JPS6345722A - Vacuum valve - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a vacuum valve, and particularly to an electrode structure with excellent low surge performance and high current interrupting performance.

(Prior Art) As an example of a vacuum valve considering low surge performance, one described in Japanese Patent Laid-Open No. 58-38425 is known.

As shown in FIG. 7, this vacuum valve consists of a pair of fixed ( 1t
! ! Electrode 4. It is configured by disposing a movable side electrode 5,
The fixed electrode 4 is attached to a fixed current-carrying shaft 6a that passes through the fixed end plate 2a in an airtight manner, and the movable electrode 5 is supported by the movable end plate 2b via a bellows 7 and is movable in the axial direction. It is attached to the movable surveying electrode 6b. In addition,
Inside the vacuum container 3, an arc shield 8 is attached to the insulating container 1 to prevent metal vapor generated from the fixed electrode 4 and the movable electrode 5 from adhering to the inner wall of the insulating container 1 when the current is cut off. It is being

As shown in FIGS. 8 and 9, the structure of the movable electrode 5 described above is such that the opposing contact surfaces are Ag -1i1
The contact 9a is made of c-based sintered material.
A coil electrode 11 is electrically connected to the back surface of the coil via a current-carrying portion 10a. The fixed side electrode 4 also has a similar structure, with a contact 9b made of Ag-tilc-based sintered material on the opposing contact surface, and a coil electrode connected to the back surface of this contact 9b via a current-carrying part 10b. 12 are electrically connected. Here, the coil electrode 11 is.

It is composed of a circular arc portion 13a having one end connected to the current carrying portion 10a, and a coil shunting arm portion 14a having the other end of the circular arc portion 13a and a movable passage connected between the shaft 6b. The coil electrode 12 also has a similar structure, with a circular arc portion 13b having one end connected to the current-carrying portion 10b, and a fixed current-carrying shaft 6 connected to the other end of the circular arc portion 13b.
It is composed of a coil shunt arm 14b connected between two coils.

The current from the movable current-carrying shaft 6b or the fixed current-carrying shaft 6a flows through the coil electrode 11.12 through the coil shunt arm 14a.
, 14b and flows to the arcuate portions 13a, 13b, and the current flowing to the arcuate portions 13a, 13b generates an axial magnetic field in the interelectrode space. This axial magnetic field uniformly diffuses the arc ignited between the contacts 9a and 9b, and can minimize damage to the contacts 9a and 9b. Electrode 5) was able to cut off a larger current than a flat plate electrode or a spiral electrode. Moreover, since the contacts 9a and 9b are made of low-surge contact material Ag-WC,
It also had low surge performance that could keep the cutting current below IA. In addition.

The contacts 9a, 9b are provided with slits 15a, 15b, and the contacts 9a, 9b and the coil current 11.1
A reinforcing material 16a is provided between the parts 2 and 2.

16b is provided.

(Problems to be Solved by the Invention) However, low-surge contact materials such as Ag-We are generally sintered fine powders with low thermal conductivity and ttC. It is more susceptible to thermal shock than Cr and has a relatively small breaking current. Also, even if A, -1c and Cu-Cr are bonded together as contact materials, Ag
-The arc ignited on the WC does not transfer to the Cu-Cr due to the local concentration of heat due to the low thermal conductivity of Ag-WC and the low arc voltage, resulting in low surge performance and large current interrupting performance. It was not possible to create an electrode structure that had both of these characteristics.

Therefore, it is an object of the present invention to provide an electrode structure for a vacuum valve that has excellent low surge performance and high current interruption performance.

[Structure of the invention]

(Means and effects for solving the problems) The present invention has the following features:
In a vacuum valve, the openings at both ends of an insulating container are closed with end plates to form a vacuum container, and a pair of electrodes that can be freely connected and separated are arranged inside the vacuum container. A contact point slightly protruding from the surrounding surface, a first electrode member provided around the contact point and made of a material having voltage resistance and large current interrupting ability, and a first electrode member with the first electrode member placed on the surface side. A second electrode member is provided with a coil electrode that is fixed to the contact surface and generates an axial magnetic field on the back surface, and a resistance member with a large temperature coefficient of electrical resistance is provided on the back surface of the contact. In a vacuum valve equipped with an electrode configured to be electrically connected to the first electrode member surrounding the electrode member 1 and the upper contact point, when the contacts in contact are separated at the time of current interruption, Ag-Cu The arc ignited on the contact made of the material is diffused to some extent by the action of the axial magnetic field, and a small amount of the arc is also ignited on the first electrode part made of the Cu-Cr material, causing an instantaneous increase in the breaking current. Then, N
The electric current flowing through the resistance member made of i, Fe, or their alloy increases its electrical resistance value, the current shunted to the first electrode member increases, the arc moves onto the first electrode member, and the contact point This improves breaking performance by igniting an arc on the connecting and disconnecting points when the current is small.

(Example) Hereinafter, an example of the vacuum valve of the present invention, particularly an IIt electrode structure, will be described with reference to the drawings. Note that the general configuration of the vacuum valve is the same as the conventional one, and the structures of the movable side electrode and the fixed side electrode are the same.

The following description will be made regarding the movable electrode. In FIGS. 1 and 2, the movable electrode 20 includes an electrode portion 21 facing the fixed electrode, and a current-carrying portion provided on the back surface of the electrode portion 21. It consists of a coil electrode 22 and a reinforcing member 23 provided between the coil electrode 22 and the back surface of the electrode section 21 and made of a material with low conductivity such as stainless steel.

Thus, the electrode section 21 includes a donut-shaped first electrode member 24 made of a Cu-Cr material, and a donut-shaped first electrode member 24 made of a Cu-Cr material.
The second electrode member 2 is fixed to the donut-shaped recess 24a.
5, and 2 to 3+n in the center part of the first electrode member 24.
Contact 26 made of Ag-WC material and protruding from the contact point 26
A resistance member 27, which is provided on the second electrode member 25 on the back side of this contact 26 and is made of Ni or an alloy thereof having a diameter the same as or smaller than that of the contact 26 and has a large temperature coefficient of electrical resistance, is connected concentrically to the second electrode member 25. In general, brazing is something that is fixed and attached using something like brazing. Note that the contact 26, the second
The first electrode member 25 is electrically connected to the first electrode member 25 via the resistance member 27, and the first electrode member 24 is electrically connected to the first electrode member 24 on the side surface (outer surface).

Further, the coil electrode 22 has one end fixed to the back side of the second electrode member 25 via the current-carrying part 28a, and has a coil arc part 22a having the same outer diameter as the second electrode member 25, and one end of the coil arc part 22a having the same outer diameter as the second electrode member 25. It is composed of a coil shunting arm member 22b which is connected to the portion 22a and whose other end is fixed to the movable energizing shaft 6b, and one or more of the arm members 22b are attached.

Note that the upper surface of the reinforcing member 23 is the second 1! 2 are attached to the back surface of the pole member 25 with their lower surfaces fixed to the coil electrodes 22, respectively, and the first electrode member 24 and the second l! The pole member 25 is provided with a linear slit 29 in the radial direction. Furthermore, if the diameter of the contact 26 is large, the slit 29 may be extended to the contact 26.

In the movable electrode 20 configured as described above, when the current I flows in the direction shown by the arrow in FIG. 3o fires.

This arc 30 is diffused all at once onto the contact point 26 by an axial magnetic field generated by the current flowing through the coil electrode 22. Then, a part of it also transfers onto the first electrode member 24, although slightly, and on this first electrode member 24, -
That is, ignition also occurs on Cu-Cr.

In case 2, the large current 11 shunted to the contact point 26 flows through the resistance member 27, so the resistance member 27 generates heat due to its resistance. However, since the resistance member 27 has a large temperature coefficient of electrical resistance, its resistance value further increases due to this heat, the current i1 flowing to the contact 26 decreases, and the current 12 flowing to the first electrode member 24 increases. However, when a large current is cut off, the arc is on the first electrode member 24, that is, on the Cu
- Migrate onto Cr. Furthermore, in combination with the coil electrode 22, the arc voltage is reduced as shown in FIG.

Therefore, the energy incident on the electrode surface is reduced,
Damage to the contacts 26 is reduced. Further, the arc voltage of Cu-Cr is equal to or lower than that of Ag-WC due to the action of the axial magnetic field, and the arc ignited on the contact 26 made of Ag-WC is
This facilitates diffusion and transfer onto the first electrode member 24 made of r. Therefore, the damage to the contact 26 made of Ag-WC is minimized due to the large current interruption, and the interruption performance is improved.

Note that the first electrode member 24. The slit 29 provided in the second electrode member 25 can prevent eddy currents flowing in the second electrode member 25 and effectively generate an axial magnetic field. In addition, the back surface of the first electrode member 24 and the coil electrode 2
The reinforcing member 27 made of a low conductivity material such as stainless steel and fixed between the electrode parts 21 and the coil fit poles 22 can be prevented from deforming during the opening/closing operation of the vacuum valve. Furthermore, the movable side electrode 20 configured as above
By applying current aging to the electrode section 21, a thin film layer of fine particles of Ag, Cu, and Cr is formed on the surface of the electrode part 21 (the surface facing the fixed electrode), which reduces the welding force and increases the withstand voltage. effect can be obtained.

Therefore, by configuring as above.

Due to the effects of the axial magnetic field and the resistance member, when a large current is interrupted, the current share is increased by the electrode member made of Cu-Cr material, and the damage caused by the interruption of large current to the contact made of Ag-1c material is minimized. At load current or rated current, an arc can be ignited on the contact made of Ag-WC material, improving the breaking performance and creating a vacuum valve with low surge performance with a breaking current of 0.8A or less. can be provided.

Note that the present invention is not limited to the above-described embodiment, and a plurality of contacts may be arranged at predetermined positions on the electrode. , the fixed side electrode and the fixed side electrode have the same structure, so the following explanation will be given for the movable side electrode. In FIGS.
, a coil electrode 37 provided on the back surface of this electrode section 36 via a current-carrying section, and a reinforcement made of a material with low conductivity such as stainless steel material, provided between this coil electrode 37 and the back surface of the electrode section 36 . It is composed of a member 38.

Thus, the electrode section 36 includes a first electrode member 40 formed in a disk shape from a Cu-Cr material, and a first electrode member 40 formed from a Cu-Cr material.
0 is fixed in a circular recess 41a, the lower part is inserted into a plurality of holes 40a provided in the first electrode member 40, and the upper surface is provided so as to protrude by 2 to 3I from the other parts,
A plurality of contacts 4z made of Ag-WC material and a first i$
! A plurality of resistance members 43 each made of Ni or Fe or an alloy thereof having a large temperature coefficient of electrical resistance are inserted into the plurality of holes 40a of the No. 11 member 40 to form the lower part of the contact 42. It is concentrically brazed, etc., and is fixedly attached.

Here, when the radius of the second electrode member 41 is R, the contacts 42 are arranged in three to four equal positions at a distance of R/2 from the center and within the plane of the first electrode member 40. It is provided with a radius of 5 to 10 am.

Further, the contact 42 is attached so as to be electrically connected to the second electrode member 41 on the lower surface and electrically connected to the first electrode member 40 on the side surface (outer peripheral surface).

Further, the coil electrode 37 has one end fixed via a current-carrying part 44a, a coil arc part 37a having the same outer diameter as the second electric f4i member 41, one end connected to this coil arc part 37a, and the other end connected to the movable side current-carrying part 37a. Coil shunt arm 3 fixed to shaft 6b
7b, and one or more can be attached.

The reinforcing material 38 has an upper surface fixedly attached to the back surface of the pole member 41 and a lower surface fixedly attached to the coil electrode 37.
is provided with a plurality of slits 45 extending linearly in the radial direction.

In the case of this embodiment as well, when the electrode I flows in the direction shown by the arrow in FIG. 5 and is separated from the fixed electrode of the same structure by an operating mechanism (not shown), an arc 46 is ignited on the contact point 42. . This arc 46 is uniformly spread over each contact 42 by the axial magnetic field generated by the current flowing through the coil electrode 37. Then, since the axial magnetic field at the center of the first electrode member 40 is slightly lower than that on the contact 42 as shown in FIG. 6, the arc is further diffused and The electrode member 40 is also ignited.

At this time, the large current 11 shunted to the contact 42 flows through the resistance member 43, and the resistance member 43 generates heat due to its resistance. However, since the resistance member 43 has a large temperature coefficient of electrical resistance, the resistance value further increases due to this heat.
The current 11 shunted to the contact 42 decreases and the first 21! The current 12 shunted to the pole member 40 increases.

When the large current is cut off, the arc moves onto the first electrode member 40, that is, onto Cu-Cr. Furthermore, carp 1. In combination with the lumi pole 37, the arc voltage is reduced as shown in FIG.

Therefore, the energy incident on the electrode surface is reduced,
Damage to the contacts 42 is reduced. Further, the arc voltage of Cu-Cr is equal to or lower than that of Ag-WC due to the action of the axial magnetic field, and the arc ignited on the contact 42 made of Ag-vC is
Since it diffuses and transfers onto the first electrode member 40 made of r,
By interrupting the large current, damage to the contact 42 made of Ag-wc becomes slight and the interrupting performance is improved.

Note that the first electrode member 40. The slit 45 provided in the second electrode member 41 can prevent eddy currents flowing in the second electrode member 41 and effectively generate an axial magnetic field. In addition, the back surface of the second electrode member 41 and the coil electrode 3
The reinforcing member 38 made of a low conductivity material such as stainless steel and fixed between the parts 7 can prevent deformation of the electrode part 36 and the coil electrode 37 during opening and closing operations of the vacuum valve. Furthermore, a movable antistatic device configured as above! By subjecting 35 to current aging, a thin film layer of fine particles of Ag, Cu, and Cr is formed on the surface of the @ pole part 21 (facing the fixed side electrode), reducing the welding pull-off force and increasing the withstand voltage. You can obtain effects such as

Therefore, by configuring as above.

As in the above embodiment, due to the effect of the axial magnetic field and the resistance member, when a large current is interrupted, the current share is increased by the electrode member made of Cu-Cr material, and the contact made of Ag-WC material is damaged due to the large current interruption. The current can be made very small, and an arc can be ignited on the contact made of Ag-WC material at the load current or rated current, improving the breaking performance and reducing the breaking current as low as 0.8A or less. A vacuum valve with surge performance can be provided. Moreover, the breaking capacity can also be increased compared to the embodiments described above.

Furthermore, the present invention is not limited to the above-mentioned embodiments, and the contact material is made of a low-surge material made of an alloy containing a high vapor pressure, low melting point material based on Ag or Cu, and the back surface of the contact material is It is possible to provide a vacuum valve having low surge performance with improved interrupting performance and exhibiting the same effect even with a vertical magnetic field electrode in which a resistance member is provided at the 7211 and the electrode member surrounding the electrode member is made of a Cu-Cr material. can.

〔Effect of the invention〕

The present invention is configured as described above.

Due to the low surge performance and the effect of arc diffusion on Cu-Cr during large current interruption, it is possible to provide a vacuum valve with low surge and large interruption capacity.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the electrode structure of the vacuum valve of the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1 and viewed in the direction of the arrow, and FIG. An explanatory diagram showing the relationship between the arc voltage, the axial magnetic field, and the breaking current value of the contact material related to the present invention, FIG. 4 is a plan view showing another embodiment of the present invention,
FIG. 5 is a cross-sectional view taken along the line A-0-A in FIG. 4 and viewed in the direction of the arrow; FIG. 61g is an explanatory diagram showing the magnetic flux distribution density of the interelectrode space related to the present invention; FIG. is a cross-sectional view showing the configuration of a conventional vacuum valve, FIG. 8 is a plan view showing the electrode structure of a conventional vacuum valve, and FIG. 9 is a cross-sectional view showing the electrode structure of a conventional vacuum valve. FIG. 1... Insulating container, 3... Vacuum container 20...
・Movable side electrode, 22...Coil 1! Extreme 23...
・Reinforcing member, 24...first electrode member 25・
...Second electrode member, 26...Contact 27...Resistance member, 29...Slit (8733) Agent Patent attorney Yoshiaki Inomata (1 person) Figure 2 ◆Yukirei p Kidney wo Tsu: 'E&<r)→ Fig. 3 Fig. 5 Fig. O Fig. 7 Fig. 7 Fig. 8 Fig. q Fig.

Claims (10)

[Claims] (1) In a vacuum valve in which the openings at both ends of an insulating container are closed with end plates to form a vacuum container, and a pair of electrodes that can be freely connected and separated are arranged inside this vacuum container, a material with low surge properties is used. a contact point that is formed from and slightly protrudes from the surrounding surface; a first electrode member that is provided around this contact point and is made of a material that has voltage resistance and large current interrupting ability; and this first electrode member. A second electrode member is provided with a coil electrode fixed to the front side and generates an axial magnetic field on the back side, and a resistance member with a large temperature coefficient of electrical resistance is provided on the back side of the contact, and this resistance member is attached to the lower part of the second electrode member. 1. A vacuum valve comprising an electrode having a structure electrically connected to a second electrode member, a surrounding first electrode member, and an upper contact point. (2) In a vacuum valve in which the openings at both ends of an insulating container are closed with end plates to form a vacuum container, and a pair of electrodes that can be freely connected and separated are arranged inside the vacuum container, a material with low surge properties is used. A first electrode member formed around the plurality of contacts and made of a material having withstand voltage and large current interrupting properties; a second electrode member having an electrode member fixed to the front side and a coil electrode for generating an axial magnetic field on the back side;
A resistance member having a large temperature coefficient of electrical resistance is provided on the back surface of each of the plurality of contacts, and each of the resistance members has an electrical connection with the lower second electrode member, the surrounding first electrode member, and each upper contact. 1. A vacuum valve characterized in that the electrodes have a structure in which the plurality of contacts are equally spaced at approximately R/2 positions, where R is the radius of the second electrode member. (3) The vacuum valve according to claim 1 or 2, wherein the contacts are made of Ag-WC material. (4) The vacuum valve according to claim 1 or 2, wherein the first electrode member is made of a Cu-Cr material. (5) The vacuum valve according to claim 1 or 2, wherein the contact points protrude 2 to 3 mm from the surrounding surface. (6) The vacuum valve according to claim 1 or 2, wherein the resistance member is made of Ni, Fe, or an alloy thereof. (7) The vacuum valve according to claim 1 or 2, wherein the diameter of the resistance member is the same as or smaller than that of the contact. (8) The vacuum valve according to claim 1 or 2, wherein a ring-shaped reinforcing member made of a low conductivity material is provided between the back surface of the second electrode member and the coil electrode. (9) The vacuum valve according to claim 1 or 2, wherein the first electrode member and the second electrode member are provided with a plurality of slits extending linearly in the radial direction. (10) Cu is applied to the opposing surface of the electrode by current aging.
3. The vacuum valve according to claim 1 or 2, wherein a thin film layer is formed of fine particles of Cr, Cr, and Ag.