JPH0449799Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a vacuum interrupter, and particularly to the structure of a lead rod having a connecting fitting such as a bolt or screw pusher at the end.

B. Summary of the invention The present invention relates to the structure of a lead rod that is brazed to connecting fittings such as bolts and screw pushers in a vacuum interrupter. When inserting a connecting fitting and brazing the two, a ring-shaped protrusion is formed around the hole, and the protrusion is plastically deformed relative to the connecting fitting to form a hole for the lead rod of the connecting fitting. This is to prevent it from falling off.

C. Prior Art An example of a typical vacuum interrupter used for opening and closing electric circuits is shown in Fig. 4.

This vacuum interrupter includes a pair of fixed electrodes and a movable electrode in a vacuum vessel 1, and these fixed electrodes and movable electrodes each have a fixed lead rod 2 and a movable lead rod 3 made of copper, which are led out of the vacuum vessel 1. Moreover, these pair of electrodes are configured to be able to approach and separate freely within the vacuum container 1. The fixed lead rod 2 is connected to one of the lead conductors (terminal conductor) with a bolt 4 as a connection fitting made of stainless steel (SUS) or other steel provided at its outer end, and the movable lead rod 3 is connected or slidably connected to another lead conductor (terminal conductor), and a bolt 5 is used as a connecting fitting made of stainless steel (SUS) or other steel provided at the outer end of the movable lead rod 3. It is connected to the operating side via.

By the way, in the vacuum interrupter having the above structure, the fixed lead rod 2, the bolt 4, and the movable lead rod 3 are
and bolts 5 are connected to each other by providing recessed holes at the ends of the lead rods, into which the respective bolts 4 and 5 are fitted, and by brazing.

Methods for brazing the fixed lead rod 2 and the bolt 4 or the movable lead rod 3 and the bolt 5 include an upward brazing method and a downward brazing method.

By the way, when performing downward brazing,
A means for temporarily fixing the movable lead rod 3 by screwing the bolt 5 into the hole 7 was adopted. With this screw-in method, the movable lead rod 3 and the bolt 5 can be easily and reliably aligned, but since the shape of the flow area of the solder is complicated, it is difficult for the solder to flow, resulting in poor brazing. Occasionally, this occurred. Further, since it is a screw-in type, there is a problem in that it takes time and effort to process the screws and fit the two together.

In particular, when performing downward brazing, conventionally, as shown in FIG. Insert the end into the hole 7 provided in the movable lead rod 3 (or the fixed lead rod 2, the same applies hereinafter), and in this state, insert a punch into the outer end of the lead rod 3 to prevent the bolt 5 from falling off. It was driven in and temporarily fixed, and in this state it was placed in a vacuum furnace and brazed. In the figure, reference numeral 8 indicates a portion caulked by a punch.

D Problems to be solved by the invention The caulking described above is performed by caulking the edge of the hole 7 along the circumference with a punch at several points, but it is difficult to perform uniform caulking and the caulking is incomplete. As a result, the operating bolt 5 may fall off from the movable lead rod 3.

Further, since the caulked portion is minute, the solder that seeped out during brazing eroded the caulked portion, sometimes causing the operating bolt 5 to fall off. Furthermore, there was a problem in that the caulking work itself was difficult because it needed to be caulked evenly.

E. Means for Solving the Problems In order to solve the above problems, in the present invention, the opening of the hole in the end face of the lead rod in the vacuum interrupter is made to face downward, and the inner end of the connection fitting is In the device in which the lead rod and the connecting fitting are brazed together by wrapping a brazing material and inserting the inner end portion into the hole, the connecting fitting is connected to the lead rod in order to prevent the connecting fitting from falling off the lead rod. The lead rod of the vacuum interrupter is constructed by providing a ring-shaped protrusion around the opening on the end face of the lead rod, which can be plastically deformed and brought into contact with the connection fitting.

F Function After inserting the connecting member into the hole provided at the end of the lead rod, the ring-shaped protrusion provided on the end surface of the lead rod is plastically deformed diametrically inward using an appropriate tool to contact and connect to the lead rod. By doing so, the connection fitting is reliably temporarily fixed to the lead rod.

G. Example The structure of the lead rod according to the present invention will be explained based on an example shown in FIG. This structure can be applied not only to movable lead rods but also to fixed lead rods, but in this embodiment, a movable lead rod is taken as an example.

A hole 7 is provided in the movable lead rod 3 coaxially from its outer end surface 3a. A ring-shaped groove 9 with a rectangular cross section is provided around the opening of the hole 7 on the outer end surface 3a.
By cutting the hole 7, a ring-shaped projection 10 is cut out around the opening of the hole 7.

In this embodiment, since the protrusion 10 is formed by cutting the groove 9 in the end surface 3a as described above, the end surface 10a and the outer end surface 3a of the protrusion 10 are on the same plane, so that handling of the movable lead rod 3, etc. This prevents the protrusion 10 from being damaged during this process.

On the other hand, the bolt 5 has the same shape as a conventional bolt. Tip part 5 on the side that is inserted into the hole 7 of the bolt 5
A has a slightly smaller diameter, and the brazing material 6 is wrapped around this portion. Further, a step 5b is provided at a portion corresponding to the entrance (opening) of the hole 7 to make caulking strong and reliable, and the threaded portion side is thereafter made into a small diameter portion. A straight portion 5c is provided between the tip portion 5a and the step portion 5b, which creates a slight gap between the tip portion 5a and the step portion 5b and the inner peripheral surface of the hole 7.
It is becoming. Note that 5d is a threaded portion of the operating bolt 5.

Prior to brazing work, in order to assemble the movable lead rod 3 and the operating bolt 5, insert the bolt 5 with the brazing material 6 wrapped around the tip into the hole 7 of the movable lead rod 3, and in this state, attach the movable lead rod 3 to the operating bolt 5. This is done by plastically deforming the protrusion 10 around the opening of the hole 7 of the rod 3 inward (so-called caulking operation). The lead rod used for caulking work is made of copper, so
For example, a tool such as radio pliers with elongated tips is sufficient, and this can be done by simultaneously caulking two diametrically opposed points of the ring-shaped protrusion 10. The protrusion 10 after caulking is the operation bolt 5
It engages securely with the stepped portion 5b. Furthermore, by caulking at one to several points (for example, two points in the diameter direction that are 90 degrees out of phase), the caulking becomes strong. In FIG. 3, the left half shows the state before crimping, and the right half shows the state after crimping.

By caulking as described above, the bolt 5 is securely held (temporarily connected) to the movable lead rod 3, and the bolt 5 is completely prevented from falling off.

Thereafter, the combination of the movable lead rod 3 and the operating bolt 5 is heated and brazed in a non-oxidizing atmosphere.

In the above embodiment, the size of the groove 9 into which the protrusion 10 is cut may be any size that allows the tip of a tool such as radio pliers to fit therein.

For example, as shown in FIG. 3, the width a of the protrusion 10, the height b of the protrusion 10, and the width c of the groove 9 are a=0.3 to 1.0 mm, b=0.3 to 1.0 mm, and c=6 mm, respectively. Ru.

FIG. 2 shows another embodiment. This is protrusion 1
The groove forming 0 is a groove 9a having a triangular cross-sectional shape.

In addition, the present invention can be similarly applied to the fixed lead rod side, and the objects to be temporarily fixed by caulking are not limited to bolts, but can also be applied to other connecting fittings such as threaded bushings, and the same effect can be obtained. It is something that can be done.

H. Effects of the invention According to the lead rod of the vacuum interrupter according to the invention, a protrusion is provided around the opening end surface of the recessed hole provided at the end of the lead, and this protrusion is plastically deformed toward the lead rod side, and the connection fitting is Since it is engaged with the small diameter part, it is possible to securely temporarily fix the lead rod and the connection fitting before brazing, which allows the two to be reliably brazed and stabilizes the joint strength. It can be strengthened.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a lead structure according to an embodiment of the present invention with different left and right states, FIG. 2 is a similar sectional view of another embodiment, and FIG. 3 is an implementation of the lead structure shown in FIG. 1. A half-sectional view of the example, FIG. 4 is a schematic external view of the vacuum interrupter, and FIG. 5 is an explanatory diagram of the brazing operation. In the drawing, 1 is a vacuum container, 2 is a fixed lead rod, 3
is a movable lead rod, 4 is a fixing bolt, 5 is an operating bolt, 6 is a brazing material, 7 is a hole, 9 and 9a are grooves, 1
0 is a protrusion.

Claims (1)

[Scope of utility model registration request] With the opening of the hole in the end face of the lead rod in the vacuum interrupter facing downward, a brazing material is wrapped around the inner end of the connection fitting, and the inner end is inserted into the hole of the lead rod to connect the lead. In the device for joining a rod and the connecting fitting by brazing, the connecting fitting is plastically deformed with respect to the connecting fitting around the end face opening of the lead rod in order to prevent the connecting fitting from falling off from the lead rod. A lead rod for a vacuum interrupter characterized by being provided with a ring-shaped protrusion that can be connected in contact.