أسباب الطلب والاسطوانة في آلة الحياكة الدائرية

The smooth operation of circular knitting machines relies on precise movement in a circular direction, with most parts rotating around a common center. Regular maintenance is crucial to ensure the machine's accuracy and performance. During overhauls, besides cleaning and replacing worn parts, it's essential to inspect the installation and operation accuracy of each component. Any deviation beyond acceptable accuracy standards must be rectified promptly.

Several factors can affect the roundness and flatness of components like the needle cylinder and dial. Here are some common issues:

Factors Affecting Cylinder Roundness:

1.1. Inaccurate Gear Plate Operation:

Wear and tear in the positioning mechanisms between the base plate and gear plate, especially common in wear-resistant plate operation modes, can cause looseness or wear in the steel ball wire track (common in steel ball wire track operation modes). Similarly, wear and looseness in components like the center sleeve gear on double jersey circular knitting machines can impact cylinder roundness. To inspect, keep the machine static and place a dial indicator on a specific point of the dial bracket or needle cylinder. Apply force to the gear plate or dial tray and observe the dial indicator's pointer. Deviations less than 0.01 mm indicate excellent running accuracy, while deviations greater than 0.05 mm signal poor accuracy, making it difficult to adjust the dial's roundness within acceptable limits. In such cases, restoring the gear plate or tray's running accuracy is necessary.

1.2 Uneven Contact Surfaces between Components:

When the contact surface between the gear plate and the needle cylinder or between the dial plate and the bracket is uneven, tightening the fastening screws can lead to issues. Uneven contact surfaces result in forced compression between the components, causing elastic deformation of the needle cylinder and dial. Consequently, the roundness deviates beyond acceptable limits.

During actual operation, loosening the fastening screw and slowly rotating the gear plate can easily adjust the roundness of the needle cylinder and dial to within 0.05 mm. However, upon rechecking the roundness after tightening the screw, it often exceeds the acceptable range.

(1). Loosen the fastening screw and roughly adjust the needle cylinder and dial to form a circle with a diameter just under 0.03 mm.

(2). Position the dial indicator head on the end face of the needle cylinder or dial. Gradually tighten each fastening screw until the dial indicator needle stabilizes. Observe any decrease in the dial indicator reading, indicating a gap between the needle cylinder, needle plate, and the gear plate or bracket.

(3). If the dial indicator reading changes, place appropriately sized gaskets on both sides of the fastening screw. Continue tightening the screw until the change in the dial indicator reading is less than 0.01 mm, preferably stabilizing completely. Repeat this process for each fastening screw until all are tightened, ensuring the change in the dial indicator reading is less than 0.01 mm, indicating no gap between the components.

Note: After adjusting each screw, loosen it before proceeding to the next one to maintain a relaxed state for the needle cylinder and dial throughout the adjustment process.

(4). Inspect the round flatness of the needle cylinder and dial. If the dial indicator needle changes by more than 0.05 mm, insert a gasket to adjust it to less than 0.05 mm.

(5). Loosen the dial indicator head and place it on the side of the needle cylinder or the dial opening. Adjust the roundness of the needle cylinder and dial to less than 0.05 mm, then tighten the screws.

1.3 Cylinder Defects:

Identifying defects in the cylinder of circular knitting machines is a straightforward process. Begin by following the steps outlined in section 1.1.12 to eliminate interference factors from the gear plate and bracket. Next, attempt to adjust the roundness of the needle cylinder and needle dial as much as possible. If the roundness still exceeds 0.05 mm at this stage, meticulously record the roundness values of each point on the needle cylinder and needle dial.

Analyze these recorded data points. If the difference between the roundness values of two points on opposite corners of the needle cylinder and dial is less than 0.02 mm, yet the overall roundness of the cylinder and dial exceeds 0.05 mm, it suggests an oval shape, indicating defects in the cylinder and dial themselves.

Alternatively, if the roundness value is consistent throughout most of the circle but exceeds the standard at a specific point, and this value remains unchanged after loosening the fastening screw, it indicates biased roundness in the cylinder and dial, signaling a defective cylinder.

When detecting such defects, meticulous execution of the steps outlined in sections 1.1 and 1.2 is essential. Accurate and detailed sampling data, organized analysis, and rigorous logic are crucial. Conclusions drawn using this method are precise and withstand scrutiny.