BACKGROUND OF THE IVNENTION
1. FIELD OF THE INVENTION:
[0001] The present invention relates to electrodes of a vacuum circuit breaker, and especially
to the electrode construction having sub-electrode on the back face of main electrode.
2. DESCRIPTION OF THE RELATED ART
[0002] In FIG.1, which is a sectional side view of a typical example of a general vacuum
circuit breaker,the vacuum circuit breaker comprises, an upper and a lower electrodes
3 and 3' facing to each other, a pair of conductor rods 1 and 2, a vacuum tube 6 to
define a chamber, a fixed base 5a, a moving base 5b, shield members 9 and a bellows
10. The upper electrode 3 is fixed on the fixed base 5a via the conductor rod 1 connected
inbetween, and the lower electrode 3' is mounted on the moving base 5b via the conductor
rod 2 and the bellows 10.
[0003] FIG.2 is a perspective vies of a conventional electrode of vacuum circuit breaker,
which is shown, for example, in the Japanese publised patent unexamined application
Sho 58-100325. In FIG.2, the top part of the conductor rod 1 has a cylinder part la,
which fits into a center hole 7e of a connection ring 7a of a connection member 7.
The connection member 7 has four arms 7b extended in radial directions, and the tip
part of the arms 7b have respectively contact parts 7c in vertically upper direction
of the arms 7b. The main electrode 3 is fixed on the connection member 7, which has
a disk part 3a, and four coil parts 3b all extending in the same tangential direction
along and outside the circumference. And foundation parts 3c of the coil parts 3b
are formed continuously from the disk part 3a. The back faces 3d of the end tip parts
of the coil parts 3b and the corresponding front faces 7d of the contact parts 7c
of the connection member 7 are respectively connected with each other. Thereby, the
main electrode 3 and the conductor rod 1 are electrically connected with each other.
Further, the stick part 8a of the fixing member 8 is fitted into the hole lc of the
cylinder part la of the conductor rod 1, and the cylinder part la is fitted in the
hole 7e at the face of the center part of the connection member 7. And a pair of conductor
rods 1, the connection members 7, the main electrodes 3 and the fixing members 8 are
disposed against each other in a vacuum tube 6, which is shown in FIG.l.
[0004] In FIG.2 and FIG.3, in case that an arc spot is generated by pulling apart of electrodes
at the center part of the main electrode 3 which is designated by P, an electric currents
flow from the center point P in radial direction along the path designated by R, and
further electric currents flow through the base parts 3c, the coil parts 3b, the back
parts 3d of the coil parts 3b, the contact parts 7c of the connection member 7, the
arms 7b, and the connection ring 7a and to the conductor rod 1. Therefore, a magnetic
field is formed in the axial direction of the wain electrode 3. In this device, there
is another electric path from the main electrode 3 to the conductor rod 1 through
the fixing member 8. Since the latter electric path undesirably works to decrease
the axial magnetic field, such a high electrical resistance material as to limit the
electric current in the latter path is used for the fixing member 8, thereby intending
effectively to form the magnetic field of the axial direction.
[0005] Generally, the vacuum circuit breaker has such constitution as mentioned above, for
making the magnetic field in the axial direction in order to effectively blow out
the arc to avoid melting down of the electrode. However, since a material of the main
electrode 3 generally has a high resistance, the electric current from the main electrode
3 to the conductor rod 1 does not flow through the path of the current formed of the
disk part 3a of the main electrode 3, through the base part 3c, the coil part 3b,
the back part 3d, the contact part 7c of the connection member 7, the arm 7b, the
connection ring 7a and to the conductor rod 1, but actual current flows through a
path from the main electrode 3, through the fixing member 8 and to the conductor rod
1, (this is because the disk part 3a, the coil part 3b, the base part 3c and the back
part 3d which are parts of the main electrode 3 have a low conductivity. Thus, the
magnetic field in axial direction is not formed effectively.
SUMMARY OF THE INVENTION
[0006] Accordingly, the purpose of the present invention is to provide an improved electrode
of vacuum circuit breaker, having the conventional coil action part on its circumference
and further having a sub-electrode part which is made of higher conductivity materials
than the material of the main electrode,thereby to enable satisfactory function of
arc extinguishing.
[0007] An electrode of vacuum circuit breaker in accordance with the present invention comprises;
a conductor rod to be connected to an electric power line,
a main electrode of an electric contact metal which has a center disk part at its
center part, plural number of arm parts provided at its peripheral part and extending
in the same circumference direction with gap parts therebetween,
a sub-electrode of a metal of higher conductivity than the electric contact metal
having the same shape as and bonded on the back face of the main electrode, and
a connection member which is of an electrically conductive metal, has a center part
to be connected to the conductor rod and plural arm parts connected by their ends
to the ends of the arm parts. BRIEF DESCRIPTION OF THE DRAWINGS
FIG.1 is the cross-sectional view of the vacuum circuit breaker in general, wherein
the conventional electrode as well as an electrode in accordance with the present
invention is used.
FIG.2 is the perspective view of the constitution of the conventional electrode of
the vacuum circuit breaker.
FIG.3 is the plan view of the conventional electrode of the vacuum circuit breaker.
FIG.4 is a perspective view of a preferred embodiment of the constitution of an electrode
of vacuum circuit breaker in accordance with the present invention.
FIG.5 is a perspective view of an electrode of FIG.1, which shows an arc spot P and
an electric current.
FIG.6(a) and FIG.6(b) are cross-sectional views of two modes of main electrode 103
and sub-electrode 104 of FIG.5.
FIG.7(a),,is a side view of another embodiment of electrodes of vacuum circuit breaker
in accordance with the present invention.
FIG.7(b) and FIG.7(c) are bottom view and plan view of the electrode of FIG.7(a),respectively.
FIG.8(a) is a side view of still other embodiment of electrodes of vacuum circuit
breaker in accordance with the present invention.
FIG.8(b) and FIG.8(c) are bottom view and plan viewgs of electrode of FIG.8(a),respectively.
FIG.9(a) is a side view of still other embodiment of electrodes of vacuum circuit
breaker in accordance with the present invention.
FIG.9(b) and FIG.9(c) are bottom view and plan view of electrodes of FIG.9(a),respectively.
FIG.10 is a plan view of still other embodiment of an electrode used in the vacuum
circuit breaker of FIG.9(a),
FIG.11 is a plan view or bottom view of still other embodiment of electrodes used
in the vacuum circuit breaker of FIG.9(a).
FIG.12 is a plan view or bottom view of still other embodiment of electrodes used
in the vacuum circuit breaker of FIG.9(a).
FIG.13(a) is a side view of still other embodiment of electrodes of vacuum circuit
breaker in accordance with the present invention.
FIG.13(b) and FIG.13(c) are bottom view and plan view of electrodes of FIG.13(a),respectively.
FIG.14(a) and FIG.14(b) are bottom view and plan view of still other embodiment of
electrodes used in the vacuum circuit breaker of FIG.13(a),respectively.
FIG.15(a) and FIG.15(b) are bottom view and plan view of still other embodiment of
electrodes used in the vacuum circuit breaker of FIG.13(a),respectively.
FIG.16(a) is a cross-sectional side view of still other embodiment of electrodes of
vacuum circuit breaker in accordance with the present invention.
FIG.16(b) and FIG.16(c) are bottom view and plan view of electrodes of FIG.16(a),respectively.
FIG.17(a) is a cross-sectipnal side view of still other embodiment of electrodes of
vacuum circuit breaker in accordance with the present invention.
FIG.17(b) and FIG.17(c) are bottom view and plan view of electrodes of FIG.17(a),respectively.
FIG.18(a) is a cross-sectional side view of still other embodiment of electrodes of
vacuum circuit breaker in accordance with the present invention.
FIG.18(b) and FIG.18(c) are bottom view and plan view of electrod s of FIG.18(a),respectively.
FIG.19(a) is a cross-sectional side view of still other embodiment of electrodes of
vacuum circuit breaker in accordance with the present invention.
FIG.19(b) and FIG.19(c) are bottom view and plan view of electrodes of FIG.19(a),respectively.
FIG.20(a) is a cross-sectional side view of still other embodiment of an electrode
of vacuum circuit breaker in accordance with the present invention.
FIG.20(b) is a plan view of an electrode of FIG.20(a).
FIG.21 is a plan view of still other embodiment of an electrode used in the vacuum
circuit breaker of FIG.29.
FIG.22 is a plan view of still other embodiment of an electrode used in the vacuum
circuit breaker of FIG.20..
FIG.23 is a plan view of still other embodiment of an electrode of vacuum circuit
breaker in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] A first preferred embodiment is described with reference to FIG.4, FIG.5, FIG.6(a)
and (b).
[0009] In FIG.4, the'top part of a conductor rod 101 has a cylinder part lOla, which fits
into the center hole 107e of a connection ring 107a of a connection member 107. The
connection member 107 also has four arms 107b extended in radial directions, and the
tip part of the arms 107b have respectively contact parts 107c in vertically upper
direction of the arms 107b. A sub-electrode 104 is fixed on the connection member
107, which has disk part 104a and four coil parts 104b all extending in the same tangential
direction along and outside the circumference. And the foundation parts 104c of the
coil parts 104b are formed continuously from the disk part 104a. The back faces 104d
of the end tip parts of the coil part 104b and the corresponding front faces 107d
of the contact parts 107c of the connection member 107 are respectively connected
with each other. Further, a main electrode 103, which is made of a known electrode
alloy material, and has the same shape as that of the sub-electrode 104, is bonded
on the sub-electrode 104 by brazing or the like. So the main electrode 103 and the
sub-electrode 104 are electrically and mechanically connected with each other.
[0010] A pair of such electrodes are ordinary used as shown in FIG.1 to constitute a switch.
In turning- on of the switch, the bellows 10 is extended and the electrodes 3 and
3' are adhered to each other, and in turning-off of the swich, the electrodes 3 and
3' are pulled apart of each other. At that time, an arc spot is produced between the
two electrodes. FIG.5 shows an arc produced in the center point P of main electrode
103. Electric currents 1
1 and 1
2 are generated by the arc. The electric current I
1 flows from the point P through the center part 103a, the foundation part 103c, the
coil part 103b, the back part 103d of coil part 103b, the coil part of sub-electrode
104b, the back part 104b, the contact part 107c of the connection member 107, the
arm 107b, the connection ring 107a and to the conductor rod 101, and the electric
current 1
2 flows from the point P through the center part of sub-electrode 104a, the foundation
of sub-electrode 104c, the coil part of sub-electrode 104b, the back part of the coil
part of sub-electrode 104d, the contact part 107c of the connection member 107, the
arm 107b, the connection ring 107a and to the conductor rod 101.
[0011] Hereupon, in case that the main electrode 103 has lower conductivity and the sub-electrode
104 has higher conductivity, detailed explanation is given in following. For example,
the material of the main electrode 103 is Cu alloy, Ag alloy or the like, their electric
conductivity is about 20 - 50 % of the conductivity of the pure Cu electrode, and
the material of the sub-electrode 104 is Cu, it has about 100 % of the electric conductivity.
Assumingly that the conductivity of the material of the main electrode 103 is as high
as 20 % of the conductivity of the material of the sub-electrode 104, in other words,
the main electrode 103 has a resistance of as high as five times of that of the sub-electrode
104, and the thickness of the main electrode 103 and that of the sub-electrode 104
are equal, then the composite effective resistance of the embodiment is as high as
about 33 % of resistance of conventional electrode shown in FIG.2, which is made of
the electrode alloy metal and has a thickness equal to the total thickness of the
main electrode 103 and the sub-electrode 104. In other words, the total thickness
of the main electrode and the sub-electrode 104 in accordance with the present invention
can be made thinner than that of the conventional electrode, which can make the same
magnitude of electric current for making the arc extinguish magnetic field effectively.
In another case that the main electrode 103 has the same conductivity as the sub-electrode
104, the total thickness of the main electrode 103 and the sub-electrode 104 is equal
to that of the conventional electrode. The material of the main electrode, however,
is generally expensive, and the material of the sub-electrode is relatively inexpensive.
Accordingly, by forming the sub-electrode 104 behind the back face of the main electrode
103, can make the thickness of the main electrode 103 can be made thinner, so that
the total cost of the electrode can be reduced. The magnetic field is generated in
the axial direction of the conductor rod 101 by the electric currents as shown in
FIG.5, so that making of arc in the center part of the electrode designated by P is
effective for circuit breaking. FIG.6(a) shows the cross-sectional side view of the
electrode having a terraced shape, and FIG.6(b) shows the cross-sectional side view
of the electrode having slant periphery shape. These shapes are designed for confining
the arc spot in the center part of the electrode.
[0012] FIG.7(a), FIG.7(b) and FIG.7(c) show another embodiment in accordance with the present
invention. In FIG.7(a), FIG.7(b) and FIG.7(c), conductor rods 151 and 151' respectively
have one connection arm 157 and 157'. Furthermore, main electrodes 153 and 153', and
sub-electrodes 154 and 154' respectively have a center slit. Holding members 158 and
158' are respectively disposed between the conductor rods 151, 151' and the sub-electrodes
154, 154', and respective holding members 158 and 158' are made of high electric
lesistance material. Accordingly, the electric currents does not flow from the conductor
rod 151 through the holding member 158 to the sub-electrode 154, but disirably flow
as designated by arrow marks. And the magnetic field is generated cirtainly in the
axial direction. The arc is generated between P and P'.
[0013] FIG.8(a), FIG.8(b) and FIG.8(c) show still other embodiment in accordance with the
present invention. This embodiment does not have any connection member, and conductor
rod is thicker than the other embodiment shown in FIG.7s. And the contact part of
each of the conductor rods 161 and 161' is constituted by a low electric resistance
part 165 and 165' and a high electric resistance part 168 and 168'. The high electric
resistance part 168 and 168' have a little over three quarters circular region, which
are hatched with dotted lines in FIG.8(a),FIG.8(b) and FIG.8(c). The main electrodes
163 and 163', and the sub-electrodes 164 and 164' have respectively cross- shaped
slit 163a, 163'a. The electric current flows from the conductor rod 161 through the
low electric resistance part 165 and the sub-electrode 164 to the main electrode 163.
The magnetic field is generated in the axial direction, and the arc spot is generated
between P and P'.
[0014] FIG.9(a), FIG.9(b) and FIG.9(c) show still other embodiment in accordance with the
present invention. In such embodiment conductor rods 171 and 171' have one connection
arm 177 and 177' of low electric resistance, respectively, and the cor tact parts
178 and 178' of the conductor rods 171 and 171' are made of high electric resistance
material, respectively.
[0015] FIG.10, FIG.11 and FIG.12 are plan views of main electrodes which are used in the
embodiment of FIG.9s. Of course, the sub-electrodes have respectivrely the same plan
views in each case.
[0016] FIG.13(a), FIG.13(b) and FIG.13(c) show still other embodiment in accordance with
the present invention. In this embodiment, the main electrodes, of course the sub-electrodes
have plural slits in parallel. In this case, plural number of arcs are generated as
shown in the figures.
[0017] FIG.14(a), FIG.14(b), FIG.15(a) and FIG.15(b) are the plan view of main electrodes
which are used in the embodiment of FIG.13(a), FIG.13(b) and FIG.13(c).
[0018] FIG.16(a), FIG.16(b) and FIG.16(c) show still other embodiment in accordance with
the present invention. In this embodiment, the connection arms 197 and 197' face alternately
each other.
[0019] And FIG.17(a), FIG.17(b) and FIG.17(c) show still other embodiment in accordance
with the present invention. In this embodiment, the connection arms 207 and 207' confront
with each other. In such embodiments shown in FIG.13 through FIG.17, the electric
currents flow as lines designated by arrow marks, and arcs occur plurally as shown
in the figures.
[0020] FIG.18(a), FIG.18(b) and FIG.18(c) show still other embodiment in accorcance with
the present invention.
[0021] FIG.19(a), FIG.19(b) and FIG.19(c) show still other embodiment in accordance with
the present invention.
[0022] FIG.20(a) and FIG.20(b) show still other embodiment in accordance with the present
invention. In this embodiment, a connection member 237 has a pair of opposit arms,
and a main electrode 233 has terraced shape.
[0023] FIG.21 and FIG.22 are the plan view of the main electrode 233 used in the embodiment
shown in FIG.21.
[0024] FIG.23 shows still other embodiment in accordance with the present invention. In
this embodiment, the connection member 247 has three arms 247a.
1. An electrode of vacuum circuit breaker comprising; (in Fig. 4)
a conductor rod to be connected to an electric power line,
a main electrode (103) of an electric contact metal which has a center disk part (103a)
at its center part, plural number of arm parts (103b) provided at its peripheral part
and extending in the same circumference direction with gap parts therebetween,
a sub-electrode (104) of a metal of higher conducti-- vity than said electric contact
metal having the same shape as and bonded on back face of said main electrode (103),
and
a connection member (107) which is on an electrically conductive metal, has a center
part to be connected to said conductor rod (101) and plural arm parts connected by
their ends to said ends of said arm parts.
2. An electrode of vacuum circuit breaker in accordance with claim 1, wherein
conductivity of said sub-electrode is higher than that of said main electrode.
3. An electrode of vacuum circuit breaker in accordance with claim 1, wherein (Fig.
6a) said main electrode is of terraced shape.
4. An electrode of vacuum circuit breaker in accordance with claim 1, wherein (Fig.
6b)
said main electrode is of slant shape.
5. An electrode of vacuum circuit breaker comprising; (Fig. 7)
a main electrode (153) having at least one gap part,
a sub-electrode (154) having the same shape of said main electrode and being disposed
on back face of said main electrode,
a conductor rod connected with an electric power line and having at least one connection
part (157) with said sub-electrode, and
a fixing means (158) disposed between said conductor rod (151) and said sub-electrode
(154), and having low electric conductivity.
6. An electrode of vacuum circuit breaker in accordance - with claim 5, wherein
material of said sub-electrode has higher electric conductivity than that of said
main electrode.
7. An electrode of vacuum circuit breaker in accordance with claim 5, wherein
said main electrode is of terraced shape.
8. An electrode of vacuum circuit breaker in accordance with claim 5, wherein
said main electrode is of slant shape.