JPH0245951Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a protection structure for a vacuum switch pipe, particularly its exhaust pipe.

FIG. 1 is a sectional view showing an example of a conventional vacuum switch tube. In the figure, 1 is a vacuum container made of an insulator, 2 is an end plate on the fixed electrode side, 3 is an end plate on the movable electrode side, and 4 is an end plate on the movable electrode side. Bellows, 5 is the fixed electrode side current-carrying shaft,
Reference numeral 6 denotes a movable electrode side energizing shaft, 7 a fixed electrode, and 8 a movable electrode, which are fixed to the fixed electrode side energizing shaft 5 and the movable electrode energizing shaft 6, respectively. The bellows 4 is provided between the movable electrode side end plate 3 and the movable electrode side energizing shaft 6, and allows the electrodes 7 and 8 to be brought into contact with and separated from each other while maintaining vacuum tightness inside the container. A shield 9 prevents metal vapor emitted from the electrodes 7 and 8 from adhering to the inner surface of the insulating container and deteriorating its insulation properties when the current is switched on and off.

Reference numeral 10 denotes an exhaust pipe, which is attached to the end plate 2 by brazing or the like, is connected to a vacuum pump, and is crimped and cut after the vacuum switch pipe is degassed. Oxygen-free copper with good ductility is used for the exhaust pipe in order to perform crimp cutting. The tip of the cut part after crimping and cutting is sharp and dangerous during handling operations such as attaching vacuum switch pipes.Also, since the meat is thin, it is weak in strength and is used to prevent leaks due to damage. It is covered with a protective resin 11. For the resin 11, a resin containing a hardening agent is used, and the resin is applied manually and left to harden for a long time, or the exhaust pipe section is heated and coated repeatedly to adhere the resin to a predetermined thickness. Therefore, the workability is poor and it is not suitable for mass production. Additionally, in order to increase the strength of the exhaust pipe 10, it is possible to thicken the wall thickness or increase the diameter, but this would require a crimping cutting device with a large crimping force, and the crimping stroke would become long, reducing work efficiency. However, it has not been adopted.

Since the exhaust pipe 10 has the function of vacuum sealing by crimping and cutting after evacuation, there is a need for a simpler and more mechanically strong protection method.

This idea was made in order to eliminate the drawbacks of the conventional ones as mentioned above. A pipe-shaped protective cap with one end closed is provided so that at least the crimped cut part of the exhaust pipe is inserted, and it is protected by heating. The purpose of this method is to protect the crimped and cut portion of the exhaust pipe in a simple manner by bonding the cap to the exhaust pipe and curing it at the same time, and at the same time improve the strength of the exhaust pipe.

An embodiment of this invention will be described below with reference to the drawings. FIG. 2 shows the structure of the exhaust pipe protection, and since the structure of other parts of this vacuum switch is the same as that of FIG. 1, the explanation thereof will be omitted. FIG. 2 shows that after the exhaust pipe 10 is crimped and cut, a pipe-shaped protection pipe 12 is provided so that the exhaust pipe 10 is inserted therein, and
The tip is closed, and the adhesive is bonded to the exhaust pipe 10 by heating and cured at the same time. The pipe-shaped protection pipe 12 can be easily attached by wrapping a resin-impregnated sheet around the exhaust pipe 10, or by making a pipe-shaped product in advance.
The protective pipe material used is an epoxy resin-impregnated material, so-called epoxy prepreg sheet material, which has a base material such as polyester nonwoven fabric or glass fiber and is impregnated with epoxy resin. The epoxy resin impregnated into the sheet material is eluted by heating, adheres to the exhaust pipe, and at the same time hardens to firmly protect the exhaust pipe. Also,
The tip of the exhaust pipe crimp-cut section is filled with epoxy resin from the sheet material that is eluted by heating, and the protective pipe is adhered and cured on top of the epoxy resin, so that it is strongly reinforced mechanically. As shown in FIG. 3, the tip of the protective pipe can be easily covered by attaching a fluorine-coated jig 13 during heating, and a protective cap 14 is formed to prevent foreign matter from entering. In addition, the other end of the protective pipe 12 is connected to the end plate 2.
The exhaust pipe 10 is bonded after heating by covering the
The strength of the joint between the end plate 2 and the end plate 2 can be greatly improved.

The curing time of the protective cap 14 impregnated with epoxy resin is about 30 minutes at about 100°C, which is much shorter than the conventional method of leaving it in the natural environment for a long time.

In this way, the protective cap 14 adhesively hardened to the exhaust pipe 10 mechanically reinforces the exhaust pipe 10, and the exhaust pipe 10 is not damaged during handling during the work process, making it highly reliable.

Although the present invention uses epoxy resin as the resin for the protective cap material, other resins may be used as long as they adhere to metal and harden when heated.

As described above, according to this invention, at least the crimped cut portion of the exhaust pipe is covered with a protective cap formed by closing one end of a pipe-shaped epoxy resin-impregnated material, and the cap is bonded to the exhaust pipe by heating and curing. Therefore, the crimped and cut portion of the exhaust pipe can be protected and the strength of the exhaust pipe can be improved.

[Brief explanation of the drawing]

Figure 1 shows a conventional vacuum switch tube, Figure 2 shows a conventional vacuum switch tube.
The figure is a cross-sectional view of the vicinity of the exhaust pipe showing one embodiment of the vacuum switch tube according to the present invention, and FIG. 3 is a cross-sectional view showing another embodiment of the present invention. 1... Insulating container, 2, 3... End plate, 5, 6...
Current-carrying shaft, 7, 8... Electrode, 10... Exhaust pipe, 11
... Exhaust pipe protection resin, 12 ... Protection pipe, 1
4...Protective cap. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] In a vacuum switch tube equipped with a pair of electrodes that can be hermetically connected to and separated from each other through a bellows in a vacuum container, a pipe-shaped epoxy tube is inserted into at least a part of an exhaust pipe provided in the vacuum container. A vacuum switch tube comprising a protective cap formed by closing one end of a resin-impregnated material, and the protective cap being adhesively hardened to the exhaust pipe by heating.