In recent years, processing technology has become more and more advanced, and the machining industry has entered a new stage of higher precision and faster efficiency. Today, we bring you the latest machining process and quotation. Let's see if the price of your factory is similar?
01 Different machining equipment
In machining, different equipment has different "skills" and is responsible for specific tasks. Choosing the right equipment and using it well are the keys to improving efficiency and product quality.
1) Ordinary lathe
Ordinary lathe is a common "old friend" in machining. It is mainly used to process workpieces with rotating surfaces such as shafts and disks. It can accurately process outer circles, inner holes and conical surfaces by cooperating with the rotation of the workpiece and the movement of the tool. Ordinary lathes are widely used and can meet the processing needs of most parts. The accuracy can reach 0.01mm. It is an indispensable "basic player" in the factory.
2) Ordinary milling machine
Ordinary milling machines are mainly used to process planes and grooves, and the tool is driven to cut the workpiece by the rotation of the spindle. It has high flexibility and is suitable for processing small and medium-sized parts. The accuracy is generally around 0.05mm. It is often used for the initial processing of parts or scenes with moderate accuracy requirements.
3) Grinding machine
It is a device specially used for precision surface processing. It can obtain extremely high surface finish by grinding the workpiece with a high-speed rotating grinding wheel. The processing accuracy of the grinder usually reaches 0.005mm, and even 0.001mm can be achieved for small parts. It is a key equipment to ensure the surface quality of the workpiece.
4) Benchwork
Benchwork is a traditional manual processing method, including operations such as filing, sawing, drilling, and tapping. It is suitable for small batch production or detailed finishing of parts. Although CNC equipment is now popular and there are fewer benchwork jobs, it is still an irreplaceable part of the factory in finishing complex parts and assembly.
5) CNC lathe
CNC lathe is the "efficiency king" of modern production. It combines the functions of traditional lathes and the precise control of CNC technology. It is particularly suitable for processing high-precision parts. It is programmed for automated operation, with high efficiency and stable processing accuracy within 0.01mm. It is an ideal tool for processing complex parts and large-scale products.
6) CNC milling machine
CNC milling machine can handle products with complex shapes. Through multi-axis linkage, it can not only complete ordinary milling, but also process three-dimensional curved surfaces and mold parts. Its accuracy can reach within 0.01mm.
7) Wire cutting
Wire cutting is specially used to process high-precision holes, slots and other through-shapes. Slow wire cutting can achieve an accuracy of up to 0.002mm, which is suitable for high-precision processing in the mold industry. Medium wire cutting is suitable for scenes with slightly lower precision requirements, with an accuracy of about 0.02mm.
8) Spark machine
Spark machine specializes in processing materials with complex shapes and high hardness, such as grooves, small holes, and special-shaped holes in molds. Since there is no cutting force during the processing, no burrs or knife marks are generated, the quality is guaranteed, and the accuracy can reach 0.005mm. It is a "master" in mold manufacturing and high-hardness material processing.
02 Process flow
Mechanical processing is a rigorous and intelligent job. Its core is the "process specification", which is a detailed operating guide that guides us to turn parts from blanks into finished products that meet the requirements step by step. The process specification is like a construction drawing, which clarifies the processing flow and operation methods of each step to ensure that the whole process is efficient and orderly.
The entire machining process is usually divided into several processes, and each process is further divided into specific steps such as installation, workstation, work step and tool path. Whether the process design is good or not depends on the structural complexity, precision requirements and production scale of the parts. For example, large parts produced in batches may require efficient CNC equipment, while single-piece or small-batch production may require traditional lathes or benchwork to assist in processing.
Formulating a process flow is a very important step in machining. It is necessary to ensure the precision and surface quality of the parts and to maximize efficiency. In addition, the flexibility of the process specification is also very important to meet different processing requirements.
Some common process points:
1) Holes with a precision of less than 0.05 cannot be milled by CNC; if it is a through hole, it can also be wire cut.
2) Fine holes (through holes) after quenching require wire cutting; blind holes require rough machining before quenching and fine machining after quenching. Non-precision holes can be made in place before quenching (with a quenching allowance of 0.2 on one side).
3) Slots with a width of less than 2mm require wire cutting, and 3~4mm grooves with a very deep depth also require wire cutting.
4) The minimum allowance for rough machining of quenched parts is 0.4, and the allowance for rough machining of non-quenched parts is 0.2.
5) The thickness of the coating is generally 0.005~0.008mm, and the processing should be based on the pre-plating size.
03 Process working hours
The time quota is the time required to complete a process, which is an indicator of labor productivity. According to the time quota, production operation plans can be arranged, cost accounting can be carried out, the number of equipment and staffing can be determined, and the production area can be planned. Therefore, the time quota is an important part of the process specification.
The time quota should be determined based on the production and technical conditions of the enterprise, so that most workers can achieve it through hard work, some advanced workers can exceed it, and a few workers can reach or approach the average advanced level through hard work.
With the continuous improvement of the production and technical conditions of the enterprise, the time quota is revised regularly to maintain the average advanced level of the quota.
The time quota is usually determined by the combination of process personnel and workers, by summarizing past experience and referring to relevant technical data. Or it can be calculated based on the time quota of workpieces or processes of similar products, or it can be determined by measuring and analyzing the actual operation time.
Process time = preparation time + basic time
Preparation time is the time consumed by workers to familiarize themselves with process documents, receive blanks, install fixtures, adjust machine tools, disassemble fixtures, etc.
Calculation method: Estimate based on experience. Basic time is the time consumed to cut metal.
04 Quotation cost calculation method
Machining quotation is directly related to whether the company can survive. In such a competitive market environment, if the machining plant cannot make a reasonable profit, the processing quality will definitely be affected. Therefore, everyone in the industry should focus on win-win cooperation and work together to promote the machining industry towards high-quality and sustainable development to form a virtuous circle.
Cost of processed parts = (material cost + processing fee) * 1.2 [1.2 coefficient includes management fee]
Equipment cost = (material cost of processed parts + processing fee + purchased product cost + assembly and debugging fee + design fee) * 1.2 [1.2 coefficient includes management fee]
Material cost = weight (density * volume) * unit price (yuan/kg)Processing fee = process time * unit price (yuan/hour)Design fee = work time * unit price (yuan/hour)
Japanese purchase cost (yuan) = purchase price (yen) / exchange rateDomestic purchase cost is based on supplier quotation
Quotation reference:
1) Lathe: 60 yuan/hour. 2) Milling machine: 60 yuan/hour. 3) Grinding machine: 60 yuan/hour. 4) Fitter: 80 yuan/hour. 5) Machining center: 60~120 yuan/hour. 6) CNC lathe: 60~120 yuan/hour. 7) Spark machine: 80~150 yuan/hour. 8) Slow wire cutting: 60~150 yuan/hour; small pieces start at 80 yuan, large pieces are based on area: 0.06~0.08 yuan/mm². 9) Fine hole discharge: carbon steel, tungsten steel, Φ0.3 and above 1 yuan/mm, Φ0.3 below 2~3 yuan/mm; Φ0.3 and above 1.8~2 yuan/mm. 10) Management fee: cost price*0.2.
