The hottest oil-free technology has become the dev

2022-08-09
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Oil free technology has become the development direction of sewing machines

oil free technology of machine head is an important direction developed by famous sewing machine companies in the world in recent years. In the s, the development of sewing machines in the world took increasing speed as a breakthrough to improve sewing efficiency. Sewing machine products with high speed as the performance index of sewing machine products were particularly popular in the market. For a time, high-speed has become a major buying point of sewing machine sales in the world

as a result, the running speed of sewing machines has developed from 3000 rpm in the 1950s to 4500, 5000, 6000 rpm, especially for over sewn 1471 machine products. By the 1970s, enterprises in the world had launched products up to 10000 rpm, known as ultra-high speed sewing machines. However, due to the high-speed operation mode of sewing machines, the general system of machines must adopt a structure to ensure high-speed and stable operation. In general, the traditional way is to use the lubrication system to add grease and oil to each motion pair inside the sewing machine. When the running speed of the machine is below 3000 rpm, it is generally used to add lubricant to the motion pair, such as adding butter to the gear motion pair, regularly dripping lubricating oil to the sliding pair of the needle bar mechanism, and dripping lubricating oil to the rotary shuttle in the thread hook mechanism and the rolling pairs of the shaft sleeves of the machine, The way of regular dripping of lubricating oil is adopted in the rolling pair of the shaft sleeve and bearing of the take-up mechanism, and the way of regular dripping of lubricating oil is adopted in the rolling pair of the shaft sleeve and bearing of the feeding mechanism. This lubrication method is widely used in sewing machine products with an average speed of less than 3000 rpm, such as household sewing machines, low-speed industrial flat sewing machines, medium speed industrial flat sewing machines, medium speed overlock sewing machines, etc

however, due to the requirements of the high-speed trend of the sewing machine, the sewing machine, as a mechanical system, the sliding friction pair thread speed and rolling friction pair thread speed of the motion pair of each motion mechanism are also greatly improved. There are a large number of motion pairs in the sewing machine. Under the condition of high-speed line, it is impossible to only use lubricating oil drip or grease to ensure the stability of the lubricating film supporting the normal operation of the motion pair in the motion component of the motion pair under the condition of high-speed line. Often, under the condition of high line speed, the lubricating film supporting the normal operation of the moving pair in the moving components of the moving pair is damaged, and the moving components of the moving pair lose the lubricating film, so that the moving components of the moving pair work without lubricating film, Even if two relatively sliding or rolling moving components carry out dry friction at a high-speed of 10 ~ 15 m/S (the linear speed of the rotary shuttle guide rail reaches 15 m/s under the working condition of 5000 needles/min), the mechanical motion theory proves that the dry friction cannot be sustained without the adoption of allowable dry friction measures. Under the working condition of 10 ~ 15 m/s high-speed line, the dry friction between the two moving components of the moving pair will soon cause the moving component to generate heat, form high temperature, scorch and melt the surface of the moving component material, and finally bite the structural moving component due to the dry friction movement

therefore, according to the requirements of mechanical motion theory, when the lubricating film of the moving pair in the mechanical structure is unstable, the structural mode of forced lubrication must be adopted in the mechanical system to solve the problem of maintaining the stability of the lubricating film in the moving pair after the mechanical motion speed is accelerated. Therefore, after the speed of industrial sewing machine products exceeded 4000 rpm, in the general system of sewing machine, the way of built-in lubrication pump is more often used, and the lubrication pump is forced to supply lubricating oil to each moving pair, so that the moving pair can maintain the stability of lubricating film under the condition of high-speed in the sewing machine system, so as to ensure the long-term and stable normal operation of each moving pair

however, sewing machines are equipment for sewing clothes, shoes, hats, bags, etc. these products have strict quality requirements without oil pollution in the processing process. Therefore, it is a basic requirement of garment, shoes and hats, bags and other product manufacturers that the sewing machine does not leak oil during the sewing process

in this way, on the one hand, because the sewing machine wants to improve the sewing efficiency and the sewing speed, and because the sewing speed is increased, a forced lubricating oil supply system must be established in the sewing machine system to ensure that the sewing machine can work normally for a long time and stably; On the other hand, due to the requirements of the sewing object of the sewing machine, during the sewing process, the sewing material must not be stained with oil and pollution-free quality requirements, that is, the sewing machine had better not use lubricating oil. This contradiction has always been the contradiction between the manufacturers of sewing machine products and the users of sewing machine products, and it is also the technical problem currently faced by the world's sewing machine R & D personnel

in the past few decades, sewing machine manufacturers have adopted the following technical methods to prevent oil pollution in the production of high-speed sewing machine products:

first, strengthen sealing and reduce the possibility of oil leakage

control the oil supply and reduce the possibility of oil leakage. For example, the mating parts of the rolling pair to be exposed are generally sealed with sealing rings, such as the upper shaft rear sleeve on the lockstitch machine, the hand shaft of the inverted loose rod plate, etc

the second is to improve the accuracy of fitting

in the exposed sliding pair, it is generally used to improve the accuracy of fitting and the wear resistance of the sliding pair components, so as to ensure that the accuracy of fitting will not be reduced and the clearance of fitting will increase due to the wear of the components of the mechanism after friction, and the lubricating oil will seep or leak out from the clearance of fitting, such as the needle bar and presser foot bar on the lockstitch sewing machine

third, establish a stable oil supply and return oil volume balance system in the parts prone to oil leakage

for example, in the needle bar mechanism and thread take-up mechanism of the flat sewing machine, there is a special oil supply pump mechanism inside the sewing machine to forcibly supply oil to ensure the normal operation of the motion pair because the friction of the motion pair in the two motion mechanisms is relatively large. At the same time, in order to prevent excessive oil supply from causing excessive oil storage in the small oil storage tank in the inner cavity of the shell face, a return oil pump mechanism is specially set to suck away the oil storage in the small oil storage tank in the inner cavity of the shell face, so that the excess lubricating oil supplied to the needle bar mechanism and thread take-up mechanism can be sucked out in time, forming an oil balance system of oil supply and return. However, when the oil return pump fails or the oil supply quantity is greater than the oil return quantity, the oil stored in the small oil storage tank in the inner cavity of the shell face cannot suck out the oil supply in time, and the oil will soon fill the needle rod sleeve from the small oil storage tank, and the lubricating oil will seep out in the up and down sliding process of the needle rod, so the oil leakage problem of the needle rod will appear

in the past few decades, although the R & D personnel of sewing machines have tried their best to find a way, they have never been satisfied with the solution, which eventually became a headache for users in use, seriously affecting the quality of sewing products. In order to ensure the quality of sewn products, in the last century, some sewing factories wore a mask under the face of the sewing machine casing used, and used the mask to absorb the oil seeping from the needle bar to prevent the oil from polluting the sewing products, which became a great spectacle of sewing factories. However, after the sewing machine has been used for two years, this problem becomes more and more serious, which has become a common problem in the use of high-speed lockstitch machines or the maximum tension value (the maximum tension can be recorded) when the terminal and harness are deformed directly

therefore, solving the problem of oil leakage of sewing machines has always been the goal of our sewing machine manufacturers and an important direction for the development of flat sewing machines

at this exhibition, domestic and foreign enterprises have launched oil-free high-speed flat sewing machine products, which is the embodiment of such requirements, which is the new trend of technological development transmitted by this International Sewing equipment exhibition

the oil-free technology product that entered China relatively early is the 885 series high-speed flat sewing machine co produced by Italian nanci company in Tianjin. Five or six years ago, Japan's brother companies launched db2-dd7100 series of high-speed lockstitch machines, playing the sales banner of oil-free technology, which attracted the attention of peers in the world. Then, heavy machinery company launched ddl-9000 series of high-speed lockstitch machines, and also carried out large-scale publicity with oil-free technology. Later, Japan Steel Shengjia company and Germany Baifu company successively launched oil-free high-speed lockstitch machines, Oil free technology has become an important direction for the technological development of high-speed lockstitch machines in the world

the main oil-free products introduced by foreign companies at this exhibition are:

Germany Baifu 1053 and 1181 series high-speed flat sewing machines, Japan heavy machinery company ddl5700n series and ddl-9000 series high-speed flat sewing machines, Japan brother company db2-dd7200a series high-speed flat sewing machines, Italy Nanchi 885 series high-speed flat sewing machines

at this exhibition, Japan Heavy Machinery Corporation also launched 6900 series high-speed overlock sewing machines and other oil-free products

Chinese enterprises have also followed closely, and some companies have gradually launched their own oil-free technology high-speed flat sewing machine products. The products launched at this exhibition include:

gc9000 series high-speed flat sewing machine of Shanggong company, zj9000 series high-speed flat sewing machine of Zoje company, etc

the oilless technology of the machine head generally adopts the inner cavity of the machine head face. The goal is to remove the polishing damage layer, cancel the oil supply and return system of the needle bar mechanism and thread take-up mechanism, and fundamentally solve the problem of oil leakage and oil leakage at the head of the industrial lockstitch machine. The main method is to improve the wear resistance of the main parts of the needle bar mechanism, thread take-up mechanism and thread hook mechanism

the main methods to improve the wear resistance of parts are:

in terms of processing technology, various surface treatment methods are adopted to strengthen the wear resistance of the friction surface of parts

in terms of materials, the method of changing part materials is adopted to improve the wear resistance of the friction surface of parts

at present, there is basically an important technical problem in the oil-free technology high-speed flat sewing machine products launched by various companies, that is, the maximum sewing speed of oil-free technology high-speed flat sewing machine products remains at the level of 4000 needles/minute, that is, after five or six years of efforts, the maximum sewing speed of oil-free technology high-speed flat sewing machine products has not exceeded the level of 4000 needles/minute

from the technical analysis, the main problems are:

the first is that the maximum allowable speed of the hook part of the hook mechanism under the condition of no oil is not high

although after years of process improvement and the adoption of new wear-resistant materials, the maximum allowable speed of the rotary hook under the oil-free condition is still below 000 revolutions in August (the rotary hook rotates twice for each sewing needle, and the maximum sewing speed is 4000 stitches/min. the rotary speed of the rotary hook reaches 8000 Revolutions), so, The highest sewing speed of several world-famous companies' products under oil-free conditions is 4000 stitches/min. This problem has become the main bottleneck to improve the sewing speed under oil-free conditions

at present, because the technology of rotary shuttle parts can not break through the maximum sewing speed of 4000 stitches/min under the condition of no oil, many enterprises at this exhibition adopted the opposite rotary shuttle parts to set up an independent oil supply system in the machine to solve the bottleneck of 4000 stitches/min sewing speed

therefore, the rotary shuttle component has broken through the maximum sewing speed of 4000 stitches/min under the condition of no oil, which has become a common technical problem to be broken through in the world

the second is to improve the maximum allowable speed of the needle bar of the needle bar mechanism under the condition of no oil

after years of work

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