Grinding method for two parallel end faces of chromed annular workpiece

Abstract

The invention relates to the technical field of aero-engine part machining, in particular to a grinding method for two parallel end faces of a chromed workpiece, which comprises the following steps: S1, manufacturing a box body, and flatly grinding the bottom surface of the box body; s2, the box body is filled with a resin material which can be softened after being heated and can be solidified after being cooled; s3, placing the box body filled with the resin material on a high-precision marble platform for detection, and placing a digital display height gauge on the marble platform; s4, a blast burner is used for heating the box body to soften the resin material, then the annular workpiece with the two end faces plated with chromium is placed in an inner cavity of the box body, after the annular workpiece is horizontal, the resin material is cooled and solidified, and an integral component with the annular workpiece and the box body solidified together is obtained; s5, the integral component obtained in the step S4 is placed on a surface grinding machine, an electromagnetic chuck of the surface grinding machine adsorbs the bottom face of the box body, and flat grinding is conducted; and S6, the box body is heated through a blow lamp, the annular workpiece is taken out and turned over after the resin material is softened, and the steps S4 to S5 are repeated.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft engine parts processing, in particular to a method for grinding two parallel end surfaces of a workpiece after chrome plating. Background Art

[0002] like Figure 1 The overall structure and cross-sectional view of a ring-shaped workpiece in an aircraft engine. Before grinding the two parallel end faces of the ring-shaped workpiece, the flatness is 0.01. After chrome plating the two end faces, the two end faces need to be ground to achieve a flatness of 0.0012. An annular groove is provided on the outer peripheral surface of the ring-shaped workpiece, and the annular groove has been processed in place before chrome plating. The thickness of the ring-shaped workpiece is small, and the basic thickness dimension is only 5.745mm.

[0003] The existing grinding process uses a rectangular table surface grinder, and the electromagnetic chuck is used to absorb the annular workpiece for grinding. Specifically, the annular workpiece is absorbed on the workbench of the grinder, and the other end face is ground with the absorbed end face as the reference. The thickness uniformity of the annular workpiece after grinding by this grinding process is good, but it is easy to cause serious angle deviation between the end face and the two side faces of the annular groove, the end face runout deviation, the accuracy cannot be guaranteed, and the processing qualification rate is low.

[0004] The principle of out-of-tolerance Figure 2 As shown in the figure. Since the annular workpiece produces a deformation of about 0.02 during the process of electroplating chrome and low-temperature stress elimination, the existing deformation of the workpiece is flattened after adsorption by using the existing grinding process. After grinding the other side with one side as the reference, the wall thickness uniformity of the workpiece is better, but the existing deformation of the workpiece after grinding will produce Figure 2 Therefore, with the existing grinding process, the deformation of the annular workpiece during surface grinding cannot be eliminated, and the machining stress deformation caused by the grinding force is also adsorbed by the electromagnetic chuck in the subsequent processing, and the deformation cannot be eliminated, resulting in the above-mentioned out-of-tolerance problem after grinding the two end faces of the annular workpiece. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for grinding two parallel end faces of an annular workpiece after chrome plating, aiming to solve the above technical problems.

[0006] To achieve the above object, the present invention provides a method for grinding two parallel end surfaces of an annular workpiece after chrome plating, the steps comprising:

[0007] S1. Making a box body: The box body has an inner cavity with an open top, and the inner cavity diameter of the box body is larger than the outer diameter of the annular workpiece; the box body is made of a material that can be adsorbed by the electromagnetic chuck of the surface grinder; the bottom surface of the box body is flat-grinded 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 end surfaces of the annular workpiece after chrome plating;

[0008] S2, filling the box body with a resin material that can be softened after heating and can be solidified after cooling;

[0009] S3, placing the box filled with resin material on a high-precision marble platform for testing, and placing a digital height gauge on the marble platform;

[0010] S4. Heat the box body with a blowtorch to soften the resin material, then place the annular workpiece with chrome-plated two end faces in the inner cavity of the box body, and 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 horizontal. If not, gently tap the annular workpiece to adjust its inclination angle so that the heights of various measuring points are consistent, and then wait for the resin material to cool and solidify to obtain an integral component in which the annular workpiece and the box body are solidified together;

[0011] S5, placing the whole component obtained in step S4 on a surface grinder, and using the electromagnetic chuck of the surface grinder to absorb the bottom surface of the box body; flat grinding one end surface of the annular workpiece to the size;

[0012] S6. After heating the box body with a blowtorch to soften the resin material, the annular workpiece is taken out and turned over. Steps S4 to S5 are repeated to complete the grinding of the two end faces of the annular workpiece.

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

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

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

[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 ≤0.001 mm, and the roughness does not exceed Ra0.05.

[0019] Preferably, the table top of the marble platform should be kept clean, and a clean silk cloth or cotton soaked in industrial alcohol or acetone is used to wipe the table top of the marble platform until there is no dirt on the silk cloth or cotton after wiping.

[0020] Preferably, in step S6, after the annular workpiece is taken out and turned over, step S4 is repeated to detect the height of the side surface of the annular groove using a digital height gauge, and the side surface detected before and after turning over is the same side surface.

[0021] Preferably, in step S4, after the annular workpiece and the box body are solidified together to form an integral component, the 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 not, repeat step S4.

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

[0023] (1) In the present invention, a resin material that can be softened after heating and solidified after cooling is filled in a box body, and the box body is placed on a high-precision marble platform, and a digital height gauge is arranged on the marble platform, thereby forming a device for flatness measurement and conversion. When in use, the flatness of the end face affected by chrome plating is measured and converted to the bottom surface of the box body. When grinding, the electromagnetic suction cup of the surface grinder adsorbs the bottom surface of the box body, and the annular workpiece can be flat-ground. This effectively overcomes the problem of the existing grinding technology that easily leads to serious angle deviation between the end face and the two side surfaces of the annular groove.

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

[0025] (3) In the present invention, during grinding, the bottom surface of the box body is sucked by the electromagnetic suction cup, thereby solving the problem that the flatness of the two ends of the annular workpiece is affected after chrome plating, and the problem of excessive tolerance caused by direct suction and grinding is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

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

[0028] Figure 2 The schematic diagram of the over-tolerance when grinding with direct adsorption;

[0029] Figure 3 It is a three-dimensional structural diagram of the annular workpiece and the box body;

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

[0031] Figure 5 This is a schematic diagram of a chrome-plated annular workpiece placed in a box filled with resin material for height measurement.

[0032] Explanation of the accompanying drawings: 1. Box body; 1a. Bottom of box body; 2. Annular workpiece; 2a. Annular groove; 3. Resin material; 4. Marble platform; 5. Digital height gauge. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the 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] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] Combination Figure 1As shown in the figure, it is the overall structure and cross-sectional view of a certain annular workpiece in an aircraft engine. Before the two parallel end faces of the annular workpiece 2 are ground, the flatness is 0.01. After the two end faces are chrome-plated, the two end faces need to be ground to achieve a flatness of 0.0012. An annular groove 2a is provided on the outer peripheral surface of the annular workpiece 2, and the annular groove 2a has been processed in place before chrome plating. The annular workpiece 2 has a small thickness, and the basic thickness dimension is only 5.745mm.

[0037] Embodiment 1:

[0038] Combination Figure 3 , Figure 4 As shown, a method for grinding two parallel end surfaces of a chrome-plated annular workpiece comprises the following steps:

[0039] S1. Manufacturing a box body 1: The box body 1 has an inner cavity with an open top, 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 adsorbed by the electromagnetic chuck of a surface grinder; the bottom surface 1a of the box body 1 is flat-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 end surfaces of the annular workpiece 2 after chrome plating, specifically, after the bottom surface 1a of the box body is flat-ground, the flatness is ≤0.001mm.

[0040] S2. Fill the box body 1 with a resin material 3 that can be softened after heating and can be solidified after cooling; specifically, the resin material 3 is a silicone resin that can be softened when heated to 300° C. to 400° C.

[0041] S3. Place the box body 1 filled with the resin material 3 on a high-precision marble platform 4 for testing, and place three digital height rulers 5 on the marble platform 4 at the same time.

[0042] S4, heat the box body 1 with a blowtorch to soften the resin material 3, then place the annular workpiece 2 with chrome-plated two end faces in the inner cavity of the box body 1, use the 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 judge whether the side is horizontal. Specifically, the digital height gauge 5 measures the upper side A of the annular groove 2a. When measuring, three digital height gauges 5 are evenly distributed in annular intervals of 120° and measure simultaneously. If it is not horizontal, gently tap the annular workpiece 2 to adjust its inclination angle so that the height of each measuring point is consistent, and then wait for the resin material 3 to cool and solidify, and obtain an integral component in which the annular workpiece 2 and the box body 1 are solidified. 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, so as to observe the reading changes of each digital height gauge 5 during the cooling and solidification process of the resin material 3, and judge whether the upper side A of the annular groove 2a is in a horizontal state; if it is not in a horizontal state, repeat step S4.

[0043] S5, placing the integral component obtained in step S4 on a surface grinder, and using the electromagnetic chuck of the surface grinder to absorb the bottom surface 1a of the box body; flat-grinding one end surface of the annular workpiece 2 to size.

[0044] S6. After heating the box body 1 with a blowtorch to soften the resin material 3, the annular workpiece 2 is taken out and turned over. Steps S4 to S5 are repeated to complete the grinding of the two end faces of the annular workpiece 2.

[0045] 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 ≤ 0.001 mm, and the roughness does not exceed Ra0.05. The use of a high-precision marble platform 4 in conjunction with the bottom surface of the box body 1 is conducive to ensuring the flat grinding accuracy of the end faces of the annular workpiece 2.

[0046] Furthermore, the surface of the marble platform 4 should be kept clean by using 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 silk cloth or cotton after wiping, so as to avoid impurities affecting the flat grinding accuracy.

[0047] Embodiment 2:

[0048] Combination Figure 3 , Figure 4 As shown, a method for grinding two parallel end surfaces of a chrome-plated annular workpiece comprises the following steps:

[0049] S1. Manufacturing a box body 1: The box body 1 has an inner cavity with an open top, 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 adsorbed by the electromagnetic chuck of a surface grinder; the bottom surface 1a of the box body 1 is flat-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 end surfaces of the annular workpiece 2 after chrome plating; specifically, after the bottom surface 1a of the box body is flat-ground, the flatness is ≤0.001mm.

[0050] S2. Fill the box body 1 with a resin material 3 that can be softened after heating and can be solidified after cooling; specifically, the resin material 3 is a silicone resin that can be softened when heated to 300° C. to 400° C.

[0051] S3, placing the box body 1 filled with the resin material 3 on a high-precision marble platform 4 for testing, and placing a digital height ruler 5 on the marble platform 4 at the same time.

[0052] S4. Use a blowtorch to heat the box body 1 to soften the resin material 3, then place the annular workpiece 2 with chrome-plated both end faces in the inner cavity of the box body 1, and 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 horizontal. If not, gently tap the annular workpiece 2 to adjust its inclination angle so that the heights of each measuring point are consistent, and then wait for the resin material 3 to cool and solidify to obtain an integral component in which the annular workpiece 2 and the box body 1 are solidified together.

[0053] S5, placing the integral component obtained in step S4 on a surface grinder, and using the electromagnetic chuck of the surface grinder to absorb the bottom surface 1a of the box body; flat-grinding one end surface of the annular workpiece 2 to size.

[0054] S6, after heating the box body 1 with a blowtorch to soften the resin material 3, the annular workpiece 2 is taken out and turned over, and steps S4 to S5 are repeated to complete the grinding of the two end faces of the annular workpiece 2. Specifically, after the annular workpiece 2 is taken out and turned over, step S4 is repeated to use the digital height gauge 5 to detect the height of the side of the annular groove 2a. The side detected before and after turning over is the same side. For example, if the A side is detected before turning over, the A side is also detected after turning over to ensure that the detection reference surfaces on both sides remain consistent.

[0055] In addition, in step S4, after the annular workpiece 2 and the box body 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, repeat step S4.

[0056] 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 ≤ 0.001 mm, and the roughness does not exceed Ra0.05. The use of a high-precision marble platform 4 in conjunction with the bottom surface of the box body 1 is conducive to ensuring the flat grinding accuracy of the end faces of the annular workpiece 2.

[0057] Furthermore, the surface of the marble platform 4 should be kept clean by using 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 silk cloth or cotton after wiping, so as to avoid impurities affecting the flat grinding accuracy.

[0058] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece, characterized in that the steps include: S1. Manufacturing a box body (1): the box body (1) has an inner cavity with an open top, 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 adsorbed by an electromagnetic chuck of a surface grinder; the bottom surface (1a) of the box body (1) is flat-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 end surfaces of the annular workpiece (2) after chrome plating; S2, filling the box body (1) with a resin material (3) that can be softened after heating and can be solidified after cooling; S3, placing the box body (1) filled with the resin material (3) on a high-precision marble platform (4) for testing, and placing a digital height gauge (5) on the marble platform (4); S4, using a blowtorch to heat the box body (1) to soften the resin material (3), then placing the annular workpiece (2) with chrome-plated two end faces in the inner cavity of the box body (1), using 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 horizontal. If not, gently tap the annular workpiece (2) to adjust its inclination angle so that the heights of the various measuring points are consistent, and then wait for the resin material (3) to cool and solidify, so as to obtain an integral component in which the annular workpiece (2) and the box body (1) are solidified together; S5, placing the integral component obtained in step S4 on a surface grinder, and using the electromagnetic chuck of the surface grinder to absorb the bottom surface (1a) of the box body; flat grinding one end surface of the annular workpiece (2) to the size; S6. After the box body (1) is heated with a blowtorch to soften the resin material (3), the annular workpiece (2) is taken out and turned over. Steps S4 to S5 are repeated to complete the grinding of the two end faces of the annular workpiece (2).

2. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece as claimed in claim 1, characterized in that: The number of the digital height gauges (5) is three. In step S4, when measuring the height of one side surface of the annular groove (2a), the three digital height gauges (5) are evenly distributed in a circle at intervals of 120°.

3. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece as claimed in claim 2, characterized in that: In the step S4, during the cooling and solidification of the resin material (3), the measuring heads of the three digital height gauges (5) are always supported on the upper side surface of the annular groove (2a), and the reading changes of each digital height gauge (5) after the resin material (3) is cooled and solidified are observed to determine whether the upper side surface of the annular groove (2a) is in a horizontal state; if it is not in a horizontal state, step S4 is repeated.

4. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece as claimed in claim 1, characterized in that: In the step S1, the bottom surface (1a) of the box body is flat-ground to a flatness of ≤0.001 mm.

5. The method for grinding two parallel end surfaces of a chrome-plated annular workpiece according to claim 1, characterized in that: In the step S2, the resin material (3) is a silicone resin that can be softened when heated to 300°C to 400°C.

6. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece as claimed in claim 1, 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. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece as claimed in claim 1, characterized in that: The flatness of the marble platform (4) is ≤0.001 mm, and the roughness does not exceed Ra0.

05.

8. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece as claimed in claim 1, characterized in that: The tabletop of the marble platform (4) should be kept clean by using a clean silk cloth or cotton soaked in industrial alcohol or acetone to wipe the tabletop of the marble platform (4) until there is no dirt on the silk cloth or cotton after wiping.

9. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece as claimed in claim 1, characterized in that: In step S6, after the annular workpiece (2) is taken out and turned over, step S4 is repeated to use a digital height gauge (5) to detect the height of the side surface of the annular groove (2a), and the side surface detected before and after turning over is the same side surface.

10. A method for grinding two parallel end surfaces of a chrome-plated annular workpiece as claimed in claim 1, characterized in that: In step S4, after the annular workpiece (2) and the box body (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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