WO2023024509A1

WO2023024509A1 - New finned tube machining method without self-rotation of workpiece

Info

Publication number: WO2023024509A1
Application number: PCT/CN2022/084084
Authority: WO
Inventors: 陈群; 施华林
Original assignee: 泰州驰骏智能设备有限公司
Priority date: 2021-08-26
Filing date: 2022-03-30
Publication date: 2023-03-02
Also published as: CN113634998B; CN113634998A

Abstract

A new finned tube machining method without self-rotation of a workpiece. The method comprises: roll-forming a tube blank to obtain a prefabricated coil; introducing one end of the prefabricated coil into a straightening machine, and straightening the prefabricated coil by means of the straightening machine; performing continuous variable-diameter drawing on the prefabricated coil by means of a drawing machine, and controlling the diameter and wall thickness of the prefabricated coil to obtain a tube to be machined; sleeving said tube on a slender core rod (6), a first servo electric motor (2-2) driving a hydraulic chuck (3-1) to rotate, blades (3-4) rotating around said tube, a second servo electric motor (4-6) driving a pull rod (4-5) to move axially, and the blades (3-4) performing radial engage and retract motions to machine external fins on said tube; and the slender core rod (6) being provided with an internal thread core head (6-1) at a point of intersection of extension lines of the blades (3-4), and by means of the spinning of the blades (3-4), said tube deforming and pressing against the internal thread core head (6-1) to drive the internal thread core head (6-1) to rotate, so as to machine internal threads. By means of mounting the blades (3-4) on the hydraulic chuck (3-1), the hydraulic chuck (3-1) rotates to make the blades (3-4) rotate around a tube to be machined; in addition, the blades (3-4) rotate about their own axes, so as to press against said tube to machine threads.

Description

A New Type of Finned Tube Machining Method Without Rotation of the Workpiece

technical field

The invention relates to the technical field of mechanical processing, in particular to a method for processing finned tubes without rotation of coiled tubes.

Background technique

Heat exchange tubes designed based on enhanced heat transfer are called high-efficiency heat transfer tubes, also known as finned tubes. The existing method of processing finned tube teeth generally uses rolling equipment to drive the copper tube to rotate through three sets of blades to extrude the thread, and the process is complicated. This processing method has many problems in the processing of the copper tube: such as The inner wall is bruised, only straight pipes can be processed, and the length is limited, so the work efficiency is low.

Publication number CN109732148B relates to a method for processing finned tube teeth, including the following steps: S1. Feeding, inserting the tube material through the nylon headstock and extending through the guide sleeve, and making one end of the tube material correspond to the disc cutter ; S2. Radial adjustment of the feed position, the radial transmission mechanism of the three cutters drives the respective disc cutters to approach the center at the same time, and the first reducer is activated by controlling the first motor, and the output shaft of the first reducer passes through the coupling, The screw part connected with the coupling and the screw nut matched with the screw part drive the upper plate of the first slider and the upper plate of the second slider to move along the first linear guide rail and the second linear guide respectively. The parts are moved radially, the work efficiency is high, and the product quality is improved. However, the processing process is more complicated.

Therefore, there is an urgent need for those skilled in the art to develop a novel method for processing finned tubes without rotation of the workpiece.

Contents of the invention

The purpose of the present invention is in order to solve the deficiency that exists in the above-mentioned prior art, a kind of finned tube processing method that novel workpiece does not have rotation is provided.

In order to achieve the above-mentioned purpose of the invention, the technical solution provided by the present invention is as follows: a novel method for processing finned tubes without rotation of workpieces, comprising the following steps,

Step 1: prefabricated coiled pipes, rolling and molding the pipe blanks to obtain prefabricated coiled pipes;

Step 2: straightening treatment, introduce one end of the prefabricated coil into the straightening machine, and straighten the prefabricated coil through the straightening machine;

Step 3: Continuous variable diameter drawing, the prefabricated coiled pipe is continuously variable diameter drawn through the drawing machine, and the diameter and wall thickness of the prefabricated coiled pipe are controlled to obtain the pipe to be processed;

Step 4: Finned tube forming process, specifically including the following steps:

(i) Outer wing processing, set the pipe to be processed on the slender mandrel, the first servo motor drives the hydraulic chuck to rotate at a high speed, the speed is 2500-3500 rpm, three sets of blades revolve around the pipe to be processed, and at the same time , the second servo motor drives the pull rod to move axially, and the three sets of blades advance and retreat radially, so as to process the outer fin of the pipe to be processed;

(ii) For internal thread processing, the slender mandrel is located at the intersection of the extension lines of the three sets of blades, and an internal thread core is provided. Through the spinning of the three sets of blades, the pipe to be processed is deformed and squeezes the internal thread core, thereby driving the inner thread The thread core head rotates to process the internal thread;

Step 5: sawing process, the sawing trolley saws during the movement of the finned tube;

Step 6: Pressure test, the finned tube is subjected to a pressure test after sawing, nitrogen is added to the finned tube to pressurize, and the pressure is maintained for 15 seconds without leakage;

Step 7: Surface treatment, surface treatment of finned tubes to remove dirt, grease and coolant contaminated during processing;

Step 8: Pack and pack the processed products.

Preferably, in step 4, the helix angle of the inner thread of the pipe to be processed is greater than the helix angle of the outer fin.

Preferably, in the step 3, the drawing machine specifically adopts a chain-type continuous drawing machine.

Preferably, in the step 4, during the processing of the outer fin, the first servo motor drives the hydraulic chuck to rotate at a speed of 3000 rpm.

Preferably, in the step 6, nitrogen is added into the finned tube for pressurization, and the pressure is maintained at 2.0 MPa.

Preferably, in step 7, the surface treatment process also includes passivation treatment to form a protective film on the surface of the finned tube.

Compared with the prior art, the present invention has the following beneficial effects:

The invention provides a new processing method, which uses coiled tubes to continuously process finned tubes, and forms continuous processes such as prefabricated coiled tubes, straightening treatment, continuous variable diameter drawing, finned tube forming processing, and sawing processing. The production line for processing finned tubes has high processing efficiency and is easy to form industrialization. The finned tubes are formed by setting the tubes to be processed on the slender mandrels. The first servo motor drives the hydraulic chuck to rotate at high speed. Three sets of blades surround the The pipe to be processed revolves, the second servo motor drives the pull rod to move axially, the three sets of blades advance and retreat radially, and the outer wing of the pipe to be processed is processed. Through the spinning of the three sets of blades, the pipe to be processed is deformed and extrudes the inner thread core. Drive the internal thread core head to rotate, process the internal thread, improve the forming effect of the outer fin and internal thread of the finned tube, the coil will not appear in the self-rotation state during the entire processing process, thus ensuring that the processing process is noiseless, and the inner wall of the finned tube is free from noise. bruised.

Description of drawings

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

Fig. 2 is a structural schematic diagram of the chuck rotation mechanism of the present invention.

Fig. 3 is a schematic structural view of the elongated mandrel of the present invention.

In the figure: 1. Workbench, 2. Spindle transmission device, 2-1. Spindle box, 2-2. First servo motor, 3. Chuck rotation mechanism, 3-1. Hydraulic chuck, 3-2. Jaws, 3-3. Tool seat, 3-4. Blade, 3-5. First synchronous pulley mechanism, 4. Tool seat radial movement mechanism, 4-1. Linear guide rail mechanism, 4-2. Bearing seat , 4-3. Nut seat, 4-4. Fixed seat, 4-5. Pull rod, 4-6. The second servo motor, 4-7. The second synchronous pulley mechanism, 5. Displacement compensation mechanism, 5-1 .Static pressure guide rail, 5-2. Displacement sensor, 6. Slender core rod, 6-1. Internal thread core head, 6-2. Swimming core head.

Detailed ways

The present invention will be further explained below in conjunction with the accompanying drawings and embodiments.

The straightening machine, chain type continuous drawing machine, fin forming mechanism, sawing trolley, etc. are arranged in sequence to form an integral fin tube production line for continuous processing of coil tubes. The novel workpiece is in particular a continuous coil of tubing.

Specifically, a novel method for processing finned tubes without rotation of workpieces of the present invention comprises the following steps,

Step 2: Straightening treatment, introducing one end of the prefabricated coiled pipe into the straightening machine, and straightening the prefabricated coiled pipe through the straightening machine. The straightening machine is an existing technology;

Step 3: Continuous variable-diameter drawing. The prefabricated coil is continuously variable-diameter drawn by a chain-type continuous drawing machine. The chain-type continuous drawing machine is an existing technology, and the diameter and wall thickness of the prefabricated coil are controlled. Processing pipes;

Step 4: Use the fin forming mechanism to form the finned tube. Refer to Figure 1-3. The fin forming mechanism includes a workbench 1, a spindle drive 2, a chuck rotation mechanism 3, and a tool seat radial movement mechanism 4 And displacement compensating mechanism 5, displacement compensating mechanism 5 comprises static pressure guide rail 5-1 and displacement sensor 5-2, and static pressure guide rail 5-1 is arranged on the workbench 1, and displacement sensor 5-2 is arranged on static pressure On one side of the guide rail 5-1, the main shaft transmission device 2 is arranged on the static pressure guide rail 5-1, the chuck rotation mechanism 3 is appropriately arranged on one end of the main shaft transmission device 2, and the tool seat radial movement mechanism 4 is adaptively arranged on the main shaft The other end of the transmission device 2, the chuck rotation mechanism 3, the spindle transmission device 2, and the tool seat radial movement mechanism 4 are arranged in the same linear direction, specifically including the following steps:

(i) Outer wing processing, the main shaft transmission device 2 includes the main shaft box 2-1, the first servo motor 2-2 arranged on the main shaft box; the chuck rotating mechanism 3 includes the hydraulic chuck 3-1, is arranged on the hydraulic chuck The jaw 3-2 on the jaw 3-1, the knife seat 3-3 arranged on the jaw 3-2 and the blade 3-4 arranged on the knife seat 3-3, the center line of each group of blades 3-4 and The axes of the pipes to be processed form a certain angle, and the three sets of tool holders 3-3 are installed on the jaws 3-2 of the hydraulic chuck 3-1, and the angle between the axial centerlines of adjacent tool holders 3-3 is 120°. The first servo motor 2-2 is connected to the main shaft box 2-1 through the first synchronous pulley mechanism 3-5. Spindle transmission device 2, chuck rotation mechanism 3, slender mandrel 6 on tool seat radial movement mechanism 4, the pipe to be processed is sleeved on slender mandrel 6, and the first servo motor 2-2 drives the hydraulic chuck The disc 3-1 rotates at high speed with a speed of 3000 rpm, and the three sets of blades 3-4 revolve around the pipe to be processed; the tool seat radial movement mechanism 4 includes a linear guide rail mechanism 4-1, a bearing seat 4-2, and a nut seat 4 -3. The fixed seat 4-4 and the pull rod 4-5, the bearing seat 4-2, the nut seat 4-3 and the fixed seat 4-4 are arranged on the linear guide mechanism 4-1, and the two ends of the bearing seat 4-2 are adapted The ground is provided with a plane bearing, which can realize that the blade 3-4 advances and retreats during the rotation of the chuck rotating mechanism 3, and the pull rod 4-5 is arranged in the bearing seat 4-2 and extends to the nut seat 4-3 and the fixing seat 4-4. On the top of the fixed base 4-4, there is also a second servo motor 4-6, the second servo motor 4-6 is connected to the pull rod 4-5 through the second synchronous pulley mechanism 4-7, and the blade 3-4 The radial advance and retreat of the knife is controlled by the axial displacement of the pull rod 4-5, and the feed amount and feed speed can be arbitrarily controlled by the second servo motor 4-6, so that the second servo motor 4-6 drives the pull rod 4-5 Axial displacement, three sets of blades 3-4 carry out radial advance and retreat, so as to process the outer fin of the pipe to be processed;

(ii) Internal thread processing, the slender mandrel 6 is located at the intersection of the extension lines of the three groups of blades 3-4 to be provided with an internal thread mandrel 6-1, and the slender mandrel 6 is also provided with a swimming tool for stretching The core head 6-2, the floating core head 6-2 is fixedly connected with the pull rod 4-5 during the stretching process, through the spinning of three sets of blades 3-4, the pipe to be processed is deformed and extruded the internal thread core head 6-1 , so as to drive the internal thread core head 6-1 to rotate to process the internal thread;

The helix angle of the inner thread of the pipe to be processed is greater than the helix angle of the outer wing;

Step 6: Pressure test, the finned pipe is subjected to a pressure test after sawing, and nitrogen is added to the finned pipe to pressurize, the pressure is kept at 2.0MPa, and there is no leakage after holding the pressure for 15s;

Step 7: Surface treatment, the surface treatment of the finned tube removes the dirt, grease and coolant contaminated during the processing, and then passivation treatment forms a protective film on the surface of the finned tube;

Step 8: Pack and pack the processed products.

During the processing, the displacement compensation mechanism is used to solve the problem that the fin forming speed and the variable diameter drawing speed cannot be controlled consistently. The friction coefficient of the static pressure guide rail is almost negligible, which is different from the friction of ordinary hard rails and linear guide rails. The coefficient is large, and the displacement sensor is used to monitor the position of the sliding table on the hydrostatic guide rail and give real-time feedback to adjust the speed of the first servo motor and the second servo motor to compensate for the speed difference between fin forming and variable-diameter drawing.

The above content is an example and description of the present invention, but it does not mean that the advantages that the present invention can obtain are limited by this, and any simple transformation of the structure that may be possible in the practice of the present invention, and/or one of the advantages realized in some embodiments or more are within the protection scope of the present application.

Claims

A novel workpiece non-rotation finned tube processing method, characterized in that: comprising the following steps,

Step 1: prefabricated coiled pipes, rolling and molding the pipe blanks to obtain prefabricated coiled pipes;

Step 2: straightening treatment, introduce one end of the prefabricated coil into the straightening machine, and straighten the prefabricated coil through the straightening machine;

Step 3: Continuous variable diameter drawing, the prefabricated coiled pipe is continuously variable diameter drawn through the drawing machine, and the diameter and wall thickness of the prefabricated coiled pipe are controlled to obtain the pipe to be processed;

Step 4: Finned tube forming process, specifically including the following steps:

(i) Outer wing processing, set the pipe to be processed on the slender mandrel (6), and the first servo motor (2-2) drives the hydraulic chuck (3-1) to rotate at a high speed at 2500-3500 rpm /min, the three sets of blades (3-4) revolve around the pipe to be processed, and at the same time, the second servo motor (4-6) drives the pull rod (4-5) to move axially, so that the three sets of blades (3-4) perform radial Advance and retreat the knife to process the outer fin of the pipe to be processed;

(ii) internal thread processing, the slender mandrel (6) is located at the intersection of the extension lines of the three sets of blades (3-4) and is provided with an internal thread core head (6-1), which passes through the three sets of blades (3-4) Spinning, the pipe to be processed deforms and squeezes the internal thread core (6-1), thereby driving the internal thread core (6-1) to rotate, processing the internal thread, and obtaining the finned pipe;

Step 5: sawing process, the sawing trolley saws during the movement of the finned tube;

Step 6: Pressure test, the finned tube is subjected to a pressure test after sawing, nitrogen is added to the finned tube to pressurize, and the pressure is maintained for 15 seconds without leakage;

Step 7: Surface treatment, surface treatment of finned tubes to remove dirt, grease and coolant contaminated during processing;

Step 8: Pack and pack the processed products.
The novel method for processing finned tubes without rotation of the workpiece according to claim 1, characterized in that: in the step 4, the helix angle of the inner thread of the pipe to be processed is greater than the helix angle of the outer fin.
The novel method for processing finned tubes without rotation of the workpiece according to claim 1, characterized in that: in the step 3, the drawing machine is specifically a chain-type continuous drawing machine.
According to claim 1, the novel method for processing finned tubes without rotation of the workpiece is characterized in that: in the step 4, during the processing of the outer fins, the first servo motor (2-2) drives the hydraulic chuck (3-1 ) rotate at a speed of 3000 rpm.
According to claim 1, the novel method for processing finned tubes without rotation of the workpiece is characterized in that: in the step 6, nitrogen is added into the finned tubes for pressurization, and the pressure is maintained at 2.0 MPa.
The novel method for processing finned tubes without rotation of the workpiece according to claim 1, characterized in that: in the step 7, the surface treatment process also includes passivation treatment to form a protective film on the surface of the finned tube.