Five-axis impeller machining tooling

Abstract

The utility model belongs to the technical field of impeller processing equipment, concretely relates to a five -axis impeller processing frock, including base and double -end screw rod, the centre of base top is provided with mounting hole, mounting hole bottom is provided with the threaded hole concentrically, be provided with positioning axle seat in mounting hole, the top of positioning axle seat is fixedly connected with positioning axle, the top of positioning axle is provided with the jack -up hole coaxial with threaded hole, the bottom end of double -end screw rod is connected in threaded hole through the jack -up hole thread, its top end passes through the central hole of the impeller to be processed and is connected with the nut assembly to realize the axial fixed of impeller, the top of base is located mounting hole outside and is distributed a plurality of positioning hole groups in circumference, every positioning hole group includes a plurality of positioning holes that distribute along the radial of base, through respectively inserting positioning pin both ends into positioning hole and impeller process hole, realize the accurate circumferential positioning of different specifications impeller, the utility model can process various specifications impeller, and positioning accuracy is high.

Description

Technical Field

[0001] This utility model belongs to the technical field of impeller processing equipment, specifically relating to a five-axis impeller processing fixture. Background Technology

[0002] As a key component of fluid machinery such as blowers, vacuum pumps, and air compressors, impellers are characterized by complex structures, irregular blade shapes, narrow adjacent spaces with high twist, narrow flow channels, and thin, easily deformable blades. They require high machining standards and need to be machined using a five-axis machining center. Due to the special nature of impeller parts, impeller parts of different specifications have similar basic structures, all consisting of impeller blades, flow channels, and a rotating base, with a high-precision through hole in the middle for working assembly.

[0003] Since impeller parts are usually produced in single pieces and small batches, if a special fixture is made for each type of impeller or each impeller, the cost will be very high, and the time for debugging on the machine will be increased, affecting the processing efficiency.

[0004] To address the aforementioned technical problems, Chinese patent publication number CN207681987U proposes a five-axis impeller machining fixture. This fixture uses a replaceable boss-shaped transition sleeve in conjunction with a tie rod to position and fix impellers of different diameters. However, this fixture still has significant drawbacks in practical applications: First, the upper plate relies solely on anti-slip textures for planar friction fixation. For complex curved impellers, it lacks a reliable circumferential positioning structure, making it prone to displacement or jumping of parts due to centrifugal force during high-speed five-axis linkage machining. Second, the transition sleeve is not fixed, making it prone to offset rotation and relative movement with the groove during clamping and machining. This leads to inaccurate positioning, reduced fixture rigidity, and can cause vibration, wear, or even safety accidents. Utility Model Content

[0005] The main technical problem to be solved by this utility model is to provide a five-axis impeller machining fixture with a reasonable structural design, convenient operation, and the ability to process impellers of various specifications, reduce processing costs, and quickly change parts to improve productivity. In particular, it can accurately position impellers, reduce clamping errors, and improve the machining accuracy of impellers.

[0006] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0007] A five-axis impeller machining fixture includes a base and a double-ended screw. The base has a mounting hole at its top center and a threaded hole concentrically located at the bottom of the mounting hole. A detachable positioning shaft seat is installed inside the mounting hole. A positioning shaft is integrally connected to the top of the positioning shaft seat. The top of the positioning shaft has an insertion hole coaxial with the threaded hole. The bottom end of the insertion hole extends to the bottom surface of the positioning shaft seat. The bottom end of the double-ended screw passes through the insertion hole and is threaded into the threaded hole. Its top end passes through the central hole of the impeller to be machined and is threadedly connected to a nut assembly to achieve axial fixation of the impeller. Multiple sets of positioning holes are circumferentially distributed on the top of the base outside the mounting hole. Each set of positioning holes includes multiple positioning holes radially distributed along the base. By inserting the two ends of a positioning pin into the positioning holes and the impeller process holes respectively, precise circumferential positioning of impellers of different specifications can be achieved.

[0008] The following are further optimizations of the above technical solution by this utility model:

[0009] The positioning shaft seat and the base are fixedly connected by multiple fastening bolts, and the fastening bolts are internal angle bolts.

[0010] Further optimization: The outer wall of the positioning shaft seat and the inner wall of the mounting hole adopt a transition fit.

[0011] Further optimization: The outer wall of the positioning shaft is adapted to fit the inner wall of the center hole of the impeller to be processed to achieve radial positioning.

[0012] Further optimization: The outer wall of the positioning shaft and the inner wall of the center hole of the impeller to be processed adopt a transition fit.

[0013] Further optimization: The top edge of the positioning shaft adopts a rounded transition.

[0014] Further optimization: The diameter of the insertion hole is larger than the diameter of the double-ended screw, forming a radial floating gap.

[0015] Further optimization: The depth of the threaded hole is greater than the length of the engaged section of the double-ended screw.

[0016] Further optimization: The nut assembly includes a lock nut and an elastic washer, the outer diameter of which is larger than the outer diameter of the support surface of the lock nut.

[0017] This invention utilizes a circumferentially distributed adjustable positioning hole group and a double-headed screw structure, allowing a single tooling set to be adapted to the processing of impellers of different sizes, significantly reducing the investment cost of dedicated tooling and achieving flexible production.

[0018] This invention can accurately match the center holes of various impellers by replacing the positioning shafts of different diameters, ensuring coaxiality. At the same time, with the adjustable positioning hole group, the range of processing specifications can be greatly expanded. This modular design maintains versatility while ensuring the positioning accuracy of each impeller, significantly improving processing quality and efficiency.

[0019] This invention ensures axial reference uniformity through the cooperation of concentric threaded holes and positioning shafts, while the two ends of the positioning pin are precisely matched with the positioning holes of the base and the process holes of the impeller, thereby effectively constraining the circumferential degree of freedom of the impeller in high-speed five-axis linkage machining, completely eliminating the risk of rotational displacement or runout caused by centrifugal force or cutting force, and making the machining accuracy of the impeller stable and reliable.

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;

[0023] Figure 2 This is a cross-sectional view of an embodiment of the present utility model;

[0024] Figure 3 This is a schematic diagram of the base structure in an embodiment of this utility model.

[0025] In the diagram: 1-base; 2-double-ended screw; 3-mounting hole; 4-threaded hole; 5-positioning shaft seat; 6-fastening bolt; 7-positioning shaft; 8-insertion hole; 9-positioning hole; 10-positioning pin; 11-anti-loosening nut; 12-elastic washer; 13-T-slot. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] like Figure 1-3As shown, a five-axis impeller machining fixture includes a base 1 and a double-ended screw 2. The base 1 has a mounting hole 3 at the center of its top, and a threaded hole 4 coaxially at the bottom of the mounting hole 3. A positioning shaft seat 5 is detachably installed in the mounting hole 3. A positioning shaft 7 is integrally connected to the top of the positioning shaft seat 5. The top of the positioning shaft 7 has an insertion hole 8 coaxial with the threaded hole 4. The bottom end of the insertion hole 8 extends through to the bottom surface of the positioning shaft seat 5. The bottom end of the double-ended screw 2 passes through the insertion hole 8 and is threaded into the threaded hole 4. Its top end passes through the center hole of the impeller to be processed and is threadedly connected to a nut assembly to fix the impeller. Multiple sets of positioning holes are distributed circumferentially on the top of the base 1 outside the mounting hole 3. Each set of positioning holes includes multiple positioning holes 9 distributed radially along the base 1. By inserting the two ends of the positioning pin 10 into the positioning holes 9 and the impeller process holes respectively, precise circumferential positioning of impellers of different specifications can be achieved.

[0028] This design, firstly, through the circumferentially distributed adjustable positioning hole group and the double-headed screw structure, allows one set of tooling to be adapted to the processing of impellers of different sizes, significantly reducing the investment cost of special tooling and realizing flexible production.

[0029] Secondly, by replacing the positioning shaft 7 with different diameters, this tooling can accurately match the center holes of various impellers to ensure coaxiality. At the same time, with the adjustable positioning hole group, the range of processing specifications can be greatly expanded. This modular design maintains versatility while ensuring the positioning accuracy of each impeller, significantly improving processing quality and efficiency.

[0030] Furthermore, the fit between the concentric threaded hole 4 and the positioning shaft 7 ensures the uniformity of the axial reference, while the two ends of the positioning pin 10 are precisely matched with the positioning hole 9 of the base and the process hole of the impeller, thereby effectively constraining the circumferential degree of freedom of the impeller in high-speed five-axis linkage machining, completely eliminating the risk of rotational displacement or runout caused by centrifugal force or cutting force, and making the machining accuracy of the impeller stable and reliable.

[0031] The positioning shaft seat 5 and the base 1 are fixedly connected by multiple fastening bolts 6, and the fastening bolts 6 are internal angle bolts.

[0032] In this embodiment, there are 4 fastening bolts 6, which are evenly distributed around the circumference of the positioning shaft seat 5.

[0033] In addition to this embodiment, the number of fastening bolts 6 is 6 or 8.

[0034] This design, firstly, ensures that the load of the fastening bolt 6 is evenly distributed in the circumferential direction to all directions of the positioning shaft seat 5, thus avoiding the risk of deformation or breakage caused by local stress concentration.

[0035] Secondly, the evenly distributed fastening bolts 6, through symmetrical constraint forces, limit the offset or rotation of the positioning shaft seat 5 during the installation process, ensuring its coaxiality and perpendicularity with mating components (such as shafts, flanges, etc.).

[0036] Furthermore, under vibration or impact conditions, evenly distributed bolts can disperse dynamic loads, reduce the risk of fatigue damage to individual fasteners, and extend the service life of the overall structure.

[0037] The outer wall of the positioning shaft seat 5 and the inner wall of the mounting hole 3 are fitted with a transition fit.

[0038] In this embodiment, the tolerance grade of the transition fit is H7 / k6.

[0039] This design, firstly, reduces the assembly clearance between the positioning shaft seat 5 and the mounting hole 3 through a transition fit, ensuring that the impeller's central axis strictly coincides with the tooling's rotation axis, avoiding eccentricity errors, and improving machining accuracy and dynamic balance; at the same time, it helps resist circumferential cutting forces and prevents slight rotation between the positioning shaft seat 5 and the base 1.

[0040] Secondly, the transition fit allows the positioning bearing 5 to be gently pressed or tapped into the mounting hole 3, facilitating quick assembly and adjustment. Before tightening the fastening bolt 6, the bearing angle can be finely adjusted to ensure that the insertion hole 8 and the threaded hole 4 are completely coaxial, avoiding thread interference during the installation of the double-ended screw 2.

[0041] Furthermore, the moderate tightness of the transition fit reduces the fretting between the positioning shaft seat 5 and the mounting hole 3, suppresses vibration caused by high-frequency cutting forces, and prevents machining marks; at the same time, the mating surfaces share part of the radial load, reduce the shear load on the fastening bolts 6, and improve the stability of the tooling.

[0042] The outer wall of the positioning shaft 7 and the impeller through hole adopt a transition fit.

[0043] In this embodiment, the tolerance grade of the transition fit is H7 / k6.

[0044] This design, firstly, eliminates the shaft hole clearance through transition fit, ensuring that the impeller and the positioning shaft 7 fit tightly together, achieving high coaxiality, avoiding radial offset during machining, and improving the machining accuracy of the impeller.

[0045] Secondly, it ensures smooth assembly and provides sufficient friction to prevent the impeller from loosening or fretting during high-speed cutting, thereby enhancing process reliability and making it particularly suitable for five-axis dynamic machining.

[0046] The top edge of the positioning shaft 7 is rounded.

[0047] This design has several advantages. First, the rounded corners prevent sharp edges from scratching the impeller reference hole surface during assembly, ensuring the integrity of critical mating surfaces and reducing the scrap rate.

[0048] Secondly, the rounded corner structure acts as a natural guide during clamping, helping the impeller to fit more smoothly into the positioning shaft 7 and improving assembly efficiency.

[0049] Furthermore, the rounded corner design reduces stress concentration at the root of the positioning shaft 7, greatly extending the tooling life and making it particularly suitable for long-term, high-frequency use conditions.

[0050] In this embodiment, the radius of the rounded corner is 0.5mm-2mm, preferably 1mm.

[0051] In this embodiment, the positioning shaft 7 is made of 42CrMo alloy steel and has been heat-treated to a hardness of HRC40-45.

[0052] The diameter of the insertion hole 8 is larger than the diameter of the double-ended screw 2, forming a radial floating gap.

[0053] This design allows the radial floating clearance to allow the double-ended screw 2 to be slightly adjusted within the insertion hole 8, automatically compensating for coaxiality deviations during machining or assembly, ensuring uniform distribution of locking force, and improving clamping accuracy.

[0054] Secondly, it avoids forced assembly caused by slight misalignment between the threaded hole 4 of the base 1 and the insertion hole 8 of the positioning shaft 7, eliminates bending stress on the double-ended screw 2, and extends the life of the threaded connector.

[0055] Furthermore, the gap creates a tiny floating space during machining, which can absorb cutting vibration energy, reduce the impact transmitted to the tooling, and improve the quality of the machined surface.

[0056] In this embodiment, the diameter of the insertion hole 8 is 0.1mm-0.3mm larger than the diameter of the double-ended screw 2, preferably 0.2mm.

[0057] The depth of the threaded hole 4 is greater than the length of the engaged section of the double-ended screw 2.

[0058] This design, firstly, ensures that the ultra-deep threaded hole 4 retains at least 2-3 ineffective threaded empty areas after the double-ended screw 2 is screwed in, avoiding the "false tightening" phenomenon caused by machining errors, and ensuring that the locking torque is 100% effectively transmitted.

[0059] Secondly, under high-speed machining and temperature rise conditions, axial expansion margin is provided for the screw and base 1 materials (usually with different coefficients of thermal expansion) to avoid the risk of thread seizure caused by thermal stress.

[0060] In this embodiment, the depth of the threaded hole 4 is 1.2-1.5 times the length of the engaged section of the double-ended screw 2, preferably 1.35 times.

[0061] In this embodiment, the positioning hole group consists of four groups, each group containing three positioning holes 9 that are equidistantly distributed radially along the base 1.

[0062] This design, firstly, uses multiple sets of symmetrical positioning holes to form a "cross" constraint, which counteracts cutting forces and improves torsional rigidity.

[0063] Secondly, the radial multi-stage hole is compatible with process holes of different radii, allowing for the switching of impeller specifications without changing tooling.

[0064] Furthermore, the positioning hole 9 enables immediate insertion and positioning, greatly improving clamping time and making it particularly suitable for small-batch, multi-variety production.

[0065] In addition to this embodiment, the number of positioning hole groups can be set according to actual needs.

[0066] In addition to this embodiment, the number of positioning holes 9 in the positioning hole group can be set according to actual needs.

[0067] The nut assembly includes a lock nut 11 and an elastic washer 12, wherein the outer diameter of the elastic washer 12 is larger than the outer diameter of the support surface of the lock nut 11.

[0068] This design firstly ensures that the anti-loosening nut 11 forms friction or mechanical engagement with the thread of the double-ended screw 2 through its own structure, preventing the nut from loosening on its own under cutting vibration and impact load, thus avoiding the risk of the impeller shifting its machining position or falling off due to loosening.

[0069] Secondly, the elastic washer 12 undergoes elastic deformation under pressure, continuously applying axial tension to the nut, further offsetting the gap between the threaded pairs. Thus, when minor vibrations occur during processing, the elastic deformation of the washer can absorb energy, preventing relative rotation between the nut and the screw, and enhancing the anti-loosening effect.

[0070] Furthermore, the outer diameter of the elastic washer 12 is larger than the outer diameter of the support surface of the anti-loosening nut 11, so that the axial clamping force of the nut is transmitted to the impeller surface through a larger area, avoiding indentation, deformation or stress concentration caused by insufficient contact area.

[0071] In this embodiment, the elastic gasket 12 is made of 65Mn spring steel with a thickness of 2-5mm.

[0072] In this embodiment, both the anti-loosening nut 11 and the elastic washer 12 are industrial standard parts.

[0073] The upper side wall of the base 1 is provided with multiple T-slots 13 that match the worktable of the five-axis machine tool for quick installation and positioning.

[0074] This design, firstly, ensures that the T-slot 13 is compatible with the standard interface of the machine tool worktable, allowing for quick tooling positioning and installation without the need for additional fixture adjustments, significantly shortening changeover time and improving production efficiency.

[0075] Secondly, the T-slot 13 structure provides a stable mechanical locking force, ensuring that the tooling does not shift during high-speed, high-load machining, thus guaranteeing the machining accuracy and safety of the impeller.

[0076] Furthermore, the standardized T-slot 13 design is compatible with the worktables of five-axis machine tools from different brands, enhancing the applicability of tooling, reducing the cost of dedicated tooling for equipment, and making it suitable for flexible production needs of multiple machine models.

[0077] In this embodiment, the base 1 is made of AL6061 aluminum alloy.

[0078] This design, firstly, leverages the excellent strength-to-weight ratio of AL6061 aluminum alloy. While ensuring the rigidity of the tooling structure, it reduces the weight by 60% compared to steel, thereby reducing the moment of inertia of the five-axis machine tool and improving dynamic machining accuracy.

[0079] Secondly, the material's inherent damping properties can absorb cutting vibrations, and its coefficient of thermal expansion matches that of most impeller materials, reducing positioning errors caused by thermal deformation, making it particularly suitable for long-term continuous machining.

[0080] Working principle: First, align the T-slot 13 at the bottom of the base 1 with the T-shaped guide rail of the five-axis machine tool table, and tighten the bolts through the T-slot 13 to fix it, so that the tooling can be quickly positioned and stably installed on the machine tool.

[0081] Subsequently, the positioning shaft seat 5 is placed in the mounting hole 3 at the top of the base 1, and multiple fastening bolts 6 are passed through the corresponding holes of the positioning shaft seat 5 and the base 1. The fastening bolts 6 are tightened to fix the positioning shaft seat 5 to the base 1. The positioning shaft 7 is integrally formed with the positioning shaft seat 5, and no additional installation steps are required.

[0082] Then, pass the bottom end of the double-ended screw 2 through the insertion hole 8 at the top of the positioning shaft 7, and screw it into the threaded hole 4 at the bottom of the mounting hole 3. Tighten the double-ended screw 2 initially to ensure that it is vertically fixed and in a stable position.

[0083] Subsequently, according to the specifications of the impeller to be processed, a suitable set of positioning holes is selected, one end of the positioning pin 10 is inserted into the corresponding positioning hole 9 in the positioning hole set of the base 1, and the other end is inserted into the process hole of the impeller. Through multiple sets of positioning pins 10, the impeller is accurately positioned circumferentially on the base 1, ensuring that the impeller is in the correct processing position.

[0084] Subsequently, align the center hole of the impeller to be processed with the top of the double-ended screw 2 and insert it. Install the elastic washer 12 and the anti-loosening nut 11 in sequence on the top of the double-ended screw 2. Tighten the anti-loosening nut 11 with a tool. Use the elastic deformation of the elastic washer 12 to generate a pre-tightening force to firmly press the impeller onto the positioning shaft 7, thus completing the fixing of the impeller.

[0085] Finally, start the five-axis machine tool to process the impeller; after processing, loosen the anti-loosening nut 11, remove the elastic washer 12, remove the impeller from the double-ended screw 2, pull out the positioning pin 10, and complete the disassembly of the impeller, ready for the next clamping and processing.

[0086] For those skilled in the art, any changes, modifications, substitutions, and variations made to the implementation methods without departing from the principles and spirit of this utility model, based on the teachings of this utility model, still fall within the protection scope of this utility model.

Claims

1. A five-axis impeller machining fixture, comprising a base (1) and a double-ended screw (2), characterized in that: The base (1) has a mounting hole (3) at the top center and a threaded hole (4) at the bottom of the mounting hole (3). A positioning shaft seat (5) is detachably installed in the mounting hole (3). A positioning shaft (7) is integrally connected to the top of the positioning shaft seat (5). An insertion hole (8) coaxial with the threaded hole (4) is opened on the top of the positioning shaft seat (5). The bottom end of the insertion hole (8) extends to the bottom surface of the positioning shaft seat (5). The bottom end of the double-ended screw (2) passes through the insertion hole (8) and is threaded into the threaded hole (4). Its top end passes through the center hole of the impeller to be processed and is threaded with a nut assembly to achieve axial fixation of the impeller. Multiple sets of positioning holes are distributed circumferentially on the top of the base (1) outside the mounting hole (3). Each set of positioning holes includes multiple positioning holes (9) distributed radially along the base (1). By inserting the two ends of the positioning pin (10) into the positioning hole (9) and the impeller process hole respectively, the precise circumferential positioning of impellers of different specifications can be achieved.

2. The five-axis impeller machining fixture according to claim 1, characterized in that... The positioning shaft seat (5) and the base (1) are fixedly connected by multiple fastening bolts (6), and the fastening bolts (6) are internal angle bolts.

3. A five-axis impeller machining fixture according to claim 1 or 2, characterized in that: The outer wall of the positioning shaft seat (5) and the inner wall of the mounting hole (3) are fitted with a transition fit.

4. A five-axis impeller machining fixture according to claim 1 or 2, characterized in that: The outer wall of the positioning shaft (7) is used to fit with the inner wall of the center hole of the impeller to be processed to achieve radial positioning.

5. The five-axis impeller machining fixture according to claim 4, characterized in that: The outer wall of the positioning shaft (7) and the inner wall of the center hole of the impeller to be processed adopt a transition fit.

6. A five-axis impeller machining fixture according to claim 1 or 2, characterized in that: The top edge of the positioning shaft (7) is rounded.

7. A five-axis impeller machining fixture according to claim 1, characterized in that: The diameter of the socket (8) is larger than the diameter of the double-ended screw (2) and forms a radial floating gap.

8. The five-axis impeller machining fixture according to claim 1, characterized in that: The depth of the threaded hole (4) is greater than the length of the engagement section of the double-ended screw (2).

9. A five-axis impeller machining fixture according to claim 1, characterized in that: The nut assembly includes a lock nut (11) and an elastic washer (12), the outer diameter of which is larger than the outer diameter of the support surface of the lock nut (11).

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