Common Process Methods In Mechanical Parts Processing

Common process methods in mechanical parts processing

In the category of machining selection, boring processing is the most common pitfall when confusing the two concepts of boring and drilling. Once the wrong process is selected, the parts will be scrapped directly.

What exactly is being processed in boring processing?

Boring is a process that is performed on boring machines or machining center equipment. It specializes in finely trimming the internal surfaces of existing holes. The core point is that the position and size of the holes must be corrected. Box-like parts , as well as engine cylinder blocks, including structural parts with multiple axes that require very high coaxiality, basically rely on the boring process to ensure that the hole positions can reach high precision and high standards.

Unlike the drilling operation that is only used to drill a hole, the cutting tools used in boring have very good rigidity and strong adjustability, so they can undertake the task of processing large-diameter holes, and can also handle high-precision hole system problems that require high accuracy. In many factories, when they make hydraulic cylinder blocks or gearbox housing products, the final step of determining the size is completely dependent on boring processing .

Don’t mix drilling and boring

Drilling is the first step in processing holes. Whether you want to drill a hole or make a blind hole, you all rely on it.

However, after the drill bit is drilled, the size deviation is quite large, so it is necessary to carry out enlarging, reaming or boring work to make the hole finer and repair it. If you use a diamond as a boring head, the accuracy of the hole position will not be able to meet the various requirements put forward in the drawing.

In actual workshop production, the common processing sequence is drilling, reaming and reaming, or a combination of drilling and boring. When box-type parts require very high coaxiality accuracy and need to be controlled within a few wires, the reaming process cannot meet the requirements. At this time, the boring process must be used. If you choose the wrong processing step, the cost of rework will be much higher than the cost of direct re-production.

Turning, milling and grinding

When we turn things like pipe rotors, parts like shafts, discs, and sleeves are inseparable from it. Milling is particularly good at processing planes, grooves, and areas with complex contours. With multi-axis linkage, curved surfaces can be processed in the future. Grinding is the final finishing step, which is to reduce the surface roughness to the micron level.

These processes are not substitutes, but relays. The gearbox may go through processes such as turning, milling, drilling, boring, and grinding from cutting to assembly. The boundaries of the respective capabilities of these processes must be clarified so that the route will not go astray.

CNC compound machining makes boring more precise

With the widespread popularization and application of turn-milling combined processing technology and five-axis linkage machining centers in industrial production, the boring process that used to have to be completed by a separate boring machine is no longer necessary to operate a boring machine.

Because the turning of the outer circumference of the workpiece, the milling of the plane and the boring of the internal holes can be completed at the same time through one clamping operation, a large part of the human error caused by multiple clampings can be directly reduced. In this way, the overall machining accuracy has been improved, and the production efficiency has also been accelerated and improved accordingly.

In the aerospace and automotive powertrain industries, composite machining is now widely used for high-end box parts that require high precision and complex structures. The measured accuracy value can be stably maintained within the range of two to three wires. The cycle time consumed by the entire production process can be about 40% faster than the previous step-by-step traditional process. This efficiency improvement is suitable for companies that need to perform boring processing in large quantities. It has strong appeal and market competitiveness.

How to choose technology for actual production

The selection of machining technology must not be based on feeling. Four factors must be comprehensively considered. These factors are the structural shape of the part, the level of accuracy, the characteristics of the material itself, and the batch size of the production.

For parts such as thin-walled boxes, the boring process should be given priority to control stress. If it is a common process method in the processing of hardened hardware mechanical parts, the grinding process is used as the final quality assurance method. When faced with large-volume production needs, the use of CNC milling can effectively reduce the overall cycle time.

First use an ordinary older lathe and a hand-operated milling cutter to do small batch trial production. The cost is relatively low. After the production volume increases, you can switch to CNC equipment to do it. This can ensure that the accuracy of repeated production is reliable. Once the process route is determined, it will not be changed. Later modifications will cause very high cost losses, so it is completely worth spending an extra two days in the early evaluation.

The trend of machining under flexible manufacturing

The digital factory sends process parameters directly to the machine tool, and the boring feed, speed, and coolant flow are all digitized. Changeover time has been reduced from hours to tens of minutes, and mixed-line production has become the norm.

In the future, machining work is definitely not a one-man show that relies on a certain process alone, but a process of coordination and scheduling of lathe processing, milling, drilling, boring and grinding in the same system. The process planning software can directly output the best path arrangement, and manual experience will return to the role of final check.

When you are producing and processing box parts, do you choose to take out the boring process step separately, or use a composite processing method to complete it? Everyone is welcome to exchange opinions in the comment area. If you think these contents are valuable, please click the like button to like it, and forward it to share with your peers and friends.