Three-step honing process method for aluminum-silicon alloy cylinder sleeve

Abstract

The invention discloses a three-step honing process method for an aluminum-silicon alloy cylinder sleeve, and relates to the technical field of cylinder sleeve honing processes, and the three-step honing process method specifically comprises the following steps: S1, rough honing: a diamond honing oilstone is mounted on a honing head, the interior of the aluminum-silicon alloy cylinder sleeve is honed, and the honing head reciprocates while rotating to form crossed net-shaped honing lines; s2, fine honing is conducted, specifically, a rubber strip is installed on a honing head, Al2O3 particles are evenly sprayed to the surface of the cylinder sleeve, then honing is conducted on the interior of the aluminum-silicon alloy cylinder sleeve, the honing head conducts reciprocating motion while rotating, and silicon particles on the surface protrude; and S3, laser finish machining is conducted, specifically, a laser probe extends into the cylinder sleeve, the characteristic that laser is rapidly cooled after being rapidly heated is utilized, the laser probe rapidly scans the whole inner wall of the cylinder sleeve step by step in sequence in the circumferential direction, and honed machining burrs are removed through heat of the laser. The method is simple in operation process, good in antifriction and wear-resistant effect, capable of prolonging the service life of the engine and suitable for industrial application and popularization.

Description

Technical Field

[0001] The invention relates to the technical field of cylinder liner honing technology, and in particular to a three-step honing process for an aluminum-silicon alloy cylinder liner. Background Art

[0002] Aluminum-silicon alloy cylinder liners are lighter than traditional cast iron cylinder liners and have good application prospects in the field of small and medium-power engines. They are one of the important components to achieve the goal of lightweight vehicles. However, their wear resistance is insufficient, which restricts their widespread application. In terms of improving wear resistance, domestic and foreign scholars have conducted a lot of research. Some scholars focus on refining the size of silicon particles to increase the strength and hardness of aluminum-silicon alloys, while others process the surface of aluminum-silicon alloys.

[0003] Honing is an effective surface processing technology for reducing friction and making cylinder liners wear-resistant. For round barrel-shaped cylinder liners, the oilstone is assembled on the honing head, and the honing head rotates inside the cylinder liners while performing reciprocating motion, producing a mesh of honing patterns on the inner wall of the cylinder liners. These mesh honing patterns form an oil delivery path, which improves the lubrication performance of the cylinder liners and has a good effect of reducing friction and wearing. At present, almost all cylinder liners shipped out of the factory have been honed. The honing process has been developed for decades on traditional cast iron cylinder liners and is recognized by the industry as a means of reducing friction and wearing of cylinder liners.

[0004] However, in terms of aluminum-silicon alloy cylinder liners, the traditional honing process is not very effective in improving friction reduction and wear resistance. It is found that the surface of the aluminum-silicon alloy cylinder liners after honing is relatively rough, and the damaged corners of silicon particles are easy to scratch the piston rings. The debris dropped by the damaged corners of silicon particles during friction will cause abrasive wear and increase the amount of wear. If the wear of the cylinder liner increases, it will cause oil leakage and poor emissions, shortening the service life of the engine. Based on this, for lightweight cylinder liners made of "soft matrix + hard particles" materials such as aluminum-silicon alloy, it is a technical problem that technical personnel in this field urgently need to solve to develop a honing process with simple operation process, good honing effect, and suitable for production lines. Summary of the invention

[0005] In view of the above problems, the present invention provides a three-step honing process for an aluminum-silicon alloy cylinder liner.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: The present invention provides a three-step honing process for an aluminum-silicon alloy cylinder liner, which specifically comprises the following steps: S1: Rough honing: Install the diamond honing oilstone on the honing head to hone the inside of the aluminum-silicon alloy cylinder liner. The honing head reciprocates while rotating to form a cross-net honing pattern. S2: Fine honing: Install the rubber strip onto the honing head, and evenly spray Al2O3 particles onto the surface of the cylinder liner, and then hone the inside of the aluminum-silicon alloy cylinder liner. The honing head reciprocates while rotating, so that the silicon particles on the surface protrude, and the corners of the silicon particles are polished and rounded in the process, thereby obtaining a surface structure with protruding silicon particles and chamfered corners; S3: Laser finishing: Insert the laser probe into the cylinder liner, and use the characteristics of rapid heating and rapid cooling of the laser to quickly scan the entire inner wall of the cylinder liner in a circular direction step by step. Use the heat of the laser to remove the burrs after honing, making the contour of the protruding silicon particles smoother. Under the influence of heat, the silicon particles are more closely combined with the aluminum matrix and are not easy to fall off.

[0007] Furthermore, in step S1, the rotation speed of the honing head is 180 r / min, the reciprocating speed is 20 m / min, the pressure is 36 bar, and the time is 40-60 s.

[0008] Furthermore, in step S2, the rotation speed of the honing head is 100 r / min, the reciprocating speed is 5-10 m / min, the pressure is 5-10 bar, and the time is 3-5 min.

[0009] Furthermore, in step S3, the laser power is 200 W-500 W, and the speed is 800 mm / min-1000 mm / min.

[0010] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, through rough honing and fine honing, a network honing pattern appears on the surface of the cylinder liner, and silicon particles on the surface are protruding and the corners are chamfered; through laser finishing, on the one hand, the processing burrs after honing are removed, and a structure with protruding silicon particles and rounded and smooth corners is obtained, and on the other hand, the aluminum matrix after laser is quickly melted and quickly cooled to form, and under the action of surface energy, it is more tightly combined with the edges of the silicon particles, thereby increasing the firmness of the silicon particles protruding on the surface and making it difficult to fall off; through the three-step honing process of rough honing, fine honing and laser finishing, a structure with a network honing pattern and protruding silicon particles on the surface and rounded and smooth corners is obtained, on the one hand, the oil storage space is increased, thereby improving the lubrication effect, and on the other hand, the structure with protruding silicon particles and rounded and smooth corners is not easy to scratch the grinding piston ring, the silicon particles are more tightly combined with the aluminum matrix, the probability of abrasive wear is reduced, and the overall friction reduction and wear resistance effect of the aluminum-silicon cylinder liner-piston ring pair is enhanced, thereby extending the service life of the engine. The method of the invention has simple operation process, good friction reduction and wear resistance effect, can prolong the service life of the engine, and is suitable for industrial application and promotion. DETAILED DESCRIPTION

[0011] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0012] The instruments, reagents, materials, etc. involved in the following examples, unless otherwise specified, are all conventional instruments, reagents, materials, etc. in the prior art and can be obtained through regular commercial channels. The experimental methods, detection methods, etc. involved in the following examples, unless otherwise specified, are all conventional experimental methods, detection methods, etc. in the prior art.

[0013] Example 1 This embodiment provides a three-step honing process for an aluminum-silicon alloy cylinder liner, which specifically includes the following steps: S1: Rough honing: Install the diamond honing oilstone on the honing head and hone the inside of the aluminum-silicon alloy cylinder liner. The speed of the honing head is 180 r / min. The honing head reciprocates while rotating. The reciprocating speed is 20 m / min, the pressure is 36 bar, and the time is 40 s, forming a cross-net honing pattern. S2: Fine honing: Install the rubber strip on the honing head, and evenly spray Al2O3 particles with a particle size of 3 μm on the surface of the cylinder liner, and then hone the inside of the aluminum-silicon alloy cylinder liner. The honing head rotates at a speed of 100 r / min. The honing head reciprocates while rotating, so that the silicon particles on the surface protrude, and the corners of the silicon particles are polished and rounded in this process, thereby obtaining a surface structure with protruding silicon particles and chamfered corners. The honing speed of this step should not be too fast, and the pressure should not be too high. Among them, the reciprocating speed is 5 m / min, the pressure is 5 bar, and the time is 3 min. At this time, the protruding height of the silicon particles is 2 μm; S3: Laser finishing: Insert the laser probe into the cylinder liner with a laser power of 200 W and a speed of 800 mm / min. Utilize the characteristics of rapid heating and rapid cooling of the laser to quickly scan the entire inner wall of the cylinder liner in a circular direction. Use the heat of the laser to remove the burrs after honing and make the outline of the protruding silicon particles smoother. Moreover, under the influence of heat, the silicon particles are more closely combined with the aluminum matrix and are not easy to fall off.

[0014] Example 2 This embodiment provides a three-step honing process for an aluminum-silicon alloy cylinder liner, which specifically includes the following steps: S1: Rough honing: Install the diamond honing oilstone on the honing head and hone the inside of the aluminum-silicon alloy cylinder liner. The speed of the honing head is 180 r / min. The honing head reciprocates while rotating. The reciprocating speed is 20 m / min, the pressure is 36 bar, and the time is 50 s, forming a cross-net honing pattern. S2: Fine honing: Install the rubber strip on the honing head, and evenly spray Al2O3 particles with a particle size of 6 μm on the surface of the cylinder liner, and then hone the inside of the aluminum-silicon alloy cylinder liner. The honing head rotates at a speed of 100 r / min. The honing head reciprocates while rotating, so that the silicon particles on the surface protrude, and the corners of the silicon particles are polished and rounded in this process, thereby obtaining a surface structure with protruding silicon particles and chamfered corners. The honing speed of this step should not be too fast, and the pressure should not be too high. Among them, the reciprocating speed is 8 m / min, the pressure is 8 bar, and the time is 4 minutes. At this time, the protruding height of the silicon particles is 3 μm; S3: Laser finishing: Insert the laser probe into the cylinder liner, with a laser power of 350 W and a speed of 900 mm / min. Utilize the characteristics of rapid heating and rapid cooling of the laser to quickly scan the entire inner wall of the cylinder liner in a circular direction. Use the heat of the laser to remove the burrs after honing, making the contour of the protruding silicon particles smoother. Moreover, under the influence of heat, the silicon particles are more closely combined with the aluminum matrix and are not easy to fall off.

[0015] Example 3 This embodiment provides a three-step honing process for an aluminum-silicon alloy cylinder liner, which specifically includes the following steps: S1: Rough honing: Install the diamond honing oilstone on the honing head and hone the inside of the aluminum-silicon alloy cylinder liner. The speed of the honing head is 180 r / min. The honing head reciprocates while rotating. The reciprocating speed is 20 m / min, the pressure is 36 bar, and the time is 60 s, forming a cross-net honing pattern. S2: Fine honing: Install the rubber strip on the honing head, and evenly spray Al2O3 particles with a particle size of 10 μm on the surface of the cylinder liner, and then hone the inside of the aluminum-silicon alloy cylinder liner. The honing head rotates at a speed of 100 r / min. The honing head reciprocates while rotating, so that the silicon particles on the surface protrude, and the corners of the silicon particles are polished and rounded in this process, thereby obtaining a surface structure with protruding silicon particles and chamfered corners. The honing speed of this step should not be too fast, and the pressure should not be too high. Among them, the reciprocating speed is 10 m / min, the pressure is 10 bar, and the time is 5 min. At this time, the protruding height of the silicon particles is 4 μm; S3: Laser finishing: Insert the laser probe into the cylinder liner with a laser power of 500 W and a speed of 1000 mm / min. Utilize the characteristics of rapid heating and rapid cooling of the laser to quickly scan the entire inner wall of the cylinder liner in a circular direction. Use the heat of the laser to remove the burrs after honing and make the protruding silicon particles smoother. Moreover, under the influence of heat, the silicon particles are more closely combined with the aluminum matrix and are not easy to fall off.

[0016] Comparative Example 1 Traditionally honed aluminum-silicon alloy cylinder liner (the inner wall of the cylinder liner is processed using an oilstone embedded in the honing head).

[0017] The chromium-based ceramic composite plated piston ring was used to conduct a sample-level friction and wear test with the conventionally honed aluminum-silicon alloy cylinder sleeve in the above-mentioned comparative example 1 and the cylinder sleeve of the honing process of the present embodiment 1-3. The test process was fully oiled, and the temperature was 150°C, the load was 10MPa, and the speed was 200 r / min. The test time was 24h, and the friction coefficient and wear amount of the two pairs were measured. The friction coefficient was obtained by dividing the average value of the dynamic friction force measured by the reciprocating wear tester by the pressure, that is, μ=F / N; the wear amount was obtained by the difference in weight before and after the test, that is, weight before the test-weight after the test. Each group was measured 3 times, and the results are shown in Table 1.

[0018] Table 1 Friction coefficient and wear measurement results (average value)

[0019] The experimental results show that the friction coefficient and wear amount of the aluminum silicon cylinder liner produced by the honing process of this embodiment are reduced by more than 20% compared with those produced by the traditional honing process.

[0020] In this embodiment, through rough honing and fine honing, a network of honing patterns appears on the surface of the cylinder liner, and the silicon particles on the surface are protruding and the corners are chamfered; through laser finishing, on the one hand, the processing burrs after honing are removed to obtain a structure with protruding silicon particles and smooth rounded corners, and on the other hand, the aluminum matrix after laser is quickly melted and quickly cooled to form, and under the action of surface energy, it is more tightly combined with the edges of the silicon particles, thereby increasing the firmness of the silicon particles protruding on the surface and making them not easy to fall off; through the three-step honing process of rough honing, fine honing and laser finishing, a structure with a network of honing patterns and protruding silicon particles on the surface and smooth rounded corners is obtained, which, on the one hand, increases the oil storage space, thereby improving the lubrication effect, and on the other hand, the structure with protruding silicon particles and smooth rounded corners is not easy to scratch the grinding piston ring, and the silicon particles are more closely combined with the aluminum matrix, which reduces the probability of abrasive wear, enhances the overall friction reduction and wear resistance of the aluminum-silicon cylinder liner-piston ring pairing, thereby extending the service life of the engine.

[0021] In summary, the method provided in this embodiment can achieve a mesh-like honing pattern on the aluminum-silicon alloy cylinder liner while the silicon particles protrude from the surface to carry the load, and the edges and corners are rounded, with fewer burrs on the entire surface, forming a relatively smooth concave and convex contour line, a large oil storage space, and the piston ring is not easily damaged during friction, thereby improving the friction reduction and wear resistance effect, and the operation process is simple, which is particularly suitable for industrial application promotion.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-step honing process for aluminum-silicon alloy cylinder liners. Features: The specific steps include: S1: Rough honing: Install the diamond honing oilstone on the honing head to hone the inside of the aluminum-silicon alloy cylinder liner. The honing head reciprocates while rotating to form a cross-net honing pattern. S2: Fine honing: Install the rubber strip on the honing head and spray Al evenly on the surface of the cylinder liner. 2 O 3 The inside of the aluminum-silicon alloy cylinder liner is honed, and the honing head reciprocates while rotating, so that the silicon particles on the surface are protruded, and the corners of the silicon particles are polished and rounded in the process, thereby obtaining a surface structure with protruding silicon particles and chamfered corners; S3: Laser finishing: Insert the laser probe into the cylinder liner, and use the characteristics of rapid heating and rapid cooling of the laser to quickly scan the entire inner wall of the cylinder liner in a circular direction step by step. Use the heat of the laser to remove the burrs after honing, making the contour of the protruding silicon particles smoother. Under the influence of heat, the silicon particles are more closely combined with the aluminum matrix and are not easy to fall off.

2. A three-step honing process for aluminum-silicon alloy cylinder liners according to claim 1, Features: In step S1, the rotation speed of the honing head is 180 r / min, the reciprocating speed is 20 m / min, the pressure is 36 bar, and the time is 40-60 s.

3. The three-step honing process for aluminum-silicon alloy cylinder liner according to claim 1, Features: In step S2, the rotation speed of the honing head is 100 r / min, the reciprocating speed is 5-10 m / min, the pressure is 5-10 bar, and the time is 3-5 min.

4. The three-step honing process for aluminum-silicon alloy cylinder liner according to claim 1, Features: In step S3, the laser power is 200 W-500 W, and the speed is 800 mm / min-1000 mm / min.

Images