinning into teeth: Start the second motor to drive the spinning assembly to work. By adjusting the gear ring, multiple threaded rods are synchronously driven. The position of the wedge block is adjusted to determine the spinning amount. The first spinning ring, the second spinning ring and the steel ball are used to spin the preliminarily formed tube blank to form a threaded tooth profile on the inner surface of the tube blank. During the spinning process, the rotation speed of the spinning assembly is 20000 r / min; Step 5: subsequent processing, the pipe that has been spun into teeth is rolled up to finally obtain the finished internal thread pipe; The sizing treatment adopts a sizing die, and the diameter deviation of the pipe after sizing does not exceed ±0.02mm.

[0020] The circuits and mechanical connections involved in the present invention are conventional means used by those skilled in the art, and technical inspiration can be obtained through limited experiments, and they are common knowledge.

[0021] Components not described in detail herein are prior art.

[0022] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A process for forming an internally threaded pipe, characterized in that: The following steps are involved: Step 1: Prepare the tube blank. Place the threaded core rod and threaded core head into the tube blank and inject an appropriate amount of stretching endofilm oil. The operator uses the head making machine to make the tube blank into a head so that the tube blank can enter the high-speed motor smoothly and the equipment can be started easily. Step 2: Preliminary forming: the pre-treated tube blank is placed on the threaded core head of the core rod assembly, and the movable plug (3) is driven to move by the servo system to adjust the relative position of the core rod assembly and the spinning assembly, and the tube blank is preliminarily stretched and reduced in diameter by using the movable stretching die and the movable core head; Step three, spinning adjustment, controlling the rotation of the servo motor (1) in the servo system, driving the rotation of the adjusting nut (4) through the deceleration of the hollow turntable (2), converting the rotary motion into linear motion through the threaded connection between the adjusting nut (4) and the movable plug (3), driving the displacement of the movable die sleeve and the movable stretching die, thereby adjusting the relative position of the core rod body and the spinning assembly, and realizing the spinning position adjustment of the threaded core head and the spinning ring; Step 4: Spinning into teeth: Start the second motor to drive the spinning assembly to work. By adjusting the gear ring, multiple threaded rods are synchronously driven. The position of the wedge block is adjusted to determine the spinning amount. The first spinning ring, the second spinning ring and the steel ball are used to spin the preliminarily formed tube blank to form a threaded tooth profile on the inner surface of the tube blank. Step five, subsequent processing, the pipe that has been spun into teeth is sized and rolled up to finally obtain the finished internal thread pipe.

2. The internal threaded pipe forming process according to claim 1, characterized in that: The hollow turntable (2) in the step 3 is provided with a driving chamber (21) and a rotating chamber (22), and the driving chamber (21) and the rotating chamber (22) are communicated with each other. A driving shaft (6) is rotatably connected to the driving chamber (21) via a bearing (7). A supporting sleeve (23) is provided in the rotating chamber (22), and a connecting sleeve (5) is rotatably connected to the supporting sleeve (23).

3. The internal threaded pipe forming process according to claim 2, characterized in that: The driving shaft (6) includes a supporting portion (61) and driving teeth (62), wherein the supporting portion (61) is rotatably connected to the hollow turntable (2) via a bearing (7), and the supporting portion (61) corresponds to the position of the servo motor (1) and is connected to the output shaft of the servo motor (1). The driving shaft (6) is also provided with a retaining ring (63) for positioning between the driving shaft and the hollow turntable (2), and the driving teeth (62) are provided at one end of the driving shaft (6) close to the rotating chamber (22) for meshing transmission with the connecting sleeve (5).

4. The internal threaded pipe forming process according to claim 2, characterized in that: One end of the connecting sleeve (5) is connected to the adjusting nut (4) via a bolt, and a transmission tooth groove (51) for meshing and transmitting with the driving shaft (6) is provided on the side wall of the connecting sleeve (5).

5. The internal threaded pipe forming process according to claim 2, characterized in that: The inner wall of the connecting sleeve (5) is rotatably connected to the supporting sleeve (23), and a sealing ring (8) is provided between the outer wall of the connecting sleeve (5) and the hollow turntable (2).

6. The internal threaded pipe forming process according to claim 1, characterized in that: In the step 1, the diameter deviation of the tube blank does not exceed ±0.05 mm, and the wall thickness deviation does not exceed ±0.03 mm.

7. The internal threaded pipe forming process according to claim 1, characterized in that: In the step 2, during the initial stretching and diameter-changing process, the stretching speed is 5-10 m / min.

8. The internal threaded pipe forming process according to claim 1, characterized in that: In the step 4, during the spinning process, the rotation speed of the spinning component is 19000-26000 r / min.

9. The internal threaded pipe forming process according to claim 1, characterized in that: In the step 5, the sizing process uses a sizing die, and the diameter deviation of the pipe after sizing does not exceed ±0.02 mm.

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