A fixture and clamping method for five-axis machining of biaxial journal blades.

Abstract

This invention relates to the field of aero-engine blade machining technology, and particularly to a fixture and clamping method for five-axis machining of double-journal blades. The fixture includes a vise, which comprises a vise base and vise clamping blocks. Two vise clamping blocks are slidably mounted on the vise base. An isolation block is fixedly mounted on the vise base, and a bidirectional screw is rotatably mounted on the isolation block. The screws at both ends of the bidirectional screw are threaded into the vise clamping blocks to drive the two vise clamping blocks to move closer together or separate. A journal clamping seat is mounted on the top of each vise clamping block, and a clamping groove is provided on the journal clamping seat. The radius of the clamping groove matches the journal radius on the double-journal blade to be machined. When the two vise clamping blocks move closer together, the clamping grooves on the two journal clamping seats together encircle the journal on the double-journal blade to be machined.

Description

Technical Field

[0001] This invention relates to the field of aero-engine blade machining technology, and in particular to a fixture and clamping method for five-axis machining of dual-journey blades. Background Technology

[0002] In the machining of twin-judge blades, five-axis CNC milling of the blade body and boss is a key process. In the existing technology, the fixtures and clamping methods used to machine the blade body profile of this type of blade have problems such as long changeover time, insufficient positioning accuracy, and difficulty in being compatible with automation.

[0003] The commonly used clamping method is to use a vise to hold the journals at both ends of the dual-journal rectifier blade before machining. Existing vise clamping structures are as follows: For example, the patent with announcement number CN221389925U discloses an integrated machining fixture for machining stator blades of aero-engines. The large end of the blade is clamped by vise carriers c and d in the right clamping device to ensure the accuracy of machining. The self-centering slider a on vise carrier a and the self-centering slider b on vise carrier b in the left clamping device can swing.

[0004] For example, patent CN218556754U discloses a clamping device, including: a base, a bidirectional lead screw, an isolation block, a lead screw limiting component, and clamping modules located at both ends of the bidirectional lead screw.

[0005] For example, patent CN221910875U discloses a quick-release base structure for a centering vise, and patent application CN220331058U discloses a manual dual-axis vise structure.

[0006] However, in the aforementioned prior art, the clamping surface of the vise clamping block is usually flat, which is unsuitable for the rapid and precise clamping of the journals of dual-journal rectifier blades. The small contact area between the flat clamping surface and the journal easily leads to unstable positioning and uneven distribution of clamping force, affecting machining accuracy. There is an urgent need to provide a fixture and clamping method for five-axis machining of dual-journal blades. Summary of the Invention

[0007] The main objective of this invention is to provide a fixture and clamping method for five-axis machining of biaxial journal blades, aiming to solve the aforementioned technical problems.

[0008] To achieve the above objectives, on the one hand, the present invention proposes a fixture for five-axis machining of double-journal blades, including a vise, wherein the vise includes a vise base and vise clamping blocks; two vise clamping blocks are slidably mounted on the vise base, an isolation block is fixedly mounted on the vise base, and a bidirectional screw is rotatably mounted on the isolation block, the screws at both ends of the bidirectional screw being threadedly engaged with the vise clamping blocks respectively, for driving the two vise clamping blocks to move closer or separate; a journal clamping seat is mounted on the top of the vise clamping blocks, and a clamping groove is provided on the journal clamping seat, the radius of the clamping groove matching the journal radius on the double-journal blade to be machined; when the two vise clamping blocks move closer, the clamping grooves on the two journal clamping seats together encircle the journal on the double-journal blade to be machined.

[0009] Preferably, the clamping groove forms an enclosing contact angle of not less than 120° with the journal on the double-journal blade to be processed, so as to enhance clamping stability and distribute clamping force.

[0010] Preferably, the journal clamping seat includes a connecting seat and a semi-circular clamping rod; the clamping rod is integrally formed on the connecting seat; the clamping groove extends from top to bottom through the clamping rod and the connecting seat; the connecting seat is fastened to the vise clamping block by multiple screws to achieve quick replacement.

[0011] Preferably, a first groove is provided on the bottom surface of the connecting seat; a second groove is provided on the top surface of the vise clamping block; a limiting block is installed in the second groove, and the upper part of the limiting block is embedded in the first groove. Further, a strip-shaped protrusion is provided on the bottom surface of the connecting seat; a third groove is provided on the top surface of the vise clamping block, the third groove being perpendicular to the second groove; the strip-shaped protrusion is embedded in the third groove. This structure is used to limit the displacement of the journal clamping seat relative to the vise clamping block in two horizontal directions.

[0012] Preferably, a pull stud is installed on the bottom surface of the vise base for cooperating with the zero-point clamping module on the five-axis machine tool tray to achieve rapid positioning and clamping.

[0013] Preferably, a guide post is installed on the bottom surface of the vise base. This post is used to engage with the positioning holes on the five-axis machine tool tray to restrict the angular degree of freedom of the vise.

[0014] Preferably, the directional post is used to mate with the positioning hole on the five-axis machine tool tray. The directional post and the positioning hole on the five-axis machine tool tray are interference fit with a tolerance of H7 / h6 to ensure high-precision positioning.

[0015] Secondly, the present invention also proposes a clamping method for five-axis machining of biaxial journal blades, using the above-mentioned fixture, comprising the following steps: S1. Select the appropriate journal clamping seat according to the journal radius on the double journal blade to be processed, and fix the journal clamping seat on the vise clamping block. The radius of the clamping groove on the selected journal clamping seat matches the journal radius on the double journal blade to be processed. S2. Install the two clamps onto the zero-point clamping module on the five-axis machine tool tray; S3. Clamp the journals at both ends of the double-journal blade to be processed onto two fixtures respectively, drive the bidirectional screw to rotate, so that the two vise clamping blocks on each vise move closer to each other, thereby driving the two journal clamping seats to move closer to each other. The clamping grooves on the two journal clamping seats together hold the journals on the double-journal blade to be processed, thus completing the clamping.

[0016] Preferably, a pull stud and a guide post are installed on the bottom surface of the vise base; in step S2, the pull stud is tightened by the zero-point clamping module, and the guide post is inserted into the positioning hole on the five-axis machine tool tray, and the two adopt an interference fit of H7 / h6 to restrict the angular degree of freedom of the vise.

[0017] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: (1) Quick changeover: With the design of a replaceable journal holder, the radius of the clamping groove matches the radius of the journal. Only the journal holder needs to be replaced to adapt to different sizes of blade journals, which greatly reduces changeover time and improves production efficiency.

[0018] (2) High positioning accuracy: The clamping groove forms an enveloping contact angle of not less than 120° with the journal, which increases the contact area, makes the clamping force evenly distributed, avoids local stress concentration, and ensures clamping stability and machining accuracy.

[0019] (3) Compatible with automation: The design of the pull stud and the directional column, together with the zero-point clamping module on the five-axis machine tool tray, realizes the rapid positioning and clamping of the fixture, which is easy to integrate into the automated production line and reduces manual intervention.

[0020] (4) Reliable structure: The combination of the limiting block and the strip protrusion with the groove effectively restricts the displacement and rotation of the journal clamping seat, enhances the overall rigidity, and prevents vibration or displacement during processing.

[0021] (5) Easy clamping: The clamping method is simple and easy to operate. The journal can be clamped by rotating the bidirectional screw, which reduces the clamping time and improves the clamping consistency. Attached Figure Description

[0022] 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.

[0023] Figure 1 This is an exploded view of the fixture provided by the present invention; Figure 2 A three-dimensional model of the fixture provided by this invention; Figure 3 This is a front view of the three-dimensional model of the journal clamping seat in this invention; Figure 4 This is a top view of the three-dimensional model of the journal clamping seat in this invention; Figure 5 This is a schematic diagram showing the usage state of the clamp provided by the present invention.

[0024] The reference numerals in the attached diagram are as follows: 1. Vise; 101. Vise base; 102. Vise slider; 102a. Second groove; 102b. Third groove; 103. Bidirectional screw; 104. Isolation block; 2. Journal clamping seat; 2a. Clamping groove; 201. Connecting seat; 201a. First groove; 201b. Strip-shaped protrusion; 202. Clamping rod; 3. Screw; 4. Limiting block; 5. Pull stud; 6. Orientation post; 7. Zero-point clamping module. Detailed Implementation

[0025] 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.

[0026] 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 positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0027] 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.

[0028] like Figures 1 to 4 As shown in the figure, this embodiment provides a fixture for five-axis machining of dual-journal blades, including a vise 1. The vise 1 consists of a vise base 101 and two vise clamping blocks 102. The two vise clamping blocks 102 are mounted on the vise base 101 through a precision sliding fit, ensuring smooth and accurate movement. This ensures that the vise clamping blocks 102 do not wobble during movement, allowing the two journal clamping seats 2 to be precisely aligned, effectively avoiding blade clamping deviations caused by misalignment of the fixture. An isolation block 104 is fixedly mounted on the vise base 101. The isolation block 104 is made of high-strength alloy steel, and a bidirectional screw 103 is rotatably mounted on it. That is, the bidirectional screw 103 can rotate on the isolation block 104, but cannot move axially. The screws at both ends of the bidirectional screw 103 are threadedly engaged with the two vise clamping blocks 102, and the threads are precision trapezoidal threads with a self-locking function. When the bidirectional screw 103 is rotated, it can precisely drive the two vise clamping blocks 102 to move closer or separate synchronously. In actual use, the operator can precisely control the rotation torque of the bidirectional screw 103 using a torque wrench, thereby achieving quantitative control of the clamping force. The vise 1 is a conventional existing device and will not be described in detail again.

[0029] A journal clamping seat 2 is mounted on top of the vise clamping block 102. The journal clamping seat 2 has precisely machined clamping grooves 2a, the radius of which matches the journal radius on the dual-journal blade to be machined, with a tolerance controlled within ±0.005mm. When the two vise clamping blocks 102 approach each other, the clamping grooves 2a on the two journal clamping seats 2 together encircle the journal, forming a stable surface contact clamping. The precise fit between the clamping grooves 2a and the journal ensures maximum contact area. Compared to traditional planar clamping, the contact area is significantly increased, significantly reducing contact stress and avoiding indentation damage to the blade journal surface. In practical applications, this design is particularly suitable for machining aero-engine blades with high surface quality requirements.

[0030] Combination Figure 4As shown, the containment contact angle β between the clamping groove 2a and the journal is designed to be no less than 120°. This angle has been optimized to ensure sufficient clamping force while avoiding clamping interference caused by an excessively large containment angle. After clamping, the 120° containment contact angle can provide sufficient constraint force in both the axial and circumferential directions, preventing the blade from undergoing minor displacement due to cutting forces during five-axis machining. Actual machining verification shows that this design controls the blade displacement to within 0.002mm when subjected to large cutting forces.

[0031] In this embodiment, the journal clamping seat 2 includes a connecting seat 201 and a semi-circular clamping rod 202; the clamping rod 202 is integrally formed on the connecting seat 201; the clamping groove 2a extends from top to bottom through the clamping rod 202 and the connecting seat 201; the connecting seat 201 is fastened to the vise clamping block 102 by four screws 3, forming a detachable connection structure. When different specifications of blades need to be processed, only the corresponding journal clamping seat 2 needs to be replaced, reducing the changeover time from 30 minutes for traditional fixtures to less than 5 minutes, significantly improving production efficiency.

[0032] To further improve positioning accuracy and rigidity, a first groove 201a is provided on the bottom surface of the connecting seat 201, and a second groove 102a is provided on the top surface of the vise clamping block 102. A limiting block 4 is installed in the second groove 102a, and the upper part of the limiting block 4 is precisely embedded in the first groove 201a. Furthermore, a strip-shaped protrusion 201b is provided on the bottom surface of the connecting seat 201, and a third groove 102b is provided on the top surface of the vise clamping block 102. The third groove 102b is perpendicular to the second groove 102a, and the strip-shaped protrusion 201b is precisely embedded in the third groove 102b. By adopting the above structure, the lateral movement of the journal clamping seat 2 in the horizontal plane is effectively limited, enhancing the overall rigidity of the fixture. During five-axis machining, even under large radial cutting forces, the journal clamping seat 2 will not displace, ensuring machining stability.

[0033] A pull stud 5 and a guide post 6 are mounted on the bottom surface of the vise base 101. The pull stud 5 is used to mate with the zero-point clamping module 7 on the five-axis machine tool tray. Both the pull stud 5 and the zero-point clamping module 7 are standard parts and commonly used structural components on machine tool fixtures, and will not be described in detail here. The guide post 6 is made of high-strength alloy steel with a hardened surface treatment. It is used to insert into the positioning hole on the five-axis machine tool tray, using an H7 / h6 interference fit, to restrict the angular degree of freedom of the vise 1.

[0034] The engagement of the pull stud 5 and the zero-point clamping module 7 enables rapid positioning and locking of the fixture. The interference fit of the guide post 6 ensures angular positioning accuracy, meeting the requirements of five-axis simultaneous machining for fixture positioning accuracy. This design is particularly suitable for achieving rapid changeover in automated production lines.

[0035] Combination Figure 5 As shown in the figure, this embodiment provides a clamping method for five-axis machining of biaxial journal blades, using the above-mentioned fixture, and includes the following detailed steps: Step S1: Fixture Preparation Stage Based on the journal radius of the dual-journal blade to be processed, select a matching journal clamping seat from the serially manufactured journal clamping seats 2. Use a torque wrench to tighten the four high-strength screws 3 in a diagonal sequence to securely fix the journal clamping seat 2 onto the vise clamping block 102. During installation, ensure that the limiting block 4 is fully embedded in the first groove 201a and the strip-shaped protrusion 201b is fully inserted into the third groove 102b.

[0036] The serialized journal holder 2 design allows the same set of fixtures to be adapted to the machining of blades of different specifications, greatly improving the versatility of the fixtures. In actual production, only different specifications of journal holder 2 are needed to meet the machining needs of the entire series of products, reducing tooling investment costs.

[0037] Step S2: Machine tool installation stage The two prepared clamps are precisely installed onto the zero-point clamping module 7 on the five-axis machine tool tray using pull pins 5 and guide pins 6. During installation, first align the guide pins 6 with the tray positioning holes and gently press until fully in place. Then, activate the zero-point clamping system to tighten the pull pins 5 via the hydraulic tensioning mechanism.

[0038] The use of a zero-point clamping system standardizes and speeds up the fixture installation process, eliminating the need for operators to perform tedious alignment procedures. In practical applications, this feature allows even unskilled workers to quickly complete fixture installation, reducing operational difficulty and improving production preparation efficiency.

[0039] Step S3: Blade clamping stage The journals at both ends of the blade are gently placed into the clamping grooves 2a of the journal clamping seats 2 of the two clamps. Using a torque wrench, the double-ended screw 103 is slowly rotated, causing the two vise clamping blocks 102 to move closer together synchronously, driving the two clamping grooves 2a to evenly grip the journals. Rotation is stopped when the torque wrench reaches the preset torque value, at which point the clamping force reaches its optimal state. In this embodiment, a torque of 20 N·m is used, resulting in a constant clamping force of not less than 2000 N generated by the journal clamping seats 2 to clamp the blade journals. This torque-controlled clamping method ensures that each blade receives a consistent clamping force, avoiding fluctuations in clamping quality due to differences in operator experience. In actual production, this feature significantly improves the consistency of product processing quality and reduces the scrap rate.

[0040] 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 fixture for five-axis machining of a dual-axis journal blade, comprising a vise (1), the vise (1) comprising a vise base (101) and vise clamping blocks (102); two vise clamping blocks (102) are slidably mounted on the vise base (101), an isolation block (104) is fixedly mounted on the vise base (101), and a bidirectional screw (103) is rotatably mounted on the isolation block (104), the screws at both ends of the bidirectional screw (103) respectively engaging with the vise clamping blocks (102) for driving the two vise clamping blocks (102) to move closer together or separate; characterized in that: A journal clamping seat (2) is installed on the top of the vise clamping block (102). A clamping groove (2a) is provided on the journal clamping seat (2), and the radius of the clamping groove (2a) matches the journal radius on the double journal blade to be processed; When the two vise clamping blocks (102) come close to each other, the clamping grooves (2a) on the two journal clamping seats (2) together encircle the journal on the double journal blade to be processed; The clamping groove (2a) forms an enclosing contact angle of not less than 120° with the journal on the double journal blade to be processed; The journal clamping seat (2) includes a connecting seat (201) and a semi-circular clamping rod (202). The clamping rod (202) is integrally formed on the connecting seat (201); the clamping groove (2a) passes through the clamping rod (202) and the connecting seat (201) from top to bottom; the connecting seat (201) is fastened to the vise clamping block (102) by a plurality of screws (3); A first groove (201a) is provided on the bottom surface of the connecting seat (201); a second groove (102a) is provided on the top surface of the vise clamping block (102); a limiting block (4) is installed in the second groove (102a), and the upper part of the limiting block (4) is embedded in the first groove (201a); A strip-shaped protrusion (201b) is provided on the bottom surface of the connecting seat (201); a third groove (102b) is provided on the top surface of the vise clamping block (102), the third groove (102b) being perpendicular to the second groove (102a); the strip-shaped protrusion (201b) is embedded in the third groove (102b); A rivet (5) is installed on the bottom surface of the vise base (101); a guide post (6) is installed on the bottom surface of the vise base (101). The directional post (6) is used to mate with the positioning hole on the five-axis machine tool tray, and the directional post (6) and the positioning hole on the five-axis machine tool tray are interference fit.

2. A clamping method for five-axis machining of biaxial journal blades, characterized in that, The clamp described in claim 1 comprises the following steps: S1. Select the appropriate journal clamping seat (2) according to the journal radius on the double journal blade to be processed, and fix the journal clamping seat (2) on the vise clamping block (102). The radius of the clamping groove (2a) on the selected journal clamping seat (2) matches the journal radius on the double journal blade to be processed. S2. Install the two clamps on the zero-point clamping module (7) on the five-axis machine tool tray; S3. Clamp the journals at both ends of the double journal blade to be processed onto two fixtures respectively, drive the bidirectional screw (103) to rotate, so that the two vise clamping blocks (102) on each vise (1) move closer to each other, thereby driving the two journal clamping seats (2) to move closer to each other, and the clamping grooves (2a) on the two journal clamping seats (2) together hold the journals on the double journal blade to be processed, thus completing the clamping. A pull stud (5) and a guide post (6) are installed on the bottom surface of the vise base (101); in step S2, the pull stud (5) is tightened by the zero-point clamping module (7), and the guide post (6) is inserted into the positioning hole on the five-axis machine tool tray. The two are interference fit to restrict the angular degree of freedom of the vise (1).

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