A manufacturing process for large figure-eight blind flanges

Abstract

This invention discloses a manufacturing process for a large figure-eight blind flange, comprising: S1: casting a figure-eight shaped blank and pre-reserving process holes for clamping; S2: milling the outer edge of the figure-eight blind flange; S3: scribing the cross-shaped positioning center of the connecting holes of the figure-eight blind flange on a lathe; S4: drilling holes according to the positioning center; S5: machining the core hole and the flange end face outside one side of the core hole on a lathe with center positioning; S6: machining the positioning step and the flange end face outside one side of the positioning step on a lathe with center positioning; S7: machining the flange end face outside the other side of the core hole on a lathe with center positioning; S8: machining the flange end face outside the other side of the positioning step on a lathe with center positioning. The beneficial effects of this invention are: by first machining the positioning edge into shape through milling center, and then using the positioning edge as the machining datum for each machining process, the coaxiality requirements of the workpiece can be guaranteed. At the same time, through reasonable process arrangement, production costs are reduced and quality requirements are met.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a production process for large figure-eight blind flanges. Background Technology

[0002] like Figure 1 As shown, a large figure-eight blind flange has a length of about 1 meter and a width of about 0.5 meters. The blind flange has a core hole and a positioning step, which are located at the two centers of the figure-eight shape. The core hole is surrounded by a sealing surface and a flange connection hole, and the positioning step is also surrounded by a sealing surface and a flange connection hole. The two middle flange connection holes are shared holes. The coaxiality requirement between the center circle of the flange connection hole and the corresponding core hole and positioning step is 0.5 mm. If this is done directly in a machining center, the production cost will increase. In order to ensure coaxiality and reduce production costs, it is necessary to make reasonable process arrangements using existing processing equipment. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned technical problems by providing a production process for large figure-eight blind plates. By making reasonable process arrangements using existing processing equipment, the coaxiality requirements of the workpieces can be met while reducing production costs.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a large figure-eight blind flange manufacturing process, comprising:

[0005] S1: Cast an eight-shaped blank and reserve process holes for clamping;

[0006] S2: Mill the outer edge of the figure-eight blind plate in the shape of an eight;

[0007] S3: Clamp the workpiece on the lathe, move the cutting tool to the scale of the circle where the center of the connecting hole is located, cut the tool to draw the positioning circle, and then draw the workpiece on the indexer to form the cross positioning center of the connecting hole.

[0008] S4: Drill a hole according to the crosshair positioning center;

[0009] S5: Machining of the core hole and the flange end face on the outer side of one core hole on a center-positioned lathe;

[0010] S6: Machining of the positioning step and the flange end face on the outer side of one side of the positioning step on a lathe with center positioning;

[0011] S7: Machining the flange end face on the outer side of the core hole on a lathe with center positioning;

[0012] S8: Machining the flange end face on the outer side of the positioning step on a lathe with center positioning.

[0013] To improve production efficiency and meet product quality requirements, a combination of roughing and finishing can be used. A further optimized technical solution is that, in steps S5-S8, roughing is performed first, and a 0.5-0.8mm allowance is reserved for finishing.

[0014] To increase the contact friction and sealing performance between the convex flange sealing surface and the gasket, a further preferred technical solution is to perform fine-line machining on the sealing end face of the workpiece after precision machining, with a depth of 0.05mm, a pitch of 0.5mm, and a tool radius of 1.6mm.

[0015] To facilitate clamping and positioning during the milling process and reduce production costs, a further preferred technical solution is that, in step S1, a core hole is reserved as a process hole when casting the blank.

[0016] To facilitate clamping and positioning during the milling process and ensure the coaxiality of the workpiece, a further preferred technical solution is that, in step S2, the workpiece is clamped and positioned through a core hole, making it easy to mill the outer side in one go and ensuring the form and position tolerance of the workpiece's figure-eight outer edge.

[0017] To ensure that the coaxiality of the center circle of the connecting hole with the core hole and the positioning table meets the workpiece quality requirements, a further preferred technical solution is that, in step S3, the milled outer edge is used for clamping and positioning on a lathe, and the center of the connecting hole is scribed and positioned to ensure the form and position tolerance of the connecting hole relative to the core hole and the positioning step.

[0018] A further preferred technical solution is that, in step S4, the connecting hole is drilled according to the positioning center of the connecting hole.

[0019] Compared with the prior art, the beneficial effects of the present invention are: the outer edge is first machined into a positioning edge by a milling center, and then each machining process is based on the positioning edge as the machining reference. This can ensure the coaxiality requirement of the workpiece. At the same time, by making reasonable process arrangements, the positioning edge is machined by a CNC center, and then the remaining processes are processed by ordinary machine tools, which reduces production costs and meets quality requirements. Attached Figure Description

[0020] Figure 1 This is an isometric view of the workpiece of the present invention;

[0021] In the diagram: 10. Workpiece; 11. Core hole; 12. Connecting hole; 13. Positioning step; 14. Outer edge. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] Example

[0024] like Figure 1 As shown, a manufacturing process for a large figure-eight blind flange includes the following steps:

[0025] S1: Cast an eight-shaped blank and reserve process holes for clamping;

[0026] S2: Mill the outer edge of the figure-eight blind plate in the shape of 14;

[0027] S3: Clamp the workpiece 10 on the lathe, move the cutting tool to the scale of the circle where the center of the connecting hole 12 is located, cut the tool to draw the positioning circle, and then draw equal-division rays on the workpiece 10 on the indexer to form the cross positioning center of the connecting hole 12.

[0028] S4: Drill a hole according to the crosshair positioning center;

[0029] S5: Machining of the core hole 11 and the flange end face outside one side of the core hole 11 on a lathe with center positioning;

[0030] S6: Machining of the positioning step 13 and the flange end face on the outer side of the positioning step 13 on a lathe with center positioning;

[0031] S7: Machining the flange end face outside the core hole 11 on the other side on a lathe with the center positioning;

[0032] S8: Machining the flange end face on the outer side of the positioning step 13 on the center-positioned lathe;

[0033] The figure-eight blind plate is relatively large in size. The blank is cast and formed into a figure-eight shape. At the same time, the 300mm core hole 11 is pre-formed during casting to leave machining allowance, which can save materials, prevent waste, and reduce production costs.

[0034] In step S2, the 300mm core hole 11 is used for clamping and positioning, and the outer edge 14 of the workpiece 10 of the figure-eight blind plate, i.e. the positioning edge, is fully opened, so that the milling center can mill the entire outer edge positioning edge in one go. The milling is first rough milled until a 0.4-0.6mm allowance is left, and then the finish milling cutter is changed to finish milling in one go to ensure the accuracy of the entire positioning edge.

[0035] Before drilling, clamp workpiece 10 onto the lathe. When workpiece 10 is aligned, use a fixed scriber with the height adjusted to the center height of the lathe spindle. Use slow jogging to rotate the workpiece and use a cutting tool or scriber to draw the circle where the center is located. According to the position and size requirements of the drilling, use the positioning edge as a reference and the hole position on the drawing to use an indexer to draw radial lines of the hole position. Then, form a cross center of the hole with the circle where the center is located. The center line is easy to be clear and accurate when using a scribing tool, and the finer the better. After scribing, use a vernier caliper or steel ruler to check.

[0036] Then remove workpiece 10, clamp workpiece 10 onto the drilling machine, drill connecting hole 12 according to the positioning cross center, after the connecting hole is shaped as 12, return workpiece 10 to the original scribing lathe for turning.

[0037] In step S5, the positioning edge formed by milling is used for clamping and positioning. The core hole 11 is machined from the rear end face to the front end face of the workpiece 10 along its axial direction. Then, the front end face is machined radially along the workpiece 10. Finally, the positioning step 13 is machined from the front end face to the end face of the positioning step 13 along its axial direction. The machining process begins with rough turning of the core hole 11 and the flange end face, reducing the allowance to 0.5-0.8 mm. Then, a finishing tool is used. The core hole 11 is machined from the rear end face of the workpiece 10 to the front end face. Then, the front end face is machined radially along the workpiece 10. Then, the positioning step 13 is machined axially from the front end face of the workpiece 10 to the end face of the positioning step 13. After precision machining, the water line of the sealing end face of the workpiece is machined with a depth of 0.05 mm, a pitch of 0.5 mm, and a tool radius of 1.6 mm. One end face of one side of the figure-eight blind plate is machined. Then, the workpiece is removed and re-clamped.

[0038] In step S6, the positioning edge formed by milling is used for clamping and positioning. The front end face of the workpiece 10 is turned radially. Then, the positioning step 13 is turned from the front end face of the workpiece 10 to the end face of the positioning step 13 along the axial direction of the workpiece 10. The turning is first rough turning, which rough turns the positioning step 13 and the flange end face of the workpiece to a margin of 0.5-0.8mm. Then, the finishing tool is changed to turn the front end face of the workpiece 10 radially. Then, the positioning step 13 is turned from the front end face of the workpiece 10 to the end face of the positioning step 13 along the axial direction of the workpiece 10. After finishing turning, the water line of the sealing end face of the workpiece is machined with a depth of 0.05mm, a pitch of 0.5mm, and a tool radius of 1.6mm. The other end face on the same side of the figure-eight blind plate is machined. Then, the workpiece is removed and re-clamped.

[0039] In step S7, the positioning edge formed by milling is used for clamping and positioning. The front end face is radially turned along the end face corresponding to the core hole 11 of the workpiece 10. Then, the positioning step 13 is turned along the axial direction of the workpiece to be processed, from the front end face of the workpiece to the end face of the positioning step 13. The turning is first rough turned, and the positioning step 13 and the flange end face of the workpiece are rough turned to a allowance of 0.5-0.8mm. Then, the finishing tool is changed, and the front end face of the workpiece 10 is radially turned. Then, the positioning step 13 is turned along the axial direction of the workpiece to be processed, from the front end face of the workpiece to the end face of the positioning step 13. After finishing, the water line of the sealing end face of the workpiece is machined with a depth of 0.05mm, a pitch of 0.5mm, and a tool radius of 1.6mm. The end face of the other side of the figure-eight blind plate is completed. Then, the workpiece is removed and re-clamped.

[0040] In step S8, the positioning edge formed by milling is used for clamping and positioning. The front end face of the workpiece 10 is turned radially. Then, the positioning step 13 is turned axially from the front end face of the workpiece 10 to the end face of the positioning step 13. The turning is first rough turned, rough turning the positioning step 13 and the flange end face of the workpiece 10 to a allowance of 0.5-0.8mm. Then, the finishing tool is changed, and the front end face of the workpiece 10 is turned radially. Then, the positioning step 13 is turned axially from the front end face of the workpiece 10 to the end face of the positioning step 13. The other side of the figure-eight blind plate... Once one end face is machined, the entire figure-eight blind plate is completed. Then, workpiece 10 is removed, inspected, and put into storage. Throughout the entire machining process, the outer edge of the figure-eight blind plate is used as the positioning reference. The milled outer edge is used for clamping and positioning on a lathe. The cross center of the connecting hole 12 is scribed and positioned to ensure that the shape tolerance of the connecting hole 12 relative to the core hole 11 and the positioning step 13 is met. The workpiece 10 is then machined and clamped, and the core hole, end face, and step are machined to ensure the coaxiality and position requirements of the workpiece 10. At the same time, through reasonable process arrangement, the positioning edge is machined using a CNC center, and then the remaining processes are processed using ordinary machine tools to reduce production costs and meet quality requirements.

[0041] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A manufacturing process for large figure-eight blind flanges, characterized in that, Includes the following steps, S1: Cast an eight-shaped blank and reserve process holes for clamping; S2: Mill the outer edge of the figure-eight blind plate in the shape of an eight; S3: Clamp the workpiece on the lathe, move the cutting tool to the scale of the circle where the center of the connecting hole is located, and make the cutting tool to draw the positioning circle. Then, make equal division ray scribing on the indexer to form the cross positioning center of the connecting hole. Clamp and position the workpiece on the lathe with the milled outer edge, and scribing the center of the connecting hole to ensure the form and position tolerance of the connecting hole relative to the core hole and the positioning step. S4: Drill a hole according to the crosshair positioning center; S5: Machining of the core hole and the flange end face on the outer side of one core hole on a center-positioned lathe; S6: Machining of the positioning step and the flange end face on the outer side of one side of the positioning step on a lathe with center positioning; S7: Machining the flange end face on the outer side of the core hole on a lathe with center positioning; S8: Machining the flange end face on the outer side of the positioning step on a lathe with center positioning.

2. The manufacturing process for a large figure-eight blind flange as described in claim 1, characterized in that, In steps S5-S8, rough turning is performed first, and a 0.5-0.8mm allowance is reserved for finish turning.

3. The manufacturing process for a large figure-eight blind flange as described in claim 2, characterized in that, After precision turning, the sealing end face of the workpiece is machined with dense water lines to a depth of 0.05mm and a pitch of 0.5mm, with a tool radius of 1.6mm.

4. The manufacturing process for a large figure-eight blind flange as described in claim 1, characterized in that, In step S1, when casting the blank, a core hole is reserved as a process hole.

5. The manufacturing process for a large figure-eight blind flange as described in claim 4, characterized in that, In step S2, the workpiece is clamped and positioned through the core hole, making it easy to mill the outer side in one go and ensuring the form and position tolerance of the workpiece's figure-eight outer edge.

6. The manufacturing process for a large figure-eight blind flange as described in claim 1, characterized in that, In step S4, the connecting hole is drilled according to the positioning center of the connecting hole.

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