JPH0229621Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Use This invention relates to the structure of a bushing that is inserted into and fixed to a sealed switch.

Conventional technology Conventionally, a bushing that is inserted and fixed into a switch case has a conductive rod inserted and fixed therein, a lead wire is connected to the outer end of the conductive rod, and a fixed electrode is provided at the inner end via a connecting metal member. was. An engaging flange was formed projecting from the outer periphery of the inner end of the connecting fitting, and the engaging flange was hermetically covered with the inner end of the bushing via an O-ring. However,
When a load is applied to the fixed electrode during the opening/closing operation of the switch, or when the connecting fitting is fixed to the conductive rod, the pressure applied to the O-ring is not constant and the pressure between the inner end of the bushing and the engagement flange is There was a risk that airtightness could not be maintained.

Purpose of the invention The purpose of this invention was to solve the above-mentioned problem. ), and furthermore, it is possible to prevent external forces in the eccentric and axial directions due to swinging of the lead wire from being transmitted into the case, thereby maintaining the airtightness of the switch. The purpose is to provide a structure for bushing that is possible.

Structure of the invention In order to achieve the above object, this invention forms locking steps at each end of the inner and outer ends of the inner cavity of the bushing that is inserted and fixed into the switch case, and the inner and outer ends of the bushing are provided with locking steps. A conductive rod equipped with a locking flange that locks into the locking step is inserted, and the outer end of the conductive rod is provided with an integral molded cone along with a lead wire, while the inner end of the conductive rod is provided with a tightening cone. A connecting fitting to which a fixed electrode is fixed is screwed and fixed to the tightening threaded part so that the outer end of the connecting fitting is locked to the inner locking step, and the inner part of the connecting fitting is fixed. An engaging flange is formed in a cylindrical shape so as to cover the inner end of the bushing on the outer periphery of the bushing, and an O is provided between the outer periphery of the inner end of the bushing and the inner periphery of the engaging flange to make the space between the two airtight. A ring and a spacing regulating ring are arranged.

Embodiment An embodiment embodying this invention will be described below with reference to the drawings.

In the figure, 1 is a gas-filled switch case, 2 is a bushing that is penetrated through the corresponding left and right side walls for each phase, and is attached by a mounting bolt 3 to a packing press plate 4, packings 5 and 6, and a bushing cover. It is fixed via 7. Note that 8 is an O-ring interposed airtightly between the inner circumferential surface of the bushing through hole 1a of the switch case 1 and the bushing 2.
Locking step portions 10 and 11 are formed at each of the inner and outer ends of the inner cavity 9 of the bushing 2, respectively.

Reference numeral 12 denotes a conductive rod inserted into the inner cavity 9 of the bushing 2, and a lead wire 13 is caulked to the outer end of the conductive rod, and the outer end is locked to the outer locking step 10. A locking flange 14 is formed to protrude, and a tightening screw portion 15 is provided at the inner end.
is formed. An integral molded cone 16 is provided at the outer end of the conductive rod 12 together with the lead wire 13, and the molded cone 16 is fitted into a mounting cylinder 2a formed on the inner periphery of the outer end of the bushing 2. .

17 and 18 are locking flanges 1 of the conductive rod 12;
4 and the outer locking step 10 are an adjustment washer and a packing. 19 is the conductive rod 12
A spring washer 20 is provided between the connecting fitting 19 and the locking step 11, and a locking device that is locked to the inner locking step 11 is provided. A stopper 21 and a packing 22 are interposed.

An engaging flange 23 is provided on the outer periphery of the inner end of the connection fitting 19 and is formed in a cylindrical shape so as to cover the inner end of the bushing 2. An O-ring 24 is interposed between them to maintain airtightness. 2
5 is the inner periphery of the engagement flange 23 and the bushing 2
A spacing regulating ring made of reinforced plastic with excellent gas resistance is interposed closer to the tip end of the engagement flange 23 than the O-ring 24 between the inner end outer periphery of the bushing 2 and the engagement flange 23. The pressure applied to the O-ring 24 over the entire circumference is made uniform by the narrow pressure between the two.

Reference numerals 26 and 29 are fixed electrodes that are screwed onto the inner end of the connecting fitting 19, and are fixed by tightening the nut 27 screwed onto the outer periphery of the base end to the connecting fitting 19 via the spring washer 28. firmly fixed. A movable electrode 30 is slidably provided with respect to the fixed electrode 26, and is capable of coming into contact with and separating from the opposing fixed electrode 29. The movable electrode 30 can be driven to open and close by a support tube 31 disposed around its outer periphery.

32 is a bellows whose both ends are fitted onto the connecting fitting 19 and the support cylinder part 31 in an airtight manner,
The interior thereof is a pressure chamber, and arc-extinguishing gas is blown out from a nozzle provided at the tip of the support tube 31 when the movable electrode 30 is opened. Reference numeral 33 denotes a drive arm that drives the movable electrode 30 in an open/closed path via the support cylinder portion 31.

Now, in the bushing configured as described above, since the O-ring 24 and the spacing regulating ring 24 are arranged between the inner circumference of the inner end of the bushing 2 and the inner circumference of the engagement flange 23, Even if the bushing 2 and the connecting fitting 19 move relative to each other, the O-ring 24 and the spacing regulating ring 25 can maintain airtightness while sliding between the inner circumference of the inner end of the bushing 2 and the inner circumference of the engagement flange 23. Furthermore, even when the connecting fitting 19 is tightened to the conductive rod 12, and when the movable electrode 30 is opened and closed, uneven pressure is not applied to the O-ring 24, so that the airtightness between the two 2 and 19 is broken. There isn't.

Furthermore, the tightening screw portion 15 of the conductive rod 12
When the connecting fitting 19 is tightened against the conductive rod 1
The locking flange 14 of the bushing 2 and the outer end of the connecting fitting 19 are locked to the locking steps 10 and 11 of the inner cavity 9 of the bushing 2, and the conductive rod 12 is fixed to the bushing 2 so as not to be able to swing. Since the integrally molded cone 16 is provided at the outer end of the conductive rod 12, it is possible to reliably prevent external forces in the eccentric direction and axial direction due to swinging of the lead wire 13 from being transmitted into the case 1.

Therefore, the switching performance of the switch does not deteriorate due to the deterioration of airtightness.

Furthermore, since the spacing regulating ring 25 allows the connecting fitting 19 to be easily centered, it is also possible to prevent eccentricity when the fixed electrode 26 is attached.

Effects of the invention As detailed above, this invention provides not only an O-ring but also a spacing regulating ring between the inner periphery of the engaging flange of the connecting fitting fitted to the inner end of the bushing and the outer periphery of the inner end of the bushing. Since the O-ring is also interposed, it is possible to equalize the surface pressure (compressibility) in the eccentric direction applied to the O-ring, thereby maintaining the airtightness of the switch. When the conductive rod is screwed and fixed to the bushing, the conductive rod is tightened and fixed to the bushing so that it cannot swing, and since the outer end of the conductive rod is provided with an integral molded cone, it will not be affected by eccentric direction or axis caused by swinging of the lead wire. It is possible to prevent external force in the direction of the core from being transmitted into the case, and it is possible to more reliably maintain the airtightness of the switch. Furthermore, even when the bushing and the flange member move relative to each other in the axial direction of the bushing, the O-ring and the spacing regulating ring can maintain airtightness while sliding between the outer circumference of the inner end of the bushing and the inner circumference of the engaging flange. Furthermore, since the flange member can be easily centered, eccentricity can be prevented when the fixed electrode is attached, which is an excellent invention for industrial use.

[Brief explanation of the drawing]

The figure is a sectional view of a switch according to an embodiment of this invention. 1... Switch case, 2... Bushing, 9...
... Inner cavity, 10, 11 ... Locking step, 12 ... Conductive rod, 13 ... Lead wire, 14 ... Locking flange, 15 ... Tightening screw section, 16 ... Integral mold cone, 19 ... ... Connection fitting, 23 ... Engagement flange, 24 ... O ring, 25 ... Spacing regulation ring, 26, 29 ... Fixed electrode.

Claims (1)

[Scope of claim for utility model registration] Bushing 2 inserted and fixed into switch case 1
A conductive rod 12 has locking steps 10 and 11 formed at each end of the inner and outer lumen 9 of the conductive rod 12, and a locking flange 14 that locks with the outer locking step 10 in the inner lumen 9. A molded cone 16 is provided at the outer end of the conductive rod 12 together with the lead wire 13, and a tightening screw portion 15 is formed at the inner end of the conductive rod 12. fixed electrodes 26, 29
The connecting fitting 19 to which the connecting fitting 19 is fixed is screwed and fixed so that the outer end of the connecting fitting 19 is locked to the inner locking step 11, and the bushing 2 is attached to the outer periphery of the inner end of the connecting fitting 19.
An engaging flange 23 is formed in a cylindrical shape so as to cover the inner end of the bushing 2.
The structure of the bushing is characterized in that an O-ring 24 and a spacing regulating ring 25 are arranged between the inner periphery of the bushing 2 and the inner periphery of the bushing.