Machining process of sealing ring special for triple-eccentric multi-layer butterfly valve and sealing ring

Abstract

The invention discloses a processing technology of a sealing ring special for a triple-eccentric multi-layer butterfly valve and the sealing ring, and the technology comprises the following steps: preparing a blank: alternately laminating, bonding and cutting a plurality of layers of metal sheets and graphite sheets to prepare an annular blank of the sealing ring; a special clamp is arranged and comprises an inclination disc, a positioning seat, an auxiliary butterfly plate and a pressing ring, the positioning seat is movably and obliquely arranged on the inclination disc and provided with a bearing part, the auxiliary butterfly plate is provided with a positioning step and a bearing face, the annular blank is placed on the auxiliary butterfly plate, an inner side hole of the annular blank is matched with the positioning step, and the positioning face is attached to the bearing face; the pressing ring and the bearing face are matched to clamp and fix the annular blank, the auxiliary butterfly plate is arranged on the bearing portion, the machine tool drives the inclination disc to rotate, the cutting tool is used for conducting forward and reverse feeding cutting on the annular blank on the special clamp, and therefore the sealing ring with the inclined conical sealing face is manufactured. According to the invention, the possibility of deformation of the sealing ring, burrs, flanging and other problems can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valve production, in particular to a processing technology of a special sealing ring for a three-eccentric multi-layer butterfly valve and the sealing ring. BACKGROUND

[0002] The three-eccentric butterfly valve is an industrial valve designed with a three-eccentric structure. In addition to the two eccentric designs of the valve rod deviating from the center of the butterfly plate and the valve rod deviating from the center of the valve body, the third eccentric design is that the sealing surface of the sealing ring on the butterfly plate is in the form of an inclined cone (not a right circular cone), so that the axis thereof forms a certain angle with the axis of the valve body passage (the sealing surface is eccentric), thereby reducing the sealing friction. Some existing three-eccentric butterfly valves have a sealing ring with a multi-layer structure. During production, multiple metal sheets and multiple graphite sheets are alternately stacked, and then a ring-shaped blank is cut out. The ring-shaped blank is then positioned on an inclined disc, the center line of the required processing cone surface is adjusted to be consistent with the center line of the inclined disc, and then the cone surface is processed by numerical control turning program and cutting to obtain a sealing ring with an inclined conical sealing surface. During the processing of the sealing ring, the sealing ring placed on the inclined disc has one side higher and the other side lower. When cutting the sealing surface, the cutting is intermittent, and the ring-shaped blank lacks effective support. The processed sealing ring is prone to deformation towards the positioning surface. In addition, in the multi-layer structure, the graphite layer is relatively soft. When cutting from the metal layer to the graphite layer, burrs or flanges may occur at the edge of the processed metal sheet, and some burrs or flanges may be trapped in the graphite layer, affecting the sealing performance of the sealing ring. SUMMARY

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application provides a processing technology of a special sealing ring for a three-eccentric multi-layer butterfly valve, which can reduce the possibility of deformation of the sealing ring and the occurrence of burrs, flanges and other problems on the sealing surface, and ensure the sealing performance of the sealing ring.

[0004] The present application also provides a sealing ring made by the processing technology of the special sealing ring for the three-eccentric multi-layer butterfly valve.

[0005] The processing technology of the special sealing ring for the three-eccentric multi-layer butterfly valve according to the first aspect of the present application comprises the following steps:

[0006] Preparation of the blank: multiple metal sheets and multiple graphite sheets are alternately stacked and fixed by bonding to obtain a ring-shaped blank of the sealing ring, so that the ring-shaped blank has multiple metal layers and graphite layers arranged alternately, and the metal layers and the graphite layers satisfy the relationship: n≥2, m=n+1, where m is the number of metal layers and n is the number of graphite layers;

[0007] The conical surface processing device comprises a special fixture, the special fixture comprises a slope disc, a positioning seat, an auxiliary butterfly plate and a pressing ring, the positioning seat is obliquely arranged on the slope disc and is movable to adjust the position relative to the slope disc, the positioning seat is provided with a supporting part, the auxiliary butterfly plate is provided with a positioning step and a supporting surface, a ring-shaped blank is placed on the auxiliary butterfly plate, the inner hole of the ring-shaped blank is matched with the positioning step, and the positioning surface of the ring-shaped blank is attached to the supporting surface, the pressing ring is detachably connected to the auxiliary butterfly plate to be matched with the supporting surface to clamp and fix the ring-shaped blank, and the auxiliary butterfly plate is detachably arranged on the supporting part.

[0008] According to the special sealing ring processing technology of the three-eccentric multi-layer butterfly valve, the following beneficial effects are achieved: during production, the inner hole of the ring-shaped blank is matched with the positioning step to position the ring-shaped blank of the sealing ring, the positioning surface of the ring-shaped blank is attached to the supporting surface, the supporting surface supports the positioning surface, the possibility of deformation of the sealing ring to the positioning surface is reduced, the pressing ring is matched with the supporting surface to clamp and fix the ring-shaped blank, the metal layers and the graphite layers are closely matched during the fixing of the ring-shaped blank, which is beneficial to the close degree of the graphite layers during processing, then, the cutting tool adopts the special cutting method of forward and reverse cutting, the cutting tool moves from the small-diameter end to the large-diameter end (forward cutting) during the first cutting, the initial cutting amount is small, the cutting force is small, the tool impact load is low, the tool tip is protected, and the cutting chip is naturally discharged to the bottom end of the cone, if burrs are generated, the burrs are located on the side of the metal layer opposite to the bottom end of the cone, and the cutting tool moves from the large-diameter end to the small-diameter end (reverse cutting) during the second cutting, on the one hand, the burrs generated on the side of the metal layer opposite to the bottom end of the cone during the forward cutting are effectively removed, and on the other hand, the cutting stress generated during the forward cutting can be partially eliminated during the reverse cutting, which is beneficial to the suppression of deformation. The above process can reduce the possibility of deformation of the sealing ring and the generation of burrs and flanging of the sealing surface through the special fixture and the special cutting method, and ensure the sealing performance of the sealing ring.

[0009] According to some embodiments of the present application, the cutting tool used in the conical surface processing step has a tool tip arc radius R≤0.2mm.

[0010] According to some embodiments of the present application, the cutting tool used in the conical surface processing step is a PCD diamond tool or a CVD-coated cemented carbide tool.

[0011] According to some embodiments of the present application, in the conical surface machining step, a machining allowance of 0.1-0.2mm is needed for the second pass cutting when the first pass cutting is performed.

[0012] According to some embodiments of the present application, in the conical surface machining step, the parameters for the two pass cuttings are configured as: 80m / min≤Vc1≤120m / min, 0.05mm / rev≤fn1≤0.1mm / rev, ap1≤0.2mm, wherein Vc1 is the cutting speed, fn1 is the feed rate, and ap1 is the cutting depth.

[0013] According to some embodiments of the present application, in the conical surface machining step, an allowance b of 0.5-0.6mm is needed between the outer edge of the positioning surface of the ring-shaped blank and the outer edge of the supporting surface.

[0014] According to some embodiments of the present application, before the conical surface machining step, the outer diameter of the ring-shaped blank is adjusted to the required size range by cutting machining.

[0015] According to some embodiments of the present application, in the blank preparation step, after the multiple layers of metal sheets and multiple layers of graphite sheets are alternately stacked and fixedly bonded, the alternately stacked multiple layers of metal sheets and graphite sheets are subjected to press forming, and the press ratio d is 1.03-1.05, wherein: d=t1 / t2, t1 is the thickness size before pressing, and t2 is the thickness size after pressing.

[0016] According to some embodiments of the present application, the special fixture further comprises a tensioning seat, the upper side of the tensioning seat is rotationally connected to the lower side of the auxiliary butterfly plate, and the lower side of the tensioning seat is detachably connected to the positioning seat through a bolt.

[0017] The sealing ring according to the second aspect of the present application is prepared by using the processing technology of the special sealing ring for the three-eccentric multi-layer butterfly valve according to the first aspect of the present application.

[0018] The sealing ring according to the embodiments of the present application has at least the following beneficial effects: by using the processing technology of the special sealing ring for the three-eccentric multi-layer butterfly valve, the possibility of deformation of the sealing ring and the problems of burrs and flanging on the sealing surface can be reduced, and the sealing performance of the sealing ring can be ensured.

[0019] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the following drawings of which:

[0021] Figure 1 Structure diagram of special fixture in the embodiment of the present application;

[0022] Figure 2 Structure diagram of special fixture in the embodiment of the present application; Figure 1 Structure diagram of special fixture in the embodiment of the present application;

[0023] Figure 3 Structure diagram of special fixture in the embodiment of the present application; Figure 1 Structure diagram of special fixture in the embodiment of the present application;

[0024] Figure 4 Structure diagram of special fixture in the embodiment of the present application; Figure 3 Structure diagram of special fixture in the embodiment of the present application;

[0025] Reference signs:

[0026] Sealing ring 10, sealing surface 11, positioning surface 12, taper angle a, allowance b;

[0027] Special fixture 100, bevel disc 110, positioning seat 120, supporting part 121, auxiliary butterfly plate 130, positioning step 131, supporting surface 132, second connecting hole 133, compression ring 140, tensioning seat 150, first connecting hole 151, connecting shaft 152. DETAILED DESCRIPTION

[0028] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0029] In the description of the present application, it should be understood that if the orientation description is involved, for example, the orientation or position relationship indicated by the upper, lower, front, rear, left, right, etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0030] In the description of the present application, if the words such as several, more than, less than, exceed, above, below, within, etc. appear, wherein the meaning of several is one or more, the meaning of more than is two or more, more than, less than, exceed, etc. are understood as not including the number, above, below, within, etc. are understood as including the number.

[0031] If there are descriptions to the first, second only for the purpose of distinguishing technical features, and can not be understood as indicating or implying relative importance or implied indicating the number of indicated technical features or implied indicating the relationship between the indicated technical features.

[0032] In the description of the present application, unless otherwise expressly limited, the words such as setting, installation, connection, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical scheme.

[0033] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 4 , a processing technology of a special sealing ring for a three-eccentric multi-layer butterfly valve includes the following steps:

[0034] Preparation of the blank, the multi-layer metal sheet and the multi-layer graphite sheet are alternately stacked and bonded and fixed, and the annular blank of the sealing ring 10 is prepared by cutting, so that the annular blank has a plurality of metal layers and graphite layers arranged alternately, and the metal layers and the graphite layers satisfy the relationship: n≥2, m=n+1, wherein m is the number of metal layers, and n is the number of graphite layers;

[0035] Conical surface machining, a special fixture 100 is provided, the special fixture 100 includes a slope disc 110, a positioning seat 120, an auxiliary butterfly plate 130 and a ring pressing 140, the positioning seat 120 is inclined on the slope disc 110 and can be moved to adjust the position relative to the slope disc 110, the positioning seat 120 is provided with a supporting part 121, the auxiliary butterfly plate 130 is provided with a positioning step 131 and a supporting surface 132, the annular blank is placed on the auxiliary butterfly plate 130, so that the inner hole of the annular blank is matched with the positioning step 131, and the positioning surface 12 of the annular blank is attached to the supporting surface 132, the ring pressing 140 is detachably connected to the auxiliary butterfly plate 130 to be matched and clamped with the supporting surface 132 to fix the annular blank, the auxiliary butterfly plate 130 is detachably arranged on the supporting part 121, the slope disc 110 is driven to rotate by the machine tool, and the annular blank on the special fixture 100 is cut twice by using a cutting tool, so as to obtain the sealing ring 10 with the inclined conical sealing surface 11. In the first pass cutting, the movement direction of the cutting tool is from the tip of the cone corresponding to the sealing surface 11 to the bottom end of the cone, and in the second pass cutting, the movement direction of the cutting tool is from the bottom end of the cone corresponding to the sealing surface 11 to the tip.

[0036] It can be understood that, as Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, during production, an annular blank for the sealing ring 10 is first prepared through a blank preparation step. Then, the annular blank is machined to a conical surface. A special fixture 100 is used to position the annular blank by engaging the inner hole of the annular blank with the positioning step 131. The positioning surface 12 of the annular blank is in contact with the supporting surface 132, which supports the positioning surface 12, reducing the possibility of deformation of the sealing ring 10 towards the positioning surface 12. A pressure ring 140 is used to clamp and fix the annular blank in conjunction with the supporting surface 132. While fixing the annular blank, this ensures a tight fit between the metal and graphite layers, which helps to enhance the density of the graphite layer during machining. Subsequently, the cutting tool is used in both forward and reverse directions. The special cutting method involves a first cutting motion from the tip of the cone corresponding to the sealing surface 11 towards the bottom, and from the smaller diameter end to the larger diameter end (forward cutting). This results in a small initial cutting amount, low cutting force, and low tool impact load, protecting the tool tip. Chips naturally exit towards the bottom of the cone. If burrs are generated, they will be located on the side of the metal layer opposite the bottom of the cone. The second cutting motion is from the bottom of the cone corresponding to the sealing surface 11 towards the tip, and from the larger diameter end to the smaller diameter end (reverse cutting). This effectively removes burrs generated on the side of the metal layer opposite the bottom of the cone during the forward cutting motion. Furthermore, the cutting stress generated during the forward cutting motion can be partially eliminated during the reverse cutting motion, which helps suppress deformation. This process, combined with a special fixture 100 and the special cutting method, reduces the possibility of deformation of the sealing ring 10 and the appearance of burrs or flanges on the sealing surface 11, ensuring the sealing performance of the sealing ring 10.

[0037] In practical applications, the specific parameters during cutting and the specific structure of the special fixture 100 can be set according to the actual needs. They will not be described in detail here, but will be explained in detail below.

[0038] In some embodiments, during the tapered surface machining step, the cutting tool's tip radius R is ≤ 0.2 mm. It is understood that when the cutting tool's tip radius R is ≤ 0.2 mm, the cutting tool has higher sharpness, which helps reduce the tendency for tearing and lowers the possibility of burrs. In practical applications, the specific value of the cutting tool's tip radius can be set according to actual usage requirements.

[0039] In some embodiments, the cutting tool used in the tapered surface machining step is a PCD diamond tool or a CVD-coated carbide tool. It is understood that using PCD diamond tools or CVD-coated carbide tools provides higher hardness and better anti-sticking capabilities, which helps reduce the likelihood of burr formation. In practical applications, the specific material of the cutting tool can be varied according to actual usage requirements.

[0040] In some embodiments, during the conical surface machining step, a machining allowance of 0.1–0.2 mm needs to be reserved for the second cutting pass during the first cutting pass. It is understood that reserving a machining allowance of 0.1–0.2 mm (including the endpoint value) reduces the machining amount of the second cutting pass, which helps reduce the possibility of burrs and facilitates the removal of burrs and flaking defects generated during the first cutting pass. In practical applications, the reserved machining allowance can be 0.1 mm, 0.15 mm, or 0.2 mm, and can be set according to actual usage requirements.

[0041] Furthermore, in the conical surface machining step, the parameters used for the two cutting passes are configured as follows: 80m / min≤Vc1≤120m / min, 0.05mm / rev≤fn1≤0.1mm / rev, ap1≤0.2mm, where Vc1 is the cutting speed, fn1 is the feed rate, and ap1 is the depth of cut.

[0042] Understandably, by adopting the above cutting parameters, the cutting speed is relatively low, and the feed rate and depth of cut are relatively small, which helps to reduce the possibility of burrs during cutting. In practical applications, the cutting speed Vc1 can be 80m / min, 100m / min, or 120m / min, the feed rate fn1 can be 0.05mm / rev, 0.08mm / rev, or 0.1mm / rev, and the depth of cut ap1 can be 0.2mm or 0.15mm, which can be set according to the actual needs of the application.

[0043] In some embodiments, during the conical surface machining step, a clearance amount b needs to be reserved between the outer edge of the positioning surface 12 of the annular blank and the outer edge of the supporting surface 132, and the clearance amount b is 0.5 to 0.6 mm.

[0044] Understandably, such as Figure 3 and Figure 4 As shown, by reserving a clearance amount b between the outer edge of the positioning surface 12 and the outer edge of the supporting surface 132 of the annular blank, it is beneficial to provide the necessary clearance space for the second cutting pass, facilitating the removal of burrs and flanges generated by the first cutting pass. Simultaneously, the clearance amount b is set to 0.5–0.6 mm (inclusive of the endpoint value). A smaller clearance amount b allows the outer edge of the supporting surface 132 to approach the outer edge of the positioning surface 12 of the annular blank, achieving better support, reducing the possibility of deformation, and facilitating use. In practical applications, the clearance amount b can be 0.5 mm, 0.55 mm, or 0.6 mm, and can be set accordingly based on actual usage requirements.

[0045] In some embodiments, before performing the tapered surface machining step, the outer diameter of the annular blank is adjusted to the desired size range by cutting.

[0046] Understandably, after obtaining the annular blank of the sealing ring 10 through the blank preparation step, the annular blank is first rough-machined. By cutting, the outer diameter of the annular blank is adjusted to the required size range. This helps to reduce the machining amount when machining the sealing surface 11, reduce machine tool occupancy time, and alleviate the machine tool process pressure. In practical applications, the cutting speed Vc2 used for rough machining can be 200m / min, the feed rate fn2 can be 0.15mm / rev, and the depth of cut ap2 can be 1.5mm. The specific outer diameter range of the annular blank can be set according to the actual usage requirements.

[0047] In some embodiments, in the blank preparation step, after the multilayer metal sheets and multilayer graphite sheets are alternately stacked and bonded, the alternately stacked multilayer metal sheets and graphite sheets are pressed into shape, and the pressing ratio d is 1.03 to 1.05, where: d = t1 / t2, t1 is the thickness dimension before pressing, and t2 is the thickness dimension after pressing.

[0048] Understandably, in the blank preparation step, multiple layers of metal sheets and multiple layers of graphite sheets are first alternately stacked and bonded together. Then, the alternately stacked multiple layers of metal sheets and graphite sheets are pressed into shape, so that the metal sheets and graphite sheets are tightly bonded together without gaps, which is beneficial to enhance the density of the graphite layer during subsequent processing.

[0049] In this embodiment, the number of metal layers m is 4 and the number of graphite layers n is 3. That is, in the blank preparation step, four metal sheets and three graphite sheets are alternately stacked and bonded together. The thickness of each metal sheet and each graphite sheet is 1 mm, and the thickness after stacking and bonding is about 7 mm. Then, it is pressed and formed, and the thickness after pressing is 6.7 mm. The pressing ratio d is about 1.045.

[0050] In practical applications, the compression ratio d can also be 1.03 or 1.05, which can be set according to the actual needs of use.

[0051] In some embodiments, the special clamp 100 further includes a tensioning seat 150, the upper side of which is rotatably connected to the lower side of the auxiliary butterfly plate 130, and the lower side of which is detachably connected to the positioning seat 120 by bolts.

[0052] Understandably, such as Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, based on the vertical position of the inclined plate 110, the upper side of the inclined plate 110 is an inclined surface. The positioning seat 120 is inclined on the inclined plate 110 and can move relative to it to adjust its position. The positioning seat 120 is provided with a support part 121 to increase the support height of the auxiliary butterfly plate 130 and reserve space for the cutting tool. The upper side of the auxiliary butterfly plate 130 is provided with a positioning step 131 and a support surface 132. The annular blank is placed on the auxiliary butterfly plate 130. The cone angle corresponding to the machining sealing surface 11 is α. The upper side of the tensioning seat 150 is provided with a first connecting hole 151. Its lower side is detachably connected to the positioning seat 120 by bolts. A connecting shaft 152 is provided between the tensioning seat 150 and the auxiliary butterfly plate 130. The lower side of the auxiliary butterfly plate 130 is provided with a second connecting hole 133. The connecting shaft 152 passes through the first connecting hole 151 and the second connecting hole 133, so that the tensioning seat 150 and the auxiliary butterfly plate 130 are rotatably connected. In use, the auxiliary butterfly plate 130 can be tightened and fixed to the positioning seat 120 by tightening the bolts between the tensioning seat 150 and the positioning seat 120. Loosening the bolts allows for adjustment of the auxiliary butterfly plate 130. The auxiliary butterfly plate 130 can be disassembled by removing the tensioning seat 150 or the connecting shaft 152. Its structure is simple and easy to use. In practical applications, in addition to the above structure, the auxiliary butterfly plate 130 can also be detachably connected to the positioning seat 120 via a snap-fit ​​structure or other threaded structure, depending on the specific application requirements.

[0053] The sealing ring 10 according to the second aspect of the present invention is manufactured using the processing technology of the triple eccentric multi-layer butterfly valve sealing ring according to the first aspect of the present invention.

[0054] According to the embodiment of the present invention, the sealing ring 10, by adopting the above-mentioned processing technology of the triple eccentric multi-layer butterfly valve special sealing ring, can reduce the possibility of deformation of the sealing ring 10 and the occurrence of problems such as burrs and flanging on the sealing surface 11, and ensure the sealing performance of the sealing ring 10.

[0055] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A processing technology for a sealing ring specifically designed for triple-eccentric multi-layer butterfly valves, characterized in that, Includes the following steps: To prepare a blank, multiple layers of metal sheets and multiple layers of graphite sheets are alternately stacked and bonded together. The ring-shaped blank of the sealing ring is obtained by cutting. The ring-shaped blank has multiple alternating metal layers and graphite layers. The metal layers and graphite layers satisfy the relationship: n≥2, m=n+1, where m is the number of metal layers and n is the number of graphite layers. For tapered surface machining, a special fixture is used. This fixture includes an inclined plate, a positioning seat, an auxiliary disc plate, and a pressure ring. The positioning seat is inclined on the inclined plate and its position can be adjusted relative to the inclined plate. The positioning seat has a support portion. The auxiliary disc plate has a positioning step and a support surface. An annular blank is placed on the auxiliary disc plate, so that the inner hole of the annular blank mates with the positioning step, and the positioning surface of the annular blank is in contact with the support surface. The pressure ring is detachably connected to the auxiliary disc plate to... The supporting surface is used to clamp and fix the annular blank. The auxiliary butterfly plate is detachably set on the supporting part. The machine tool drives the inclined plate to rotate and uses a cutting tool to perform two passes of cutting on the annular blank on the special fixture to process a sealing ring with an inclined conical sealing surface. In the first pass of cutting, the direction of movement of the cutting tool is from the tip of the cone corresponding to the sealing surface to the bottom of the cone. In the second pass of cutting, the direction of movement of the cutting tool is from the bottom of the cone corresponding to the sealing surface to the tip.

2. The processing technology of the special sealing ring for triple eccentric multi-layer butterfly valve according to claim 1, characterized in that, In the conical surface machining step, the cutting tool used has a tip radius R ≤ 0.2 mm.

3. The processing technology of the special sealing ring for triple eccentric multi-layer butterfly valve according to claim 1, characterized in that, In the tapered surface machining step, the cutting tools used are PCD diamond tools or CVD coated carbide tools.

4. The processing technology of the special sealing ring for triple eccentric multi-layer butterfly valve according to claim 1, characterized in that, In the conical surface machining process, a machining allowance of 0.1 to 0.2 mm needs to be reserved for the second cutting step during the first cutting pass.

5. The processing technology of the special sealing ring for triple eccentric multi-layer butterfly valve according to claim 4, characterized in that, In the conical surface machining step, the parameters used for the two cutting passes are configured as follows: 80m / min≤Vc1≤120m / min, 0.05mm / rev≤fn1≤0.1mm / rev, ap1≤0.2mm, where Vc1 is the cutting speed, fn1 is the feed rate, and ap1 is the depth of cut.

6. The processing technology of the special sealing ring for triple eccentric multi-layer butterfly valve according to claim 1, characterized in that, In the conical surface machining step, a clearance amount b needs to be reserved between the outer edge of the positioning surface of the annular blank and the outer edge of the supporting surface. The clearance amount b is 0.5 to 0.6 mm.

7. The processing technology of the special sealing ring for triple eccentric multi-layer butterfly valve according to claim 1, characterized in that, Before performing the tapered surface machining step, the outer diameter of the annular blank is adjusted to the required size range by cutting.

8. The processing technology of the special sealing ring for triple eccentric multi-layer butterfly valve according to claim 1, characterized in that, In the blank preparation step, after alternatingly stacking and bonding multiple layers of metal sheets and multiple layers of graphite sheets, the alternatingly stacked multiple layers of metal sheets and graphite sheets are pressed into shape. The pressing ratio d is 1.03 to 1.05, where: d = t1 / t2, t1 is the thickness dimension before pressing, and t2 is the thickness dimension after pressing.

9. The processing technology of the special sealing ring for triple eccentric multi-layer butterfly valve according to claim 1, characterized in that, The special clamp also includes a tensioning seat, the upper side of which is rotatably connected to the lower side of the auxiliary butterfly plate, and the lower side of which is detachably connected to the positioning seat by bolts.

10. A sealing ring, characterized in that, The sealing ring for a triple-eccentric multi-layer butterfly valve is manufactured using the processing technology described in any one of claims 1 to 9.

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