A shot peening protection method for machined and non-machined surfaces of disc-ring forgings

Abstract

This invention belongs to the field of tooling protection for localized shot peening of machined surfaces, specifically a method for shot peening protection of both machined and non-machined surfaces of disc-ring forgings. The principle is to utilize a tooling system primarily composed of aluminum and nylon, combined with PVC pads and red lead powder, to protect the non-shot-peened areas of the part, ensuring the shot peening treatment meets design requirements. After implementing this tooling, parts processing no longer suffers from under-peening due to excessive tooling protection, nor from over-peening due to incomplete tooling shielding. Processing time has been reduced from 8 hours to 3.5 hours, and the pass rate has increased to over 99.8%. This not only improves processing efficiency but also significantly reduces production costs, laying a solid foundation for mass production of parts.

Description

Technical Field

[0001] This invention belongs to the field of tooling protection for local shot peening strengthening of machined surfaces, specifically a shot peening protection method for machined and non-machined surfaces of disc-ring forgings. Background Technology

[0002] The purpose of shot peening the surface of the rotating ring is to increase the strength and service life of the part; aluminum alloy parts are usually shot peened with glass beads with a diameter of 0.7-0.8 mm. Except for surface A and all internal holes, the rest of the part requires shot peening; the machined surfaces of the part include surface A, internal holes, fork lugs, and the lower plane; the rest are forging blank surfaces (see...). Figure 1 ).

[0003] The technical challenges faced are:

[0004] 1. There are many transition areas between the machined and non-machined surfaces of the parts;

[0005] 2. Surface A of the part is not shot-peened, and the size of surface A is greatly affected by the forging blank. During shot peening, it is difficult to completely protect the non-shot-peened area surface A with a set of tooling. The poor versatility of tooling restricts the mass production of the part.

[0006] 3. During the shot peening process, the shot particles exert a certain impact force on the tooling. After prolonged use, the tooling will deform and will not be able to completely adhere to the A side of the part, resulting in over-peening.

[0007] The commonly used protection method involves using tooling combined with medical pressure-sensitive adhesive tape to protect the A-side. To ensure effective protection, operators typically apply at least four layers of tape, ensuring alignment with the outer edges of the A-side. This is the most time-consuming and labor-intensive step in processing such parts. However, medical pressure-sensitive adhesive tape has two weaknesses: firstly, it can be shattered by shot peening, which is why at least four layers are required; secondly, its adhesive strength is significantly affected by temperature, weakening in winter. During shot peening, the tape often flips due to impact from the shot, losing its protective function and resulting in the entire A-side being shot-peened. Summary of the Invention

[0008] A shot peening protection method for machined and non-machined surfaces of disc-ring forgings has been invented. The principle is to use a tooling set with aluminum and nylon as the main materials, combined with PCV pads and red lead powder, to protect the non-shot peening areas of the parts, so that the shot peening treatment of the parts surface can meet the design requirements.

[0009] Technical solution

[0010] A shot peening protection method for machined and non-machined surfaces of disc-ring forgings, the specific operation steps are as follows:

[0011] 1. Apply red lead powder evenly to the surfaces of the parts that require protection;

[0012] 2. Print the colored side of the part onto the PVC pad. After the red lead powder dries, cut the outer contour according to the shape. Also, cut a hole larger than the stud diameter in the center of the cut PVC pad.

[0013] 3. Install the expansion tire in the center hole of the part, and lay the PVC pad on the surface of the part that needs to be protected. The PVC pad should be aligned with the surface of the part.

[0014] 4. After covering the PVC pad with the cover plate, try to ensure that the PVC pad is exposed evenly (see...). Figure 2 (Central N Zone);

[0015] 5. Place the mandrel in the expansion groove and gently apply force to open the expansion and make it fit firmly against the inner hole of the part;

[0016] 6. Install and tighten the bolts. The bolts should pass through the holes in the cover plate, PVC gasket, expansion tire, and mandrel.

[0017] 7. After the tooling is installed, there should be no gap between the protective surface of the parts and the PVC surface.

[0018] Furthermore, during shot peening, the machine tool nozzle should maintain an angle of 50° to 90° with the PVC pad.

[0019] Furthermore, the cover plate and spindle are preferably made of aluminum.

[0020] Furthermore, the mandrel should be made in a tapered shape.

[0021] Furthermore, the expansion tires are made of nylon rods.

[0022] Furthermore, the PVC plastic mat is 2mm thick and has a certain degree of hardness.

[0023] Furthermore, the cover plate should be 3mm to 4mm smaller than the surface of the part that needs protection, with a thickness of 15mm, and the cover plate should use countersunk bolt holes.

[0024] Furthermore, the thickness of the expansion tire should be determined according to the requirements of the parts, and the outer diameter of the expansion tire should be 0.08mm smaller than the hole size on the mating parts.

[0025] Furthermore, the grooves on the expanded tire are specifically cross-shaped or star-shaped, and the depth of the grooves and the tire grooves is consistent, with a depth of 15mm.

[0026] Technical effect

[0027] Practical verification has shown that the method of this invention successfully completed shot peening of the rotating ring parts without any instances of over- or under-peening, achieving the desired result in compliance with the design drawings. After implementing the tooling of this invention, the parts no longer experienced under-peening due to tooling over-protection or over-peening due to incomplete tooling shielding. The processing time has been reduced from 8 hours to 3.5 hours, and the pass rate has increased to over 99.8%. This not only improves processing efficiency but also significantly reduces production costs, laying a solid foundation for mass production of the parts.

[0028] This invention provides a protective method for forged or cast parts when partial shot peening is required. It is effective for both regular and irregular shaped areas. The tooling requires low manufacturing precision and uses readily available and affordable materials. The tooling is simple to operate, easy to learn, and has a long service life, making it suitable for widespread application in this field. Attached Figure Description

[0029] Figure 1 A schematic diagram of the machined surface of the part;

[0030] Where: N: Non-shot-peened area; A: Surface to be protected;

[0031] Figure 2 A diagram showing the part after the cover plate has been placed over it;

[0032] Among them: 1. Expansion tire; 2. PVC gasket; 3. Cover plate; 4. Mandrel; 5. Bolt; 6. Part N, Exposed part of PVC gasket.

[0033] Figure 3 This is an exploded view;

[0034] Among them: 1-Inflated tire; 2-PCV pad; 3-Cover plate; 4-Mandrel; 5-Bolt; 6-Parts Detailed Implementation

[0035] The present invention will be further described below with reference to embodiments. The following description represents only a portion of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] 1) Tooling design: The tooling consists of a cover plate, expansion tire, mandrel, PVC pad and bolts; material selection: aluminum is preferred for the mandrel of the cover plate, nylon rod is preferred for the expansion tire; PVC plastic pad is 2mm thick and has a certain degree of hardness; auxiliary material is red lead powder.

[0037] 2) Cover plate: The outer dimensions of the cover plate should be 3-4mm smaller than the A side of the part, and the thickness should be about 15mm. The countersunk bolt holes on the cover plate help to stabilize the workpiece when it is placed on the worktable.

[0038] 3) Expansion tire: The height of the expansion tire should be determined according to the needs of the parts. The outer diameter of the expansion tire should be 0.08 to 0.03 mm smaller than the inner diameter of the expansion tire to facilitate disassembly and assembly. The tire grooves on the expansion tire can be cut in a cross or star pattern. The nylon material has good shrinkage and will not damage the part body.

[0039] 4) Mandrel; The mandrel and the expansion tire are interference fit; The mating area of ​​the mandrel should be conical and guided, with a diameter 0.2-0.4 mm larger than the expansion tire groove and a length 2-4 mm smaller than the expansion tire groove; Countersunk bolt holes help ensure the workpiece is placed stably on the worktable.

[0040] 5) PVC pad: PVC plastic pads are mainly used between the cover plate and the A side of the part (the plane of the part that needs to be protected), mainly to avoid gaps in the tooling clamping; PVC plastic is easy to cut and will not be broken by the impact of shot during shot peening.

[0041] 6) Bolts: Bolts are used to fasten parts and tooling.

[0042] 7) Red lead powder: Red lead powder is mainly used for coloring the A side of parts and printing on PVC pads, and for cutting PVC pads.

[0043] 8) When shot peening, it is best to keep the angle between the machine tool nozzle and the surface of the part between 50° and 90°.

[0044] Example 1

[0045] The shot peening protection method for machined and non-machined surfaces of disc-ring forgings, with the following specific operating steps:

[0046] 1. Apply red lead powder evenly to the surfaces of the parts that require protection;

[0047] 2. Print the colored side of the part onto the PVC pad. After the red lead powder dries, cut the outer contour according to the shape. Also, cut a hole larger than the stud diameter in the center of the cut PVC pad.

[0048] 3. Install the expansion tire in the center hole of the part, and lay the PVC pad on the surface of the part that needs to be protected. The PVC pad should be aligned with the surface of the part.

[0049] 4. After covering the PVC pad with the cover plate, try to ensure that the PVC pad is exposed evenly (see...). Figure 2 (Central N Zone);

[0050] 5. Place the mandrel in the expansion groove and gently apply force to open the expansion and make it fit firmly against the inner hole of the part;

[0051] 6. Install and tighten the bolts. The bolts should pass through the holes in the cover plate, PVC gasket, expansion tire, and mandrel.

[0052] 7. After the tooling is installed, there should be no gap between the protective surface of the parts and the PVC surface.

[0053] During shot peening, the optimal angle between the machine tool nozzle and the PVC pad should be between 50° and 90°. Avoid flipping the PVC pad upwards over any areas not covered during shot peening. Aluminum is preferred for the cover plate and mandrel; aluminum parts are easier to machine and lighter than steel parts. The mandrel should be tapered, primarily for fixing parts and tooling; its maximum and minimum outer diameters should be greater than and less than the inner diameter of the expansion groove, respectively, and its thickness should ideally be at least 3mm greater than the depth of the expansion groove. The expansion groove should be made of nylon rod material; nylon material provides good toughness and will not scratch precision holes in parts. The PVC plastic pad should be 2mm thick and have a certain degree of hardness to ensure the material surface is not damaged after shot peening. The cover plate's dimensions should be 3mm to 4mm smaller than the surface of the part to be protected, with a thickness of 15mm. The cover plate uses countersunk bolt holes to help stabilize the workpiece when placed on the worktable. The thickness of the expansion groove should be determined according to the requirements of the part, and the outer diameter of the expansion groove should be 0.08mm smaller than the hole size on the mating part. The thickness of the expansion tire should be chosen to avoid interference; to facilitate the installation and removal of the expansion tire, its outer diameter should be smaller than the hole size. The grooves on the expansion tire are specifically cross-shaped or star-shaped, and the depth of the grooves and the tire grooves is consistent, with a depth of 15mm.

[0054] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A shot peening method for protecting the organic and non-organic surfaces of a disc ring type forging, characterized in that, This is achieved using a tooling system, which includes an expansion coil, a cover plate, and a mandrel. The expansion coil has grooves, and the cover plate's dimensions should be smaller than the surface of the part requiring protection. The cover plate uses countersunk bolt holes, and the mandrel has an interference fit with the expansion coil. The mandrel's mating area is tapered and has a guiding structure. The specific operating steps are as follows: 1) Apply red lead powder evenly to the surfaces of the parts that need protection; 2) Print the colored side of the part onto the PVC pad. After the red lead powder dries, cut the outer contour according to the shape. Also, cut a hole larger than the diameter of the stud in the center of the cut PVC pad. 3) Install the expansion tire in the center hole of the part, and lay the PVC pad on the surface of the part that needs to be protected. The PVC pad should be aligned with the surface of the part. 4) After covering the PVC pad with the cover plate, try to ensure that the PVC pad is exposed evenly; 5) Place the mandrel in the groove of the expansion coil and gently apply force to open the expansion coil so that it fits snugly against the inner hole of the part; 6) Install and tighten the bolts. The bolts should pass through the holes in the cover plate, PVC gasket, expansion tire, and mandrel. 7) After the tooling is installed, there should be no gap between the protective surface of the parts and the PVC surface.

2. The shot peening protection method for machined and non-machined surfaces of disc-ring forgings according to claim 1, characterized in that, When shot peening, the machine tool nozzle should be kept at an angle of 50° to 90° with the PVC pad.

3. The shot peening protection method for machined and non-machined surfaces of disc-ring forgings according to claim 1, characterized in that, The cover plate and mandrel are made of aluminum.

4. The shot peening protection method for machined and non-machined surfaces of disc-ring forgings according to claim 1, characterized in that, The mandrel should be made in a tapered shape.

5. The shot peening protection method for machined and non-machined surfaces of disc-ring forgings according to claim 1, characterized in that, The tires are made of nylon rods.

6. The shot peening protection method for machined and non-machined surfaces of disc-ring forgings according to claim 1, characterized in that, The PVC plastic mat is 2mm thick and has a certain degree of rigidity.

7. The shot peening protection method for machined and non-machined surfaces of disc-ring forgings according to claim 1, characterized in that, The cover plate is 15mm thick.

8. The shot peening protection method for machined and non-machined surfaces of disc-ring forgings according to claim 1, characterized in that, The thickness of the expansion tire should be determined according to the requirements of the parts, and the outer diameter of the expansion tire should be 0.08mm smaller than the hole size on the mating parts.

9. A shot peening protection method for machined and non-machined surfaces of disc-ring forgings according to claim 1, characterized in that, The grooves on the expanded tire are specifically cross-shaped or star-shaped, and the depth of the grooves and the tire grooves is consistent, with a depth of 15mm.

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