Machining technology and man-hour

Single single universal joint wheel shaft: machining technology and man-hour

1.  Processing equipment

1)  Ordinary lathe:

Lathes are mainly used for processing shafts, plates, sleeves and other workpiece with rotary surface, and are the most widely used type of machine tool processing in mechanical manufacturing. (Can achieve accuracy of 0.01mm)

2)  General milling machine:

It can process plane, groove, also can process all kinds of curved surface, gear, etc., but also can process more complex surface. (Can achieve accuracy of 0.05mm)

3) The grinding machine

Grinder is a machine tool for grinding workpiece surface. Most of the grinding machine is the use of high-speed rotary grinding wheel grinding processing, a few is the use of whetstone, belt and other abrasive tools and free abrasive processing, such as ultra-finishing machine tools, belt grinding machine, grinding machine and polishing machine. (Can achieve precision of 0.005mm, small pieces can achieve 0.002mm)

4)  The fitter

Bench work mainly includes filing, sawing, marking, drilling, reaming, tapping and threading, scraping, grinding, straightening, bending and riveting.

5)  CNC lathe

Main processing batch products, high precision parts, etc. (Can achieve accuracy of 0.01mm)

6)  CNC milling machine

CNC mainly processes batch products, high precision parts, complex parts, large parts and so on. (Can achieve accuracy of 0.01mm) (Can achieve accuracy of 0.01mm)

7)  The cutting

The electrode used for the slow wire is brass wire and for the middle wire is molybdenum wire. Slow wire processing precision is high, the surface finish is good. Processing some fine hole, fine groove, etc. (Slow wire can achieve precision of 0.003mm, middle wire can achieve precision of 0.02mm)

8)  Sparks machine

Edm can process the material and complex shape workpiece which is difficult to cut by ordinary cutting processing method (such as the groove corner of mold, small hole, malformed hole, hard alloy processing), without cutting force, without burr and knife mark grooves and other defects. It is not affected by material hardness and thermal treatment. (Can achieve accuracy of 0.005mm)

2.  Process Flow

Mechanical processing process is one of the technical documents that stipulate the mechanical processing process and operation method of parts. It is under the specific production conditions, the more reasonable process and operation method, in accordance with the prescribed form, is written into the technical documents to guide production.

The machining process of parts is composed of many processes, and each process can be divided into a number of installation, station, work step and knife.

What processes a process needs to include are determined by the complexity of the structure of the machined parts, the requirements of machining accuracy and the type of production.

Different production quantity, there are different processing technology.

Process knowledge

1)  The hole milling with accuracy less than 0.05 cannot be done, and CNC machining is needed; If it is through hole can also be wire cut.

2)  After quenching fine hole (through hole) need wire cutting processing; Blind holes need rough machining before quenching and finishing after quenching. The non-fine hole can be achieved before quenching (leaving a quenching allowance of 0.2 on one side).

3)  The width of the slot below 2MM need wire cutting processing, 3-4mm deep groove also need wire cutting processing.

4)  The minimum allowance for rough machining of hardened parts is 0.4, and that for rough machining of non-hardened parts is 0.2.

5)  Plating thickness is generally 0.005-0.008, processing should be according to the size before plating.

3.  Process hours

Time quota is the time needed to complete a process, it is the labor productivity index. According to the time quota, we can arrange the production operation plan, conduct cost accounting, determine the equipment quantity and staffing, and plan the production area. So time quota is an important part of the process.

Determine time norm should be based on the production technical conditions of this enterprise, make most workers can achieve through efforts, partial advanced workers can exceed, a few workers can achieve or close to average advanced level through efforts.

With the continuous improvement of production technology, the time quota is revised regularly to maintain the average advanced level of the quota.

The time quota is usually estimated directly by a combination of technicians and workers by summarizing past experience and referring to relevant technical data. Or it can be calculated based on the time quota of the workpiece or process of the same product by comparative analysis, or it can be determined by the determination and analysis of the actual operation time.

Process time = preparation time + basic time

Preparation time is the time consumed by workers to familiarize themselves with process documents, get blank, install fixture, adjust machine tool, disassemble fixture, etc. Calculation method: Estimate based on experience.

Base time is how long it takes to cut away the metal.