A sealing ring grinding fixture and grinding method

Abstract

The present invention belongs to the field of mechanical processing, and discloses a sealing ring grinding fixture and a grinding method, including an upper positioning plate and a lower positioning plate; a circular arc groove is provided on one side of the upper positioning plate, and a circular arc protrusion is provided on one side of the lower positioning plate; when in use, the surface of the circular arc groove is in close contact with the outer surface of the sealing ring to be ground, and the surface of the circular arc protrusion is in close contact with the inner surface of the sealing ring to be ground, and when grinding, the sealing ring to be ground is clamped and fixed on a grinding machine by the sealing ring grinding fixture, and then the opening of the sealing ring to be ground is filled with grinding paste, and after the grinding paste solidifies, the sealing ring to be ground is ground by a grinding wheel. The sealing ring to be ground is stably clamped, and the sealing ring to be ground is ensured to be uniformly stressed during grinding, and the clamping operation is convenient and simple, which effectively reduces the scrap rate of the sealing ring and greatly reduces the processing cost.

Description

Technical Field

[0001] The invention belongs to the field of mechanical processing and relates to a sealing expansion ring grinding fixture and a grinding method. Background Art

[0002] At present, in the design of aircraft engines and gas turbines, the structure of the sealing ring is generally an open elastic ring, which is installed on the rotor journal when in use. The sealing ring is cut into a whole circle and has elasticity. Before installing the rotor, the sealing ring is placed in the ring groove. The sealing ring is in an open state and its outer diameter is larger than the inner diameter of the sealing sleeve. It plays a sealing role in the lubricating oil cavity during operation.

[0003] The blank of the sealing ring is generally cast iron, which is cast from CrMo material. This material is relatively brittle, which makes the sealing ring very easy to break even during transit transportation and clamping in a non-processing state. Especially after the circular ring is cut and opened, the parts are deformed near the opening and the positioning surface is uneven, which can cause the positioning to be unreliable during grinding, and then the parts break and become scrapped during the grinding process of the grinding wheel. At the same time, the deformation of each sealing ring after the incision is also different, resulting in inconsistent clamping states of each sealing ring during processing. The existing surface grinding method is to simply adsorb the sealing ring on the workbench for processing, which has a high scrap rate and requires a large amount of raw materials, which in turn causes waste and affects production progress. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art, that is, the high scrap rate during the grinding of the existing sealing ring, which leads to high processing costs, and to provide a sealing ring grinding fixture and a grinding method.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a sealing ring grinding fixture, comprising an upper positioning plate and a lower positioning plate; a circular arc groove is provided on one side of the upper positioning plate, and a circular arc protrusion is provided on one side of the lower positioning plate; when in use, the surface of the circular arc groove is in close contact with the outer surface of the sealing ring to be ground, and the surface of the circular arc protrusion is in close contact with the inner surface of the sealing ring to be ground; the radius of the circular arc groove R1 = 0.9 / 2π ~ 1.2 / 2π, the depth of the circular arc groove H1 = 1 / 3R1 ~ 1 / 4R1, and the thickness of the circular arc groove The degree δ1 is 0.15 to 0.3 mm smaller than the final thickness S of the sealing ring to be ground; the radius R2 of the arc-shaped protrusion is 0.8 / 2π to 1.1 / 2π, the height H2 of the arc-shaped protrusion is 1 / 3R2 to 1 / 4R2, and the thickness δ2 of the arc-shaped protrusion is 0.15 to 0.3 mm smaller than the final thickness S of the sealing ring to be ground; wherein D is the outer diameter of the sealing ring before opening, L is the opening width of the sealing ring to be ground, and d is the inner diameter of the sealing ring before opening.

[0007] Optionally, the upper positioning plate and the lower positioning plate are both made of No. 45 steel.

[0008] Optionally, the contour of the arc-shaped protrusion of the arc-shaped groove is ≤0.2mm, and the flatness of the surface of the upper positioning plate away from the arc-shaped groove and the surface of the lower positioning plate away from the arc-shaped protrusion are ≤0.2mm.

[0009] The second aspect of the present invention provides a sealing ring grinding method based on the above-mentioned sealing ring grinding fixture, comprising: clamping the sealing ring to be ground by the sealing ring grinding fixture and fixing it on a grinding machine; filling grinding paste into the opening of the sealing ring to be ground, and after the grinding paste solidifies, grinding the sealing ring to be ground by a grinding wheel.

[0010] Optionally, clamping the sealing ring to be ground by means of a sealing ring grinding fixture includes: fitting the surface of the arc-shaped groove with the outer surface of the opening of the sealing ring to be ground, and there is at least one contact point between the surface of the arc-shaped groove and the outer surface of the opening of the sealing ring to be ground, and fitting the surface of the arc-shaped protrusion with the inner surface of the opening of the sealing ring to be ground, and there is at least one contact point between the surface of the arc-shaped protrusion and the inner surface of the opening of the sealing ring to be ground.

[0011] Optionally, when the sealing expansion ring to be ground is clamped and fixed on the grinding machine by the sealing expansion ring grinding fixture, the gap between the positioning surface of the sealing expansion ring to be ground and the worktable surface of the grinding machine is not greater than 0.02 mm.

[0012] Optionally, when the sealing expansion ring to be ground is clamped and fixed on the grinding machine by the sealing expansion ring grinding fixture, the opening direction of the opening of the sealing expansion ring to be ground is the same as the movement direction of the grinding wheel.

[0013] Optionally, the grinding wheel is a white corundum grinding wheel.

[0014] Optionally, when the sealing ring to be ground is ground by the grinding wheel, the grinding is started from the edge of the sealing ring to be ground away from the opening.

[0015] Optionally, when the sealing ring to be ground is ground by the grinding wheel, rough grinding is first performed to a preset roughness and then fine grinding is performed, wherein the cutting depth of each layer of the grinding wheel during rough grinding is progressively increased by 0.015 to 0.02 mm, and the cutting depth of each layer of the grinding wheel during fine grinding is progressively increased by 0.005 to 0.01 mm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The sealing expansion ring grinding fixture of the present invention realizes stable clamping of the sealing expansion ring to be ground by arranging an arc-shaped groove on the upper positioning plate and an arc-shaped protrusion on the lower positioning plate, and limits the specific structural size requirements of the arc-shaped groove and the arc-shaped protrusion, thereby ensuring that the sealing expansion ring to be ground is evenly stressed during grinding, and the clamping operation is convenient and simple, avoiding the problem of easy breakage of the sealing expansion ring to be ground due to uneven force during grinding, effectively reducing the scrap rate of the sealing expansion ring, and improving the processing efficiency of the sealing expansion ring, meeting the process requirements of open ring surface grinding of brittle materials, and can be applied to the end face grinding of various types of open sealing expansion rings, greatly reducing the processing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the sealing expansion ring to be ground according to an embodiment of the present invention.

[0019] Figure 2 It is a side view of the sealing expansion ring structure to be ground according to an embodiment of the present invention.

[0020] Figure 3 This is a front view of the upper positioning plate according to an embodiment of the present invention.

[0021] Figure 4 This is a front view of the lower positioning plate according to an embodiment of the present invention.

[0022] Figure 5 It is a schematic diagram of the clamping state of the sealing expansion ring grinding fixture according to an embodiment of the present invention.

[0023] Among them: 1-upper positioning plate; 2-lower positioning plate; 3-sealing ring to be ground; 4-grinding paste. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0027] See also Figures 1 to 5 In one embodiment of the present invention, a sealing ring grinding fixture is provided, which can be used for processing open sealing rings of brittle materials such as aircraft engines and gas turbines to solve the problems of easy breakage of sealing rings during grinding and high processing scrap rate. It can greatly reduce the scrap rate of sealing rings, improve the processing efficiency of open sealing rings, and meet the process requirements of surface grinding of open rings of brittle materials.

[0028] Specifically, the sealing expansion ring grinding fixture includes an upper positioning plate 1 and a lower positioning plate 2; an arc-shaped groove is provided on one side of the upper positioning plate 1, and an arc-shaped protrusion is provided on one side of the lower positioning plate 2; when in use, the surface of the arc-shaped groove is in close contact with the outer surface of the sealing expansion ring 3 to be ground, and the surface of the arc-shaped protrusion is in close contact with the inner surface of the sealing expansion ring 3 to be ground; wherein, the radius of the arc-shaped groove R1=0.9(D+L) / 2π~1.2(D+L) / 2π, the depth of the arc-shaped groove H1=1 / 3R1~1 / 4R1, and the thickness δ1 of the arc-shaped groove is greater than that of the sealing expansion ring to be ground. The final thickness S of the ring 3 is 0.15 to 0.3 mm smaller; the radius of the arc-shaped protrusion R2 is 0.8 (d + L) / 2π to 1.1 (d + L) / 2π, the height of the arc-shaped protrusion H2 is 1 / 3R2 to 1 / 4R2, and the thickness δ2 of the arc-shaped protrusion is 0.15 to 0.3 mm smaller than the final thickness S of the sealing ring 3 to be ground; wherein, D is the outer diameter of the sealing ring 3 before opening to be ground, L is the opening width of the sealing ring 3 to be ground, S is the final thickness of the sealing ring 3 to be ground, and d is the inner diameter of the sealing ring 3 before opening to be ground.

[0029] In a possible implementation, in order to ensure the clamping quality of the workpiece in the grinder and reduce the cost, the upper positioning plate 1 and the lower positioning plate 2 are both made of 45 steel with good rigidity and magnetic attraction, which can prevent the problem of unreliable positioning of the sealing ring 3 to be ground due to extrusion, deformation and other factors during grinding.

[0030] At the same time, after the opening of the sealing ring 3 to be ground is cut, it is heat treated and shaped to keep a certain opening size. At this time, the sealing ring 3 to be ground has been deformed into a non-standard circular ring, which is approximately elliptical. Since the deformation of the sealing ring 3 to be ground is uncertain at this time, in order to facilitate the production of the upper positioning plate 1 and the lower positioning plate 2, the arc-shaped groove and the arc-shaped protrusion can be designed as a standard circle. In actual clamping applications, the surfaces of the arc-shaped groove and the arc-shaped protrusion only need to be partially in contact with the inner and outer surfaces of the sealing ring 3 to meet the processing requirements. The thickness of the upper positioning plate 1 and the lower positioning plate 2 must be smaller than the final thickness of the workpiece to prevent grinding to the tooling surface during grinding, and there must be as much thickness and workpiece positioning as possible.

[0031] In a possible implementation, in order to ensure the fit between the upper positioning plate 1 and the lower positioning plate 2 and the inner and outer circles of the sealing ring 3 to be ground, the contour of the arc-shaped protrusion of the arc-shaped groove needs to meet certain requirements. In this implementation, the contour of the arc-shaped protrusion of the arc-shaped groove is ≤0.2mm.

[0032] At the same time, in order to ensure that the upper positioning plate 1 and the lower positioning plate 2 fit tightly against the workbench and prevent the sealing ring 3 to be ground from breaking due to unbalanced force during processing, the flatness of the surface of the upper positioning plate 1 away from the arc-shaped groove and the surface of the lower positioning plate 2 away from the arc-shaped protrusion are both ≤0.2mm.

[0033] To sum up, the sealing ring grinding fixture of the present invention realizes stable clamping of the sealing ring 3 to be ground by arranging an arc-shaped groove on the upper positioning plate 1 and an arc-shaped protrusion on the lower positioning plate 2, and limiting the specific structural size requirements of the arc-shaped groove and the arc-shaped protrusion, thereby ensuring that the sealing ring 3 to be ground is evenly stressed during grinding, and the clamping operation is convenient and simple, avoiding the problem of easy breakage of the sealing ring 3 to be ground due to uneven force during grinding, effectively reducing the scrap rate of the sealing ring, and improving the processing efficiency of the sealing ring, meeting the process requirements of open ring surface grinding of brittle materials, and can be applied to the end face grinding of various types of open sealing rings, greatly reducing the processing cost.

[0034] In yet another embodiment of the present invention, a sealing expansion ring grinding method is provided, which is implemented based on the above-mentioned sealing expansion ring grinding fixture to further reduce the damage rate of the sealing expansion ring during grinding.

[0035] Specifically, the sealing ring grinding method includes the following steps: clamping the sealing ring 3 to be ground by a sealing ring grinding fixture and fixing it on a grinding machine; filling the opening of the sealing ring 3 to be ground with grinding paste 4, and after the grinding paste 4 solidifies, grinding the sealing ring 3 to be ground by a grinding wheel.

[0036] Optionally, by selecting the grinding surface, single-sided processing or double-sided processing of the sealing expansion ring 3 to be ground can be performed.

[0037] In a possible embodiment, clamping the sealing ring 3 to be ground by a sealing ring grinding fixture includes: fitting the surface of the arc-shaped groove with the outer surface of the opening of the sealing ring 3 to be ground, and there is at least one contact point between the surface of the arc-shaped groove and the outer surface of the opening of the sealing ring 3 to be ground, and fitting the surface of the arc-shaped protrusion with the inner surface of the opening of the sealing ring 3 to be ground, and there is at least one contact point between the surface of the arc-shaped protrusion and the inner surface of the opening of the sealing ring 3 to be ground.

[0038] In a possible implementation manner, when the sealing expansion ring 3 to be ground is clamped and fixed on the grinding machine by the sealing expansion ring grinding fixture, the gap between the positioning surface of the sealing expansion ring 3 to be ground and the worktable surface of the grinding machine is not greater than 0.02 mm.

[0039] Specifically, after the sealing expansion ring 3 to be ground and the sealing expansion ring grinding fixture are fixed on the grinding machine, use a feeler gauge to check the fit between the positioning surface of the sealing expansion ring 3 to be ground and the worktable surface of the grinding machine. If the full circle of 0.02mm feeler gauge does not pass, it is considered qualified, otherwise it is considered unqualified. If it is unqualified, re-clamp it.

[0040] In a possible implementation manner, when the sealing expansion ring 3 to be ground is clamped and fixed on the grinding machine by the sealing expansion ring grinding fixture, the opening direction of the opening of the sealing expansion ring 3 to be ground is the same as the moving direction of the grinding wheel.

[0041] Specifically, after the entire ring of the sealing expansion ring is cut, the opening area is most likely to warp and deform. After clamping and positioning, the area where the positioning surface of the sealing expansion ring and the worktable surface of the grinder are most difficult to ensure is near the opening. Therefore, fractures are prone to occur near the opening during the grinding process. When the movement direction of the grinding wheel is the same as the opening direction of the opening of the sealing expansion ring, when the grinding wheel moves back and forth to impact the workpiece, the inner and outer upper positioning plates 1 and lower positioning plates 2 can play a better supporting role, thereby avoiding workpiece fracture.

[0042] In a possible implementation manner, the grinding wheel is a white corundum grinding wheel.

[0043] Specifically, the white corundum grinding wheel generates little heat during grinding and has little burn to the workpiece. It is well applied in grinding thin-walled parts and easily deformed parts, and has positive significance for the deformation control of sealing expansion rings. In addition, no harmful substances are produced during the grinding process, which is beneficial to operators and the surrounding environment.

[0044] In a possible implementation manner, when the sealing ring 3 to be ground is ground by a grinding wheel, the grinding starts from the edge of the sealing ring 3 to be ground away from the opening.

[0045] Specifically, after the entire ring of the sealing expansion ring is cut, the opening area is most likely to warp and deform. After clamping and positioning, the area where the positioning surface of the sealing expansion ring and the worktable surface of the grinder are most difficult to ensure is near the opening. Therefore, fractures are likely to occur near the opening during the grinding process. Grinding starts from the edge leaving the opening, and gradually the workpiece, the upper positioning plates 1 and the lower positioning plates 2 inside and outside, and the filler reach a stable state; secondly, the grinding path is also the shortest movement route.

[0046] In a possible implementation, when the sealing ring 3 to be ground is ground by a grinding wheel, rough grinding is first performed to a preset roughness and then fine grinding is performed, wherein the cutting depth of each layer of the grinding wheel during rough grinding is progressively increased by 0.015 to 0.02 mm, and the cutting depth of each layer of the grinding wheel during fine grinding is progressively increased by 0.005 to 0.01 mm.

[0047] Specifically, rough grinding with a larger grinding depth can improve grinding efficiency, reduce tool wear, and lay the foundation for fine grinding; fine grinding must ensure the final accuracy requirements. According to the final accuracy required by the workpiece, the grinding depth should be smaller and the speed should be slower.

[0048] In a possible implementation, a sealing ring of an aircraft engine is used as an example, wherein the material is annealed CrMo, the outer diameter D before opening is 152 mm, the inner diameter d before opening is 144 mm, the final thickness S is 2 mm, and the opening width L is 14 mm.

[0049] The sealing ring is placed on a grinding machine and clamped by a sealing ring grinding fixture. When the sealing ring is clamped, the opening direction is consistent with the movement direction of the grinding wheel. The upper positioning plate (1) and the lower positioning plate (2) are sucked tightly against the sealing ring to ensure that the positioning surface of the sealing ring fits the workbench for a full circle without a 0.02mm feeler gauge passing through.

[0050] In this embodiment, a French RIVELEC brand sample paste is selected, with a specification of 978 7003SRD6XL. After the sample A and B are mixed evenly at a ratio of 1:1, they are filled into the opening of the sealing ring, the sample paste is pressed and flattened to ensure that it does not exceed the end surface of the part, and the sample paste solidifies after waiting for 8 minutes. Compared with conventional fillers such as dental tray powder and paraffin, it has the advantages of fast solidification time, convenient and safe operation, moderate elasticity after solidification, and easy cleaning.

[0051] For the flat grinding end face of the clamped sealing ring, a white corundum grinding wheel is selected, and the grinding wheel model is 1-350×40×127WA / F46K 6V40 m / s. The grinding movement starts from the edge of the sealing ring away from the opening, first rough grinding to the preset roughness and then fine grinding. During rough grinding, the cutting depth of each layer of the grinding wheel is progressively 0.015mm, and the cutting depth of fine grinding is 0.008mm.

[0052] After repeated tests, compared with the existing grinding method, the scrap rate of the sealing expansion ring grinding method of the present invention has been significantly reduced.

[0053] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A sealing ring grinding fixture, characterized in that: It comprises an upper positioning plate (1) and a lower positioning plate (2); An arc-shaped groove is provided on one side of the upper positioning plate (1), and an arc-shaped protrusion is provided on one side of the lower positioning plate (2); When in use, the surface of the arc-shaped groove is in close contact with the outer surface of the sealing ring (3) to be ground, and the surface of the arc-shaped protrusion is in close contact with the inner surface of the sealing ring (3) to be ground; The radius of the arc-shaped groove R1=0.9(D+L) / 2π~1.2(D+L) / 2π, the depth of the arc-shaped groove H1=1 / 3R1~1 / 4R1, and the thickness δ1 of the arc-shaped groove is 0.15~0.3mm smaller than the final thickness S of the sealing ring (3) to be ground; The radius of the arc-shaped protrusion R2=0.8(d+L) / 2π~1.1(d+L) / 2π, the height of the arc-shaped protrusion H2=1 / 3R2~1 / 4R2, and the thickness δ2 of the arc-shaped protrusion is 0.15~0.3mm smaller than the final thickness S of the sealing ring (3) to be ground; Wherein, D is the outer diameter of the sealing ring (3) to be ground before opening, L is the opening width of the sealing ring (3) to be ground, and d is the inner diameter of the sealing ring (3) to be ground before opening; The sealing ring is an open sealing ring; The arc-shaped groove is a partial arc-shaped groove, and the arc-shaped protrusion is a partial arc-shaped protrusion; In actual clamping applications, the surfaces of the arc-shaped groove and the arc-shaped protrusion are in local point contact with the inner and outer surfaces of the sealing expansion ring (3) to be ground, thereby achieving local clamping.

2. The sealing ring grinding fixture according to claim 1 is characterized in that: The upper positioning plate (1) and the lower positioning plate (2) are both made of No. 45 steel.

3. The sealing ring grinding fixture according to claim 1 is characterized in that: The contour of the arc-shaped protrusion of the arc-shaped groove is ≤0.2 mm, and the flatness of the surface of the upper positioning plate (1) away from the arc-shaped groove and the surface of the lower positioning plate (2) away from the arc-shaped protrusion are both ≤0.2 mm.

4. A method for grinding a sealing ring based on the sealing ring grinding fixture according to any one of claims 1 to 3, characterized in that: include: The sealing ring (3) to be ground is clamped by a sealing ring grinding fixture and fixed on the grinding machine; The grinding paste (4) is filled into the opening of the sealing ring (3) to be ground, and after the grinding paste (4) solidifies, the sealing ring (3) to be ground is ground by a grinding wheel.

5. The sealing ring grinding method according to claim 4, characterized in that: The step of clamping the sealing ring (3) to be ground by means of a sealing ring grinding fixture comprises: The surface of the arc-shaped groove is fitted with the outer surface of the opening of the sealing ring (3) to be ground, and there is at least one contact point between the surface of the arc-shaped groove and the outer surface of the opening of the sealing ring (3) to be ground; the surface of the arc-shaped protrusion is fitted with the inner surface of the opening of the sealing ring (3) to be ground, and there is at least one contact point between the surface of the arc-shaped protrusion and the inner surface of the opening of the sealing ring (3) to be ground.

6. The method for grinding the sealing ring according to claim 4, characterized in that: When the sealing ring (3) to be ground is clamped and fixed on the grinding machine by the sealing ring grinding fixture, the gap between the positioning surface of the sealing ring (3) to be ground and the working table surface of the grinding machine is not greater than 0.02 mm.

7. The method for grinding the sealing ring according to claim 4, characterized in that: When the sealing ring (3) to be ground is clamped and fixed on the grinding machine by the sealing ring grinding fixture, the opening direction of the opening of the sealing ring (3) to be ground is the same as the moving direction of the grinding wheel.

8. The method for grinding the sealing ring according to claim 4, characterized in that: The grinding wheel is a white corundum grinding wheel.

9. The method for grinding the sealing ring according to claim 4, characterized in that: When the sealing ring (3) to be ground is ground by the grinding wheel, the grinding starts from the edge of the sealing ring (3) to be ground away from the opening.

10. The method for grinding the sealing ring according to claim 4, characterized in that: When the sealing ring (3) to be ground is ground by the grinding wheel, it is firstly rough ground to a preset roughness and then fine ground, wherein the cutting depth of each layer of the grinding wheel is progressively increased by 0.015 to 0.02 mm during rough grinding, and the cutting depth of each layer of the grinding wheel is progressively increased by 0.005 to 0.01 mm during fine grinding.

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