The piston connecting rod group is an important component in the engine, and the piston rings in the piston ring work for a long time under high temperature, high pressure, and high speed, and the lubrication conditions are poor, and the wear and failure thereof are often fast. With the increase of wear and tear, the elasticity of the piston ring gradually weakens, the end play and backlash increase, and the airtightness of the cylinder deteriorates, resulting in engine oil and air leakage, which will reduce the power and economy of the engine. Therefore, it is very important to maintain the normal state of the piston ring. If the maximum cylindricity error of the cylinder reaches 0.09-0.11 mm, the piston ring should be replaced when the engine is overhauled.

First, the selection of piston rings. When replacing the optional piston ring, it should be tested and tested, and should meet the following requirements:

(1) The working surface of the ring must not have nicks, scratches, or flaking, and the external cylindrical surface finish should meet the requirements. (2) The light leakage in the circumferential direction of the ring shall not exceed two points. The sum of the central angles corresponding to the arc lengths of light leakage at each spot should not exceed 45. The gap between the two sides of the gap should not be more than 30. The maximum gap at the light leakage point should not exceed 0.03 mm. (3) The degree of warpage of the ring is generally not more than 0.02 mm. (4) The standard sinking of the piston ring in the groove must not exceed 0.15-0.25 mm. (5) The end play, backlash, backlash, elasticity, etc. of the piston ring shall comply with the regulations.

Second, the grinding of the piston ring. In the matching process, if the end play and backlash of the piston ring do not meet the requirements, it should be made to meet the requirements through grinding.

1, Piston ring end gap grinding. If the piston ring end play is too large, the cylinder seal performance will be degraded. In this case, the piston ring must be replaced. If the end play of the piston ring is too small, it may cause thermal expansion and seizure. At this time, the method of repairing the end of the ring mouth can be used to correct it. Care should be taken to keep the end face of the ring mouth flat and to adjust the edge edge amount. The outer end of the rear ring should be chamfered to prevent pulling the cylinder.

2, the piston ring plane grinding. If the backlash of the piston ring is too large, it will cause the cylinder to leak air and bleed. In this case, replace the piston ring. If the backlash of the piston ring is too small, it will cause the piston ring to get stuck in the ring groove. At this time, the piston ring ring can be repaired by turning the upper and lower surfaces of the piston ring grooves. The repair can also be performed by grinding the piston ring plane. Grinding the piston ring plane can be done on a special grinding machine or it can be manually ground on 0# sandpaper.

Third, the piston ring assembly. Piston rings are easy to break, and special fixtures should be used during installation. If there are no special fixtures, the piston ring ports can also be properly opened with two thumbs. The other four fingers protect the circumference of the ring and carefully put the ring into the piston ring groove. At the same time pay attention to the structure and installation direction of each ring:

1. The twisted ring should be distinguished positively and negatively. When installing, the inner circle cuts and chamfers, the notch is upward; the outer circle cuts and chamfers, the notch is downward; two rings are mixed, and the inner circle is cut. The first ring groove is installed in the chamfer, and the second and third ring grooves are installed in the outer groove and the chamfer.

2. Some chrome plated rings should be installed in the first ring groove. Some conical rings are marked. The side with the mark should be upward when installing.

3. To prevent the combustible mixture from leaking from the open gap of the piston ring, the opening of each ring should be staggered during assembly. With four rings, each opening is 180 apart and three rings are mounted. Each opening is 120 apart. The opening of each ring should be 45 degrees apart from the centerline of the piston pin.

4. After the piston ring is installed in the piston, apply lubricant to the ring.

The above is the problem that the piston ring should pay attention to in the selection, grinding and assembly process. When the piston ring needs to be replaced, it should follow the above principles and be replaced correctly to ensure the good performance of the locomotive. (Zhao Zhishui, Agricultural Mechanization Technology School, Xingtai City, Hebei Province)

Jinan Jianfeng Chemical Co., Ltd was established in 2011. Jianfeng has long been a supplier of pharmaceutical Intermediates, the complex chemical compounds that are the building blocks used in producing APIs. Faced with significant economic pressures as well as ever-increasing regulatory barriers, innovative drug companies look to us as a source for high quality intermediates. Jianfeng  employs, on occasion, the same second source strategy for our pharmaceutical intermediates business that we use in our API business. As manufacturers find their margins under pressure, they continue to look for ways to reduce costs. Utilizing our global sourcing regulatory support and quality assurance network, Jianfeng works with the large and small pharmaceutical companies, sourcing lower cost, quality pharmaceutical intermediates that meet the same high level standards adhered to by their current commercial products.

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