A method for grinding two parallel end surfaces of annular workpiece after chrome plating

Abstract

This invention relates to the field of aero-engine component processing technology, and particularly to a grinding method for the two parallel end faces of a workpiece after chrome plating. The steps include: S1, fabricating a box and grinding the bottom surface of the box; S2, filling the box with a resin material that softens upon heating and solidifies upon cooling; S3, placing the box filled with resin material on a high-precision marble platform for inspection, and simultaneously placing a digital height gauge on the marble platform; S4, heating the box with a blowtorch to soften the resin material, then placing the annular workpiece with chrome-plated end faces into the inner cavity of the box, leveling it, and allowing the resin material to cool and solidify, obtaining an integral component where the annular workpiece and the box are solidified together; S5, placing the integral component obtained in step S4 on a surface grinder, with the electromagnetic chuck of the surface grinder adsorbing the bottom surface of the box for surface grinding; S6, heating the box with a blowtorch to soften the resin material, then removing the annular workpiece, flipping it over, and repeating steps S4 to S5.

Description

Technical Field

[0001] This invention relates to the field of aero-engine component processing technology, and in particular to a grinding method for the two parallel end faces of a workpiece after chromium plating. Background Technology

[0002] like Figure 1 This is a view of the overall structure and cross-section of a ring-shaped workpiece used in an aero-engine. Before grinding, the two parallel end faces of this ring-shaped workpiece have a flatness of 0.01. After chrome plating of both end faces, grinding is required to achieve a flatness of 0.0012. An annular groove is provided on the outer circumference of the ring-shaped workpiece; this groove was machined before chrome plating. The ring-shaped workpiece has a small thickness, with a basic thickness of only 5.745 mm.

[0003] Existing grinding processes use a rectangular table surface grinder, where annular workpieces are gripped by an electromagnetic chuck for grinding. Specifically, the annular workpiece is gripped on the grinder's worktable, and the other end face is ground using the gripped end face as a reference. This grinding process produces annular workpieces with good thickness uniformity, but it easily leads to significant deviations in the angle between the end face and the two sides of the annular groove, excessive end face runout, compromised accuracy, and a low machining pass rate.

[0004] The principle of out-of-tolerance is as follows: Figure 2 As shown. Due to the deformation of approximately 0.02 mm generated during the electroplating and low-temperature stress relief process of the ring-shaped workpiece, the existing deformation is flattened after grinding using the existing grinding process. After grinding the other side using one side as a reference, the workpiece wall thickness uniformity is good. However, the existing deformation of the workpiece after grinding will cause… Figure 2 As shown in the diagram. Therefore, using existing grinding processes, the deformation of the ring-shaped workpiece cannot be eliminated during surface grinding. The machining stress deformation caused by the grinding force is also absorbed by the electromagnetic chuck in subsequent machining, and the deformation cannot be eliminated either, resulting in the above-mentioned out-of-tolerance problem after grinding the two end faces of the ring-shaped workpiece. Summary of the Invention

[0005] The main objective of this invention is to propose a grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, in order to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, this invention proposes a grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, comprising the following steps:

[0007] S1. Making the box body: The box body has an open-top inner cavity, and the inner cavity diameter of the box body is larger than the outer diameter of the ring workpiece; the box body is made of a material that can be attracted by the electromagnetic chuck of the surface grinder; the bottom surface of the box body is ground flat so that the flatness of the bottom surface of the box body does not exceed the flatness required to be achieved by grinding the two ends of the ring workpiece after chrome plating.

[0008] S2. Fill the box with a resin material that can be softened by heating and solidified by cooling;

[0009] S3. Place the box filled with resin material on a high-precision marble platform for testing, and place a digital height gauge on the marble platform at the same time.

[0010] S4. Heat the box with a blowtorch to soften the resin material. Then place the chrome-plated annular workpiece on both ends into the inner cavity of the box. Use a digital height gauge to simultaneously measure the height of at least three points on one side of the annular groove of the annular workpiece and determine whether the side is level. If it is not level, gently tap the annular workpiece to adjust its tilt angle so that the height of each measurement point is consistent. Then wait for the resin material to cool and solidify to obtain an integral component where the annular workpiece and the box are solidified together.

[0011] S5. Place the overall component obtained in step S4 on a surface grinder, and let the electromagnetic chuck of the surface grinder adhere to the bottom surface of the box; grind one end face of the ring-shaped workpiece to the required size.

[0012] S6. After heating the box with a blowtorch to soften the resin material, take out the ring-shaped workpiece, turn it over, and repeat steps S4 to S5 to complete the grinding of the two end faces of the ring-shaped workpiece.

[0013] Preferably, the number of digital height gauges is three. In step S4, when measuring the height of one side of the annular groove, the three digital height gauges are evenly distributed in a ring at 120° intervals.

[0014] Preferably, in step S4, during the process of resin material cooling and solidification, the measuring heads of the three digital height gauges are always supported on the upper side of the annular groove, and the changes in the readings of each digital height gauge are observed after the resin material cools and solidifies to determine whether the upper side of the annular groove is in a horizontal state; if it is not in a horizontal state, step S4 is repeated.

[0015] Preferably, in step S1, after the bottom surface of the box is ground flat, the flatness is ≤0.001mm.

[0016] Preferably, in step S2, the resin material is a silicone resin that can be softened when heated to 300°C to 400°C.

[0017] Preferably, the flatness of the marble platform does not exceed the flatness required to be achieved by grinding the two end faces of the annular workpiece after chrome plating.

[0018] Preferably, the flatness of the marble platform is ≤0.001mm and the roughness is no more than Ra0.05.

[0019] Preferably, the surface of the marble platform should be kept clean. Use a clean silk cloth or cotton soaked in industrial alcohol or acetone to wipe the surface of the marble platform until the cloth or cotton is free of dirt after wiping.

[0020] Preferably, in step S6, after the annular workpiece is removed and flipped over, when step S4 is repeated to detect the height of the side of the annular groove using a digital height gauge, the side detected before and after flipping over is the same side.

[0021] Preferably, in step S4, after the annular workpiece and the box solidify together to form an integral component, a digital height gauge is used again to measure at least three points on the side of the annular groove to determine whether the side is horizontal. If it is not horizontal, step S4 is repeated.

[0022] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows:

[0023] (1) In this invention, a flatness measurement and conversion device is constructed by filling the box with a resin material that softens upon heating and solidifies upon cooling, placing the box on a high-precision marble platform, and simultaneously configuring a digital height gauge on the marble platform. In use, the flatness measurement of the end face affected by chrome plating is transferred to the bottom surface of the box. During grinding, the electromagnetic chuck of the surface grinder adheres to the bottom surface of the box, allowing for surface grinding of the annular workpiece. This effectively overcomes the problem in existing grinding technologies where the angle between the end face and the two sides of the annular groove easily exceeds the tolerance.

[0024] (2) The model method provided by the present invention is low in cost. After grinding, the silicone resin can be removed by hot melting and reused, which is economical.

[0025] (3) In this invention, during grinding, the bottom surface of the box is attracted by an electromagnetic chuck, thereby solving the problem that the flatness of the two ends of the ring workpiece is affected by chrome plating and the grinding is caused by direct attraction, resulting in out-of-tolerance. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is an overall structure and cross-sectional view of a ring-shaped workpiece in an aero-engine. The flatness in the figure is the flatness before chrome plating.

[0028] Figure 2 This is a schematic diagram illustrating the principle of out-of-tolerance grinding using direct adsorption.

[0029] Figure 3 A three-dimensional structural diagram of the ring-shaped workpiece and the box body;

[0030] Figure 4 A schematic diagram showing how the chromium layer affects the flatness of the two parallel end faces of a ring-shaped workpiece after chromium plating.

[0031] Figure 5 This is a schematic diagram showing the height measurement of a chrome-plated ring-shaped workpiece placed in a box containing resin material.

[0032] Explanation of reference numerals in the attached drawings: 1. Box body; 1a. Bottom surface of the box body; 2. Circular workpiece; 2a. Circular groove; 3. Resin material; 4. Marble platform; 5. Digital height gauge. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not 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 effort are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0036] Combination Figure 1The diagram shows the overall structure and cross-sectional view of a ring-shaped workpiece in an aero-engine. Before grinding, the two parallel end faces of the ring-shaped workpiece 2 have a flatness of 0.01. After chrome plating of both end faces, grinding is required to achieve a flatness of 0.0012. An annular groove 2a is provided on the outer circumferential surface of the ring-shaped workpiece 2, and this groove 2a was machined before chrome plating. The ring-shaped workpiece 2 has a small thickness, with a basic thickness of only 5.745 mm. Example

[0037] Combination Figure 3 , Figure 4 As shown, a grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating includes the following steps:

[0038] S1. Making box 1: The box 1 has an open-top inner cavity, and the inner cavity diameter of the box 1 is larger than the outer diameter of the annular workpiece 2; the box 1 is made of a material that can be attracted by the electromagnetic chuck of the surface grinder; the bottom surface 1a of the box 1 is surface ground so that the flatness of the bottom surface 1a does not exceed the flatness required to be achieved by grinding the two end faces of the annular workpiece 2 after chrome plating. Specifically, after surface grinding, the flatness of the bottom surface 1a is ≤0.001mm.

[0039] S2. Fill the box 1 with a resin material 3 that can be softened by heating and solidified by cooling; specifically, the resin material 3 is a silicone resin that can be softened when heated to 300℃~400℃.

[0040] S3. Place the box 1 filled with resin material 3 on the high-precision marble platform 4 for testing, and place three digital height gauges 5 on the marble platform 4.

[0041] S4. Heat the box 1 with a blowtorch to soften the resin material 3. Then, place the annular workpiece 2, with chrome-plated ends, into the inner cavity of the box 1. Use a digital height gauge 5 to simultaneously measure the height of at least three points on one side of the annular groove 2a of the annular workpiece 2, and determine whether the side is level. Specifically, the digital height gauge 5 measures the upper side A of the annular groove 2a. During the measurement, three digital height gauges 5 are evenly distributed in a ring at 120° intervals and measured simultaneously. If it is not level, gently tap the annular workpiece 2 to adjust its tilt angle so that the height of each measurement point is consistent. Then, wait for the resin material 3 to cool and solidify, resulting in an integral component where the annular workpiece 2 and the box 1 are solidified together. In addition, during the cooling and solidification process of the resin material 3, the measuring heads of the three digital height gauges 5 are always supported on the upper side A of the annular groove 2a to observe the changes in the readings of each digital height gauge 5 during the cooling and solidification process, and to determine whether the upper side A of the annular groove 2a is level. If it is not level, repeat step S4.

[0042] S5. Place the overall component obtained in step S4 on a surface grinder, and the electromagnetic chuck of the surface grinder adsorbs the bottom surface 1a of the box; grind one end face of the ring workpiece 2 to the required size.

[0043] S6. After heating the box 1 with a blowtorch to soften the resin material 3, take out the ring workpiece 2 and turn it over. Repeat steps S4 to S5 to complete the grinding of the two end faces of the ring workpiece 2.

[0044] In this embodiment, the flatness of the marble platform 4 does not exceed the flatness required for grinding the two end faces of the annular workpiece 2 after chrome plating. Specifically, the flatness of the marble platform 4 is ≤0.001mm, and the roughness does not exceed Ra0.05. Using a high-precision marble platform 4 to mate with the bottom surface of the box body 1 helps to ensure the flat grinding accuracy of the end face of the annular workpiece 2.

[0045] Furthermore, the surface of the marble platform 4 must be kept clean. Use a clean silk cloth or cotton soaked in industrial alcohol or acetone to wipe the surface of the marble platform 4 until the cloth or cotton is free of dirt. This is to avoid impurities affecting the flat grinding accuracy. Example

[0046] Combination Figure 3 , Figure 4 As shown, a grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating includes the following steps:

[0047] S1. Making box 1: The box 1 has an open-top inner cavity, and the inner cavity diameter of the box 1 is larger than the outer diameter of the annular workpiece 2; the box 1 is made of a material that can be attracted by the electromagnetic chuck of the surface grinder; the bottom surface 1a of the box 1 is surface ground so that the flatness of the bottom surface 1a does not exceed the flatness required to be achieved by grinding the two end faces of the annular workpiece 2 after chrome plating; specifically, after the bottom surface 1a of the box is surface ground, the flatness is ≤0.001mm.

[0048] S2. Fill the box 1 with a resin material 3 that can be softened by heating and solidified by cooling; specifically, the resin material 3 is a silicone resin that can be softened when heated to 300℃~400℃.

[0049] S3. Place the box 1 filled with resin material 3 on the high-precision marble platform 4 for testing, and at the same time place a digital height gauge 5 on the marble platform 4.

[0050] S4. Heat the box 1 with a blowtorch to soften the resin material 3. Then place the annular workpiece 2 with chrome-plated ends into the inner cavity of the box 1. Use a digital height gauge 5 to simultaneously measure the height of at least three points on one side of the annular groove 2a of the annular workpiece 2 and determine whether the side is level. If it is not level, gently tap the annular workpiece 2 to adjust its tilt angle so that the height of each measurement point is consistent. Then wait for the resin material 3 to cool and solidify to obtain an integral component where the annular workpiece 2 and the box 1 are solidified together.

[0051] S5. Place the overall component obtained in step S4 on a surface grinder, and the electromagnetic chuck of the surface grinder adsorbs the bottom surface 1a of the box; grind one end face of the ring workpiece 2 to the required size.

[0052] S6. After heating the box 1 with a blowtorch to soften the resin material 3, remove the annular workpiece 2 and flip it over. Repeat steps S4 to S5 to complete the grinding of the two end faces of the annular workpiece 2. Specifically, after removing and flipping the annular workpiece 2, when repeating step S4 and using the digital height gauge 5 to detect the height of the side of the annular groove 2a, the side detected before and after flipping is the same side. For example, if side A is detected before flipping, side A is also detected after flipping to ensure that the detection reference surfaces on both sides are consistent.

[0053] In addition, in step S4, after the annular workpiece 2 and the box 1 are solidified together to form an integral component, the digital height gauge 5 is used again to measure at least three points on the side of the annular groove 2a to determine whether the side is horizontal. If it is not horizontal, step S4 is repeated.

[0054] In this embodiment, the flatness of the marble platform 4 does not exceed the flatness required for grinding the two end faces of the annular workpiece 2 after chrome plating. Specifically, the flatness of the marble platform 4 is ≤0.001mm, and the roughness does not exceed Ra0.05. Using a high-precision marble platform 4 to mate with the bottom surface of the box body 1 helps to ensure the flat grinding accuracy of the end face of the annular workpiece 2.

[0055] Furthermore, the surface of the marble platform 4 must be kept clean. Use a clean silk cloth or cotton soaked in industrial alcohol or acetone to wipe the surface of the marble platform 4 until the cloth or cotton is free of dirt. This is to avoid impurities affecting the flat grinding accuracy.

[0056] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, characterized in that the steps include... include: S1. Making the box body (1): The box body (1) has an open-top inner cavity, and the inner cavity diameter of the box body (1) is larger than the outer diameter of the annular workpiece (2); The box body (1) is made of a material that can be attracted by the electromagnetic chuck of the surface grinder; The bottom surface (1a) of the box body (1) is ground so that the flatness of the bottom surface (1a) of the box body does not exceed the flatness required to be achieved by grinding the two ends of the annular workpiece (2) after chrome plating; S2. Fill the box (1) with a resin material (3) that can be softened by heating and solidified by cooling. S3. Place the box (1) filled with resin material (3) on the high-precision marble platform (4) for testing, and place a digital height gauge (5) on the marble platform (4). S4. Heat the box body (1) with a blowtorch to soften the resin material (3). Then place the ring workpiece (2) with chrome-plated ends into the inner cavity of the box body (1). Use a digital height gauge (5) to simultaneously measure the height of at least three points on one side of the annular groove (2a) of the ring workpiece (2) and determine whether the side is horizontal. If it is not horizontal, gently tap the ring workpiece (2) to adjust its tilt angle so that the height of each measurement point is consistent. Then wait for the resin material (3) to cool and solidify to obtain the overall component where the ring workpiece (2) and the box body (1) are solidified together. S5. Place the overall component obtained in step S4 on a surface grinder, and the electromagnetic chuck of the surface grinder adsorbs the bottom surface (1a) of the box; grind one end face of the ring workpiece (2) to the required size; S6. Heat the box (1) with a blowtorch to soften the resin material (3), then take out the ring workpiece (2) and turn it over. Repeat steps S4 to S5 to complete the grinding of the two end faces of the ring workpiece (2).

2. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 1, is characterized in that... The number of digital height gauges (5) is three. In step S4, when measuring the height of one side of the annular groove (2a), the three digital height gauges (5) are evenly distributed in a ring at a distance of 120°.

3. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 2, is characterized in that... In step S4, during the process of the resin material (3) cooling and solidifying, the measuring heads of the three digital height gauges (5) are always supported on the upper side of the annular groove (2a), and the changes in the readings of each digital height gauge (5) are observed after the resin material (3) cools and solidifies, to determine whether the upper side of the annular groove (2a) is in a horizontal state; if it is not in a horizontal state, step S4 is repeated.

4. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 1, is characterized in that... In step S1, after the bottom surface (1a) of the box is ground flat, the flatness is ≤0.001mm.

5. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 1, is characterized in that... In step S2, the resin material (3) is a silicone resin that can be softened when heated to 300°C to 400°C.

6. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 1, is characterized in that... The flatness of the marble platform (4) does not exceed the flatness required to be achieved by grinding the two end faces of the annular workpiece (2) after chrome plating.

7. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 1, is characterized in that... The flatness of the marble platform (4) is ≤0.001mm and the roughness is no more than Ra0.

05.

8. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 1, is characterized in that... The surface of the marble platform (4) should be kept clean. Use a clean silk cloth or cotton soaked in industrial alcohol or acetone to wipe the surface of the marble platform (4) until there is no dirt on the cloth or cotton after wiping.

9. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 1, is characterized in that... In step S6, after the annular workpiece (2) is taken out and flipped over, when step S4 is repeated and the height of the side of the annular groove (2a) is detected by the digital height gauge (5), the side detected before and after flipping over is the same side.

10. The grinding method for the two parallel end faces of a ring-shaped workpiece after chromium plating, as described in claim 1, is characterized in that... In step S4, after the annular workpiece (2) and the box (1) are solidified together to form an integral component, the digital height gauge (5) is used again to measure at least three points on the side of the annular groove (2a) to determine whether the side is horizontal. If it is not horizontal, step S4 is repeated.

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