Blade grinding device and automatic grinding method

Abstract

The invention relates to a blade grinding device and an automatic grinding method, and solves the problems of high labor intensity, low efficiency and poor consistency of a method for completely grinding weld beading manually. The driving wheel drives the abrasive belt to rotate so as to drive the contact wheel to rotate, the limiting wheels are arranged on the two sides of the contact wheel, the inner support and the outer support achieve radial positioning and relative movement of the limiting wheels through the gap C. The linear electric cylinder adjusts the telescopic distance of the limiting wheels through the inner support, and fine adjustment of the distance between the blade base body and the abrasive belt is achieved through adjustment. Therefore, the step allowance after weld beading polishing is adjustable and controllable, the distance adjusting function of the linear electric cylinder is integrated in the PLC, and automatic control is facilitated. And when the robot clamps the blade for grinding, the rigid contact wheel of the abrasive belt rotates to grind and remove the blade weld beading. The linear guide rail and the air cylinder achieve floating in the polishing process of the whole device, and even if the robot gives a large feeding amount, the blade cannot be damaged. The sliding block adjusts the idle wheel to move up and down, and tightness of the abrasive belt is adjustable. And the floating polishing device is fixed by the fixing seat.

Description

Technical Field

[0001] The present invention belongs to the field of aircraft engine blade repair, and specifically relates to a blade grinding device and an automatic grinding method, which are suitable for automatic subtractive grinding and repair in additive manufacturing such as compressor blade tip extension. Background Art

[0002] During the repair process of aircraft engine blades, additive manufacturing is often used to achieve local repair of faulty parts. Subtractive grinding of weld nodules is a necessary step in the additive manufacturing process. Currently, commonly used methods include five-axis machine tool adaptive processing, robot grinding, manual grinding, etc. Due to the base offset of the repaired blades and blade deformation, five-axis adaptive processing is difficult and inefficient. Especially for the processing of thin-walled compressor blades, in order to ensure that the base material is not damaged, the remaining steps exceeding 0.5mm need to be manually ground and polished after processing, and the overall subtractive grinding efficiency is extremely low; robot grinding generally uses a grinding wheel or abrasive belt to grind according to the blade trajectory. In order to avoid damaging the base material, weld nodules exceeding 0.3mm will also be retained for manual processing; the method of completely manually grinding weld nodules is labor-intensive, inefficient, and inconsistent, and does not meet the development needs of automated repair. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a post-weld grinding device and automatic grinding method. Specifically, it relates to a floating contact wheel grinding device with a limiting wheel. This device enables a robot to clamp a blade and quickly grind the weld nub along the blade profile trajectory. The limiting wheel ensures that the base material is not damaged during the grinding process while optimizing the step margin between the weld nub and the base material. The automatic grinding method, which combines the robot and this grinding device, increases post-weld grinding efficiency by more than three times, and the weld nub step margin can be controlled within 0.05 mm.

[0004] The present invention is achieved by the following technical solutions:

[0005] A blade grinding device includes a motor, a contact wheel 3, an abrasive belt 4, an idler wheel 5, a slider 6, a drive wheel 7, a limit wheel 13, an inner bracket 15, an outer bracket 16, a cylinder 8, a fixing seat 9, a linear guide rail 10 and a linear electric cylinder;

[0006] The motor drives the driving wheel 7 to rotate, and the driving wheel 7 drives the sanding belt 4 to rotate, thereby driving the contact wheel 3 to rotate. The contact wheel 3 is a rigid contact wheel, close to the blade to be polished, and the limiting wheels 13 are installed on both sides of the contact wheel 3. The contact wheel 3 and the motor that drives the driving wheel 7 are fixedly installed on the linear guide 10. The linear guide 10 is connected to the cylinder 8. The limiting wheel 13 is fixedly connected to the inner bracket 15. The inner bracket 15 is connected to the linear electric cylinder 11 and installed in the outer bracket 16. The linear electric cylinder 11 adjusts the telescopic distance of the limiting wheel 13 through the inner bracket 15. The adjustment distance is the gap A. The automatic control distance adjustment function of the linear electric cylinder 11 is integrated in the PLC. The inner bracket 15 and the outer bracket 16 are both installed on the linear guide 10. The inner bracket 15 and the outer bracket 16 have an adjustable gap C in the radial direction of the limiting wheel 13. The cylinder 8 is fixed to the fixed seat 9.

[0007] A slider 6 is also mounted on the linear guide rail 10 , an idler wheel 5 is mounted on the slider 6 , and the abrasive belt 4 passes through the idler wheel 5 .

[0008] The limiting wheel 13 adjusts the distance A to 2 mm.

[0009] A blade grinding device and automatic grinding method, comprising the following steps:

[0010] (1) Design a floating contact wheel grinding device with a limiting wheel;

[0011] (2) The robot clamps the blade tenon and is tested in conjunction with the grinding device. The robot motion trajectory is planned according to the theoretical model trajectory of the blade shape of the additive part. The sanding belt rotation is turned off during the initial debugging of the trajectory. After the program debugging is completed, the scrapped blade is selected for process testing. The grinding process is as follows: the robot clamps the blade tenon, and the weld nodule is pressed against the sanding belt and ground in a certain direction. A feed of 1mm to 5mm is given at the theoretical point where the blade base contacts the sanding belt. The blade is reciprocated for 3 to 10 times. When the weld nodule is removed to a certain extent, the blade base gradually contacts the limit wheel to achieve weld nodule allowance control.

[0012] (3) Detect the step allowance of the blade weld nodule after grinding, feedback and adjust the position of the limit wheel and the robot posture, detect the step allowance between the blade weld nodule and the substrate, and control the step allowance to be within 0.05mm by adjusting the position of the limit wheel. According to the change of the step difference on the blade profile, optimize the robot posture and keep the step thickness as consistent as possible;

[0013] (4) Belt grinding database test: test how many blades a single belt can complete grinding and number the blades, detect and record the step difference of each blade, repeat the test of the single belt data, and when the step difference is greater than 0.06mm, adjust the position of the limit wheel to compensate for the step difference, ensuring that the step allowance of each blade after grinding is controlled within 0.05mm, and record the position data of the limit wheel under the single belt;

[0014] (5) Design enough loading and unloading positions to realize unmanned automatic grinding. Design loading and unloading according to the number of polishing of a single belt. The number of blades loaded on the loading and unloading positions should at least ensure the number of grindings of a single belt. In this way, the automatic grinding process can realize unmanned grinding of a single belt. If multiple grinding devices are equipped, the number of loading and unloading positions can be further increased to increase the unmanned time.

[0015] The beneficial effects of the present invention are:

[0016] (1) A floating belt grinding device with adjustable step allowance for post-weld grinding is provided, which can control the step allowance after post-weld grinding within 0.05 mm without damaging the substrate.

[0017] (2) A method for automatic batch blade grinding is provided, which increases the efficiency of post-weld grinding by more than 3 times compared with traditional methods and is unmanned. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A front view of the robot and grinding device layout;

[0019] Figure 2 for Figure 1 Partial magnification of area H;

[0020] Figure 3 Provide a top view of the robot and grinding device layout;

[0021] Figure 4 for Figure 3 Partial magnification of area M;

[0022] In the figure, 1-robot; 2-blade; 3-contact wheel; 4-abrasive belt; 5-idler wheel; 6-slider; 7-driving wheel; 8-cylinder; 9-fixed seat; 10-linear guide; 11-linear electric cylinder; 12-blade weld nodule; 13-limiting wheel; 14-bearing; 15-inner bracket; 16-outer bracket. DETAILED DESCRIPTION

[0023] like Figure 1-4 As shown, a blade grinding device of the present invention includes a robot 1, a contact wheel 3, a grinding belt 4, an idler wheel 5, a slider 6, a driving wheel 7, a limiting wheel 13, an inner bracket 15, an outer bracket 16, a cylinder 8, a fixing seat 9, a linear guide rail 10 and a linear electric cylinder.

[0024] The motor drives the driving wheel 7 to rotate, and the driving wheel 7 drives the sanding belt 4 to rotate, thereby driving the contact wheel 3 to rotate. The contact wheel 3 is a rigid contact wheel with limit wheels 13 on both sides of the contact wheel. The limit wheels 13 can rotate freely during operation through bearings 14. Figure 1The belt 4 can be extended and retracted in the left and right directions, and two limiting wheels prevent it from straying. The inner bracket 15 and the outer bracket 16 achieve radial positioning and relative movement of the limiting wheel 13 through the gap C. The linear cylinder 11 adjusts the extension and retraction distance of the limiting wheel 13 via the inner bracket 15. The adjustment distance, namely gap A, is 2 mm. By adjusting gap A, the distance between the blade base and the sanding belt, namely gap B, can be fine-tuned, thereby achieving adjustable and controllable step margin after weld nodule grinding. The distance adjustment function of the linear cylinder 11 is integrated into the PLC for easy automated control. When the robot 1 clamps the blade 2 for grinding, the rigid contact wheel of the sanding belt rotates, grinding away the blade weld nodule 12. The linear guide 10 and cylinder 8 enable the entire device to float during the grinding process, preventing damage to the blade even if the robot applies a large feed rate. The slider 6 adjusts the up and down movement of the idler wheel 5 to achieve adjustable tightness of the sanding belt. The fixed seat 9 secures the floating grinding device.

[0025] Example:

[0026] The high-pressure compressor rotor blade of a certain type of aircraft engine is additively manufactured in the 4mm area near the blade tip. Post-weld grinding is completed by a robot in conjunction with a post-weld grinding device. The post-weld grinding device consists of a floating contact wheel device with a limiting wheel and an abrasive belt to achieve efficient and automatic grinding of the weld nodules of the additively manufactured blades.

[0027] The implementation steps of the grinding device and method are shown in steps (1) to (5).

[0028] (1) Design a floating contact wheel grinding device with a limiting wheel. The motor drives the driving wheel 7 to rotate, and the driving wheel 7 drives the sanding belt 4 to rotate, thereby driving the contact wheel 3 to rotate. The contact wheel 3 is a rigid contact wheel with limiting wheels 13 on both sides of the contact wheel. The limiting wheel 13 can rotate freely during operation through the bearing 14. Figure 1 The belt 4 can be extended and retracted in the left and right directions, and two limiting wheels prevent it from straying. The inner bracket 15 and the outer bracket 16 achieve radial positioning and relative movement of the limiting wheel 13 through the gap C. The linear cylinder 11 adjusts the extension and retraction distance of the limiting wheel 13 via the inner bracket 15. The adjustment distance, namely gap A, is 2 mm. By adjusting gap A, the distance between the blade base and the sanding belt, namely gap B, can be fine-tuned, thereby achieving adjustable and controllable step margin after weld nodule grinding. The distance adjustment function of the linear cylinder 11 is integrated into the PLC for easy automated control. When the robot 1 clamps the blade 2 for grinding, the rigid contact wheel of the sanding belt rotates, grinding away the blade weld nodule 12. The linear guide 10 and cylinder 8 enable the entire device to float during the grinding process, preventing damage to the blade even if the robot applies a large feed rate. The slider 6 adjusts the up and down movement of the idler wheel 5 to achieve adjustable tightness of the sanding belt. The fixed seat 9 secures the floating grinding device.

[0029] (2) Robot clamping blade and grinding device coordination test. The robot motion trajectory is planned according to the theoretical model trajectory of the blade shape of the additive part. The sanding belt rotation is turned off during the initial debugging of the trajectory. When the program debugging is completed, the scrapped blade is selected for process testing. The grinding process is as follows: the robot 1 clamps the blade 2 tenon, and the blade weld 12 is pressed against the sanding belt and ground in a certain direction. When the blade base contacts the sanding belt theoretical point ( Figure 2 A feed rate of 2mm to 4mm is applied to the blade at the middle grinding point, and reciprocating grinding is repeated 6 to 8 times. During the grinding process, when the blade weld overhang 12 is removed to a certain extent, the blade base gradually contacts the limiting wheel 13. At this point, continued reciprocating grinding will not damage the base, achieving control of the step difference between the blade base and the weld overhang. During the blade contact belt feed process, the contact wheel is subjected to force and moves via the linear guide 10. When the blade retracts, the cylinder 8 drives the contact wheel 3 to reset. The floating contact wheel device during the reciprocating grinding process protects the blade base.

[0030] (3) Detect the step allowance of the blade weld bead after grinding, and adjust the limit wheel position and robot posture as feedback. Detect the step difference between the test blade weld bead 12 and the base of blade 2. Control the step difference within 0.05mm by adjusting the limit wheel position. Repeat the grinding process for at least 10 blades to verify process stability. Detect the change in the step difference on the blade profile, optimize the robot posture, and keep the step thickness on the blade profile as consistent as possible.

[0031] (4) Belt grinding database test. Test a single belt to see how many blades it can grind and number the blades. Detect and record the step difference of each blade. Repeat the test of the single belt data. When the step difference is greater than 0.06mm, adjust the position of the limit wheel to compensate for the step difference and ensure that the step margin of each blade after grinding is controlled within 0.05mm. Record the position data of the lower limit wheel of the single belt. Grinding can be achieved at both ends of the belt, so the actual number of blades that can be grinded by a single belt is twice that of the single-side test, that is, 20 blades.

[0032]

[0033]

[0034] (5) Design sufficient loading and unloading positions to achieve unmanned automatic grinding. The grinding software system automatically adjusts the limit wheel position according to the grinding sequence. In this case, one robot is equipped with two grinding devices, and two sanding belts are loaded at a time. 40 blades can be polished in one clamping. The blade grinding cycle is about 3 minutes per blade, achieving 2 hours of unmanned operation.

[0035] The above-described grinding device and automated grinding method enable automated post-weld grinding of batches of blades without damaging the substrate, significantly reducing manual post-polishing workload. Before the improvement, the grinding cycle was 8 minutes per blade, with a residual step allowance of approximately 0.3 mm for post-polishing. After the improvement, the grinding cycle for a single blade was reduced to 3 minutes per blade, with a residual step allowance of 0.05 mm or less. Overall post-weld grinding efficiency has increased by more than three times.

Claims

1. A blade grinding device, characterized by: It includes a motor, a contact wheel (3), an abrasive belt (4), a driving wheel (7), a limiting wheel (13), an inner bracket (15), an outer bracket (16), a cylinder (8), a fixing seat (9), a linear guide rail (10) and a linear electric cylinder; The motor drives the driving wheel (7) to rotate, and the driving wheel (7) drives the grinding belt (4) to rotate, thereby driving the contact wheel (3) to rotate. The contact wheel (3) is a rigid contact wheel and is close to the blade to be polished. The limiting wheels (13) are installed on both sides of the contact wheel (3). The contact wheel (3) and the motor driving the driving wheel (7) are fixedly installed on the linear guide rail (10). The linear guide rail (10) is connected to the cylinder (8). The limiting wheel (13) is fixedly connected to the inner bracket (15). The inner bracket (15) is connected to the linear electric cylinder ( 11) is connected and installed in the outer bracket (16), the linear electric cylinder (11) adjusts the telescopic distance of the limiting wheel (13) through the inner bracket (15), and the adjustment distance is a gap A. The automatic control distance adjustment function of the linear electric cylinder (11) is integrated in the PLC. The inner bracket (15) and the outer bracket (16) are both installed on the linear guide rail (10). The inner bracket (15) and the outer bracket (16) have an adjustable gap C in the radial direction of the limiting wheel (13). The cylinder (8) is fixed to the fixed seat (9).

2. A blade grinding device according to claim 1, characterized in that: A slider (6) is also installed on the linear guide rail (10), an idler wheel (5) is installed on the slider (6), and the abrasive belt (4) passes through the idler wheel (5).

3. A blade grinding device according to claim 1, characterized in that: The regulating distance A of the limiting wheel (13) is 2 mm.

4. A blade grinding device and automatic grinding method, characterized by: The following steps are involved: (1) Designing a blade grinding device as described in any one of claims 1 to 3; (2) The robot clamps the blade tenon and is tested in conjunction with the grinding device. The robot motion trajectory is planned according to the theoretical model trajectory of the blade shape of the additive part. The sanding belt rotation is turned off during the initial debugging of the trajectory. After the program debugging is completed, the scrapped blade is selected for process testing. The grinding process is as follows: the robot clamps the blade tenon, and the weld nodule is pressed against the sanding belt and ground in a certain direction. A feed of 1mm to 5mm is given at the theoretical point where the blade base contacts the sanding belt. The blade is reciprocated for 3 to 10 times. When the weld nodule is removed to a certain extent, the blade base gradually contacts the limit wheel to achieve weld nodule allowance control. (3) Detect the step allowance of the blade weld nodule after grinding, feedback and adjust the position of the limit wheel and the robot posture, detect the step allowance between the blade weld nodule and the substrate, and control the step allowance to be within 0.05mm by adjusting the position of the limit wheel. According to the change of the step difference on the blade profile, optimize the robot posture and keep the step thickness as consistent as possible; (4) Belt grinding database test: test how many blades a single belt can complete grinding and number the blades, detect and record the step difference of each blade, repeat the test of the single belt data, and when the step difference is greater than 0.06mm, adjust the position of the limit wheel to compensate for the step difference, ensuring that the step allowance of each blade after grinding is controlled within 0.05mm, and record the position data of the limit wheel under the single belt; (5) Design enough loading and unloading positions to realize unmanned automatic grinding. Design loading and unloading according to the number of polishing of a single belt. The number of blades loaded on the loading and unloading positions should at least ensure the number of grindings of a single belt. In this way, the automatic grinding process can realize unmanned grinding of a single belt. If multiple grinding devices are equipped, the number of loading and unloading positions can be further increased to increase the unmanned time.

Images