Vacuum insulation cup and vacuum brazing furnace

Vacuum vacuum flask and vacuum brazing furnace Liu Yibing, Lai Kangsheng, An Yongyin, Peng Han (Chaoan Shunfa Hardware Products Co., Ltd., Guangdong Chaoan Solder, Structure.

Stainless steel vacuum cup, after reform and development, especially in the past more than 10 years in our country has made considerable progress. Our company has produced more than 50 series of vacuum cups and vacuum cups. The hundreds of varieties are still in use today. Continuous development, production, variety of ever-changing vacuum cups vary according to the way they are produced, and are simply divided into tailless vacuum cups (or integral vacuum cups) and tailed vacuum cups, which are vacuum exhausted. Acquired, similar to glass thermos and large electron tubes. On the vacuum exhaust table, insert a vacuum cup (evacuated copper tube welded to the bottom of the vacuum cup) to extract large-capacity, small-diameter vacuum cup holding time is longer, on the contrary small capacity, large-diameter vacuum cup holding time is shorter The thinner the material, the longer the holding time, but the cup is easy to break and deform, which will affect the service life; the outer layer of the vacuum cup liner metal film and copper plating and other measures can also increase the degree of insulation. 2.2 The service life of the vacuum cup also depends on the cleaning and vacuuming time of the inner layer of the cup. The most important is the structure of the vacuum furnace. The vacuum equipment for vacuum cups used in society today has vacuum exhaust stations and vacuum brazing furnaces. There are about two types of four. The second category is the tail vacuum exhaust table; the other brazing furnace type. Brazing furnace type is divided into: single room, multi-room, pumping speed multi-chamber vacuum cup exhaust terminal, and advantages: there is a tail exhaust vacuum cup that is produced with a vacuum exhaust table, when vacuuming The heating temperature is about 500C, the shell of the vacuum cup is not easy to be deformed, but the copper pipe welding place is easy to leak, and it must be specially protected during the processing of semi-finished products.

The other major category is the vacuum brazing furnace type, which can be divided into three types: 2006-U-35 single furnace integrated vacuum brazing furnace. The evacuation cycle time of this furnace is long. If the manufacturer wants to improve the production efficiency and shorten the evacuation time, it will affect the service life.

Although the multi-chamber vacuum furnace currently on the market can shorten the cycle time of vacuum pumping, only one KT-600 diffusing pump with a pumping speed of 16,000 L/s can hardly ensure the residual gas in the cup wall is exhausted. Experience, using this brazing furnace to extract the cup, the life of the cup is only about 8 years The company designed a three-chamber vacuum furnace with two sets of spread chestnut, studio with KT ~ 800 spread chestnut, pumping speed 28750L / s, Discharge chamber with KT-600 spread chestnut pumping speed 16000L / s studio pumping speed 1.8 times larger, and the former chestnut with H-150 spool valve chestnut, pumping speed 150L / s, general three-room furnace studio with 2X- 70 Rotary chestnuts, pumping speed 70L / s, so that the pumping speed of the studio before the chestnut 2.14 times. It can not only shorten the cycle time of vacuum pumping, but also can exhaust the residual gas of the inner wall of the cup as much as possible. After testing, vacuum cups of the same size and size are pumped with two kinds of furnaces, and the vacuum brazing furnace designed by cooperation is more common than the common brazing furnace. In the soldering furnace, the 6-hour cup heat preservation is at least 2~3°C, which greatly improves the service life of the vacuum cup. In the normal use of the cup, the life of the model vacuum cup reaches 12 Year or so. Moreover, the furnace has a large production capacity. The first furnace has a working time of 25 hours. After that, the production cycle of each furnace only requires 1.5 hours per furnace. Each furnace can pump 600 or so, and more than 8,000 can be pumped in 24 hours. Bright brazing, clean working environment, and high reliability, reduced many processes of exhaust desktop vacuum cup units, greatly improved the quality of vacuum cups, and increased economic benefits (see) 3 Soldering brazing solders for vacuum cups For the brazing of vacuum cups in the past, we chose two kinds of brazing solders, one for ring brazing solder and the other for powdered brazing solder.

3.2 Powdered Solder Solder The solder is powdered and mixed with a dilute binder and powdered solder to form a paste. Then it is applied to a tapered hole. After a little drying, the through hole is pierced with a Y 1.2 needle. After drying, vacuum brazing can be performed. The advantage of powdered brazing solder is that the price is cheaper. The disadvantage is that the brazing temperature is as high as 1050°C. This brings about the disadvantages of using cups of high purity nitrogen to cool the cup, deforming some of the cups, and deforming the basket. Some powdered brazing materials can reach 950C, but they are more expensive and the quality of the brazed parts is slightly worse.

For solder, we compared the internal diameter Y6 copper tube lead with a vacuum cup evacuated to calculate the ring brazing solder pattern, which is more suitable for use. For the powdered brazing solder cup bottomed evacuation round hole, the evacuation time of the cup wall clearance space was calculated to be the change of the pressure inside and outside the cup wall clearance space and the influence of temperature, it is difficult to determine the round hole conductance, and thus the cup wall clearance space The extraction time is difficult to calculate, but after long-term work has obtained data, the powdered solder cup bottom hole, the head can be, to meet the Ministry of Light Industry QB/T2332-97 standard, that is, small-caliber vacuum cup, nominal volume; for large diameter Vacuum pot, nominal capacity> 1.2~1.5L, inner diameter>