A laser cutting fixture and method for a blade leading edge skin part

Abstract

This invention discloses a laser cutting fixture and method for a propeller blade leading edge skin part. The fixture includes a support, a positioning plate, a support plate, baffle bolts, and nuts. The positioning plate is mounted on the outermost boss of the support via bolts and nuts. Multiple support plates are mounted on the corresponding bosses of the support via bolts and nuts. Multiple baffles are mounted in corresponding slots on the support. The propeller blade leading edge skin part is mounted on each support plate of the fixture, with one side of the part aligned with the positioning plate. Based on the shape of the TB8 titanium alloy propeller blade leading edge skin part, it is mounted on each support plate of the fixture and positioned by the positioning plate. A positioning coordinate system is constructed in the CNC system of a multi-axis laser cutting machine using three mutually perpendicular planes of the fixture support. The assembly model of the fixture and the target part is imported, the cutting trajectory is planned, cutting is performed, and the part is removed.

Description

Technical Field

[0001] This invention belongs to the field of parts processing technology, and relates to a positioning device and method for laser cutting workpieces, specifically a fixture and method for laser cutting the shape of a propeller leading edge skin part with multiple notch features. Background Technology

[0002] The leading edge skin of a propeller blade protects the composite blade from damage caused by impacts from sand, gravel, and other foreign objects. The leading edge skin is formed by stamping thin metal sheets such as stainless steel or titanium alloy. However, after stamping, the part needs to be cut to remove excess material to achieve the desired shape and precise assembly with the propeller blade. The leading edge skin of the propeller blade involved in this invention has a complex shape, making it difficult to achieve efficient and precise cutting by manual shearing, machining, or wire EDM after stamping. A multi-axis laser cutting machine is required. In the laser cutting process for complex-shaped parts, clamping and positioning significantly affect cutting accuracy and efficiency. This invention proposes a fixture and method suitable for laser cutting of the leading edge skin of the propeller blade, enabling efficient and precise cutting. Summary of the Invention

[0003] The purpose of this invention is to improve the positioning accuracy and efficiency of laser cutting by proposing a laser cutting fixture and method for blade leading edge skin parts, thereby achieving efficient and precise cutting of blade leading edge skin parts with complex shapes.

[0004] A laser cutting fixture for blade leading edge skin parts includes: a support, a positioning plate, a support plate, baffle bolts, and nuts. The positioning plate is mounted on the outermost boss of the support via bolts and nuts. Multiple support plates are mounted on the bosses at corresponding positions on the support via bolts and nuts. Multiple baffles are mounted in corresponding slots on the support. The blade leading edge skin parts are mounted on the support plates of the fixture, with one side of the parts aligned with the positioning plate. Its application method is as follows:

[0005] Based on the shape of the TB8 titanium alloy blade leading edge skin part, a positioning plane and multiple support sections were selected. The laser cutting fixture support, positioning plate, support plates for each section, and baffles for each segment were designed and manufactured. The positioning plate and support plates were fixed to the support using bolts and nuts, and each baffle was inserted into its corresponding slot. The assembled laser cutting fixture was then fixed to the worktable of a multi-axis laser cutting machine. The blade leading edge skin part was mounted on each support plate of the fixture and positioned using the positioning plate. A positioning coordinate system was constructed within the CNC system of the multi-axis laser cutting machine using the three mutually perpendicular planes of the cutting fixture support. The assembly model of the fixture and the target part was imported, the cutting trajectory was planned, and cutting and part removal were performed. The process of part installation-laser cutting-part removal was repeated to cut other parts with the same shape.

[0006] Beneficial effects

[0007] This invention is applicable to the batch processing of blade leading edge skin parts with similar shape features, and can achieve efficient and precise laser cutting of the shape of blade leading edge skin parts. Attached Figure Description

[0008] Figure 1 A schematic diagram showing the shape of the blade leading edge skin part before cutting and the target shape;

[0009] Figure 2 A schematic diagram showing the division of the positioning plane and support section for the part;

[0010] Figure 3 This is a schematic diagram showing the support direction of the laser cutting fixture support.

[0011] Figure 4 Schematic diagram of a laser cutting fixture support design;

[0012] Figure 5 Schematic diagram of the positioning plate design;

[0013] Figure 6 Schematic diagram of a single support plate design;

[0014] Figure 7 This is a schematic diagram of the support plate design.

[0015] Figure 8 This is a schematic diagram of the baffle design.

[0016] Figure 9 This is a schematic diagram of the assembly of the laser cutting fixture and the blade leading edge skin parts.

[0017] In the figure, 1-outline before cutting, 2-target outline, 3-positioning plane, 4-11-eight supporting sections, 12-13-two outer surface boundary lines, 14-21-eight section lines, 22-23-two projections, 24-support, 25-positioning plate, 26-33-eight support plates, 34-42-nine baffles; x, y, and z represent three spatial coordinate axes. Detailed Implementation

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] A laser cutting fixture for blade leading edge skin parts includes a support 24, a positioning plate 25, eight support plates 26-33, baffle bolts, and nuts. The positioning plate 25 is mounted on the outermost boss of the support 24 via bolts and nuts. The eight support plates are mounted on the corresponding bosses of the support 24 via bolts and nuts. Nine baffles are installed in corresponding slots on the support 24. The blade leading edge skin parts are mounted on the support plates of the fixture, with one side of the parts aligned with the positioning plate. The specific application method is as follows:

[0020] 1. Division of part positioning plane and support cross-section plane

[0021] The blade leading edge skin is made of 0.5mm thick sheet metal. The pre-cut shape 1, target shape 2, and assembled shape are as follows: Figure 1 As shown. The cross-sectional shape of the target shape 2 of the part along the ridge line is approximately V-shaped, with different cross-sectional shapes and gradually twisting transitions in the opening direction. Several slender notches are evenly distributed on both sides of the ridge line. The original shape 1 and the target shape 2 of the blade leading edge skin part are assembled into a whole according to their corresponding positions.

[0022] like Figure 2 As shown, adjust the spatial position of the assembled skin parts so that the ridge line is basically aligned with the y-axis and the opening faces the z-axis. The part positioning plane 3 is perpendicular to the y-axis and tangent to the boundary line 12 of the outer surface of the skin part's shape 1 before cutting. Create eight support sections 4 to 11, which are parallel to the positioning plane 3. The first and second support sections 4 and 11 should be close to both ends of the target shape 2 of the part and not exceed the range of the target shape 2. The spacing between the support sections is basically the same and they should not intersect with the notches in the target shape 2 of the part. The eight support sections 4 to 11 intersect with the inner surface of the target shape 2 of the part to form eight section lines 14 to 21.

[0023] 2. Selection of support direction for laser cutting fixture support

[0024] like Figure 3 As shown, the combined blade leading edge skin part is projected onto the xz plane before cutting the shape 1 and the target shape 2. The projections 22 and 23 of the boundary lines 12 and 13 of the outer surface of the shape 1 before cutting can be obtained. The angle bisectors of the transition fillets in the middle of the projections 22 and 23 are drawn respectively, and the angle between the two angle bisectors is α. The angle bisectors of the two angle bisectors are then taken as the support direction of the laser cutting fixture support.

[0025] 3. Laser cutting fixture support design

[0026] Laser cutting fixture support 24 Figure 4As shown, the bottom surface of its base is perpendicular to the support direction of the laser cutting fixture support 24, and its length direction is parallel to the y-axis. At the center of the top surface of the laser cutting fixture support 24 base, there is a groove 5 mm wide and 10 mm high, the shape of which matches the ridge line of the target shape 2 of the blade leading edge skin part. The top surface of the support 24 base has nine bosses of equal thickness, each boss having two symmetrical through holes. The plane of each boss on the -y-axis side coincides with the positioning surface 3 and the support sections 4-11, respectively.

[0027] 4. Positioning plate design

[0028] like Figure 5 As shown, the projection 22 of the boundary line 12 is drawn within the positioning surface 3. The outer contour of the upper part of the positioning plate 25 should extend beyond the projection 22, and the shape of the lower part of the positioning plate 25 should be consistent with the cross-sectional shape of the boss on the support 24. The positioning plate 25 can be made of 2 mm titanium alloy plate or other thickness plates, and should have sufficient rigidity to ensure that the skin parts do not deform during installation and positioning.

[0029] 5. Support plate design

[0030] Support section 4 inner support plate 26 as shown Figure 6 As shown, the upper part of the support plate 26 coincides with the section line 14, and both ends are shorter than the section line 14. The lower part of the support plate 26 has the same cross-sectional shape as the boss on the laser cutting fixture support 24. The support plate 26 can be made of 1-2 mm titanium alloy plate or other plates of similar thickness, and should have sufficient rigidity to ensure that the skin parts do not deform during installation. Following the same method, eight support plates 27-33 are designed based on section lines 15-3421, as follows. Figure 7 As shown.

[0031] 6. Baffle design

[0032] To prevent the laser from penetrating the material on the opposite side of the part during laser cutting, a baffle needs to be designed for shielding. The baffle 34-42 is designed as follows: Figure 8 As shown, each baffle can be made of 4 mm thick steel plate. The upper contour of baffles 34-42 is consistent with the contour of the ridge line of the part, and the lower end is flush with the bottom of the central groove of the support 24. A gap is left between each baffle to avoid the support plate and the boss on the support 24. Baffle 34 is flush with the positioning surface 3 at the +y axis end. Baffle 42 is on the -y axis end face, extending beyond the outline 1 of the blade leading edge skin part before cutting.

[0033] 7. Assembly of cutting fixtures

[0034] like Figure 9 As shown, the positioning plate 3 and the support plate 2633 are fixed to the laser cutting fixture support 24 by bolts in the corresponding positions, and then the nine baffles 34 to 42 are inserted into the central groove of the support 24 in the corresponding positions.

[0035] 8. Laser cutting process

[0036] The assembled cutting fixture is installed and fixed on the working platform of the multi-axis laser cutting machine. Based on the three mutually perpendicular intersecting planes of the laser cutting fixture support 24, a laser cutting coordinate system is constructed within the CNC system of the multi-axis laser cutting machine. The assembly model of the fixture and the target part is imported, and the cutting trajectory is planned. The uncut blade leading edge skin part is installed on the assembled cutting fixture on the eight support plates 26-33, as follows. Figure 9 As shown, the outer surface boundary line 12 of the part should be close to the positioning plate 25. The part is pressed down at the eight support plates 26-33, and then laser-cut and removed. The process of part installation, laser cutting, and removal is repeated to complete the cutting of the remaining parts with the same shape.

Claims

1. A laser cutting fixture for a blade leading edge skin part, characterized in that, include: Support, positioning plate, support plate, baffle bolt and nut, the positioning plate is installed on the outermost boss of the support by bolts and nuts, multiple support plates are installed on the boss at the corresponding position of the support by bolts and nuts, multiple baffles are installed in the corresponding slots on the support, the blade leading edge skin parts are installed on each support plate of the fixture, one side of the parts is flush with the positioning plate; To prevent the laser from penetrating the material on the opposite side of the part during laser cutting, the upper contour of the baffle is consistent with the contour of the ridge of the part, and the lower end is flush with the bottom of the central groove of the support (24). There is a gap between each baffle to avoid the protrusion on the support plate and the support.

2. The method of using the fixture as described in claim 1, characterized in that, Based on the shape of the TB8 titanium alloy blade leading edge skin part, a positioning plane and multiple support sections were selected. The laser cutting fixture support, positioning plate, support plates for each section, and baffles for each segment were designed and processed. The positioning plate and support plates were fixed to the support using bolts and nuts, and each baffle was inserted into its corresponding slot. The assembled laser cutting fixture was then fixed to the worktable of a multi-axis laser cutting machine. The blade leading edge skin part was mounted on each support plate of the fixture and positioned using the positioning plate. A positioning coordinate system was constructed within the CNC system of the multi-axis laser cutting machine using the three mutually perpendicular planes of the cutting fixture support. The fixture and target part shape assembly model were imported, the cutting trajectory was planned, and cutting and part removal were performed. The process of part installation-laser cutting-part removal was repeated to complete the cutting of other parts with the same shape.

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