Round Concealed Shower Set,Head Rain Shower,Head Rain Shower Set With Brass Arm,Conceal Shower Faucet Set Kaiping Rainparty Sanitary Ware Technology Co.,Ltd. , https://www.rpshower.com
With the continuous advancement of automobile engine technology, there is a growing demand for higher power output, longer service life, compact design, and lower emissions. As a result, the precision and processing quality of engine cylinder bores have become more critical than ever. Among the various techniques available, platform honing has emerged as an effective solution to meet these stringent requirements.
**What is Platform Honing?**
Honing is a finishing process that uses one or more abrasive stones mounted on a honing head. These stones are expanded radially against the inner wall of the workpiece hole, creating controlled surface contact. The honing head rotates and reciprocates, while the part remains stationary—alternatively, the head may rotate while the workpiece moves back and forth. This process ensures a precise and uniform finish.
Platform honing builds upon traditional honing by introducing an additional step: the grinding of surface peaks to create small, flat platforms on the cylinder bore's surface. This technique improves several key performance aspects, such as enhancing the sealing between the piston ring and cylinder wall, reducing exhaust leakage, increasing engine power, improving the support of the cylinder bore, minimizing initial wear, and shortening the break-in period. It also helps maintain better oil film lubrication, reducing oil consumption during the piston's movement.
**Evaluation Parameters for Platform Reticulation**
To ensure the quality of the cylinder bore surface, several parameters are measured according to ISO 13565 (DIN 4776). These include:
1. **Rk (Core Roughness Depth)** – The depth of the roughness core profile after removing peaks and valleys.
2. **Rpk (Peak Height Removed)** – The average height of the peaks above the core profile.
3. **Rvk (Valley Depth Removed)** – The average depth of the valleys below the core profile.
4. **Mr1 (Support Rate at Peak)** – The percentage of the surface supported at the peak level.
5. **Mr2 (Support Rate at Valley)** – The percentage of the surface supported at the valley level.
6. **Roundness** – The difference between the largest and smallest diameters in a cross-section.
7. **Cylindricity** – The difference between the maximum and minimum dimensions across multiple vertical sections.
The relationship between these parameters and the support rate curve is illustrated in Figure 1. This Abbott curve provides a visual representation of how the surface texture affects performance.
Additionally, the correlation between surface quality evaluation items and engine performance is shown in the attached table. This data highlights how each parameter contributes to overall engine efficiency and durability.
**Process Requirements for Platform Honing**
Our company’s engine cylinder bores are designed with a non-cylinder structure, using gray cast iron (HT250) as the material. The technical specifications for platform honing include: a cylinder bore diameter of 750±0.015 mm, cylindricity ≤8 μm, roundness ≤6 μm, perpendicularity ≤0.05 mm, Rk between 0.2–0.8 μm, Rpk ≤0.3 μm, Rvk between 0.5–1.5 μm, Mr1 ≤8%, Mr2 between 65%–85%, and a mesh crossing angle of (45 ±5)°.
By adhering to these strict standards, we ensure that our engine components meet the highest levels of performance and reliability, supporting the evolving demands of modern automotive engineering.