A good mechanical process engineer must be a good processing equipment application engineer. He has a very precise and sufficient understanding of types, processing scope, structural characteristics and processing accuracy of various processing equipment in machinery industry. Combined with specific equipment of company where you work, make a reasonable equipment layout and arrangement for various processing parts and processing procedures, understand your processing advantages and processing disadvantages, you can make good use of strengths and avoid weaknesses to coordinate company's machining work.
Now, we will do a general analysis and understanding of several commonly used processing equipment in mechanical processing industry, let us have a relatively clear definition of processing equipment in this industry, and at the same time, we can also theoretically analyze a variety of processing equipment in order to better integrate practice in future work, so as to further guide our work and help our work.
Our introduction focuses on the most common processing equipment such as turning, milling, planing, grinding, boring, drilling, wire cutting and other processing equipment in machining industry, discusses types, scope of application, structural characteristics and processing accuracy of these processing equipment.

 

There are many types of lathes. According to statistics of a mechanical processing technician manual, there are as many as 77 kinds. More typical categories are: instrument lathes, single-axis automatic lathes, multi-axis automatic or semi-automatic lathes, revolver or turret lathes, crankshaft and camshaft lathes, vertical lathes, floor and horizontal lathes, profiling and multi-tool lathes, wheel spindles and shovel tooth lathes, etc., which are divided into many small classifications, number of which is different. In our machinery industry, the more commonly used are vertical lathes and horizontal lathes. These two types of lathes can be seen in almost all places where there is mechanical processing.

We mainly choose several typical lathe types to introduce application range of processing.
A. Horizontal lathes, suitable for turning internal and external cylindrical surfaces, conical surfaces, forming revolving surfaces and annular grooves, turning sections and various threads, drilling, reaming, reaming, tapping, sleeve threads and knurling processing. Although ordinary horizontal lathe has a low degree of automation and a lot of auxiliary time in processing process, because of its wide processing range and good general performance, this type of machine tool has been widely used and popularized in mechanical processing industry. It is one of typical representative processing equipment in our machinery industry and one of indispensable processing equipment in machinery processing industry.
B. Vertical lathe, suitable for processing various frame and shell parts, also suitable for processing inner and outer cylindrical surfaces, conical surfaces, end surfaces, grooves, cutting and drilling, expanding, reaming holes of various parts. With the help of additional equipment, it can also realize processing procedures such as threading, end face, profiling, milling and grinding.

A. Machining accuracy of usual horizontal lathe is as follows:
Roundness: 0.015mm; Cylindricity: 0.02/150mm; Flatness: 0.02/¢150mm; Surface roughness: 1.6Ra/μm.
B. Machining accuracy of vertical lathes is as follows:
Roundness: 0.02mm; Cylindricity: 0.01mm; Flatness 0.03mm.
Above processing accuracy is only a relative reference value, and does not mean that all lathes are in line. Many lathe equipment have a certain amount of up and down floating according to specific requirements of manufacturer and specific conditions of assembly, but no matter how large this floating amount is, processing accuracy value must meet requirements of national standard for this type of equipment. If accuracy of processing requirements does not meet requirements of national standard when purchasing equipment, purchaser has the right to refuse acceptance and payment.

 

Types of milling machine are equally complex and diverse. According to statistics of a machining technician manual, there are more than 70 types. More typical categories are: instrument milling machines, cantilever and ram milling machines, gantry milling machines, plane milling machines, profile milling machines, vertical lifting table milling machines, horizontal lifting table milling machines, bed milling machines, tool milling machines, etc., which are divided into many small classifications, number is different. In machinery industry, the more commonly used are vertical machining centers and gantry machining centers. These two types of milling machine can be seen in almost all machining places. We also give a rough introduction and analysis of these two typical milling machine.

Because there are too many types and structures of milling machine, and wide range of application is also very different, so we refer to two types of milling machine that are currently most commonly used, vertical machining center and gantry machining centers.
A. Vertical machining center (pictured above). Vertical machining center is actually a vertical CNC milling machine with a tool magazine. Its main feature is use of multi-edged rotary tools for cutting, which can perform planes, grooves, split parts, spiral surfaces and various curved surfaces. Especially with application of CNC technology, processing range of this type of machine tool has also been greatly improved. In addition to various milling operations, it can also perform complex machining such as drilling, boring, reaming and tapping on workpiece, which has a very broad practicality and popularization significance.
B. Compared with vertical machining center, gantry machining center is a composite application of CNC gantry milling machine and tool magazine. In terms of processing range, gantry machining center has almost all processing capabilities of ordinary vertical machining center, and it can adapt to processing of larger tools in the shape of parts, and also has a great advantage in processing efficiency and processing accuracy. Especially in practical application of five-axis linkage type gantry machining center, its processing range has also been greatly improved, laying a foundation for development of my country's manufacturing industry towards high precision.

A. Vertical machining center:
Flatness: 0.025/300mm; roughness: 1.6Ra/μm.
B. Longmen machining center:
Flatness: 0.025/300mm; roughness: 2.5Ra/μm.
Above processing accuracy is only a relative reference value, and does not mean that all milling machine are in line. Many milling machine equipment have a certain amount of up and down floating according to specific requirements of manufacturer and specific conditions of assembly, but no matter how large this floating amount is, its processing accuracy value must meet requirements of national standard for such equipment. If accuracy of processing requirements does not meet requirements of national standard when purchasing equipment, purchaser has the right to refuse acceptance and payment.

 

Compared with lathes and milling machines, there are far fewer types of planers. According to statistics of machining technician manual, there are about 21 types. More typical types are: cantilever planer, gantry planer, bull head planer, edge and mold planer, etc. These large categories are divided into many small types of planer products, and we have the highest utilization rate in machinery industry, and the most widely used should be cattle head planer and gantry planer. As shown in figure above, we will also target these two types below. A typical planer is used for a basic analysis and introduction.

Planing movement of planer is mainly a reciprocating linear movement relative to cycle of processed workpiece. Features of planing parts are mostly flat, inclined and concave and convex. It can also plan for various curved surfaces, but due to limitations of its own processing characteristics, speed of processing and planing is not too high, and planer of return stroke does not participate in machining and cutting of parts, so it causes loss of empty stroke, and therefore processing efficiency is relatively low.
At the same time, with great technical improvement of numerical control and automation of various other processing equipment, planing processing method has been on the verge of being gradually replaced. From perspective of many equipment upgrades now, this type of processing machine tool has not received a great upgrade and innovation. To a large extent, it still stays in original structure and layout, especially vigorous development of vertical machining centers and gantry machining centers, continuous innovation of machining tools, which has greatly replaced machining advantages of planers in terms of machining range. This kind of equipment with relatively low processing efficiency is in an awkward situation.

Precision of planing process can generally reach IT10-IT7 accuracy level, especially processing of long guide surface of some large machine tools can even replace grinding process. This is so-called "precision planing instead of fine grinding" processing method.

 

Compared with processing equipment of previous models, there are more types of grinding machines. According to statistics of a mechanical processing technologist's manual, there are about 194 types, which can be divided into instrument grinders, cylindrical grinders, and internal grinders, circular grinders, coordinate grinders, guide rail grinders, tool blade grinders, flat and end grinders, crankshaft camshaft spline and roll grinders, tool grinders, superfinishing machines, internal honing machines, external and other honing machines, polishing machine, belt polishing and grinding machine tools. Tool sharpening and grinding machine tools, indexable blade grinding machine tools, grinding machines, ball bearing ring groove grinders, roller bearing ring raceway grinding machines, bearing ring super-precision machines, blade grinding machine tools, roller processing machine tools , steel ball processing machine tools, valve piston and piston ring grinding machine tools, automobile tractor grinding machine tools, and other types. Because classification and grinding machines should be too broad, many grinding machines are some specific equipment in specific industries, so we refer to a basic introduction to grinding machines that are commonly used in machinery industry. In this article, we mainly choose cylindrical grinding machines and surface grinding machines to make a brief description.

A. Cylindrical grinders are mainly used to process outer surfaces and shoulder end surfaces of cylindrical surfaces, conical surfaces or other rotating bodies. Because of their better processing adaptability and processing accuracy, they are widely used in machining of some high-precision parts in mechanical processing, especially in final finishing process of these parts, which is commonly used. It can not only ensure geometric dimensions of processed parts to the greatest extent, but also achieve better surface finish requirements, so it is one of indispensable equipment in mechanical processing process.
B. Surface grinder, which is mainly used for processing surface of parts such as plane, step surface, side, etc., is also widely used in machinery industry, especially in processing of some high-precision parts surface, grinder is almost final guarantee of processing accuracy. Because of this, use of surface grinders is a compulsory course for most grinding operators. Even in some equipment assembly industries, use of surface grinders is also standard skill of assembly personnel, because of grinding work of various adjustment pads in assembly process depends on surface grinders.

A. Processing accuracy of cylindrical grinders:
Roundness and cylindricity: 0.003mm; surface roughness: 0.32Ra/μm.
B. Processing accuracy of surface grinder:
Parallelism: 0.01/300mm; surface roughness: 0.8Ra/μm.
From above processing accuracy, we can also clearly see that compared with previous lathe, milling machine, planer and other processing equipment, grinding machine can achieve higher behavior tolerance accuracy and surface roughness, so in many parts of finishing process, grinder is widely and commonly used.

 

Compared with previous types of processing equipment, boring machine is also a relatively small type of processing equipment. According to statistics of a mechanical processing technologist manual, there are about 23 types. From its major categories, it can be divided into following types: deep Hole boring machines, coordinate boring machines, vertical boring machines, horizontal milling boring machines, precision boring machines, boring machines for automobile and tractor repairs, etc. Among them, the most commonly used boring machines in our machinery industry should be a coordinate boring machine. Below we will make a brief introduction and analysis of some characteristics of coordinate boring machine.

There are many types of boring machines. We will give a brief introduction to coordinate boring machine. You can learn about other types of boring machines by this way. Coordinate boring machine is a precision machine tool with precise coordinate positioning device, which is mainly used for boring hole systems with high requirements on size, shape and position accuracy. It can also carry out coordinate measurement, precision scale and engraving etc. during processing, and has very wide and reliable processing characteristics.
However, with vigorous development of CNC technology, especially development of CNC vertical milling machines and CNC horizontal milling machines, boring machines, once hegemons of once hole processing equipment, are also in danger of being gradually replaced. Of course, they also has an irreplaceable objective side, but no matter what demise or development of equipment is, it is an advancement for machining industry. It is progress of technology, and it is also progress of manufacturing in our country.

Aperture precision of coordinate boring machine processing is generally IT6-7, and surface roughness is 0.4-0.8Ra/μm.
However, there is a very bad place in the processing of boring machines, especially when processing cast iron parts, it is called dirty. Therefore, based on practical reasons of such a processing link, possibility of such equipment being replaced in the future is also increasing, because who does not care about their face value?

 

This is the most widely used processing equipment in machinery industry, but every mechanical processing factory will basically have one. If you don’t even have this processing equipment, you are embarrassed to say that you are dry processing. According to statistics of a mechanical processing technologist's manual, there are about 38 kinds, which can be divided into following categories according to major categories: coordinate boring drilling machine, deep hole drilling machine, rocker drilling machine, bench drilling machine, vertical drilling machine, horizontal drilling machine, milling drilling machine, center hole drilling machine, etc. The most common thing we use in machinery industry is radial drilling machine. It is just standard for machinery processing industry. Without this equipment, you can basically not do this industry.

We mainly explain rocker drill. For this kind of machine tool, I only have one sentence here, that is, to drill various types of holes. In addition to drilling, it can also realize reaming, mortizing, tapping and other processing procedures. However, it has a big problem, that is, position accuracy of hole system is not high, so for some parts that require high position accuracy of hole system, we usually do not choose a drilling machine to achieve it.

Because there is basically no machining accuracy at all, just drilling a hole.

 

As for machining equipment such as wire cutting, I did not have much contact, so I did not have a lot of accumulation in this area, and did not do a lot of homework, so use of machinery industry is limited in its breadth, but it also has its unique existence value, especially for cutting and processing of some shaped parts, there are still some relative advantages, but in view of its low processing efficiency and vigorous development of laser machines, processing equipment such as wire cutting is gradually walking on the edge of eliminated industry.