Elastic wheel rim machining process

Abstract

This invention discloses a machining process for elastic wheel rims, including the following steps: S1, turning the wheel rim; S2, milling the wheel rim; wherein step S1 includes: S101, machining the inner spoke surface, noise-reducing groove, inner rim surface, wheel flange, and tread surface of the wheel rim; S102, machining the outer rim surface and outer spoke surface of the wheel rim; in step S2, multiple bottom holes and beveled hole openings are machined on the wheel rim. The elastic wheel rim machining process of this invention can improve the stability and efficiency of wheel rim machining, and reduce the machining cycle and cost.

Description

Technical Field

[0001] This invention belongs to the field of train wheel processing technology, specifically relating to a processing technology for elastic wheel rims. Background Technology

[0002] With the continuous improvement of industrial modernization and living standards, people are placing higher demands on railway passenger transport systems, especially urban rail transit, where green and low-noise operation is a key objective. Trams and low-floor cars are widely used in Europe, with a large number employing flexible wheels, which offer a quieter riding experience. Flexible wheels consist of three components: the wheel rim, the wheel core, and the pressure cap. The wheel rim, being the most vulnerable part, has the highest demand. However, these rims require high precision, featuring grooved structures for mounting noise-reducing rings and beveled hole systems for mounting rubber components. The upper part of the wheel rim has strict dimensional tolerances, with a hole position accuracy requirement of 0.2mm, and high technical requirements for profile precision. Milling the beveled holes and their openings is difficult and inefficient.

[0003] Chinese Patent Application No. 202111005465.2 discloses a steel for elastic tram wheel rims and its heat treatment and production methods. The steel for elastic tram wheel rims contains the following chemical composition by weight percentage: C 0.55 0.67%, Si 0.25 0.60%, Mn 0.70 1.00%, P≤0.015%, S≤0.015%, Cr≤0.35%, V≤0.20%, with the remainder being Fe and unavoidable impurity elements. Its strength and hardness are comparable to LG61 wheel rims and CL60 wheels, but its plasticity and toughness are significantly improved, especially its low-temperature toughness, which improves the safety of the wheel in service.

[0004] The aim is to provide an improved machining process for flexible wheel rims, particularly regarding how to improve the stability and efficiency of wheel rim machining. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a processing method for elastic wheel rims, with the purpose of improving processing efficiency.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: a processing technology for elastic wheel rims, including the following steps:

[0007] S1. Perform turning machining on the wheel rim;

[0008] S2. Milling the wheel rim;

[0009] The process step S1 includes:

[0010] S101. Complete the machining of the inner spoke surface, sound-absorbing groove, inner rim surface, wheel flange and tread surface of the wheel rim;

[0011] S102. Complete the machining of the outer rim surface and outer spoke surface of the wheel rim;

[0012] In step S2, multiple bottom holes and beveled openings are machined on the wheel rim.

[0013] In step S101, the wheel rim is fixed by a first clamping mechanism. The first clamping mechanism includes an inner claw, and multiple inner claws are provided. The inner claws are inserted into the center hole of the wheel rim and contact the inner circular surface of the wheel rim.

[0014] In step S101, the wheel rim is supported by a first shim, and multiple first shims are provided. The first shims are in contact with the outer rim surface of the wheel rim.

[0015] In step S102, a three-jaw self-centering chuck is used to fix the wheel rim. The three-jaw self-centering chuck includes multiple outer jaws, which are distributed around the outer perimeter of the wheel rim and are in contact with the wheel rim flange.

[0016] In step S102, the wheel rim is supported by a second shim, and multiple second shims are provided. The second shims are in contact with the inner rim surface of the wheel rim.

[0017] In step S2, a milling fixture is used to fix the wheel rim. The milling fixture includes a base plate and a second clamping mechanism disposed on the base plate for applying pressure to the wheel rim.

[0018] The second clamping mechanism includes a clamping actuator and a clamping head disposed on the clamping actuator and used to contact the outer rim surface of the wheel hub. Multiple clamping actuators are provided and distributed around the outer side of the wheel hub.

[0019] In step S2, a Renishaw measurement system is used to automatically complete the milling machining reference calibration.

[0020] In step S2, a bottom hole is first drilled on the wheel rim, then the bottom hole is precision bored, and finally a drum-shaped tool is used to complete the machining of the two beveled holes on the front and back.

[0021] The drum-shaped cutter includes two circular blades, each with a bottom positioning groove.

[0022] The elastic wheel rim processing technology of the present invention can improve the stability and efficiency of wheel rim processing, and reduce the processing cycle and processing cost. Attached Figure Description

[0023] This manual includes the following figures, which illustrate the following:

[0024] Figure 1 This is a flowchart of the processing technology for the elastic wheel rim of the present invention;

[0025] Figure 2 This is a schematic diagram of the tooling structure used in step S101;

[0026] Figure 3 This is a schematic diagram of the tooling structure used in step S102;

[0027] Figure 4 This is a schematic diagram of the blade of the fourth cutting tool;

[0028] Figure 5 This is the main view of the milling fixture used in step S2;

[0029] Figure 6 This is a schematic diagram of the milling fixture structure used in step S2;

[0030] Figure 7 These are the front and side views of a drum-shaped cutting tool;

[0031] Figure 8 These are the front and side views of a circular blade;

[0032] Figure 9 This is a schematic diagram of the machining of a drum-shaped cutting tool;

[0033] Figure 10 These are the front and side views of the noise reduction groove tool;

[0034] The diagram is marked as follows:

[0035] 1. Inner rim surface; 2. Tread surface; 3. Noise-reducing groove; 4. First shim; 5. Inner chuck; 6. First base plate; 7. First cutting tool; 8. Second cutting tool; 9. Third cutting tool; 10. Fourth cutting tool; 11. Outer rim surface; 12. Wheel flange; 13. Outer chuck; 14. Second shim; 15. Second base plate; 16. Clamping actuator; 17. Third base plate; 18. Drilling tool; 19. Drum-shaped cutting tool; 20. Positioning groove; 21. Tool holder; 22. Second tool holder; 23. Fastening screw; 24. Cutting head; 25. First tool holder; 26. Circular cutting blade. Detailed Implementation

[0036] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solutions of the present invention, and to facilitate its implementation.

[0037] It should be noted that in the following embodiments, the terms "first", "second", "third" and "fourth" do not represent an absolute distinction in structure and / or function, nor do they represent the order of execution, but are merely for the convenience of description.

[0038] like Figure 1 As shown, the present invention provides a processing technology for elastic wheel rims, including the following steps:

[0039] S1. Perform turning machining on the wheel rim;

[0040] S2. Mill the wheel rim.

[0041] Specifically, such as Figure 2 and Figure 3 As shown, the wheel rim is a component of a train wheel. It has a circular structure and includes spokes, a rim, and a hub. The hub's surface includes an inner spoke surface, an outer spoke surface, an inner rim surface, an outer rim surface, a first inner surface, and a second inner surface. The inner and outer rim surfaces are the two end faces along the axial direction of the rim and are perpendicular to the wheel rim's axis. The tread is the outer circular surface of the wheel rim. The first and second inner surfaces are the inner circular surfaces of the rim and are cylindrical surfaces. The inner and outer spoke surfaces are the two end faces along the axial direction of the spokes. The two end faces, the inner spoke face and the outer spoke face are conical surfaces. The inner spoke face and the outer spoke face are coaxially arranged with the first inner side, the second inner side, the inner rim face, the outer rim face and the tread face. The inner rim face is a circular plane. One edge of the first inner side is connected to the inner edge of the inner rim face, and the other edge of the first inner side is connected to the edge of the inner spoke face. One edge of the second inner side is connected to the inner edge of the outer rim face, and the other edge of the second inner side is connected to the edge of the outer spoke face. The spokes are located between the first inner side and the second inner side.

[0042] The machining process of the wheel rim in this embodiment of the invention consists of two major processes: turning and milling. The turning process is completed on a CNC vertical lathe and is divided into two steps; the milling process is completed in one step through tool innovation.

[0043] The above-mentioned step S1 includes:

[0044] S101. Complete the machining of the inner spoke surface, sound-absorbing groove, inner rim surface, wheel flange and tread surface of the wheel rim;

[0045] S102. Complete the machining of the outer rim surface and outer spoke surface of the wheel rim.

[0046] In the above-mentioned step S101, such as Figure 2As shown, a first clamping mechanism is used to fix the wheel rim. The first clamping mechanism includes an inner claw, and multiple inner claws are provided. The inner claws are inserted into the center hole of the wheel rim and contact the second inner side surface of the wheel rim. All the inner claws are evenly distributed circumferentially with the axis of the wheel hub as the center line.

[0047] In the above-mentioned step S101, such as Figure 2 As shown, the wheel rim is supported by multiple first shims, which are in contact with the outer rim surface of the wheel rim. The first shims and inner claws are set on the first base plate, and all the first shims are evenly distributed circumferentially with the axis of the wheel hub as the center line.

[0048] In the above-mentioned step S101, such as Figure 2 As shown, the first tool is used to machine the inner rim surface, wheel flange and tread surface, the second tool is used to machine the sound-dampening groove on the first inner side surface, and the third tool is used to machine the inner spoke surface.

[0049] The finishing of the noise-absorbing groove and the first inner surface is performed using a second cutting tool. The noise-absorbing groove is an annular groove extending along the entire axial direction on the first inner surface. The dimensions of the noise-absorbing groove are indirectly ensured by measuring the diameter of the first inner surface, reducing the measurement difficulty. The first cutting tool can simultaneously machine the inner rim surface, the wheel flange, and the tread surface, ensuring excellent tread surface profile.

[0050] like Figure 10 As shown, the second tool includes a tool holder and a cutting insert. The cutting insert includes a second cutting shank and a cutting head. The cutting head is fixedly connected to one end of the second cutting shank. The second cutting shank is installed inside the tool holder, and the cutting head is located outside the tool holder and is used for cutting. The tool holder has a rectangular mounting hole for inserting the second cutting shank. The tool holder has fastening screws for locking the second cutting shank onto the tool holder. The second cutting shank has a rectangular structure. Multiple fastening screws are provided and distributed on both sides of the second cutting shank. The fastening screws contact the first and second sides of the second cutting shank respectively, applying pressure to the second cutting shank. The tool holder has threaded holes for inserting the fastening screws. The first and second sides are rectangular planes. The width direction of the first side is perpendicular to the width direction of the second side, and the length direction of the first side is parallel to the length direction of the second side. The width 'a' of the first side is 25 mm, and the width 'b' of the second side is 32 mm. The first side is clamped by two fastening screws, and the second side is clamped by one fastening screw. Existing conventional cutting tools use open slot clamping with a tool shank cross-section of 20x20mm. In this invention, the second cutting tool uses a closed rectangular slot clamping, with a tool shank cross-section of 32x25mm. Side screws are added for securing the tool and preventing movement during cutting. The larger tool shank cross-section provides higher cutting force, improving machining efficiency.

[0051] In the above-mentioned step S102, a three-jaw self-centering chuck is used to fix the wheel rim. The three-jaw self-centering chuck includes outer jaws, and multiple outer jaws are provided. The outer jaws are distributed around the outer side of the wheel rim and contact the wheel rim flange. All outer jaws are evenly distributed circumferentially with the axis of the wheel hub as the center line. All outer jaws cooperate to clamp the wheel hub.

[0052] In step S102 above, the wheel rim is supported by multiple second shims, which are in contact with the inner rim surface of the wheel rim. The second shims and the outer claws are set on the second base plate, and all the second shims are evenly distributed circumferentially with the axis of the wheel hub as the center line.

[0053] In the above-mentioned step S102, such as Figure 3 As shown, the first tool is used to machine the outer rim surface, the third tool is used to machine the outer spoke surface, and the fourth tool is used to machine a scrap line on the outer rim surface.

[0054] like Figure 3 As shown, the outer jaws clamp the wheel rim, and the roundness is calibrated to 0.02mm using the wheel rim tread as a reference. This completes the semi-finishing and finishing of the outer rim surface. A shaped scrap line tool is used to process the scrap line, completing the semi-finishing and finishing of the spokes. The fourth tool uses a custom-made shaped tool, which has high processing efficiency and produces a precise scrap line shape. The blade shape of the fourth tool is as follows... Figure 4 As shown, the blade.

[0055] In step S2 above, multiple bottom holes and beveled openings are machined on the wheel rim. The bottom holes penetrate the inner and outer spoke surfaces, which are conical surfaces. The beveled openings formed by the bottom holes on the inner and outer spoke surfaces are inclined.

[0056] In the above step S2, such as Figure 5 and Figure 6 As shown, a milling fixture is used to fix the wheel rim. The milling fixture includes a third base plate, third shims, and a second clamping mechanism mounted on the third base plate for applying pressure to the wheel rim. The second clamping mechanism includes clamping actuators and clamping heads mounted on the clamping actuators for contacting the outer rim surface of the wheel rim. Multiple clamping actuators are provided and distributed around the outer perimeter of the wheel hub. The clamping actuators are mounted on the third base plate, and all clamping actuators are evenly distributed circumferentially with the wheel hub axis as the center line. The wheel rim is supported by third shims, of which multiple third shims are provided and contact the inner rim surface of the wheel rim. The third shims are mounted on the third base plate, and all third shims are evenly distributed circumferentially with the wheel hub axis as the center line.

[0057] In this embodiment, the clamping actuator is a hydraulic cylinder. The clamping actuator controls the movement of the clamping head to achieve contact and separation between the clamping head and the wheel rim, such as... Figure 6As shown, four clamping actuators are set.

[0058] In step S2 above, a Renishaw measuring system is used to automatically complete the milling machining datum calibration. The inner rim of the wheel hoop is placed on the third shim, and after the wheel hoop is clamped, the Renishaw measuring system is used for alignment to establish a coordinate system. The rotation accuracy of the probe of the Renishaw measuring system is controlled within 0.002mm (manual rounding).

[0059] In the above step S2, such as Figure 5 and Figure 6 As shown, the wheel rim is first fixed by pressing down the outer rim surface of the wheel rim through the second clamping mechanism. Then, a drilling tool is used to drill a bottom hole on the spoke plate of the wheel rim. The bottom hole is then precision bored. Finally, a drum-shaped tool is used to process the two beveled holes formed on the inner and outer spoke plates of the bottom hole.

[0060] like Figure 7 and Figure 8 As shown, the drum-shaped cutting tool includes a first tool holder and two circular inserts mounted on the first tool holder. The circular inserts are bolted to the first tool holder, and the axes of the two circular inserts are parallel. All the circular inserts are evenly distributed circumferentially with the axis of the first tool holder as the center line. The axes of the two circular inserts are perpendicular to the axis of the first tool holder, and the axis of the first tool holder is located between the axes of the two circular inserts. A positioning groove is provided on the first end face of the circular insert, and a positioning protrusion is provided on the first tool holder for embedding in the positioning groove. The shape of the positioning protrusion matches the shape of the positioning groove, providing better positioning capability during cutting and effectively preventing the circular insert from rotating circumferentially during cutting. When the circular insert wears out and rotates, the positioning groove can accurately rotate the cutting edge by 90° or 180°.

[0061] like Figure 8 As shown, the positioning groove includes a central groove and side grooves. The central groove is a circular groove located at the center of the first end face of the circular blade. Four side grooves are located on the first end face of the circular blade. All side grooves are evenly distributed circumferentially with the axis of the central groove as the center line. The side grooves are connected to the central groove, and the included angle between two adjacent side grooves is 90°, providing a precise angular reference for blade rotation. The positioning protrusion has a first part embedded in the central groove and a second part embedded in the side grooves; four of the second parts are provided. With this structure, the circular blade can be easily rotated after wear by changing the position of the second part of the positioning protrusion embedded in the side grooves, ensuring the unworn cutting edge faces outwards. The precise fit between the positioning groove and the positioning protrusion not only ensures a stable connection of the blade but also facilitates blade rotation. Due to the precise fit between the positioning groove and the positioning protrusion, the blade can easily rotate 90° or 180°, aligning the unworn cutting edge with the cutting direction. This design not only extends the blade's service life but also improves cutting efficiency and accuracy.

[0062] like Figure 7 and Figure 8 As shown, the circular insert has a conical structure. Both the first and second ends of the circular insert are equipped with circular cutting edges. The first and second ends are opposite ends of the circular insert along its axial direction. The first end face is the end face of the first end, and the second end face is the end face of the second end. The diameter of the second end face is larger than the diameter of the first end face. The drum-shaped design allows the tool to avoid cutting interference during machining. The cutting edges at the second and first ends can respectively machine the two faces of the beveled hole.

[0063] like Figure 9 As shown, the axis of the first tool holder is parallel to the axis of the wheel rim. When machining the holes at both ends of the bottom hole, the hole on the outer spoke surface is machined first, followed by the hole on the inner spoke surface, completing the chamfering of the beveled hole. In this process, a drum-shaped beveled hole machining tool is used, breaking away from the traditional process that requires two clamping operations to complete the machining of the holes on the spoke. A single clamping operation can complete the machining of the upper and lower beveled holes of each bottom hole on the spoke; reducing the workpiece flipping, clamping, and alignment work; and in the traditional process, after the tool wears out, the tool holder needs to be disassembled and the tool replaced, and after replacement, the tool length needs to be measured and the tool compensation value reset. In this invention, a drum-shaped beveled hole machining tool is used, and the circular insert can be directly replaced or its cutting edge angle adjusted without needing to reset the tool compensation value, making it more convenient to use.

[0064] The elastic wheel rim processing technology of the present invention has the following advantages:

[0065] 1) The turning process adopts the internal clamping method, which completes the machining of the inner rim, wheel flange and tread surface in one go. The contour accuracy is good, which breaks the traditional machining method of connecting the tool at the throat and avoids the generation of the tool connecting table.

[0066] 2) The tool clamping of the noise reduction groove adopts a closed groove tool clamp, which effectively improves the strength of the tool system and realizes efficient machining of the noise reduction groove.

[0067] 3) Through process optimization, the inner circular surface and the noise reduction groove are machined in one go by a groove cutting tool. The accuracy of the noise reduction groove is indirectly guaranteed by measuring the inner circular surface size, which reduces the measurement difficulty.

[0068] 4) The inner hole of the spoke plate breaks away from the traditional milling process. A U-drill is used, which improves the strength of the drill rod. With the optimized selection of cutting tools, a direct drilling process is realized, which significantly improves the processing efficiency and greatly reduces the processing cost.

[0069] 5) An innovative drum-shaped cutting tool was designed for machining oblique holes, using a round insert with a bottom positioning groove. This allows for the completion of both oblique and reverse oblique hole machining in a single clamping operation. This changes the traditional process where reverse oblique hole machining required flipping and re-clamping for separate machining.

[0070] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A process for the manufacture of a resilient wheel rim, characterized in that, Including the following steps: S1. Perform turning machining on the wheel rim; S2. Milling the wheel rim; The process step S1 includes: S101. Complete the machining of the inner spoke surface, sound-absorbing groove, inner rim surface, wheel flange and tread surface of the wheel rim; S102. Complete the machining of the outer rim surface and outer spoke surface of the wheel rim; In step S2, multiple bottom holes and beveled openings are machined on the wheel rim.

2. The elastomeric wheel hoop machining process of claim 1, wherein, In step S101, the wheel rim is fixed by a first clamping mechanism. The first clamping mechanism includes an inner claw, and multiple inner claws are provided. The inner claws are inserted into the center hole of the wheel rim and contact the inner circular surface of the wheel rim.

3. The elastomeric wheel hoop machining process of claim 2, wherein, In step S101, the wheel rim is supported by a first shim, and multiple first shims are provided. The first shims are in contact with the outer rim surface of the wheel rim.

4. The elastic wheel rim processing technology according to any one of claims 1 to 3, characterized in that, In step S102, a three-jaw self-centering chuck is used to fix the wheel rim. The three-jaw self-centering chuck includes multiple outer jaws, which are distributed around the outer perimeter of the wheel rim and are in contact with the wheel rim flange.

5. The elastomeric wheel hoop machining process of claim 4, wherein, In step S102, the wheel rim is supported by a second shim, and multiple second shims are provided. The second shims are in contact with the inner rim surface of the wheel rim.

6. The elastomeric wheel band machining process of any one of claims 1 to 5, wherein, In step S2, a milling fixture is used to fix the wheel rim. The milling fixture includes a base plate and a second clamping mechanism disposed on the base plate for applying pressure to the wheel rim.

7. The elastomeric wheel hoop machining process of claim 6, wherein, The second clamping mechanism includes a clamping actuator and a clamping head disposed on the clamping actuator and used to contact the outer rim surface of the wheel hub. Multiple clamping actuators are provided and distributed around the outer side of the wheel hub.

8. The elastomeric wheel hoop machining process of claim 6, wherein, In step S2, a Renishaw measurement system is used to automatically complete the milling machining reference calibration.

9. The elastomeric wheel hoop machining process of claim 6, wherein, In step S2, a bottom hole is first drilled on the wheel rim, then the bottom hole is precision bored, and finally a drum-shaped tool is used to complete the machining of the two beveled holes on the front and back.

10. The elastomeric wheel hoop machining process of claim 9, wherein, The drum-shaped cutter includes two circular blades, each with a bottom positioning groove.

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