A processing technology for seamless fitting of split graphite sealing rings

Abstract

The present invention discloses a processing technology for seamless fitting of split graphite sealing rings, belonging to the field of machining. The present invention adopts the split ring bonding technology to split the graphite blank, and then form two half rings by splitting, and process after bonding into a whole ring. The maximum diameter of the product is extended to D = 1000 mm. At the same time, back-to-back grinding is adopted to improve the sealing performance of the bonding surface of the two split rings, and the fitting rate of the fitting surface reaches more than 85%. The designed CNC vertical lathe clamping tooling ensures that the product does not hang in the air and will not deform.

Description

Technical Field

[0001] The present invention belongs to the field of machining, and particularly relates to a processing technology for seamless fitting of split graphite sealing rings. Background Art

[0002] Graphite sealing rings are commonly used components in the engine field. For convenient installation and good sealing effect, they are usually processed in a split form. The existing split graphite sealing rings are directly split after being processed into a complete circle. The complete-circle sealing rings do not adopt bonding and grinding of the bonding surfaces, resulting in large gaps in the bonding surfaces of the complete rings after being processed into products, small maximum directly processable size, D < 500 mm, and low fitting rate, about 40% or so. Summary of the Invention

[0003] To solve the technical problems existing in the prior art, the present invention provides a processing technology for seamless fitting of split graphite sealing rings. The present invention adopts a split-ring bonding technology (such as dividing into 4 segments, bonding the 4 segments into 2 segments respectively, and then bonding into a complete ring for processing), and the maximum diameter of the product is extended to D = 1000 mm; back-to-back grinding improves the sealing performance of the bonding surfaces of the two split rings, and the fitting rate of the bonding surfaces reaches more than 85%.

[0004] The present invention provides a processing technology for seamless fitting of split graphite sealing rings, including the following steps:

[0005] Dividing a graphite blank into a plurality of first sector-shaped plates with the same thickness;

[0006] Performing a first turning on the first sector-shaped plates, turning the outer diameter, inner diameter, and sector end faces to obtain second sector-shaped plates, ensuring that the chord length of the second sector-shaped plates is not less than the design requirements;

[0007] Impregnating the second sector-shaped plates with epoxy resin;

[0008] Performing a second turning on the impregnated second sector-shaped plates, turning the outer diameter, inner diameter, and sector end faces to obtain third sector-shaped plates, ensuring that the chord length of the third sector-shaped plates is not less than the design requirements;

[0009] Grinding the sector end faces of the third sector-shaped plates to obtain fourth sector-shaped plates;

[0010] Milling the chord lengths and Z-shaped bonding locations of the fourth sector-shaped plates to obtain fifth sector-shaped plates, ensuring that the fifth sector-shaped plates can be bonded into a complete circle;

[0011] Performing bonding of the fifth sector-shaped plates to form a complete-circle sealing ring.

[0012] Preferably, after forming the complete-circle sealing ring, the following steps are further included:

[0013] Cleaning the bonding substances;

[0014] Grind the end face of the flat ground and bonded into a complete circular sealing ring;

[0015] Precision turn the complete circular sealing ring into shape;

[0016] Grind the sealing end face of the complete circular sealing ring.

[0017] Preferably, after grinding the end face of the flat ground and bonding into a complete circular sealing ring and before precision turning the complete circular sealing ring into shape, it also includes checking the ground grinding surface, and the parallelism error of the end face is required to be ≤0.02mm.

[0018] Preferably, after precision turning the complete circular sealing ring into shape and before grinding the sealing end face of the complete circular sealing ring, it also includes an intermediate inspection step to check whether the complete circular sealing ring meets the design requirements.

[0019] Preferably, after precision turning the complete circular sealing ring into shape, the three-coordinate method is used to check whether the dimensional and geometric tolerance accuracy of the complete circular sealing ring meets the design requirements.

[0020] Preferably, for a split graphite sealing ring composed of two half rings, after bonding to form a complete circular sealing ring, the following steps are also included:

[0021] Wire cut the complete circular sealing ring into two half rings;

[0022] Mill the mating surfaces of the two half rings;

[0023] Use a back-to-back tooling to make the two half rings back-to-back and fix them, and then grind the mating surfaces of the two half rings.

[0024] Preferably, when precision turning the complete circular sealing ring into shape, a complete ring clamping tooling is used to clamp the complete circular sealing ring. The complete ring clamping tooling includes a tooling backing plate, a plurality of tooling pressing plates, and a process chuck; the tooling backing plate and the process chuck are circular, the outer ring of the process chuck matches the inner ring of the tooling backing plate, the process chuck protrudes above the upper surface of the tooling backing plate, and the complete circular sealing ring can be fixed on the tooling backing plate through the tooling pressing plates. The plurality of tooling pressing plates are fixed on the machine tool workbench through T-shaped screws; the outer ring of the process chuck matches the inner ring of the complete circular sealing ring.

[0025] Preferably, a saw is used to divide the graphite blank into sheet materials with the same thickness.

[0026] Preferably, a CNC vertical lathe is used for the first turning and the second turning.

[0027] Preferably, there are subsequent auxiliary processes, including cleaning, marking, final inspection, and packaging.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention first performs splitting, and then utilizes the bonding technology of the splitting ring (bonding multiple segments into 2 segments or a complete ring for subsequent processing, or directly bonding multiple segments into a complete ring for subsequent processing). The maximum diameter of the product is extended to D = 1000 mm, which is much larger than the existing diameter.

[0030] 2. The present invention grinds two half-rings back to back, improving the sealing performance of the bonding surface between the two half-rings, and the fitting rate of the fitting surface reaches more than 85%.

[0031] 3. The present invention designs a tooling for precision turning of the complete ring. First, the outer ring and one surface of the complete ring are precision turned to the process chuck. After machining to the designed dimensions, the tooling pressing plate presses the complete ring, and is tightened by screws. Then, the process chuck is removed, and the screws are kept tightened. The inner ring of the complete ring is machined to the designed dimensions. Then, it is turned over, and the other surface, inner and outer rings are machined using the same process. In this machining method, the product does not hang in the air and will not deform. While in the traditional clamping method, generally three-jaw chucks, centers, etc. are used to fix the product by pressing the inner and outer diameters, and the product hangs in the air. The traditional clamping method (as shown in Figure 9 ), including multiple conventional center clamping 5 in the figure) is prone to generating machining stress and deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is the top view of the sheet metal after the first turning for an embodiment of the present invention;

[0033] Figure 2 is the front view of the sheet metal after the first turning for an embodiment of the present invention;

[0034] Figure 3 is the top view of the sheet metal after the second turning for an embodiment of the present invention;

[0035] Figure 4 is the front view of the sheet metal after the second turning for an embodiment of the present invention;

[0036] Figure 5 is the three-dimensional schematic diagram of the complete circle bonding for an embodiment of the present invention;

[0037] Figure 6 is the three-dimensional schematic diagram of the complete circle formed by bonding two half-rings for an embodiment of the present invention;

[0038] Figure 7 is the three-dimensional schematic diagram of the fitting surface of the two half-rings milled when the final product of an embodiment of the present invention is in the form of a non-complete ring (a split graphite sealing ring composed of two half-rings);

[0039] Figure 8 is the three-dimensional schematic diagram of the fitting surface of the two half-rings ground back to back when the final product of an embodiment of the present invention is in the form of a non-complete ring (a split graphite sealing ring composed of two half-rings);

[0040] Figure 9 Schematic three-dimensional view of the traditional clamping method adopted by CNC vertical lathes in the prior art;

[0041] Figure 10 Schematic three-dimensional view of clamping a full-circle sealing ring with the back-to-back tooling designed according to the present invention in an embodiment of the present invention.

[0042] In the figure, 1 - tooling backing plate, 2 - tooling pressing plate, 3 - process chuck, 4-1 - first half ring, 4-2 - second half ring, 5 - conventional center clamping, 6 - Z-shaped bonding point, 7 - straight-shaped bonding point, 8 - back-to-back tooling, 9 - clamping screw, 10 - mating surface of the half ring, 11 - full-circle sealing ring. Detailed implementation manners

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0044] The present invention provides a processing technology for seamless fitting of split graphite sealing rings, including the following steps:

[0045] Dividing the graphite blank into a plurality of first sector-shaped plates with the same thickness; as Figure 1 and 2 shown;

[0046] Performing the first turning on the first sector-shaped plates, turning the outer diameter, inner diameter, and sector end faces to obtain second sector-shaped plates, as Figure 3 and 4 shown, ensuring that the chord length of the second sector-shaped plates is not less than the design requirements;

[0047] Impregnating the second sector-shaped plates with epoxy resin; the epoxy resin is the impregnating substance in the graphite blank;

[0048] Performing the second turning on the impregnated second sector-shaped plates, turning the outer diameter, inner diameter, and sector end faces to obtain third sector-shaped plates, ensuring that the chord length of the third sector-shaped plates is not less than the design requirements;

[0049] Grinding the sector end faces of the third sector-shaped plates to obtain fourth sector-shaped plates;

[0050] Milling the chord lengths and Z-shaped bonding points 6 of the fourth sector-shaped plates to obtain fifth sector-shaped plates, ensuring that the fifth sector-shaped plates can be bonded into a full circle;

[0051] Performing the bonding of the fifth sector-shaped plates to form a full-circle sealing ring 11.

[0052] According to a specific embodiment of the present invention, ensuring that the milled sector-shaped blanks can be bonded into a complete circle specifically includes two cases. One is that both ends of the sector-shaped blanks have Z-shaped bonding joints 6, and they are bonded pairwise to form a complete circle, as shown in Figure 5 shown; the other is that both ends of a part of the sector-shaped blanks have Z-shaped bonding joints 6, and one end of the other part of the sector-shaped blanks has a neat straight-shaped bonding joint 7, and the other end has a Z-shaped bonding joint 6. The end with the straight-shaped bonding joint 7 fits with the straight-shaped bonding joint 7 of another sector-shaped blank. As shown in Figure 6 shown.

[0053] According to a specific embodiment of the present invention, after forming the complete-circle seal ring, the following steps are further included:

[0054] Clean the adhesive;

[0055] Grind the end face of the bonded complete-circle seal ring 11 flat;

[0056] Precision-turn the complete-circle seal ring 11 into shape;

[0057] Lap the seal end face of the complete-circle seal ring 11.

[0058] According to a specific embodiment of the present invention, before precision-turning the complete-circle seal ring 11 into shape after grinding the end face of the bonded complete-circle seal ring 11 flat, it also includes checking the ground lapping surface, and the parallelism error of the end face is required to be ≤0.02 mm.

[0059] According to a specific embodiment of the present invention, after precision-turning the complete-circle seal ring 11 into shape and before lapping the seal end face of the complete-circle seal ring 11, it also includes an intermediate inspection step to check whether the complete-circle seal ring 11 meets the design requirements.

[0060] According to a specific embodiment of the present invention, after precision-turning the complete-circle seal ring 11 into shape, the three-coordinate method is used to check whether the dimensional and geometric tolerance precision of the complete-circle seal ring 11 meets the design requirements.

[0061] According to a specific embodiment of the present invention, for the split graphite seal ring composed of two half rings, after bonding to form the complete-circle seal ring, the following steps are further included:

[0062] Wire-cut the complete-circle seal ring 11 into two half rings (the first half ring 4-1, the second half ring 4-2);

[0063] Mill the mating surfaces 10 of the two half rings, as shown in Figure 7 shown;

[0064] Use the back-to-back tooling 8 to make the two half rings back-to-back, and use the clamping screw 9 for fixation, as shown in Figure 8 shown, and then lap the mating surfaces of the two half rings, which is also the mating surface.

[0065] According to a specific embodiment of the present invention, when the finish-turned integral sealing ring 11 is formed, an integral ring clamping tooling is used to clamp the integral sealing ring 11. The integral ring clamping tooling includes a tooling backing plate 1, a plurality of tooling pressing plates 2, and a process chuck 3. The tooling backing plate 1 and the process chuck are circular. The outer ring of the process chuck 3 matches the inner ring of the tooling backing plate 1. The integral sealing ring 11 can be fixed on the tooling backing plate 1 through the tooling pressing plates 2. The plurality of tooling pressing plates 2 are fixed on the machine tool workbench through T-shaped screws. The outer ring of the process chuck 3 matches the inner ring of the integral sealing ring 11. As Figure 10 shown, it is the integral ring clamping tooling after placing the integral sealing ring 11.

[0066] According to a specific embodiment of the present invention, a saw is used to divide the graphite blank into sheet materials with the same thickness.

[0067] According to a specific embodiment of the present invention, a CNC vertical lathe is used for the first turning and the second turning.

[0068] According to a specific embodiment of the present invention, there are subsequent auxiliary processes, including cleaning, marking, final inspection, and packaging.

[0069] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are all included in the protection scope of the present invention.

Claims

1. A processing technology for seamlessly fitting a split graphite sealing ring, characterized in that: The steps include: Dividing the graphite blank into a plurality of first sector-shaped plates having the same thickness; The first sector-shaped sheet is turned for the first time to turn the outer diameter, inner diameter and sector-shaped end face to obtain the second sector-shaped sheet, ensuring that the chord length of the second sector-shaped sheet is not less than the design requirement; Impregnating the second sector-shaped sheet with epoxy resin; The second fan-shaped sheet material after impregnation is turned for the second time to turn the outer diameter, inner diameter and fan-shaped end face to obtain the third fan-shaped sheet material, ensuring that the chord length of the third fan-shaped sheet material is not less than the design requirement; Grinding the fan-shaped end surface of the third fan-shaped plate material to obtain a fourth fan-shaped plate material; Mill the chord length and Z-shaped bonding point of the fourth sector-shaped sheet to obtain the fifth sector-shaped sheet, ensuring that the fifth sector-shaped sheet can be bonded into a full circle; Bonding the fifth sector-shaped sheet material to form a full-circle sealing ring; When the whole circular sealing ring is formed by precision turning, the whole circular sealing ring is clamped by a whole ring clamping tool, and the whole ring clamping tool comprises a tool pad, a plurality of tool pressure plates, and a process chuck; the tool pad and the process chuck are circular, and the outer ring of the process chuck matches the inner ring of the tool pad, and the process chuck is higher than the upper surface of the tool pad, and the whole circular sealing ring can be fixed on the tool pad by the tool pressure plate, and a plurality of the tool pressure plates are fixed on the machine tool workbench by T-screws; the outer ring of the process chuck matches the inner ring of the whole circular sealing ring; when in use, the outer ring and one surface of the whole circular sealing ring are precision turned to the process chuck first, and after processing to the designed size, the tool pressure plate is used to press the whole circular sealing ring, and it is tightened by the T-screw, and then the process chuck is removed, the screw is kept tightened, and the inner ring of the whole circular sealing ring is processed to the designed size, and then it is turned over, and the other surface and the inner and outer rings of the whole circular sealing ring are processed by the same process; For a split graphite sealing ring composed of two half rings, after bonding to form a full-circle sealing ring, the following steps are also included: Divide the full-circle sealing ring into two half rings by wire cutting; Milling the fitting surfaces of the two half rings; The two half rings are placed back to back and fixed using a back-to-back tooling, and then the mating surfaces of the two half rings are ground.

2. The seamless bonding processing technology of the split graphite sealing ring according to claim 1 is characterized in that: After forming the full-circle sealing ring, the following steps are also included: Clean the adhesive; Flat grinding and bonding to form the end face of the full-circle sealing ring; Finish turning of full-circle sealing rings; Grind the sealing end face of the full-circle sealing ring.

3. The seamless bonding processing technology of the split-flap graphite sealing ring according to claim 2 is characterized in that: After flat grinding and bonding the end face of the full-circle sealing ring, before fine turning the full-circle sealing ring, it also includes checking the flat-ground grinding surface, requiring the parallelism error of the end face to be ≤0.02mm.

4. The seamless bonding processing technology of the split graphite sealing ring according to claim 2 is characterized in that: After the full-circle sealing ring is formed by precision turning, an intermediate inspection step is also included before the sealing end face of the full-circle sealing ring is ground to check whether the full-circle sealing ring meets the design requirements.

5. The seamless bonding process of the split graphite sealing ring according to claim 4 is characterized in that: After the full-circle sealing ring is formed by fine turning, the three-coordinate method is used to check whether the size and shape and position tolerance accuracy of the full-circle sealing ring meet the design requirements.

6. The seamless bonding process of the split graphite sealing ring according to claim 1 is characterized in that: The graphite blank is cut into sheets of equal thickness using a saw.

7. The seamless bonding process of the split graphite sealing ring according to claim 1 is characterized in that: CNC vertical lathe is used for the first and second machining.

8. The seamless bonding processing technology of the split graphite sealing ring according to any one of claims 2 to 7 is characterized in that: There are also auxiliary processes afterwards, including cleaning, labeling, final inspection and packaging.

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