Processing technology of super-large-specification segmented detachable pipe die

Abstract

The invention discloses a machining process of an ultra-large-specification segmented detachable pipe die. The heat treatment route comprises normalizing, quenching, tempering and secondary tempering, and the fine boring of the inner hole comprises the steps of rough boring, boring and repairing of a bottom hole, floating fine boring, inspection, fine turning of a pipe body, fine turning of a large head and a small head, drilling and assembling; the heat treatment route comprises the steps of normalizing, quenching, tempering and secondary tempering; the fine boring of the inner hole comprises the steps of rough boring, boring and repairing of the bottom hole, floating fine boring, inspection, fine turning of a pipe body, fine turning of a large head and a small head, drilling and assembling; by reasonably formulating a process scheme and manufacturing a special tool, high-quality products meeting the requirements are finally produced, the problem that inner holes are staggered during segmented connection is effectively solved, by means of the technical scheme, the problem that more than five thousand sets of air holes are machined is solved, and finally qualified products are produced.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial mold machining, and specifically relates to a processing technology for an oversized segmented detachable pipe mold. The requirements for shape and position tolerance dimensional accuracy of the oversized segmented detachable pipe mold after assembly can be met, and the machining accuracy is high and the production efficiency is faster. Background Art

[0002] At present, the processing method for the outer circle of the integral pipe mold is that the specifications of the super-large segmented detachable pipe mold are mainly distributed in DN1400-DN3000, usually composed of 5 sections, namely the pipe head section, 2 rolling sections, the pipe middle section and the pipe tail section are connected by a connecting mechanism, wherein the rolling section has a protruding raceway, the raceway has grooves, and the outer circle has many air holes. It is a structural form that can replace the integral pipe mold in some occasions. Ordinary integral pipe molds do not need to be assembled and the outer circle does not have many air holes. The existing process flow, tooling and cutting tools cannot guarantee the dimensional accuracy, form and position tolerance and assembly requirements, and there are many air holes around the outer circle, and the processing efficiency is low. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a processing technology for an oversized segmented detachable pipe mold. By formulating a special process plan and tooling, the processing size accuracy and shape and position tolerance requirements are guaranteed, and the numerous air holes on the outer circumference can be processed efficiently and quickly.

[0004] The object of the present invention is achieved as follows: a processing technology for a super-large-sized segmented detachable pipe mold, wherein the segmented detachable pipe mold is divided into 5 parts, namely, a pipe head section, a pipe middle section, a tire rolling section, and a pipe tail section, wherein the tire rolling section is 2 sections and the rest is 1 section, which are connected by bolts, characterized in that: the processing process route of the super-large-sized segmented detachable pipe mold is forging-rough turning of the outer circle-rough boring of the inner hole-heat treatment-semi-finishing turning of the outer circle-rough and fine boring of the inner hole-drilling-assembly, wherein the pipe head section, the tire rolling section, the pipe middle section, and the pipe tail section are processed according to the following specific steps: Step 1) Rationally design the roughing and finishing dimensions: Due to the super large specifications, the total length is 1000mm-2000mm. In order to ensure the quality of the finishing product and avoid the appearance of ellipse in the heat-treated outer circle and inner hole, a 30mm margin is left for the outer circle, a 40mm margin is left for the inner hole, and a 50mm margin is left for the length; Step 2), quenching and tempering treatment adds one stress relief tempering: the material is 21CrMo10, in order to obtain a more uniform internal structure, to eliminate the stress caused by heat treatment to a greater extent, and to avoid deformation during processing and use, the heat treatment process route is normalizing-quenching-tempering-secondary tempering; the heat treatment process is specifically: normalizing at 920℃ for 8h air cooling and tempering at 640℃ for 12h air cooling; quenching at 920±10℃, average temperature time 2.5-3.5h, first tempering at 585±5℃, average temperature 5h air cooling, second tempering at 585±5℃, average temperature 5h air cooling; Step 3), semi-finishing outer circle: leave 8-10mm margin for the outer diameter of the semi-finishing workpiece, and leave 100mm long margin on both sides of the raceway; one frame position and one alignment belt; the specific processing technology is: semi-finishing outer circle: ① After alignment and clamping on the bed, the length and wall thickness difference are ≤3mm: leave 8-10mm margin for the outer diameter of the semi-finishing workpiece, and leave 100mm long margin on both sides of the raceway. If the raceway diameter is smaller than the tube body, leave the amount according to the tube body; if the tube body has black skin, after technical confirmation, the minimum margin can be 5mm; ② Rough turning the outer circle of the large and small heads with a margin of 10mm. If the margin is insufficient, rough turn to the maximum outer circle; ③ One frame position and one alignment belt, the frame roundness is required to be 0.1, and the roughness Ra≤3.2um; Step 4), Ultrasonic testing: Perform overall flaw detection on the tube mold according to GB / T 5777-2008; Step 5) Design a special processing tool: Design a tool body that integrates boring and floating functions; one end of the boring tool body is connected to the tool rod with a three-start thread, and the other end is designed with a boring block, a floating boring box base and six equally divided wooden guide key slots; the boring block wire cuts two 30.5*30.5 boring slots, the boring tool is placed in the tool square, the boring tool position is adjusted, the boring hole size is determined, and the boring tool is fixed with 2-M16 screws; the floating boring box base is milled with a 125*105 floating boring box slot, the boring block is fixed to the floating boring box base with M20 screws, there is a floating boring cover outside the floating boring box slot, and a 60*45 floating tool block is fixed with M12 to slide in the floating tool box slot; a 60*45 floating boring is installed in the floating boring box slot The tool block, the floating boring tool block is an integral type with 108*25 floating boring heads installed at both ends. The floating boring heads are fixed with 4-M10 screws. During processing, the length of the floating boring head is adjusted according to the floating boring size, and it slides in the tool groove to ensure the roundness of the inner hole; the outer circle of the rough floating boring tool body is evenly welded with wooden guide keyways. Due to the large specifications, the number of wooden guide keyways is increased to 6 for the stability of the boring hole. Before the floating tool cuts, the wooden guide key on the connecting head is ground to stabilize the tool body and effectively avoid tool vibration. The length of the wooden guide key is 300mm, the wooden guide key is 20-30mm higher than the wooden guide keyway body, and each wooden guide keyway is 40mm-50mm wide; it can reduce the resistance of the wooden guide key and facilitate increasing the feed speed; Step 6) Perform rough and fine boring of the inner hole: rough bore the inner hole from the big end, leaving 2~3mm semi-finishing boring allowance; use a special boring tool body, a floating tool body to rough bore the inner hole, lock the tool to float and repair the inner hole, and float and bore to the finished product; Step 7) Rationally match the chuck speed and tool feed: Rough boring inner hole speed 10-15r / min, feed speed 9mm / min; floating inner hole speed 15-17r / min, feed speed 20mm / min. Through scientific matching, the cutting is uniform, the iron chip breaking width is reasonable, and the chip breaking is convenient, avoiding long chips in deep holes scratching the inner hole surface and piercing the tool; Step 8), fine turning of the outer circle: take the inner hole as the reference, punch the wall thickness, align the outer circle ≤0.05, turn the dimensions of the outer circle, especially the dimensions of the raceway position. There is a groove at the raceway position of the tire rolling section, and a special grooving knife is required. The grooving depth is greater than 50mm, the R fillet is less than 0.6mm, and the knife width is greater than 8mm; the specific processing technology for fine turning the outer circle is: ① clamp the small head, push the big head, adjust the chuck alignment, control the wall thickness difference at the two end positions ≤0.05mm, and the total length wall thickness difference ≤0.2mm; ② fine turning and polishing the outer circle and raceway of the tube body; Step 9), control the size and shape and position tolerance of the matching stop to ensure that the inner hole misalignment is within 0.1mm after assembly; first turn the outer circle and inner hole at both ends: when finishing each section, ensure that the coaxiality of the inner hole and outer circle is within 0.05mm at both ends, and control it by ensuring that the wall thickness difference is within 0.05mm. Use the wall thickness gauge and dial indicator to align the outer circle with the inner hole as the reference; secondly, position and clamp the outer circle of the bracket, and after aligning the outer circle runout ≤0.05mm, turn and shape the inner hole and outer circle of the socket end according to the product drawing; Step 10) Drill flange holes and vent holes around the outer circumference: Step 11), assembly: reshape the pipe head section, two rolling sections, the middle section and the tail section, polish and repair bumps and burrs, especially the assembly stopper and flange holes, clean and blow dry, place the pipe head section on the assembly platform to align and level, align the flange holes of the rolling section, the middle section, the rolling section and the tail section one by one, assemble them into place with the cylinder pushing device, first screw in the connecting bolts, do not fix them, wait until all the installation is completed, and then tighten the flange hole bolts symmetrically to ensure assembly accuracy.

[0005] The specific processing technology of step 7) is: Step 7.1), rough boring: ① Align the spindle chuck and the rear annular chuck to the outer circle runout ≤0.5 and then clamp; ② Use a 75° boring tool to invert a 20-wide taper on the end face; ③ Rough bore the inner hole from the big end, leaving a diameter margin of 8~10mm, the boring length is L-L1-30, the inner hole of the finished socket end has no step, and the through hole is bored directly; Step 7.2), fine boring: ① Clamp the front and rear racks of the tube mold after the outer circle runout is ≤0.5mm, and check that the middle runout of the workpiece is ≤2mm; ② Rough bore the inner hole from the big end, leaving 2~3mm semi-finishing boring allowance; ③ Semi-finishing bore the inner hole, leaving 1~1.5mm floating boring allowance, and control the surface roughness Ra≤3.2um; ④ Replace the floating boring tool, and push-boring the inner hole size; ⑤ Return the tool, and self-check the inner hole size and quality; After the first rough boring, measure the wall thickness difference of the workpiece, find out the thickest and thinnest parts of the wall thickness, and mark them. After each boring, measure the wall thickness difference at the marked place, and take measures according to the wall thickness difference; ⑥ Polish the inner hole, check whether the boring quality meets the requirements after stopping, and self-check the inner hole size and quality.

[0006] Step 9) The specific processing technology is: ① Clamp the small end with the chuck, position and clamp the outer circle with the center frame, and after aligning the outer circle runout to ≤0.05, turn and polish the inner hole and outer circle of one end according to the precision turning drawing; ② Turn around, hold the small end with the center frame, align the outer circle runout of the other end to ≤0.05, and then turn and polish the inner hole and outer circle according to the product drawing; ③ Printing mark: Print mark according to the drawing requirements.

[0007] The specific processing technology of step 10) is: Step 10.1) Drilling flange holes: Align the outer circle and the end face, and drill the flange holes on the end face; Step 10.2), drilling step vent holes: Drill ΦE2-ΦC1 step vent holes; ΦE2-ΦC1 step vent holes are evenly distributed on the outer circle of the tube body, with a number of more than 5,000 groups, of which the hole range of ΦE2 is Φ8-Φ15, and the hole range of ΦC1 is Φ3-Φ2.5; because it is evenly distributed, it is necessary to use a CNC boring and milling machine with a vertical mounting drill. Because it is not easy to remove chips when drilling with a ΦE2 ordinary drill bit, it is necessary to drill a certain depth before withdrawing the chips, which is inefficient and easy to break the drill bit. The wall thickness of the tube mold is 90-120mm, and it is impossible to use the ΦC1 through hole on the CNC boring and milling machine. It is very easy to break if it is too long. Use ΦE2 twist drill is used to drill guide holes according to coordinates for positioning. ΦE2 is drilled to a depth of 10mm. A gun drill is connected to the spindle of the boring and milling machine. The ΦE2 gun drill is used to drill ΦE2 to the required depth. A homemade ΦC1 extended drill bit with a guide is clamped with an electric hand drill. The outer circle size of the guided part of the ΦC1 extended drill bit is ΦC1-0.5 (-0.1 / -0.2), which has good guidance in the ΦE2 hole. The ΦC1 hole is drilled manually with an electric hand drill. The ΦC1 drill bit is not easy to swing and break, and the effect is very good. In this way, the CNC boring and milling machine, gun drill equipment, and homemade extended drill bit are combined, and the ΦC1 hole is drilled through with an electric hand drill, the efficiency is more than doubled, and the drill bit loss is small.

[0008] The specific processing technology of step 11) is: Step 11.1) Place the workpiece on the V-shaped iron, align the outer circle and end face, drill and bore the flange evenly, and remove burrs and sharp corners; Step 11.2), ① Place the CNC boring and milling machine vertically, align the vertical and horizontal directions, and use the ΦE2 twist drill to drill the ΦE2 guide hole with a depth of 10mm; ② Connect the CNC boring and milling machine to an external gun drill, turn on the compressed air and water cooling, and drill the ΦE2 hole to the depth of the drawing; ③ Use a hand drill to clamp the homemade extended ΦC1 drill bit, drill the ΦC1 hole through, and remove burrs and flash.

[0009] The present invention has the following beneficial effects: the present invention solves the process problem of mechanical processing of super-large-sized segmented detachable pipe molds, and by making special tooling and process solutions, the processing accuracy and production efficiency of super-large-sized segmented detachable pipe molds are improved, and the processing technology is more scientific and economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the finished product of the segmented detachable pipe mold of the present invention.

[0011] Figure 2 A front view of the segmented detachable tube mold tube head section of the present invention.

[0012] Figure 3 A front view of the segmented detachable tube mold tire rolling section of the present invention.

[0013] Figure 4 A front view of the middle section of the segmented detachable tube mold of the present invention.

[0014] Figure 5 A front view of the segmented detachable tube mold tube tail section of the present invention.

[0015] Figure 6 The front view of the assembly of the oversized rough relief boring cutter body of the present invention.

[0016] Figure 7 Left side view of the oversized rough boring cutter body assembly.

[0017] Figure 8 Front view of the ΦC1 extended drill bit of the present invention. DETAILED DESCRIPTION

[0018] Embodiment: A processing technology of a super-large segmented detachable pipe mold, wherein the segmented detachable pipe mold is divided into 5 parts, namely, a pipe head section, a pipe middle section, a tire rolling section, and a pipe tail section, wherein the tire rolling section is 2 sections, and the rest is 1 section, which are connected by bolts, characterized in that: the processing process route of the super-large segmented detachable pipe mold is forging-rough turning of the outer circle-rough boring of the inner hole-heat treatment-semi-finishing turning of the outer circle-rough and fine boring of the inner hole-drilling-assembly, wherein the pipe head section, the tire rolling section, the pipe middle section, and the pipe tail section are processed according to the following specific steps: Step 1) Rationally design the roughing and finishing dimensions: Due to the super large specifications, the total length is 1000mm-2000mm. In order to ensure the quality of the fine-processing products and avoid the appearance of ellipse in the outer circle and inner hole during heat treatment, and taking cost factors into consideration, based on the previous experience of fine-processing allowances, 30mm is left for the outer circle, 40mm for the inner hole, and 50mm for the length.

[0019] The specific processing technology is as follows: Rough turning of outer circle and flat end face: ① Check the curvature of the workpiece, the surface quality of the inner and outer circles and the allowance. If there is a crack, it should be adjusted according to the allowance. If necessary, the large end of the chuck should be used to align and borrow material; ② Roughly turn the outer circle of the tube mold according to the allowance of the fine processing drawing to see the light (single-sided turning 4 to 8mm), and flatten the end faces of the workpiece, and make up the print on the original marked end faces.

[0020] Step 2), the quenching and tempering treatment adds a stress relief tempering: the material is 21CrMo10. In order to obtain a more uniform internal structure, eliminate the stress caused by the heat treatment to a greater extent, and avoid deformation during processing and use, the heat treatment process route is normalizing-quenching-tempering-secondary tempering. After heat treatment, physical and chemical tests are performed (two pulls and two punches, hardness test, ultrasonic test).

[0021] The specific heat treatment process is as follows: normalizing at 920℃ for 8h and air cooling, tempering at 640℃ for 12h and air cooling; quenching at 920±10℃, average temperature time for 2.5-3.5h, primary tempering at 585±5℃, average temperature for 5h and air cooling, secondary tempering at 585±5℃, average temperature for 5h and air cooling.

[0022] Step 3), semi-finishing outer circle: leave 8-10mm margin for the outer diameter of the semi-finishing workpiece, and leave 100mm long margin on both sides of the raceway; one frame position and one alignment belt.

[0023] The specific processing technology is as follows: Semi-finishing outer circle: ① After alignment and clamping on the bed, the length and wall thickness difference is ≤3mm: 8-10mm allowance is left for the outer diameter of each part of the semi-finishing workpiece, and 100mm long allowance is left on both sides of each raceway (if the raceway diameter is smaller than the tube body, the allowance is based on the tube body; if the tube body has black skin, after technical confirmation, the minimum allowance can be 5mm). ② Rough turning of the outer circle of the large and small heads with an allowance of 10mm (if the allowance is insufficient, rough turning to the maximum outer circle to see the circle). ③ One frame position and one alignment belt are required, and the frame position roundness is required to be 0.1 and the roughness Ra≤3.2um.

[0024] Step 4) Ultrasonic testing: Perform overall flaw detection on the tube mold according to GB / T 5777-2008.

[0025] Step 5) Design a special processing tool: design a tool body that integrates boring and floating functions.

[0026] Step 6) Perform rough and fine boring of the inner hole, start from the big end to rough bore the inner hole, leaving 2~3mm semi-finishing boring allowance; use a special boring tool body, a floating tool body to rough bore the inner hole, a locked tool to float and repair the inner hole, and float boring to the finished product.

[0027] Step 7) Rationally match the chuck speed and tool feed: Rough boring inner hole speed 10-15r / min, feed speed 9mm / min; floating inner hole speed 15-17r / min, feed speed 20mm / min. Through scientific matching, the cutting is uniform, the chip breaking width is reasonable, and the chip breaking is easy to avoid long chips in deep holes scratching the inner hole surface and piercing the tool.

[0028] The processing technology is as follows: Step 7.1), Rough boring: ① Align the spindle chuck and the rear annular chuck to a runout of ≤0.5 and then clamp. ② Use a 75° boring tool to invert a 20-wide taper on the end face. ③ Rough bore the inner hole from the big end, leaving a diameter margin of 8~10mm, and the boring length is L-L1-30 (the inner hole of the finished socket end has no step, and the through hole is bored directly).

[0029] Step 7.2), fine boring: ① Clamp the front and rear racks of the tube mold after the outer circle runout is ≤0.5mm, and check that the middle runout of the workpiece is ≤2mm. ② Rough bore the inner hole from the big head, leaving 2~3mm semi-finished boring allowance; ③ Semi-finished boring the inner hole, leaving 1~1.5mm floating boring allowance, and control the surface roughness Ra≤3.2um. ④ Replace the floating boring tool, and push-boring the inner hole size. ⑤ Return the tool and self-check the inner hole size and quality. (After the first rough boring, measure the wall thickness difference of the workpiece, find the thickest and thinnest parts of the wall thickness, and mark them. After each boring, measure the wall thickness difference at the marked place, and take measures according to the wall thickness difference.) ⑥ Polish the inner hole, check whether the boring quality meets the requirements after parking, and self-check the inner hole size and quality.

[0030] Step 8) Finish turning the outer circle: take the inner hole as the reference, punch the wall thickness, align the outer circle ≤0.05, turn the dimensions of the outer circle, especially the dimensions of the raceway position. There is a groove at the raceway position of the tire rolling section, and a special grooving tool is required. The grooving depth is greater than 50mm, the R radius is less than 0.6mm, and the tool width is greater than 8mm.

[0031] The specific processing technology is as follows: ① Clamp the small end, push the big end, adjust the chuck to align, control the wall thickness difference at both ends to ≤0.05mm, and the wall thickness difference along the entire length to ≤0.2mm. ② Fine turning and polishing the outer circle and raceway of the tube body.

[0032] Step 9) Control the size and shape tolerance of the matching stop to ensure that the inner hole misalignment is within 0.1mm after assembly: Turn the outer circle and inner hole at both ends: When finishing each section, ensure that the coaxiality of the inner hole and the outer circle at both ends is within 0.05mm, and control it by ensuring that the wall thickness difference is within 0.05mm. Use the wall thickness gauge and dial indicator to align the outer circle with the inner hole as the reference; position and clamp the outer circle of the bracket, and after aligning the outer circle runout ≤0.05mm, turn and form the inner hole and outer circle of the socket end according to the product drawing.

[0033] The specific processing technology is as follows: ① The chuck clamps the small end, the center frame is used for positioning and clamping the outer circle, and after aligning the outer circle runout to ≤0.05, the inner hole and outer circle of one end are turned and polished according to the fine turning drawing. ② Turn around, the center frame clamps the small end, aligns the outer circle runout of the other end to ≤0.05, and then turns, polishes the inner hole and outer circle according to the product drawing. ③ Printing mark: Print the mark according to the drawing requirements.

[0034] Step 10) Drill flange holes and vent holes around the outer circumference: Step 10.1) Drill flange holes: Align the outer circle and end face, and drill the flange holes on the end face.

[0035] Step 10.2), Drilling step vent holes: Drill ΦE2-ΦC1 step vent holes. The ΦE2-ΦC1 step vent holes are evenly distributed on the outer circle of the tube body, with a number of more than 5,000 groups. The ΦE2 hole range is Φ8-Φ15, and the ΦC1 hole is a small hole range of Φ3-Φ2.5. Because they are evenly distributed, they need to be drilled on a CNC boring and milling machine with a vertical mounting drill. Because it is not easy to remove chips when drilling with a ΦE2 ordinary drill bit, it is necessary to drill a certain depth before withdrawing the chips, which is inefficient and easy to break the drill bit. The wall thickness of the tube mold is 90-120mm, and it is impossible to use the ΦC1 through hole on the CNC boring and milling machine. It is very easy to break if it is too long. First, use the ΦE2 twist drill to drill the guide hole for positioning. Drill ΦE2 with a depth of 10mm. Connect an external gun drill to the spindle of the boring and milling machine, use the ΦE2 gun drill to drill ΦE2 to the depth, use a hand drill to clamp the homemade ΦC1 extended drill bit with guidance, the outer circle size of the guided part of the ΦC1 extended drill bit is ΦC1-0.5 (-0.1 / -0.2), which has good guidance in the ΦE2 hole. The hand drill is used to manually drill the ΦC1 hole. The ΦC1 drill bit is not easy to swing and break, and the effect is very good. In this way, the CNC boring and milling machine, gun drill equipment, and homemade extended drill bit are combined, and the hand drill can drill the ΦC1 hole, which is more than doubled in efficiency and has low drill bit loss.

[0036] Step 11), assembly: reshape the pipe head section, two rolling sections, the middle section and the tail section, polish and repair bumps and burrs, especially the assembly stopper and flange holes, clean and blow dry, place the pipe head section on the assembly platform to align and level, align the flange holes of the rolling section, the middle section, the rolling section and the tail section one by one, assemble them into place with the cylinder pushing device, first screw in the connecting bolts, do not fix them, wait until all the installation is completed, and then tighten the flange hole bolts symmetrically to ensure assembly accuracy.

[0037] The specific processing technology is as follows: Step 11.1) Place the workpiece on the V-shaped iron, align the outer circle and end face, drill and bore the flange evenly, and remove burrs and sharp corners.

[0038] Step 11.2), ① Place the CNC boring and milling machine vertically, align the vertical and horizontal directions, and use the ΦE2 twist drill to drill the ΦE2 lead hole with a depth of 10mm. ② Connect the CNC boring and milling machine to the gun drilling equipment, turn on the compressed air and water cooling, and drill the ΦE2 hole to the drawing depth. ③ Use the hand drill to clamp the self-made extended ΦC1 drill bit, drill the ΦC1 hole through, and remove the burrs and flash.

[0039] The implementation of the technical solution of the present invention mainly lies in two points, which are as follows: 1. Control of the machining allowance of super-large segmented pipe dies not only ensures that they can meet the requirements of fine machining after heat treatment, but also controls the allowance of forging blank and roughing from an economic perspective; 2. To ensure the dimensional accuracy and geometric tolerance of super-large segmented pipe molds, since the inner hole and outer circle are not processed in one assembly, when processing the outer circle's stopper assembly surface, it is necessary to use the inner hole as the reference to align it within 0.1. The tolerance requirements are in accordance with the drawing requirements. The hole is guaranteed according to the middle and upper difference, and the outer circle is guaranteed according to the middle and lower difference, and the inner end face of the stopper is guaranteed to be an edge.

[0040] 3. By using CNC boring and milling machines, ordinary drill bits to drill holes, gun drills to drill ΦE2 holes, and hand drills holding homemade extended ΦC1 drill bits to drill ΦC1 holes, we can ensure high-efficiency processing of more than 5,000 sets of vent holes and minimize drill bit loss.

[0041] 4. Use the experience and cylinder installation equipment of assembling hydraulic cylinders to assemble the five sections together to meet the assembly size requirements. No steps greater than 0.2mm are allowed in the inner hole.

[0042] By adopting the above manufacturing process, the following inspections are performed after processing: the dimensional accuracy, form and position tolerance, and roughness of the tube head section, roller section, middle section, and tail section all meet the design requirements of the drawings. After assembly, the design requirements of the drawings are met, and the efficiency of drilling more than 5,000 sets has been increased from one piece in 8 days to one piece in 5 days.

Claims

1. A processing technology for a super-large segmented detachable pipe mold, wherein the segmented detachable pipe mold is divided into 5 parts, namely, a pipe head section, a pipe middle section, a rolling section, and a pipe tail section, wherein the rolling section is 2 sections and the rest is 1 section, which are connected by bolts, characterized in that: The processing route of the super-large segmented detachable pipe die is forging-rough turning of the outer circle-rough boring of the inner hole-heat treatment-semi-finishing turning of the outer circle-rough and fine boring of the inner hole-drilling-assembly, among which the pipe head section, rolling section, pipe middle section and pipe tail section are processed according to the following specific steps: Step 1) Rationally design the roughing and finishing dimensions: Due to the super large specifications, the total length is 1000mm-2000mm. In order to ensure the quality of the finishing product and avoid the appearance of ellipse in the heat-treated outer circle and inner hole, a 30mm margin is left for the outer circle, a 40mm margin is left for the inner hole, and a 50mm margin is left for the length; Step 2), quenching and tempering treatment adds one stress relief tempering: the material is 21CrMo10, in order to obtain a more uniform internal structure, to eliminate the stress caused by heat treatment to a greater extent, and to avoid deformation during processing and use, the heat treatment process route is normalizing-quenching-tempering-secondary tempering; the heat treatment process is specifically: normalizing at 920℃ for 8h air cooling and tempering at 640℃ for 12h air cooling; quenching at 920±10℃, average temperature time 2.5-3.5h, first tempering at 585±5℃, average temperature 5h air cooling, second tempering at 585±5℃, average temperature 5h air cooling; Step 3), semi-finishing outer circle: leave 8-10mm margin for the outer diameter of the semi-finishing workpiece, and leave 100mm long margin on both sides of the raceway; one frame position and one alignment belt; the specific processing technology is: semi-finishing outer circle: ① After alignment and clamping on the bed, the length and wall thickness difference are ≤3mm: leave 8-10mm margin for the outer diameter of the semi-finishing workpiece, and leave 100mm long margin on both sides of the raceway. If the raceway diameter is smaller than the tube body, leave the amount according to the tube body; if the tube body has black skin, after technical confirmation, the minimum margin can be 5mm; ② Rough turning the outer circle of the large and small heads with a margin of 10mm. If the margin is insufficient, rough turn to the maximum outer circle; ③ One frame position and one alignment belt, the frame roundness is required to be 0.1, and the roughness Ra≤3.2um; Step 4), Ultrasonic testing: Perform overall flaw detection on the tube mold according to GB / T 5777-2008; Step 5) Design a special processing tool: Design a tool body that integrates boring and floating functions; one end of the boring tool body is connected to the tool rod with a three-start thread, and the other end is designed with a boring block, a floating boring box base and six equally divided wooden guide key slots; the boring block wire cuts two 30.5*30.5 boring slots, the boring tool is placed in the tool square, the boring tool position is adjusted, the boring hole size is determined, and the boring tool is fixed with 2-M16 screws; the floating boring box base is milled with a 125*105 floating boring box slot, the boring block is fixed to the floating boring box base with M20 screws, there is a floating boring cover outside the floating boring box slot, and a 60*45 floating tool block is fixed with M12 to slide in the floating tool box slot; a 60*45 floating boring is installed in the floating boring box slot The tool block, the floating boring tool block is an integral type with 108*25 floating boring heads installed at both ends. The floating boring heads are fixed with 4-M10 screws. During processing, the length of the floating boring head is adjusted according to the floating boring size, and it slides in the tool groove to ensure the roundness of the inner hole; the outer circle of the rough floating boring tool body is evenly welded with wooden guide keyways. Due to the large specifications, the number of wooden guide keyways is increased to 6 for the stability of the boring hole. Before the floating tool cuts, the wooden guide key on the connecting head is ground to stabilize the tool body and effectively avoid tool vibration. The length of the wooden guide key is 300mm, the wooden guide key is 20-30mm higher than the wooden guide keyway body, and each wooden guide keyway is 40mm-50mm wide; it can reduce the resistance of the wooden guide key and facilitate increasing the feed speed; Step 6) Perform rough and fine boring of the inner hole: rough bore the inner hole from the big end, leaving 2~3mm semi-finishing boring allowance; use a special boring tool body, a floating tool body to rough bore the inner hole, lock the tool to float and repair the inner hole, and float and bore to the finished product; Step 7) Rationally match the chuck speed and tool feed: Rough boring inner hole speed 10-15r / min, feed speed 9mm / min; floating inner hole speed 15-17r / min, feed speed 20mm / min. Through scientific matching, the cutting is uniform, the iron chip breaking width is reasonable, and the chip breaking is convenient, avoiding long chips in deep holes scratching the inner hole surface and piercing the tool; Step 8), fine turning of the outer circle: take the inner hole as the reference, punch the wall thickness, align the outer circle ≤0.05, turn the dimensions of the outer circle, especially the dimensions of the raceway position. There is a groove at the raceway position of the tire rolling section, and a special grooving knife is required. The grooving depth is greater than 50mm, the R fillet is less than 0.6mm, and the knife width is greater than 8mm; the specific processing technology for fine turning the outer circle is: ① clamp the small head, push the big head, adjust the chuck alignment, control the wall thickness difference at the two end positions ≤0.05mm, and the total length wall thickness difference ≤0.2mm; ② fine turning and polishing the outer circle and raceway of the tube body; Step 9), control the size and shape and position tolerance of the matching stop to ensure that the inner hole misalignment is within 0.1mm after assembly; first turn the outer circle and inner hole at both ends: when finishing each section, ensure that the coaxiality of the inner hole and outer circle is within 0.05mm at both ends, and control it by ensuring that the wall thickness difference is within 0.05mm. Use the wall thickness gauge and dial indicator to align the outer circle with the inner hole as the reference; secondly, position and clamp the outer circle of the bracket, and after aligning the outer circle runout ≤0.05mm, turn and shape the inner hole and outer circle of the socket end according to the product drawing; Step 10) Drill flange holes and vent holes around the outer circumference: Step 11), assembly: reshape the pipe head section, two rolling sections, the middle section and the tail section, polish and repair bumps and burrs, especially the assembly stopper and flange holes, clean and blow dry, place the pipe head section on the assembly platform to align and level, align the flange holes of the rolling section, the middle section, the rolling section and the tail section one by one, assemble them into place with the cylinder pushing device, first screw in the connecting bolts, do not fix them, wait until all the installation is completed, and then tighten the flange hole bolts symmetrically to ensure assembly accuracy.

2. The processing technology of the super-large-size segmented detachable pipe mold according to claim 1 is characterized in that: The specific processing technology of step 7) is: Step 7.1), rough boring: ① Align the spindle chuck and the rear annular chuck to the outer circle runout ≤0.5 and then clamp; ② Use a 75° boring tool to invert a 20-wide taper on the end face; ③ Rough bore the inner hole from the big end, leaving a diameter margin of 8~10mm, the boring length is L-L1-30, the inner hole of the finished socket end has no step, and the through hole is bored directly; Step 7.2), fine boring: ① Clamp the front and rear racks of the tube mold after the outer circle runout is ≤0.5mm, and check that the middle runout of the workpiece is ≤2mm; ② Rough bore the inner hole from the big end, leaving 2~3mm semi-finishing boring allowance; ③ Semi-finishing bore the inner hole, leaving 1~1.5mm floating boring allowance, and control the surface roughness Ra≤3.2um; ④ Replace the floating boring tool, and push-boring the inner hole size; ⑤ Return the tool, and self-check the inner hole size and quality; After the first rough boring, measure the wall thickness difference of the workpiece, find out the thickest and thinnest parts of the wall thickness, and mark them. After each boring, measure the wall thickness difference at the marked place, and take measures according to the wall thickness difference; ⑥ Polish the inner hole, check whether the boring quality meets the requirements after stopping, and self-check the inner hole size and quality.

3. The processing technology of the super-large-size segmented detachable pipe mold according to claim 1 is characterized in that: Step 9) The specific processing technology is: ① Clamp the small end with the chuck, position and clamp the outer circle with the center frame, and after aligning the outer circle runout to ≤0.05, turn and polish the inner hole and outer circle of one end according to the precision turning drawing; ② Turn around, hold the small end with the center frame, align the outer circle runout of the other end to ≤0.05, and then turn and polish the inner hole and outer circle according to the product drawing; ③ Printing mark: Print mark according to the drawing requirements.

4. The processing technology of the super-large-size segmented detachable pipe mold according to claim 1 is characterized in that: The specific processing technology of step 10) is: Step 10.1) Drilling flange holes: Align the outer circle and the end face, and drill the flange holes on the end face; Step 10.2), drilling step vent holes: Drill ΦE2-ΦC1 step vent holes; ΦE2-ΦC1 step vent holes are evenly distributed on the outer circle of the tube body, with a number of more than 5,000 groups, of which the hole range of ΦE2 is Φ8-Φ15, and the hole range of ΦC1 is Φ3-Φ2.5; because it is evenly distributed, it is necessary to use a CNC boring and milling machine with a vertical mounting drill. Because it is not easy to remove chips when drilling with a ΦE2 ordinary drill bit, it is necessary to drill a certain depth before withdrawing the chips, which is inefficient and easy to break the drill bit. The wall thickness of the tube mold is 90-120mm, and it is impossible to use the ΦC1 through hole on the CNC boring and milling machine. It is very easy to break if it is too long. Use ΦE2 twist drill is used to drill guide holes according to coordinates for positioning. ΦE2 is drilled to a depth of 10mm. A gun drill is connected to the spindle of the boring and milling machine. The ΦE2 gun drill is used to drill ΦE2 to the required depth. A homemade ΦC1 extended drill bit with a guide is clamped with an electric hand drill. The outer circle size of the guided part of the ΦC1 extended drill bit is ΦC1-0.5 (-0.1 / -0.2), which has good guidance in the ΦE2 hole. The ΦC1 hole is drilled manually with an electric hand drill. The ΦC1 drill bit is not easy to swing and break, and the effect is very good. In this way, the CNC boring and milling machine, gun drill equipment, and homemade extended drill bit are combined, and the ΦC1 hole is drilled through with an electric hand drill, the efficiency is more than doubled, and the drill bit loss is small.

5. The processing technology of the super-large-size segmented detachable pipe mold according to claim 1 is characterized in that: The specific processing technology of step 11) is: Step 11.1) Place the workpiece on the V-shaped iron, align the outer circle and end face, drill and bore the flange evenly, and remove burrs and sharp corners; Step 11.2), ① Place the CNC boring and milling machine vertically, align the vertical and horizontal directions, and use the ΦE2 twist drill to drill the ΦE2 guide hole with a depth of 10mm; ② Connect the CNC boring and milling machine to an external gun drill, turn on the compressed air and water cooling, and drill the ΦE2 hole to the depth of the drawing; ③ Use a hand drill to clamp the homemade extended ΦC1 drill bit, drill the ΦC1 hole through, and remove burrs and flash.

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