Finish machining process of pipe die sleeve

Abstract

The invention relates to a finish machining process for a pipe die sleeve, which is used for reducing the cost, avoiding deformation and machining a special-shaped structure in the machining process of the pipe die sleeve. The process route comprises the steps of semi-finish machining (including pipe die sleeve semi-finish turning, sealing ring semi-finish turning, first rolling belt semi-finish turning, belt pulley semi-finish turning, thrust ring semi-finish turning and second raceway semi-finish turning), welding, stress relief tempering after welding, frame position, finish boring, finish turning, dye penetrant inspection and drilling. According to the process route, the machining accuracy is guaranteed and the machining efficiency is improved by controlling the size and the structure of semi-finish machining and manufacturing a special cutter, finally, products meeting the quality requirement are produced under the guarantee of the process, the machining cost of the pipe die sleeve is effectively reduced, machining deformation of the pipe die sleeve is avoided, and the machining stress of the pipe die sleeve is reduced; and the machining problem of a special-shaped structure can be solved, the pipe die sleeve can be better used in a severe environment with alternate cooling and heating, and the requirement for the service life of the pipe die sleeve is met.

Description

Technical Field

[0001] This invention belongs to the field of industrial mold machining technology, specifically relating to a precision machining process for tube mold sleeves that reduces costs, avoids deformation, and facilitates the machining of irregular structures. This process effectively reduces the machining cost of tube mold sleeves, prevents deformation, and reduces machining stress. It also solves the machining challenges of irregular structures, better meeting the requirements for use in harsh environments with alternating hot and cold temperatures, and extending the service life of the tube mold sleeves. Background Technology

[0002] Currently, there is no specific and effective processing method for tube mold sleeves. Although both tube mold sleeves and tube molds are hollow rotary molds, tube mold sleeves have a complex structure. If the processing of tube mold sleeves is based on the processing technology of tube molds, it will be found that the utilization rate of forging blanks is low, the deformation during processing is large, the alloy layer is uneven, and irregular structures are difficult to process. In order to overcome the above problems and process tube mold sleeves smoothly, it is necessary to develop special cutting tools and precision machining processes. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a finishing process for tube mold sleeves that reduces deformation during processing and improves the utilization rate of forging blanks.

[0004] The objective of this invention is achieved as follows: a precision machining process for a pipe mold sleeve, the pipe mold sleeve comprising a body, a sealing ring, a first roller, a pulley, a thrust ring, and a second roller, wherein the sealing ring, the first roller, the second roller, the pulley, and the thrust ring are welded to the body of the pipe mold sleeve. The specific route of the precision machining process for the pipe mold sleeve is semi-precision machining: including semi-precision turning of the pipe mold sleeve, semi-precision turning of the sealing ring, semi-precision turning of the first roller, semi-precision turning of the pulley, semi-precision turning of the thrust ring, semi-precision turning of the second raceway—welding—post-weld stress-relief tempering—chassis positioning—precision boring—precision turning—dynamite testing—drilling. The specific machining steps are as follows: Step 1) Semi-finishing: Perform semi-finishing according to the semi-finishing drawings for each part. When semi-finishing the body, the lathe speed is 35-50 r / min, the feed is 0.7-1 mm / r, and the depth of cut is 4-5 mm. For subsequent welding, a mating step and a limiting step should be machined at the places where the body of the pipe mold sleeve mates with the sealing ring, the first roller, the second roller, the pulley, and the thrust ring. This facilitates positioning and ensures stability after welding. The pipe body of the pipe mold sleeve has a stepped shape, with the diameter gradually increasing from the spigot to the socket. A 6 mm allowance is left between the spigot end face and the first roller of the pipe mold sleeve body and the finished product. The remaining empty space of the body body... Leave a 9mm allowance on the finished product; leave a 7mm allowance on the mating step of the first roller to the finished product, and a 9mm allowance on the positioning step of the first roller to the finished product; leave an 11mm allowance on the mating step of the pulley to the finished product, and a 13mm allowance on the positioning step of the pulley to the finished product; leave a 15mm allowance on the mating step of the thrust ring to the finished product, and a 17mm allowance on the positioning step of the thrust ring to the finished product; leave a 19mm allowance on the mating step of the second roller to the finished product, and a 20mm allowance on the positioning step of the second roller to the finished product; when semi-finish turning the outer diameter of the sealing ring, the lathe speed is 20-40r / min, the feed is 0.6-0.8mm / r, and the depth of cut is 3-5mm. When finishing the inner diameter, the lathe speed is 40-50 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. When semi-finishing the outer diameter of the first rolling band, the lathe speed is 20-40 r / min, the feed rate is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm. When semi-finishing the inner diameter, the lathe speed is 40-50 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. When semi-finishing the outer diameter of the pulley, the lathe speed is 15-30 r / min, the feed rate is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm. When semi-finishing the inner diameter, the lathe speed is 40-50 r / min, the feed rate is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm. For semi-finish turning of the thrust ring outer diameter, the lathe speed is 15-30 r / min, the feed rate is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm. For semi-finish turning of the inner diameter, the lathe speed is 40-50 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. For semi-finish turning of the second rolling belt outer diameter, the lathe speed is 15-25 r / min, the feed rate is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm. For semi-finish turning of the inner diameter, the lathe speed is 40-50 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. Step 2) Welding: Weld the sealing ring, first roller, pulley, thrust ring, second roller, and the alloy layer of the largest outer circle of the socket by 7mm on one side. Use JIS D-308 welding wire and adjust the current to 500-600A, voltage to 30-40V, and speed to 4-6r / min during welding. Weld the sealing ring, first roller, pulley, thrust ring, and second roller to the outer circle of the pipe mold sleeve. Use H18CrMoA welding wire and adjust the current to 550-650A, voltage to 30-40V, and speed to 4-6r / min during welding. Step 3) Post-weld stress-relief tempering: The furnace temperature for post-weld stress-relief tempering should be controlled below 150℃. After preheating at 200℃, the temperature should be increased to 350℃ at full power to completely remove stress. Then, the temperature should be held for 3 hours and cooled to 150℃ in the furnace before being removed from the furnace and air-cooled. Because the diameters of the sealing ring, the first roller, the pulley, the thrust ring, the second roller, and the maximum outer diameter of the socket are inconsistent, shims should be placed in these suspended areas to reduce deformation during tempering, thereby ensuring the uniformity of the alloy layer during subsequent processing and reducing the processing difficulty caused by deformation. Step 4) Chassis position: Align with the outer circle of the sealing ring and the second roller. After alignment, observe the runout of several welding positions and the pipe body. The runout of the welding position is less than 0.5mm and the runout of the pipe body is less than 3mm. Machine a 300-500mm long chassis position on the pipe body at the socket end and machine the alignment position on the pipe body at the spigot end. Step 5) Fine boring: For fine boring, a chuck is used to clamp the outer diameter of the socket end and the center rest is used to support the bearing end. The runout is adjusted to 0.1mm. First, rough boring the inner hole, leaving a margin of 1.5-3mm in the finished inner hole. For rough boring, the machine tool speed should be adjusted to 55-70r / min, feed rate to 20-35mm / min, and depth of cut to 4-5mm. Then, float boring the inner hole according to the finished inner hole size. During float boring, the machine tool speed should be 55-70r / min, feed rate to 15-30mm / min, and depth of cut to 1-1.5mm. Step 6) Finish turning: When finishing the body, the lathe speed is 40-60 r / min, the feed is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. Align with the position and alignment position in Step 4), and then evenly machine three wall thickness bands on the tube body of the body, with a wall thickness difference within 0.2 mm. Machine the outer diameter and the dimensions of both ends according to the drawings. When finishing the outer diameter of the components to be welded together, the lathe parameters need to be adjusted as follows: When finishing the outer diameter of the sealing ring, the lathe speed is 20-30 r / min, the feed is 0.4-0.6 mm / r, and the depth of cut is 2-4 mm; finish turning the first roll When finishing the outer diameter of the belt pulley, the lathe speed is 20-30 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the belt pulley, the lathe speed is 15-25 r / min, the feed rate is 0.3-0.45 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the thrust ring, the lathe speed is 15-25 r / min, the feed rate is 0.3-0.45 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the second roller belt, the lathe speed is 20-30 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-5 mm. Step 7) Dyeing inspection: Perform dyeing inspection on the welded parts according to GB / T18851.1-2020 standard: First, clean the workpiece with a cleaning agent, then apply red penetrant to the welded position, ensuring complete coverage and wait for 10-30 minutes. Next, spray the cleaning agent onto a lint-free cloth to wipe away the excess penetrant on the surface. Finally, apply white developer and wait for 7-30 minutes. If there is a defect, the red penetrant at the defect will slowly seep out onto the white background to form a clear red mark. After the inspection, wipe off the developer coating with a cleaning agent. Step 8) Drilling: Align the outer diameter of the workpiece with a runout of ≤0.05, align the cross lines on the end face, press the workpiece firmly to drill the hole on the end face and the tube body, and pay attention to chamfering and deburring.

[0005] In step 1), the tolerances of each mating step of the pipe body are: The tolerance between the pipe body and the positioning step is To facilitate assembly and welding; the outer diameter of the sealing ring, first roller, thrust ring, second roller, and the outermost outer circle of the socket is machined to be 8mm smaller than the finished product to meet the thickness requirements of the alloy layer; the inner hole tolerances of the first roller, pulley, thrust ring, and second roller are... Its basic dimensions are consistent with the dimensions of its corresponding mating steps, reducing post-weld runout, ensuring welding stability, and maximizing the uniformity of alloy layer thickness; the length tolerance of each mating step is... The length allowance of the sealing ring, the first roller, the pulley, the thrust ring, and the second roller is 10mm to ensure sufficient allowance for subsequent processing and to ensure the stability of the welding. The sealing ring is attached to the end face of the socket by extending its length. Therefore, the welding bevel of the semi-finished machined sealing ring is an R25 arc bevel. The first roller, the pulley, the thrust ring, and the second roller are welded by fitting the inner hole and the outer circle. The welding bevel is composed of an R10 arc plus a 45-degree taper.

[0006] In step 2), before welding, the position of each part must be carefully confirmed by referring to the finished product drawing. Welding can only proceed after the position is correct.

[0007] In step 6), the pipe mold clamps the outer diameter of the spigot and the inner hole of the socket, aligning it to a wall thickness difference of 0.2mm and clamping it. First, precision machine the outer diameter, removing the plug plate, placing the center support, and precision machine the inner hole of the socket. Then, turn the mold around, aligning it to within 0.05mm of the finished pipe body and clamping it, machining the spigot components. For precision machining of the spigot sealing ring and the irregular groove in the spigot inner hole, special tools are required. The tool holder and tool body used for machining the sealing ring are designed with a 25mm width to allow for chip removal, heat dissipation, and to extend the tool's lifespan. The machine tool speed during grooving is 15-25 r / s. The feed rate is 0.2-0.3 mm / r. To ensure dimensions and root clearance, the tool body is available in two versions: forward and reverse. When machining irregular grooves, the tool holder and tool body are adjusted to a speed of 15-25 r / min and a feed rate of 0.2-0.3 mm / r. The tool body is designed with reference to the irregular groove structure, leaving a 2 mm clearance. During turning, because the irregular groove has the same arc, taper, and insert structure, it is only necessary to ensure that the tool holder travels 2 mm before retracting the tool. This not only ensures the machining accuracy of the irregular groove and saves machining time, but also solves the technical problem that conventional inserts cannot machine.

[0008] The tube mold sleeves produced by the above process have high forging billet utilization, small deformation during processing, uniform alloy layer thickness, correct dimensions of irregular structures, and all dimensional and positional tolerances can meet the drawing requirements. This invention effectively solves various difficulties in the tube mold sleeve processing process and ensures the service life of the tube mold sleeves. Attached Figure Description

[0009] Figure 1 A finished product drawing of the tube mold sleeve of the present invention.

[0010] Figure 2 A partially enlarged schematic diagram of the irregular groove of the present invention.

[0011] Figure 3 Semi-finished machining drawing of the tube mold sleeve of the present invention.

[0012] Figure 4 Semi-finished machining drawing of the sealing ring of the present invention.

[0013] Figure 5 The first semi-finishing drawing of the present invention.

[0014] Figure 6 Semi-finished machining drawing of the pulley of the present invention.

[0015] Figure 7 Semi-finished machining diagram of the thrust ring of the present invention.

[0016] Figure 8 The second semi-finishing drawing of the present invention.

[0017] Figure 9 A schematic diagram of the tool holder used in the sealing ring of this invention.

[0018] Figure 10 A schematic diagram of the blade body used in the sealing ring of the present invention.

[0019] Figure 11 A schematic diagram of the tool holder used for the irregular groove of the present invention.

[0020] Figure 12 A schematic diagram of the blade body used in the irregular groove of the present invention.

[0021] Figure 1 As shown: 1 is the body's irregular groove, 2 is the sealing ring, 3 is the first roller, 4 is the pulley, 5 is the thrust ring, and 6 is the second roller. Detailed Implementation

[0022] A finishing process for a pipe mold sleeve, the pipe mold sleeve comprising a body 1, a sealing ring 2, a first roller 3, a pulley 4, a thrust ring 5, and a second roller 6, wherein the sealing ring 2, the first roller 3, the second roller 6, the pulley 4, and the thrust ring 5 are welded to the body 1 of the pipe mold sleeve. The specific finishing process route of the pipe mold sleeve is semi-finishing: including semi-finishing turning of the pipe mold sleeve, semi-finishing turning of the sealing ring, semi-finishing turning of the first roller, semi-finishing turning of the pulley, semi-finishing turning of the thrust ring, semi-finishing turning of the second raceway—welding—post-weld stress relief tempering—chassis positioning—finish boring—finish turning—dynamite testing—drilling. The specific processing steps are as follows: Step 1) Semi-finishing: Perform semi-finishing according to the semi-finishing drawings for each part. When semi-finishing the body 1, the lathe speed is 35-50 r / min, the feed is 0.7-1 mm / r, and the depth of cut is 4-5 mm. For subsequent welding, a mating step and a limiting step should be machined at the places where the body 1 of the pipe mold sleeve mates with the sealing ring 2, the first roller 3, the second roller 6, the pulley 4, and the thrust ring 5, to facilitate positioning and ensure stability after welding. The body of the pipe mold sleeve body 1 has a stepped shape, with the diameter gradually increasing from the spigot to the socket. A 6 mm allowance is left from the spigot end face to the first roller 3 and the finished product. The remaining gaps in the body 1 are... A 9mm allowance is left from the pipe body to the finished product; a 7mm allowance is left from the mating step of the first roller to the finished product, and a 9mm allowance is left from the positioning step of the first roller to the finished product; an 11mm allowance is left from the mating step of pulley 4 to the finished product, and a 13mm allowance is left from the positioning step of pulley 4 to the finished product; a 15mm allowance is left from the mating step of thrust ring 5 to the finished product, and a 17mm allowance is left from the positioning step of thrust ring 5 to the finished product; a 19mm allowance is left from the mating step of the second roller 6 to the finished product, and a 20mm allowance is left from the positioning step of the second roller 6 to the finished product; when semi-finish turning the outer diameter of the sealing ring 2, the lathe speed is 20-40 r / min, the feed is 0.6-0.8 mm / r, and the depth of cut is 3-5m. For semi-finish turning of the inner diameter, the lathe speed is 40-50 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. For semi-finish turning of the outer diameter of the first rolling band 3, the lathe speed is 20-40 r / min, the feed rate is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm. For semi-finish turning of the inner diameter, the lathe speed is 40-50 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. For semi-finish turning of the outer diameter of the pulley 4, the lathe speed is 15-30 r / min, the feed rate is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm. For semi-finish turning of the inner diameter, the lathe speed is 40-50 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. 0.4-0.6mm / r, depth of cut 3-4mm; semi-finish turning of the thrust ring 5 outer diameter: lathe speed 15-30r / min, feed 0.6-0.8mm / r, depth of cut 3-5mm; semi-finish turning of the inner diameter: lathe speed 40-50r / min, feed 0.4-0.6mm / r, depth of cut 3-4mm; semi-finish turning of the second rolling band 6 outer diameter: lathe speed 15-25r / min, feed 0.6-0.8mm / r, depth of cut 3-5mm; semi-finish turning of the inner diameter: lathe speed 40-50r / min, feed 0.4-0.6mm / r, depth of cut 3-4mm; semi-finish turning of the sealing ring (such as... Figure 4 ), semi-finished first rolling strip (such as Figure 5 ), semi-finished pulleys (such as Figure 6 ), semi-finished turning thrust ring (such as Figure 7 ), semi-finished second rolling belt (such as Figure 8 ).

[0023] Step 2) Welding: Weld the alloy layer of the sealing ring 2, the first roller 3, the thrust ring 5, the second roller 6 and the outermost circle of the socket by 7mm on one side. Use JIS D-308 welding wire and adjust the current to 500-600A, the voltage to 30-40V and the speed to 4-6r / min during welding. Weld the sealing ring 2, the first roller 3, the pulley 4, the thrust ring 5 and the second roller 6 to the outer circle of the pipe mold sleeve. Use H18CrMoA welding wire and adjust the current to 550-650A, the voltage to 30-40V and the speed to 4-6r / min during welding.

[0024] Step 3) Post-weld stress-relief tempering: The furnace temperature for post-weld stress-relief tempering needs to be controlled below 150℃. After preheating at 200℃, the temperature is raised to 350℃ at full power to completely remove stress. Then, it is held at this temperature for 3 hours and cooled to 150℃ in the furnace before being removed from the furnace and air-cooled. Because the diameters of the sealing ring 2, the first roller 3, the pulley 4, the thrust ring 5, the second roller 6, and the maximum outer diameter of the socket are inconsistent, shims need to be placed in these suspended areas to reduce deformation during tempering, thereby ensuring the uniformity of the alloy layer during subsequent processing and reducing the processing difficulty caused by deformation. Step 4) Chassis position: Align with the outer circle of sealing ring 2 and second roller 6. After alignment, observe the runout of several welding positions and the pipe body. The runout of the welding position is less than 0.5mm and the runout of the pipe body is less than 3mm. Machine a 300-500mm long chassis position on the pipe body at the socket end and machine the alignment position on the pipe body at the spigot end. Step 5) Fine boring: For fine boring, a chuck is used to clamp the outer diameter of the socket end and the center rest is used to support the bearing end. The runout is adjusted to 0.1mm. First, rough boring the inner hole, leaving a margin of 1.5-3mm in the finished inner hole. For rough boring, the machine tool speed should be adjusted to 55-70r / min, feed rate to 20-35mm / min, and depth of cut to 4-5mm. Then, float boring the inner hole according to the finished inner hole size. During float boring, the machine tool speed should be 55-70r / min, feed rate to 15-30mm / min, and depth of cut to 1-1.5mm. Step 6) Finish turning: When finishing turning the body 1, the lathe speed is 40-60 r / min, the feed is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm. Align with the position and alignment position in Step 4), and then evenly machine 3 wall thickness bands on the tube body, with a wall thickness difference within 0.2 mm. Machine the outer diameter and the dimensions of both ends according to the drawings. When finishing the outer diameter of the components welded together, the lathe parameters need to be adjusted as follows: When finishing the outer diameter of the sealing ring, the lathe speed is 20-30 r / min, the feed is 0.4-0.6 mm / r, and the depth of cut is 2-4 mm; finish turning the first rolling band. When finishing the outer diameter of the pulley, the lathe speed is 20-30 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the pulley, the lathe speed is 15-25 r / min, the feed rate is 0.3-0.45 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the thrust ring, the lathe speed is 15-25 r / min, the feed rate is 0.3-0.45 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the second rolling belt, the lathe speed is 20-30 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-5 mm. Step 7) Dyeing inspection: Perform dyeing inspection on the welded parts according to GB / T18851.1-2020 standard: First, clean the workpiece with a cleaning agent, then apply penetrant (red) to the welded position, ensuring complete coverage and waiting for 10-30 minutes. Then, spray the cleaning agent onto a lint-free cloth to wipe away the excess penetrant on the surface. Finally, apply developer (white) and wait for 7-30 minutes. If there is a defect, the red penetrant at the defect will slowly seep out onto the white background, forming a clear red mark. After the inspection, wipe off the developer coating with a cleaning agent. Step 8) Drilling: Align the outer circle runout of the workpiece to ≤0.05, align the cross lines on the end face, press the workpiece firmly to drill the hole on the end face and the tube body, and pay attention to chamfering and deburring; In step 1), the tolerances of each mating step of the pipe body are: The tolerance between the pipe body and the positioning step is This facilitates assembly and welding. The outer diameter of the sealing ring, first roller, thrust ring, second roller, and the outermost outer circle of the socket is machined to be 8mm smaller than the finished product to meet the thickness requirements of the alloy layer. The inner hole tolerances of the first roller, pulley, thrust ring, and second roller are... Their basic dimensions are consistent with the dimensions of their corresponding mating steps. This reduces post-weld runout, ensures welding stability, and maximizes the uniformity of the alloy layer thickness. The length tolerance of each mating step is... The length allowance for the sealing ring, first roller, pulley, thrust ring, and second roller is 10mm. This ensures sufficient allowance for subsequent machining and guarantees welding stability. The sealing ring is attached to the end face of the socket by extending its length. Therefore, the welding bevel of the semi-finish-machined sealing ring is an R25 arc-shaped bevel (see attached image). Figure 4 The first roller, pulley, thrust ring, and second roller are welded together by fitting the inner and outer circumferences of the hole. The weld bevel consists of an R10 arc plus a 45-degree taper (see attached diagram). Figure 5 (Appendix) Figure 6 (Appendix) Figure 7 (Appendix) Figure 8 ); In step 2), before welding, the position of each part must be carefully confirmed by referring to the finished product drawing. Welding can only proceed after the position is correct. In step 6), the pipe mold clamps the outer diameter of the spigot and the inner hole of the socket, aligning it to approximately 0.2mm according to the wall thickness difference. First, precision machine the outer diameter, then remove the plug plate, install the center support, and precision machine the inner hole of the socket. Turn the mold around, aligning it to within 0.05mm of the finished pipe body, and clamp it. Then, precision machine the spigot components. This includes precision machining the spigot sealing ring (part 2) and the irregular groove in the spigot inner hole (attached). Figure 2 Special cutting tools need to be made, and the tool holder used to machine the sealing ring (attached) Figure 9 ) and the blade (attached) Figure 10 When machining sealing rings, the sealing ring groove width is 55mm, and the tool holder width is 25mm. The design includes a certain clearance to facilitate chip removal and heat dissipation, and also to extend the tool life. The machine tool speed is 15-25 r / min and the feed rate is 0.2-0.3 mm / r during grooving. To ensure dimensional accuracy and root clearance, this tool body is available in two versions: forward and reverse. The tool holder used for machining irregular grooves (attached) Figure 11 ) and the blade (attached) Figure 12 When machining irregular grooves, the machine tool parameters are adjusted to a speed of 15-25 r / min and a feed of 0.2-0.3 mm / r. The tool body is designed with reference to the structure of the irregular groove, with a 2 mm clearance between the tool and the cutting tool. During turning, because the irregular groove has the same arc, taper and cutting tool structure, it is only necessary to ensure that the tool holder travels 2 mm before retracting the tool. This not only ensures the machining accuracy of the irregular groove and saves machining time, but also solves the technical problem that conventional cutting tools cannot machine.

[0025] The implementation of the technical solution of this invention mainly involves two points, as follows: 1. Regarding the control of semi-finishing dimensions, in order to save costs and ensure the stability and accuracy of welding positions, specific semi-finishing dimensions and structures were developed for the welding positions to ensure that the mating clearance is controlled within 0.2-0.4mm, and the length reference is uniformly used to position the socket end face. This approach firstly avoids the cumulative error caused by reference conversion, ensuring positional accuracy. Accurate positioning allows for accurate machining with minimal allowance. Secondly, strict control of the mating clearance ensures that the mating surfaces fit as closely as possible, guaranteeing welding stability and ensuring that the external diameter runout after welding is within 0.4mm, thus ensuring the uniformity of the alloy layer thickness.

[0026] 2. Specialized turning tools were manufactured to address the narrow and deep arc grooves on the sealing ring. Taking into account both the rigidity of the tool holder and chip removal, a dedicated tool holder and body were designed. While ensuring maximum rigidity of the tool holder, sufficient clearance was provided for chip removal to prevent chip accumulation and maintain the surface quality of the sealing ring. Both forward and reverse turning tools were designed to ensure thorough cleaning. A specialized turning tool was also designed based on the shape of the irregular groove in the inner hole of the socket, ensuring both machining efficiency and dimensional accuracy.

Claims

1. A finishing process for a pipe mold sleeve, the pipe mold sleeve comprising a body (1), a sealing ring (2), a first roller (3), a pulley (4), a thrust ring (5), and a second roller (6), wherein the sealing ring (2), the first roller (3), the second roller (6), the pulley (4), and the thrust ring (5) are welded to the body (1) of the pipe mold sleeve, characterized in that: The specific machining process for the tube mold sleeve is semi-finish machining, including semi-finish turning of the tube mold sleeve, semi-finish turning of the sealing ring, semi-finish turning of the first roller, semi-finish turning of the pulley, semi-finish turning of the thrust ring, and semi-finish turning of the second raceway—welding—post-weld stress-relief tempering—chassis positioning—finish boring—finish turning—dyed colorimetric testing—drilling. The specific machining steps are as follows: Step 1) Semi-finishing: Perform semi-finishing according to the semi-finishing drawings of each part. When semi-finishing the body (1), the lathe speed is 35-50 r / min, the feed is 0.7-1 mm / r, and the depth of cut is 4-5 mm. In order to facilitate subsequent welding, a mating step and a limiting step should be machined at the places where the body (1) of the pipe mold sleeve mates with the sealing ring (2), the first roller (3), the second roller (6), the pulley (4), and the thrust ring (5) to facilitate positioning and ensure the stability after welding. The body of the pipe mold sleeve body (1) presents a stepped shape, and the diameter gradually increases from the spigot to the socket. The pipe body of the pipe mold sleeve body (1) from the spigot end face to the first roller (3) leaves a 6 mm margin from the finished product. The remaining gaps in the body (1) of the main body (1) leave a 9mm allowance to the finished product; the mating step of the first roller belt leaves a 7mm allowance to the finished product, and the positioning step of the first roller belt leaves a 9mm allowance to the finished product; the mating step of the pulley (4) leaves an 11mm allowance to the finished product, and the positioning step of the pulley (4) leaves a 13mm allowance to the finished product; the mating step of the thrust ring (5) leaves a 15mm allowance to the finished product, and the positioning step of the thrust ring (5) leaves a 17mm allowance to the finished product; the mating step of the second roller belt (6) leaves a 19mm allowance to the finished product, and the positioning step of the second roller belt (6) leaves a 20mm allowance to the finished product; when semi-finishing the outer circle of the sealing ring (2), the lathe speed is 20-40r / min and the feed is 0. When semi-finishing the inner hole, the lathe speed is 40-50 r / min, the feed is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm; when semi-finishing the outer diameter of the first rolling belt (3), the lathe speed is 20-40 r / min, the feed is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm; when semi-finishing the inner hole, the lathe speed is 40-50 r / min, the feed is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm; when semi-finishing the outer diameter of the pulley (4), the lathe speed is 15-30 r / min, the feed is 0.6-0.8 mm / r, and the depth of cut is 3-5 mm; when semi-finishing the inner hole, the lathe speed is 40-50 r / min. -50r / min, feed rate 0.4-0.6mm / r, depth of cut 3-4mm; when semi-finishing the outer diameter of the thrust ring (5), the lathe speed is 15-30r / min, feed rate 0.6-0.8mm / r, depth of cut 3-5mm; when semi-finishing the inner diameter, the lathe speed is 40-50r / min, feed rate 0.4-0.6mm / r, depth of cut 3-4mm; when semi-finishing the outer diameter of the second rolling belt (6), the lathe speed is 15-25r / min, feed rate 0.6-0.8mm / r, depth of cut 3-5mm; when semi-finishing the inner diameter, the lathe speed is 40-50r / min, feed rate 0.4-0.6mm / r, depth of cut 3-4mm; Step 2) Welding: Weld the sealing ring (2), the first roller (3), the pulley (4), the thrust ring (5), the second roller (6) and the alloy layer after welding 7mm on one side of the maximum outer circle of the socket. Use JIS D-308 welding wire and adjust the current to 500-600A, the voltage to 30-40V and the speed to 4-6r / min during welding. Weld the sealing ring (2), the first roller (3), the pulley (4), the thrust ring (5), and the second roller (6) to the outer circle of the pipe mold sleeve. Use H18CrMoA welding wire and adjust the current to 550-650A, the voltage to 30-40V and the speed to 4-6r / min during welding. Step 3) Post-weld stress-relief tempering: Post-weld stress-relief tempering requires the furnace temperature to be controlled below 150℃, and after preheating at 200℃, the temperature is raised to 350℃ at full power to completely remove stress. Then, it is held at the temperature for 3 hours and cooled to 150℃ in the furnace before being taken out of the furnace and air-cooled. Because the diameters of the sealing ring (2), the first roller (3), the pulley (4), the thrust ring (5), the second roller (6) and the maximum outer circle of the socket are inconsistent, shims need to be placed in these suspended places to reduce the deformation during tempering, thereby ensuring the uniformity of the alloy layer during subsequent processing and reducing the processing difficulty caused by deformation. Step 4) Chassis position: Align with the outer circle of the sealing ring (2) and the second roller (6). After alignment, observe the runout of several welding positions and the pipe body. The runout of the welding position is less than 0.5mm and the runout of the pipe body is less than 3mm. Machine a 300-500mm long chassis position on the pipe body at the socket end and machine the alignment position on the pipe body at the spigot end. Step 5) Fine boring: For fine boring, a chuck is used to clamp the outer diameter of the socket end and the center rest is used to support the bearing end. The runout is adjusted to 0.1mm. First, rough boring the inner hole, leaving a margin of 1.5-3mm in the finished inner hole. For rough boring, the machine tool speed should be adjusted to 55-70r / min, feed rate to 20-35mm / min, and depth of cut to 4-5mm. Then, float boring the inner hole according to the finished inner hole size. During float boring, the machine tool speed should be 55-70r / min, feed rate to 15-30mm / min, and depth of cut to 1-1.5mm. Step 6) Finish turning: When finishing turning the body (1), the lathe speed is 40-60 r / min, the feed is 0.4-0.6 mm / r, and the depth of cut is 3-4 mm; align with the position and alignment position in step 4), and then evenly machine 3 wall thickness bands on the tube body of the body (1), with a wall thickness difference within 0.2 mm. Machine the outer diameter and the dimensions of both ends according to the drawings. When finishing the outer diameter of the parts welded together, the lathe parameters need to be adjusted as follows: When finishing the outer diameter of the sealing ring, the lathe speed is 20-30 r / min, the feed is 0.4-0.6 mm / r, and the depth of cut is 2-4 mm; When finishing the outer diameter of the first rolling belt, the lathe speed is 20-30 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the pulley, the lathe speed is 15-25 r / min, the feed rate is 0.3-0.45 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the thrust ring, the lathe speed is 15-25 r / min, the feed rate is 0.3-0.45 mm / r, and the depth of cut is 2-4 mm; when finishing the outer diameter of the second rolling belt, the lathe speed is 20-30 r / min, the feed rate is 0.4-0.6 mm / r, and the depth of cut is 3-5 mm. Step 7) Dyeing inspection: Perform dyeing inspection on the welded parts according to GB / T18851.1-2020 standard: First, clean the workpiece with a cleaning agent, then apply red penetrant to the welded position, ensuring complete coverage and wait for 10-30 minutes. Next, spray the cleaning agent onto a lint-free cloth to wipe away the excess penetrant on the surface. Finally, apply white developer and wait for 7-30 minutes. If there is a defect, the red penetrant at the defect will slowly seep out onto the white background to form a clear red mark. After the inspection, wipe off the developer coating with a cleaning agent. Step 8) Drilling: Align the outer diameter of the workpiece with a runout of ≤0.05, align the cross lines on the end face, press the workpiece firmly to drill the hole on the end face and the tube body, and pay attention to chamfering and deburring.

2. The precision machining process for a tube mold sleeve according to claim 1, characterized in that: In step 1), the tolerances of each mating step of the pipe body are: The tolerance between the pipe body and the positioning step is To facilitate assembly and welding; the outer diameter of the sealing ring, first roller, thrust ring, second roller, and the outermost outer circle of the socket is machined to be 8mm smaller than the finished product to meet the thickness requirements of the alloy layer; the inner hole tolerances of the first roller, pulley, thrust ring, and second roller are... Its basic dimensions are consistent with the dimensions of its corresponding mating steps, reducing post-weld runout, ensuring welding stability, and maximizing the uniformity of alloy layer thickness; the length tolerance of each mating step is... The length allowance of the sealing ring, the first roller, the pulley, the thrust ring, and the second roller is 10mm to ensure sufficient allowance for subsequent processing and to ensure the stability of the welding. The sealing ring is attached to the end face of the socket by extending its length. Therefore, the welding bevel of the semi-finished machined sealing ring is an R25 arc bevel. The first roller, the pulley, the thrust ring, and the second roller are welded by fitting the inner hole and the outer circle. The welding bevel is composed of an R10 arc plus a 45-degree taper.

3. The precision machining process for a tube mold sleeve according to claim 1, characterized in that: In step 2), before welding, the position of each part must be carefully confirmed by referring to the finished product drawing. Welding can only proceed after the position is correct.

4. The precision machining process for a tube mold sleeve according to claim 1, characterized in that: In step 6), the pipe mold clamps the outer circle of the spigot and the inner hole of the socket, aligning it to a wall thickness difference of 0.2mm and clamping it. First, precision machine the outer circle, then remove the plug plate, install the center support, and precision machine the inner hole of the socket. Next, turn the mold around, aligning it to within 0.05mm of the finished pipe body and clamping it, then machine the spigot. For precision machining of the spigot sealing ring and the irregular groove in the spigot inner hole, special tools are required. The tool holder and tool body used for machining the sealing ring are designed with a 25mm width to allow for chip removal and heat dissipation, and to extend the tool length. For tool life, the machine tool speed is 15-25 r / min and the feed is 0.2-0.3 mm / r when grooving. To ensure dimensions and root clearance, the tool body is available in two types: forward and reverse. For machining irregular grooves, the tool shank and tool body are designed with reference to the irregular groove structure, leaving a 2 mm clearance. When turning, because the irregular groove has the same arc, taper and insert structure, it is only necessary to ensure that the tool holder travels 2 mm before retracting the tool.

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