U.S. patent application number 09/933135 was filed with the patent office on 2002-03-07 for automatic switchover device for power source.
Invention is credited to Asai, Koichi, Eguchi, Hiroyuki, Hirano, Tsutomu.
Application Number | 20020027792 09/933135 |
Document ID | / |
Family ID | 18748826 |
Filed Date | 2002-03-07 |
United States Patent
Application |
20020027792 |
Kind Code |
A1 |
Hirano, Tsutomu ; et
al. |
March 7, 2002 |
Automatic switchover device for power source
Abstract
In an automatic switchover device for a power source designed to
automatically switch over systems for supplying electric power to
an electric load in such a manner that electric power output from
an engine generator is supplied to the electric load upon power
failure of a regular power source system, a seesaw-type turn member
is mounted for turning movement between a first turned position in
which it permits a common contact to be electrically connected to a
first individual contact and a second turned position in which it
permits the common contact to be electrically connected to a second
individual contact. First and second solenoids capable of exerting
an electromagnetic force for driving the seesaw-type turn member
toward one of the first and second turned position, each include a
plunger which has an operating portion enabling the plunger to be
pushed in from the outside, thereby enabling an operator's manual
switching.
Inventors: |
Hirano, Tsutomu; (Saitama,
JP) ; Asai, Koichi; (Saitama, JP) ; Eguchi,
Hiroyuki; (Saitama, JP) |
Correspondence
Address: |
ARENT FOX KINTNER PLOTKIN & KAHN, PLLC
Suite 400
1050 Connecticut Avenue, N.W.
Washington
DC
20036-5339
US
|
Family ID: |
18748826 |
Appl. No.: |
09/933135 |
Filed: |
August 21, 2001 |
Current U.S.
Class: |
363/144 |
Current CPC
Class: |
H01H 51/12 20130101;
H02J 9/06 20130101; H01H 50/326 20130101; H01H 2300/018
20130101 |
Class at
Publication: |
363/144 |
International
Class: |
H02M 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2000 |
JP |
2000-260885 |
Claims
What is claimed is:
1. An automatic switchover device for a power source, comprising: a
switching unit which has first and second individual contacts
individually leading to a regular power source system and an engine
generator, and a common contact leading to an electric load,
wherein the common contact can be alternatively electrically
connected to the first and second individual contacts, and a
control unit for controlling said switching unit in such a manner
that said common contact is electrically connected to the second
individual contact in response to said regular power source system
being electrically failed, and said common contact is electrically
connected to the first individual contact in response to the
restoration of said regular power source system, wherein said
switching unit includes: a seesaw-type turn member carried on a
support frame for turning movement between a first turned position
in which the turn member permits said common contact to be
electrically connected to the first individual contact and a second
turned position in which the turn member permits said common
contact to be electrically connected to the second individual
contact, a spring member for exerting a spring force for retaining
said turn member in one of the first and second turned positions in
response to the turning movement of said turn member passing
through a central point between said first and second turned
positions toward one of said first and second turned positions, a
first solenoid capable of exerting an electromagnetic force for
driving said turn member toward the first turned position against
the spring force of said spring member, and a second solenoid
capable of exerting an electromagnetic force for driving said turn
member toward the second turned position against the spring force
of said spring member, said first and second solenoids each
including a plunger which integrally comprises an operating portion
enabling said plunger to be pushed in from the outside.
2. An automatic switchover device for a power source according to
claim 1, wherein said common contact is provided on a movable
contact-supporting member which is operably connected to said turn
member for turning movement about an axis coaxial with said turn
member, and said switching unit is accommodated in a box body
having an opening capable of being opened and closed by a lid
member in such a manner that said operating portions are disposed
on the side of the opening, and said turn member and said movable
contact-supporting member are disposed on the side opposite from
the opening.
3. An automatic switchover device for a power source according to
claim 2, wherein said common contact is provided at each of
opposite ends of said movable contact-supporting member; said first
and second individual contacts capable of being electrically
connected to said common contact are fixedly disposed at locations
corresponding to the opposite ends of said movable
contact-supporting member; first and second power source terminal
members individually connected to said regular power source system
and said engine generator are connected to said first and second
individual contacts; and a load terminal member leading to the
electric load and fixedly disposed at a location corresponding to a
central portion of said movable contact-supporting member is
connected to said common contact.
Description
BACKGROUND OF THE INVENTION
[0001] 1. FIELD OF THE INVENTION
[0002] The present invention relates to an automatic switchover
device for a power source, designed to automatically switch over
systems for supplying electric power to an electric load in such a
manner that electric power output from an engine generator is
supplied to the electric load upon occurrence of the power failure
of a regular power source system.
[0003] 2. Description of the Related Art
[0004] There is an automatic switchover device known, for example,
from Japanese Patent Application Laid-open No.5-64382 and the like,
which is designed so that a switch is changed over to supply
electric power output from an engine generator to an electric load
upon occurrence of the power failure of a regular power source
system.
[0005] In such an automatic switchover device for the power source,
it is necessary not only to provide an emergency automatic
switchover mechanism, but also to provide a measure for enabling
switching by an operator's manual operation in case of failure or
the liked of a control unit. It is general that a special switching
lever structure or the like is mounted on the conventional
automatic switchover device.
SUMMARY OF THE INVENTION
[0006] The present invention has been achieved with the above
circumstances in view, and it is an object of the present invention
to provide an automatic switchover device for a power source,
wherein the switching can be achieved by the operator's manual
operation without provision of a special mechanism.
[0007] To achieve the above object, according to a first aspect and
feature of the present invention, there is provided an automatic
switchover device for a power source, comprising: a switching unit
which has first and second individual contacts individually leading
to a regular power source system and an engine generator, and a
common contact leading to an electric load, wherein the common
contact can be alternatively electrically connected to the first
and second individual contacts; and a control unit for controlling
the switching unit in such a manner that the common contact is
electrically connected to the second individual contact in response
to the regular power source system being electrically failed, and
the common contact is electrically connected to the first
individual contact in response to the restoration of the regular
power source system, wherein the switching unit includes: a
seesaw-type turn member carried on a support frame for turning
movement between a first turned position in which the turn member
permits the common contact to be electrically connected to the
first individual contact and a second turned position in which the
turn member permits the common contact to be electrically connected
to the second individual contact, a spring member for exerting a
spring force for retaining the turn member in one of the first and
second turned positions in response to the turning movement of the
turn member passing through a central point between the first and
second turned positions toward one of the first and second turned
positions, a first solenoid capable of exerting an electromagnetic
force for driving the turn member toward the first turned position
against the spring force of the spring member, and a second
solenoid capable of exerting an electromagnetic force for driving
the turn member toward the second turned position against the
spring force of the spring member, the first and second solenoids
each including a plunger which integrally comprises an operating
portion enabling the plunger to be pushed in from the outside.
[0008] With such arrangement of the first feature, the supplying of
the electric power from the engine generator to the electric load
upon the occurrence of the power failure of the regular power
source system and the supplying of the electric power from the
regular power source system to the electric load upon the
restoration of the regular power source system can be automatically
switched over from one to the other by controlling the energization
and de-energization of the first and second solenoids in a
switching manner by the control unit. Moreover, in case of
emergency, the electric connection between the regular power source
system and the electric load and the electric connection between
the engine generator and the electric load can be alternatively
switched over from one to the other by pushing in the operating
portions integrally provided on the plungers included in the
solenoids, without utilizing the energization or de-energization of
the first and second solenoids. Furthermore, it is unnecessary to
mount a special lever mechanism or the like, and it is possible to
achieve the switching operation by an operator's manual operation
in a simple structure in which the operating portions are merely
integrally provided on the plungers.
[0009] According to a second aspect and feature of the present
invention, in addition to the arrangement of the first feature, the
common contact is provided on a movable contact-supporting member
which is operably connected to the turn member for turning movement
about an axis coaxial with the turn member, and the switching unit
is accommodated in a box body having an opening capable of being
opened and closed by a lid member in such a manner that the
operating portions are disposed on the side of the opening, and the
turn member and the movable contact-supporting member are disposed
on the side opposite from the opening. With such arrangement,
contact portions of the first and second contacts and the common
contact are disposed inside the box body, whereby the contact with
the contact portions from the outside can be prevented to the
utmost and moreover, the operator's manual operation can be
facilitated by the disposition of the operating portions on the
side of the opening.
[0010] According to a third aspect and feature of the present
invention, in addition to the second feature, the common contact is
provided at each of opposite ends of the movable contact-supporting
member; the first and second individual contacts capable of being
electrically connected to the common contact are fixedly disposed
at locations corresponding to the opposite ends of the movable
contact-supporting member; first and second power source terminal
members individually connected to the regular power source system
and the engine generator are connected to the first and second
individual contacts; and a load terminal member leading to the
electric load and fixedly disposed at a location corresponding to a
central portion of the movable contact-supporting member is
connected to the common contact. With such arrangement, the first
and second power source terminal members are fixedly disposed at
the opposite ends of the movable contact-supporting member, and the
load terminal member is fixedly disposed in correspondence to the
central portion of the movable contact-supporting member.
Therefore, electric cords leading to the first and second power
source terminal members and the load terminal member can be easily
arranged in such a manner that a wiring line is distributed for
each of the electric cords.
[0011] The above and other objects, features and advantages of the
invention will become apparent from the following description of
the preferred embodiment taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1 to 13 show an embodiment of the present invention,
wherein
[0013] FIG. 1 is a circuit diagram showing the arrangement of an
automatic switchover device;
[0014] FIG. 2 is a partially cutaway front view of the automatic
switchover device;
[0015] FIG. 3 is an exploded perspective view of an accommodation
box;
[0016] FIG. 4 is an enlarged front view of a switching unit;
[0017] FIG. 5 is an enlarged sectional view taken along a line 5-5
in FIG. 4;
[0018] FIG. 6 is a sectional view taken along a line 6-6 in FIG.
4;
[0019] FIG. 7 is a sectional view taken along a line 7-7 in FIG.
4;
[0020] FIG. 8 is an enlarged sectional view of a structure of
connection of an electric cord to a terminal member, taken along a
line 8-8 in FIG. 4;
[0021] FIG. 9 is a perspective view showing the structure of
connection of the electric cord to the terminal member;
[0022] FIG. 10 is an exploded perspective view showing the
structure of connection of the electric cord to the terminal
member;
[0023] FIG. 11 is a perspective view similar to FIG. 9, but showing
an eyelet-type terminal mounted at one end of the electric
cord;
[0024] FIG. 12 is a block diagram showing the arrangement of a
control system; and
[0025] FIG. 13 is a flow chart showing a controlling procedure in
an automatic switchover mode.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0026] The present invention will now be described by way of an
embodiment with reference to FIGS. 1 to 13.
[0027] Referring first to FIG. 1, an automatic switchover device 15
is designed to automatically switch over systems for supplying an
electric power to an electric load 20 so that an electric power
output by an engine generator 19 is supplied to the electric load
20 during power failure of a regular power source system 18. The
automatic switchover device 15 includes a switching unit 16
operated to alternatively select the supplying of the electric
power from the regular power source system 18 and the electric
power output from the engine generator 19 to the electric load 20,
and a control unit 17 for normally monitoring the power failure and
restoration of the regular power source system 18 and controlling
the operation of the switching unit 16 in response to the power
failure and the restoration.
[0028] Referring also to FIGS. 2 and 3, the automatic switchover
device 15 is accommodated and fixed in an accommodation box 21
attached, for example, to a wall or the like of a house or
building. The accommodation box 21 is comprised of a box body 22
formed into a bottomed quadrilateral tubular shape with its one end
face closed and the other end face opened, and a lid member 23
which can open and close the opening of the box body 22. Moreover,
the box body 22 comprises first, second, third and fourth
side-plates 24, 25, 26 and 27 which are connected to form a
quadrilateral tubular shape, and a base plate 28 which commonly and
detachably connects one-end of the first, second, third and fourth
side-plates 24, 25, 26 and 27 together.
[0029] The base plate 28 is formed into a quadrilateral flat plate
shape. Connecting plate portions 28a, 28a are integrally connected
at their base ends to two parallel sides of side edges of the base
plate 28 at right angles, and mounting plate portions 28b, 28b are
integrally connected at their base ends to edges of the connecting
plate portions 28a, 28a at right angles, respectively. A plurality
of, e.g., a pair of insertion bores 29 are provided in each of the
mounting plate portions 28b, 28b so that screw members 30 (see FIG.
2) are inserted through the insertion bores 29, when the mounting
plate portions 28b, 28b are secured to the wall or the like of the
house or building. A plurality of, e.g., three insertion bores 31
are provided in each of the connecting plate portions 28a, 28a.
Weld nuts 32 are secured to inner surfaces of the connecting plate
portions 28a, 28a at locations corresponding to the insertion bores
31.
[0030] The first and second side-plates 24 and 25 opposed to each
other are detachably connected to outer surfaces of the connecting
plate portions 28a, 28a included in the base plate 28. Three
insertion bores 33 corresponding to the insertion bores 31 in the
connecting plate portions 28a, 28a are provided along one end of
each of the first and second side-plates 24 and 25 adjacent to the
base plate 28 so that one-ends of the first and second side-plates
24 and 25 are connected to the base plate 28 at right angles by
bringing screw members 34 inserted through the insertion bores 33
and 31 into threaded engagement with the weld nuts 32 and then
tightening them.
[0031] A plurality of, e.g., three insertion bores (not shown) are
provided in each of the side edges of the base plate 28 on two
sides perpendicular to the two sides to which the connecting plate
portions 28a, 28a are connected, and weld nuts 35 individually
corresponding to these insertion bores are secured to the side
edges.
[0032] On the other hand, connecting plate portions 26a and 27a are
connected integrally and at right angles to one ends of the third
and fourth side-plates 26 and 27 adjacent to the base plate 28 at
locations corresponding to the weld nuts 35, and are superposed on
the base plate 28. Slits 36 are defined in the connecting plate
portions 26a and 27a to open at ends of the connecting plate
portions 26a and 27a so that screw members 37 threadedly engaged
with the weld nuts 35 are inserted through the slits 36. Therefore,
the third and fourth side-plates 26 and 27 are connected at their
one ends at right angles to the base plate 28 by bringing the screw
members 37 inserted through the slits 36 into threaded engagement
with the weld nuts 35 and then tightening them.
[0033] Connecting plate portions 24a, 24a; 25a, 25a are connected
integrally and at right angles to opposite side edges of the first
and second side-plates 24 and 25 and superposed on opposite side
edges of the third and fourth side-plates 26 and 27. A plurality
of, e.g., a pair of insertion bores 38 are provided in each of the
connecting plate portions 24a, 24a; 25a, 25a, and weld nuts 39
corresponding to the insertion bores 38 are secured to the
connecting plate portions 24a, 24a; 25a, 25a. On the other hand,
insertion bores 40 corresponding to the insertion bores 38 are
provided in opposite side edges of the third and fourth side-plates
26 and 27, and the first, second, third and fourth side-plates 24,
25, 26 and 27 are connected together by bringing screw members 41
inserted through the insertion bores 40 into threaded engagement
with the weld nuts 39 and then tightening them.
[0034] In such box body 22, the connection of the side-plates 24,
25, 26 and 27 to the base plate 28 is released by unscrewing the
screw members 34 and 37, and the connection of the side-plates 24,
25, 26 and 27 to one another by unscrewing the screw members
41.
[0035] Moreover, each of the side-plates 24, 25, 26 and 27 can be
removed in a direction away from the base plate 28 in a direction
parallel to the pair of adjacent to side-plates upon disconnection
of the side-plates 24, 25, 26 and 27 from one another and
disconnection of the side-plates 24, 25, 26 and 27 from the base
plate 28. When any of the side-plates 24, 25, 26 and 27 is removed,
avoided is an influence to the connection of the other side-plates
to one another as well as the connection of the other side-plates
to the base plate. For example, to remove the first side-plate 24,
the first side-plate 24 disconnected from the third and fourth
side-plates 26 and 27 and disconnected from the base plate 28 can
be removed upwards as viewed in FIG. 2 and at this time, there is
no influence affecting the connection of the second, third and
fourth side-plates 25, 26 and 27 to one another as well as the
connection of the second, third and fourth side-plates 25, 26 and
27 to base plate 28.
[0036] In the present embodiment, the weld nuts 32, 35 and 39 are
secured to the base plate 28 and the first and second side-plates
24 and 25, but in place of these weld nuts 32, 35 and 39, other
securing-type nuts, e.g., pierced nuts or the like may be used,
thereby enabling a reduction in part cost.
[0037] Collar portions 24b, 25b, 26b and 27b are connected
integrally and at right angles to other ends of the side-plates 24,
25, 26 and 27 opposite from the base plate 28 to define, by
cooperation with one another, a peripheral edge of an opening 42
which is provided in the other end of the box body 22 in such a
manner that it is closed by a lid member 23. The lid member 23 is
carried on box body 22 and hinged on the third side-plate 26 so
that the box body 22 can be opened and closed, and for example, two
sets of three fastening bores 44 are provided in the third
side-plate 26 for fastening a pair of hinge members 43, 43 fastened
to the lid member 23. A lock mechanism (not shown) for switching
over the engagement and disengagement of the fourth side-plate 27
with and from the collar portion 27b is mounted to the lid member
23 on a side opposite from a side having the hinge members 43, 43,
and a through-bore 45 for mounting the lock mechanism is provided
in the lid member 23.
[0038] The automatic switchover device 15 is comprised of the
switching unit 16 and the control unit 17, as described above. The
switching unit 16 is mounted to the base plate 28 of the box body
22, while the control unit 17 is mounted to the lid member 23.
Moreover, the switching unit 16 and the control unit 17 are mounted
separately to the box body 22 and the lid member 23, respectively,
so that they cannot be superposed on each other in a state in which
the opening in the box body 22 is closed by the lid member 23, as
shown in FIG. 2.
[0039] Referring also to FIGS. 4 to 7, the switching unit 16
includes a support frame 50 fastened to the base plate 28 of the
box body 22 with an insulating plate 49 interposed therebetween,
three first individual contacts 51 fixedly disposed on the support
frame 50 and leading to the regular power source system 18, three
second individual contacts 52 fixedly disposed on the support frame
50 and leading to the engine generator 19, three sets of a pair of
common contacts 53 leading to the electric load 20, a seesaw-type
turn member 54 carried on the support frame 50 and able to turn
between a first turned position in which it permits the common
contacts 53 to be electrically connected to the first individual
contacts 51 and a second turned position (shown in FIG. 6) in which
it permits the common contacts 53 to be electrically connected to
the second individual contacts 52, a spring member 55 for exerting
a spring force for retaining the turn member 54 at one of the first
and second turned positions in response to the turning movement of
the turn member 54 at one of the first and second turned positions,
a first solenoid 56 capable of exerting an electromagnetic force
for driving the turn member 54 to the first turned position against
the spring force of the spring member 55, and a second solenoid 57
capable of exerting an electromagnetic force for driving the turn
member 54 to the second turned position against the spring force of
the spring member 55.
[0040] A turn shaft 58 is turnably carried at its opposite ends on
the support frame 50 and disposed on a plane parallel to the base
plate 28, with its major portion excluding its axially opposite
ends being shaped into a rectangle in cross section. The turn
member 54 extends in a direction perpendicular to an axis of the
turn shaft 58, and is secured at its central portion to a portion
of the turn shaft 58 closer to one end.
[0041] Referring particularly carefully to FIG. 6, the first
solenoid 56 is disposed on the support frame 50 in correspondence
to one end (a lower end as viewed in FIG. 6) of the turn member 54,
and the second solenoid 57 is disposed on the support frame 50 in
correspondence to the other end (an upper end as viewed in FIG. 6)
of the turn member 54.
[0042] The first solenoid 56 disposed on the support frame 50
includes a stationary core 59 adjacent to the turn member 54, a
plunger 60 opposed to the stationary core 59 on a side opposite
from the turn member 54, a coil 61 which exerts an electromagnetic
force for attracting the plunger 60 to the stationary core 59, an
urging rod 62 connected to the plunger 60 and passing through a
central portion of the stationary core 59 for axial movement in
such a manner that one end thereof can be put into abutment against
one end of the turn member 54, and a return spring 63 mounted
between the urging rod 62 and the stationary core 59 while exerting
a spring force for moving the plunger 60 away from the stationary
core 59.
[0043] The second solenoid 57 disposed on the support frame 50
includes a stationary core 64 adjacent to the turn member 54, a
plunger 65 opposed to the stationary core 64 on a side opposite
from the turn member 54, a coil 66 which exerts an electromagnetic
force for attracting the plunger 65 to the stationary core 64, an
urging rod 67 connected to the plunger 65 and passing through a
central portion of the stationary core 64 for axial movement in
such a manner that one end thereof can be put into abutment against
one end of the turn member 54, and a return spring 68 mounted
between the urging rod 67 and the stationary core 64 while exerting
a spring force for moving the plunger 65 away from the stationary
core 64.
[0044] A spring-receiving arm 69 forming a substantially T-shape
together with the turn member 54 is secured at its base end to the
turn shaft 58 at right angles at a location adjacent to a portion
to which the turn member 54 is fixed, and a spring-receiving member
70 is fastened to the support frame 50 at a location corresponding
to a portion between the first and second solenoids 56 and 57.
[0045] Receiving portions 69a and 70a recessed in a triangular
shape are formed at a tip end of the spring-receiving arm 69 and
the spring-receiving member 70 in such a manner that they are
opposed to each other, and the spring member 55 which is a leaf
spring is received at its opposite ends on the receiving portions
69a and 70a. Moreover, the spring-receiving member 70 is mounted so
that, when the turn member 54 is at a location halfway between the
first and second turned positions, a straight line 71
interconnecting a central portion of the receiving portion 70a of
the spring-receiving member 70, i.e., an abutment point at one end
of the spring member 55 and an axis of the turn shaft 58 is
perpendicular to the turn member 54. When the turn member 54 is at
the location halfway between the first and second turned positions,
a central portion 69a of the spring-receiving arm 69, i.e., an
abutment point at the other end of the spring member 55 lies on the
straight line 71.
[0046] Therefore, when the central portion of the receiving portion
69a of the spring-receiving arm 69 passes the straight line 71 in
the turning movement of the turn member 54 from the second turned
position shown in FIG. 6 toward the first turned position, the
spring member 55 exerts the spring force for urging the turn member
54 toward the first turned position. On the other hand, when the
central portion 69a of the spring-receiving arm 69 passes the
straight line 51 in the turning movement of the turn member 54 from
the first turned position toward the second turned position, the
spring member 55 exerts the spring force for urging the turn member
54 toward the second turned position.
[0047] When the coil 61 is in a non-energized state, the first
solenoid 56 is in a state in which one end of the urging rod 62 is
in abutment against one end of the turn member 54 lying in the
second turned position. When the coil 61 is energized in a
non-energized state of the coil 66 in the second solenoid 57, the
urging rod 62 urges the turn member 54 toward the first turned
position, until the central portion of the receiving portion 69a of
the spring-receiving arm 69 passes the straight line 71. When the
turn member 54 is thereafter turned to the first turned position
under the action of the spring force of the spring member 55, the
one end of the turn member 54 is moved away from the one end of the
urging rod 62. On the other hand, when the coil 66 is in the
non-energized state, the second solenoid 57 is in a state in which
one end of the urging rod 67 is in abutment against the other end
of the turn member 54 lying in the first turned position. When the
coil 66 is energized in the non-energized state of the coil 61 of
the first solenoid 56, the urging rod 67 urges the turn member 54
toward the second turned position, until the central portion of the
receiving portion 69a of the spring-receiving arm 69 passes the
straight line 71. When the turn member 54 is thereafter turned to
the second turned position under the action of the spring force of
the spring member 55, the other end of the turn member 54 is moved
away from the one end of the urging rod 67.
[0048] Moreover, the position of the turn member 54 lying in the
first turned position is maintained under the action of the spring
force of the spring member 55, and a spring load of the return
spring 68 applied to the urging rod 62 in contact with the turn
member 54 lying in the first turned position is set lower than the
spring force of the spring member 55. The position of the turn
member 54 lying in the second turned position is maintained under
the action of the spring force of the spring member 55, a spring
load of the return spring 63 applied to the urging rod 62 in
contact with the turn member 54 lying in the second turned position
is set lower than the spring force of the spring member 55.
[0049] A turning force can be applied to the turn member 54 by a
manual operation with the coils 61 and 66 of the first and second
solenoids 56 and 57 remaining non-energized, and the plungers 60
and 65 provided in the first and second solenoids 56 and 57 are
integrally provided with operating portions 60a and 65a each
capable of applying a manually operating force, respectively. The
operating portions 60a and 65a are integrally provided at outer
ends of the plungers 60 and 65 in such a manner that the plungers
60 and 65 are pushed into the first and second solenoids 56 and 57
from the outside, whereby the operating force is exerted to the
turn member 54 by the urging rods 62 and 67. The operating portions
60a and 65a are formed to protrude from the support frame 50, when
the coils 61 and 66 of the first and second solenoids 56 and 57 are
in their non-energized states.
[0050] For example, three movable contact-supporting members 74
each made of an insulating material are secured being spaced apart
from one another to the turn shafts 58 on a side opposite from the
turn member 54 with respect to the spring-receiving member 70. In
other words, the movable contact-supporting members 74 are operably
connected to the turn member 54 for turning movement about an axis
coaxial with the turn member 54.
[0051] Fixed to the support frame 50 are support blocks 75 each
made of an insulating material and corresponding to the movable
contact-supporting members 74, and a plurality of, e.g., four
partition plates 76 for separating the movable contact-supporting
members 74 and the support blocks 75.
[0052] Common contacts 53, 53 are provided at opposite ends of each
of the movable contact-supporting members 74 to partially protrude
from each of the movable contact-supporting members 74. The first
and second individual contacts 51 and 52 are fixed to each of the
support blocks 75 at locations corresponding to the opposite ends
of each of the movable contact-supporting members 74. More
specifically, the first individual contact 51 is fixed to the
support block 75 in such a manner that it is brought into
conductive contact with one (upper one as viewed in FIG. 7) of the
common contacts 53 in response to the turning movement of the
movable contact-supporting members 74 to the first turned position
along with the turn member 54, and the second individual contact 52
is fixed to the support blocks 75 in such a manner that it is
brought into conductive contact with the other (lower one as viewed
in FIG. 7) of the common contacts 53 in response to the turning
movement of the movable contact-supporting members 74 to the second
turned position along with the turn member 54.
[0053] First power source terminal members 77 are connected to the
first individual contacts 51, respectively, and second power source
terminal members 78 are connected to the second individual contacts
52, respectively. Conductive members 80 are fixedly disposed on the
support blocks 75 at locations corresponding to central portions of
the movable contact-supporting members 74 and connected to the
common contacts 53 through lead wires 79, and load terminal members
81 are integrally connected to the conductive members 80 and each
leading to each pair of common contacts 53 through the conductive
members 80 and the lead wires 79.
[0054] Electric cords 82 leading to the regular power source system
18 are connected to the first power source terminal members 77;
electric cords 83 leading to the engine generator 19 are connected
to the second power source terminal members 78; and electric cords
84 leading to the electric load 20 are connected to the load
terminal members 81.
[0055] Referring to FIGS. 8 to 10, each of the first terminal
members 77 is made of a conductive material and has an insertion
bore 85 into which the electric cord 82 is inserted, and a threaded
bore 86 having an axis perpendicular to the insertion bore 85. To
connect the electric cord 82 to the first terminal member 77, a
retainer 87 made of a conductive material is mounted on the first
terminal member 77, and a bolt 88 is screwed into the first
terminal member 77.
[0056] The retainer 87 comprises a clamping plate 89 inserted into
the insertion bore 86 for clamping the electric cord 82 between the
clamping plate 89 and an inner surface of the insertion bore 85, a
plate 90 opposed to an outer surface of the first terminal member
77 and having an insertion bore 92 through which the bolt 88 is
inserted, and a connecting plate 91 connecting one ends of the
clamping plate 89 and the opposed plate 90. The clamping plate 89,
the opposed plate 90 and the connecting plate 91 are integrally
connected to one another to form a substantially U-shape in cross
section. The bolt 88 inserted through the insertion bore 92 is
screwed into the threaded bore 86 in such a manner that its tip end
can be put into abutment against the clamping plate 89, and a
insulation-removed portion at one end of the electric cord 82
inserted in the insertion bore 85 is clamped between the clamping
plate 89 and an inner surface of the insertion bore 85 by
tightening the bolt 88, whereby the electric connection of the
electric cord 82 to the first terminal member 77 is achieved.
[0057] The insertion bore 85 is provided in the first terminal
member 77 with its opposite ends opened so that the electric cord
82 can be inserted into the insertion bore 85 from any of axial
directions, and the retainer 87 is formed into the substantially
U-shape so that the clamping plate 89 can be inserted into the
insertion bore 85 from any of axial directions, and the tip end of
the bolt 88 can be put into abutment against the inserted clamping
plate 89.
[0058] Moreover, as best shown in FIG. 8, a rugged portion 89a is
formed on a surface of the clamping plate 89 on the side of the
electric cord 82. Thus, the clamping plate 89 can be forced to bite
into the insulation-removed portion of the electric cord 82,
thereby reliably retaining the electric contact state of the
electric cord 82 with the first terminal member 77.
[0059] In some cases, an eyelet-type terminal 101 shown in FIG. 11
may be mounted at one end of the electric cord 82. However, the
threaded engagement of the first terminal member 77 in the threaded
bore 88 can be released to withdraw the bolt 88 from the opposed
plate 90 of the retainer 87 and hence, the eyelet-type terminal 101
inserted between the opposed plate 90 and the outer surface of the
first terminal member 77 can be clamped between the opposed plate
90 and the outer surface of the first terminal member 77 by
tightening the bolt 88, and the eyelet-type terminal 101 can be
electrically connected to the first power source terminal member
77.
[0060] The structure of connection of the electric cord 83 to the
second power source connecting terminal 78 as well as the structure
of connection of the electric cord 84 to the load connecting
terminal 81 are basically the same as the structure of connection
of the electric cord 82 to the first power source connecting
terminal 77 and hence, the detailed description of them is
omitted.
[0061] This switching unit 16 is accommodated within the box body
22 having the opening 42 capable of being opened and closed by the
lid member 23 so that the operating portions 60a and 65a of the
first and second solenoids 56 and 57 are disposed on the side of
the opening 42, and the turn member 54 and the movable
contact-supporting members 74 are disposed on the side opposite
from the opening 42, i.e., on the side of the base plate 28.
[0062] Moreover, portions of the electric cords 82, 83 and 84
connected to the terminal members 77, 78 and 81 are covered with a
cover plate 93 which is detachably mounted at tip ends of a
plurality of support posts 94 embedded in the support frame 50.
[0063] Electric cords 82, 83 and 84 are led out of the
accommodation box 21 accommodating the switching unit 16. In the
present invention, the first side-plate 24 of the box body 22 is
provided with electric cord-leading bore 95 for leading out the
electric cords 82 connecting the first power source terminal
members 77 and the regular power source system 18 to each other,
and the second side-plate 25 is provided with an electric
cord-leading bore 96 for leading out the electric cords 83
connecting the second power source terminal members 78 and the
engine generator 19 to each other, and with an electric
cord-leading bore 97 for leading out the electric cords 84
connecting the load terminal members 81 and the electric load 20 to
each other. Moreover, lead-out pipes 98, 99 and 100 are secured to
the first and second side-plates 24 and 25 to extend through the
electric cord-leading bores 95, 96 and 97, and the electric cords
82, 83 and 84 are led out of the box body 22 through the lead-out
pipes 98, 99 and 100.
[0064] Referring also to FIG. 12, the control unit 17 comprises
microchips or the like mounted on a substrate 102 fixedly disposed
on an inner surface of the lid member 23 of the accommodation box
21. The control unit 17 receives a set-time change indicating
signal from a set-time changing means 103 disposed on the substrate
102, as well as a signal based on the operation of a control-mode
establishing means 104 disposed on the outer surface of the lid
member 23. The control unit 17 has a function to regularly monitor
the power failure and restoration of the regular power source
system 18. On the basis of a result of such detection and the
signals from the set-time changing means 103 and the control-mode
establishing means 104, the control unit 17 controls the
energization and de-energization of the first and second solenoids
56 and 57, the starting and stoppage of the engine generator 19,
and the display on a display means 105 provided on the lid member
23 and formed of a liquid crystal or the like.
[0065] The set-time changing means 103 is constituted to be able to
set the time required for warming the engine generator 19 at three
periods, e.g., 15, 30 and 120 seconds depending on the operation of
an operating portion 103a of the set-time changing means 103, and a
time set by the set-time changing means 103 is input into the
control unit 17 from the set-time changing means 103.
[0066] The control-mode establishing means 104 has an operating
dial 106 capable of being turned and, according to the turning
movement of the operating dial 106 from first to fourth positions
P1, P2, P3 and P4, different signals made at the positions P1, P2,
P3 and P4 for establishing control modes by the control unit 17 are
input into the control unit 17 from the control-mode establishing
means 104.
[0067] The first position P1 is a position for stopping the control
operation by the control unit 17, and the second position P2 is a
position for an automatic switchover control mode of a power supply
system. When the operating dial 106 is turned to the second
position P2, the switching control of the switching unit 16, the
controlling of the starting and stoppage of the engine generator 19
and the controlling of the displaying on the display means 105 are
automatically carried out by the control unit 17. The third
position P3 is a position for manually starting the engine
generator 19, and when the operating dial 106 is turned to the
third position P3, the control unit 17 starts the engine generator
19. Further, the fourth position P4 is a position for supplying
electric power output from the engine generator 19 to the electric
load 20, and when the operating dial 106 is turned to the fourth
position P4, the control unit 17 controls the operation of the
switching unit 16 to supply the electric power output from the
engine generator 19 to the electric load 20, irrespective of
whether the power failure of the regular power source system 18 has
occurred or not.
[0068] In the automatic switchover control mode, the control unit
17 controls the energization and de-energization of the first and
second solenoids 56 and 57 in the switching unit 16, the starting
and stoppage of the engine generator 19 and the display on the
display means 105 according to a procedure shown in FIG. 13. At
Step SI, it is determined whether the power failure has occurred in
the regular power source system 18. In the case of power failure,
it is checked at Step S2 whether a flag FA is "0". The flag FA is a
flag indicative of whether the engine generator 19 is in operation.
When the engine generator 19 is in operation, the FA=1.
[0069] When FA=0 has been confirmed at Step S2, i.e., when the
engine generator 19 is in a non-operated state, a time set by the
set-time changing means 103 is read at Step S3, and the engine
generator 19 is started and at the same time, the display state of
the display means 15 is switched at Step S4.
[0070] The control unit 17 is capable of controlling the display on
the display means 105 by switching over, from one to the other, a
state in which the cumulative operation time of the engine
generator 19 is displayed, and a state in which the decreasing of
the time set by the set-time changing means 103 after the starting
of the engine generator 19 is displayed in a counting-down manner
during warming operation of the engine generator 19, until the set
time is elapsed. At Step S4, the control unit 17 switches the
display means 105 into the state in which the decreasing of the set
time is displayed in the counting-down manner during the warming
operation of the engine generator 19.
[0071] At Step S5, the flag FA is set at "1" in response to the
starting of the engine generator 19 at Step S4, progressing to Step
S6. When FA=1 has been determined at Step S2, the procedure
advances to Step S6, detouring Steps S3, S4 and S5.
[0072] At Step S6, a timer for counting the time set by the
set-time changing means 103 performs the counting-down, and at Step
S7, the decreasing of the set time is displayed in the
counting-down manner on the display means 105.
[0073] At next Step S8, it is determined whether the time set by
the set-time changing means 103 has been elapsed. When the time set
by the set-time changing means 103 has been elapsed, i.e., when it
is determined that the warming operation of the engine generator 19
for the set time has been completed, the switching unit 16 is
controlled at Step S9 so that electric power to be supplied to the
electric load 20 is changed from the electric power of the regular
power source system 18 to the electric power output of the engine
generator 19, and the display means 105 is switched to the state in
which the cumulative operation time for the engine generator 19 is
displayed.
[0074] At Step S10, a flag FB is set at "1". The flag FB is a flag
indicative of which of the electric power from the regular power
source system 18 and the electric power output from the engine
generator 19 is being supplied to the electric load 20. In a state
in which the electric power output from the engine generator 19 is
being supplied to the electric load 20, FB=1, and at Step S10, the
FB=1is established in response to the switching-over of the power
source.
[0075] When it is determined at Step S1 that the power failure is
not generated, i.e., in a state in which the electric power from
the regular power source system 18 is being used and the power
failure of the regular power source system 18 is not generated, or
in a state in which the electric power output from the engine
generator 19 is being used and the regular power source system 18
has been restored to the normal state, the procedure advances from
Step S1 to Step S11, and at Step S11, it is determined whether the
flag FB is "1".
[0076] When FB=1has been determined at Step S11, i.e., when it is
determined that the regular power source system 18 has been
restored in the normal state in the state in which the electric
power output from the engine generator 19 is being used, the
switching unit 16 is controlled at Step S12 so that the electric
power to be supplied to the electric load 20 is switched from the
electric power output of the engine generator 19 to the electric
power of the regular power source system 18, and the engine
generator 19 is stopped. Thereafter, at Step S13, the timer for
counting down the set time is reset, and at Step S14, the flags FA
and FB are set at "0".
[0077] The operation of the present embodiment will be described
below. The switching unit 17 controlled by the control unit 17
includes the seesaw-type turn member 54 carried on the support
frame 50 for turning movement between the first turned position in
which it permits the common contacts 53 leading to the electric
load 20 to be electrically connected to the first individual
contacts 51 leading to the regular power source system 18 and a
second turned position in which it permits the common contacts 53
to be electrically connected to the second individual contacts 52
leading to the engine generator 19, the spring member 55 for
exerting the spring force for retaining the turn member 54 at one
of the first and second turned positions in response to the turning
movement of the turn member 54 to one of the first and second
turned positions, the first solenoid 56 capable of exerting the
electromagnetic force for driving the turn member 54 to the first
turned position against the spring force of the spring member 55,
and the second solenoid 57 capable of exerting the electromagnetic
force for driving the turn member 54 to the second turned position
against the spring force of the spring member 55.
[0078] With the switching unit 16, the supplying of the electric
power from the engine generator 19 to the electric load 20 upon the
occurrence of the power failure of the regular power source system
18 and the supplying of the electric power from the regular power
source system 18 to the electric load 20 upon the restoration of
the regular power source system 18 can be switched over
automatically from one to the other by controlling the energization
and de-energization of the first and second solenoids 56 and 57 in
the switching-over manner by the control unit 17.
[0079] The plungers 60 and 65 of the first and second solenoids 56
and 57 are integrally provided with the operating portions 60a and
65a which can be operated from the outside to push the plungers 60
and 65. For example, when the control unit 17 breaks down, the
connection of the regular power source system with the electric
load 20 and the connection of the engine generator 19 with the
electric load 20 can be alternatively switched over by an operator
from one to the other by pushing the operating portions 60a and
65a, irrespective of the energization and de-energization of the
first and second solenoids 56 and 57. Moreover, it is unnecessary
to mount a special lever mechanism, and the switching operation can
be achieved by the operator's manual operation using a simple
structure in which the operating portions 60a and 65a are merely
integrally provided on the plungers 60 and 65.
[0080] The common contacts 53 are mounted on the movable
contact-supporting member 74 operably connected to the turn member
54 for turning movement about the axis coaxially with the turn
member 54, and the switching unit 16 is accommodated in the box
body 22 having the opening 42 capable of being opened and closed by
the lid member 23 in such a manner that the operating portions 60a
and 65a are disposed on the side of the opening 42, and the turn
member 54 and the movable contact-supporting member 64 are disposed
on the side opposite from the opening 42. Therefore, the
connections between the first and second individual contacts 51 and
52 and the common contacts 53 are disposed inside the box body 22,
whereby the contact with the connections from the outside is
prevented to the utmost, and moreover, the manual operation of the
operating portions 60a and 65a can be easily achieved by the
operator, because the operating portions 60a and 65a are disposed
on the side of the opening 42.
[0081] Further, the common contacts 53 are mounted at the opposite
ends of the movable contact-supporting member 74, and the first and
second individual contacts 51 and 52 capable of being electrically
connected to the common contacts 53 are fixedly disposed at the
locations corresponding to the opposite ends of the movable
contact-supporting member 74. The first and second terminal members
77 and 78 individually leading to the regular power source system
18 and the engine generator 19 are connected to the first and
second individual contacts 51 and 52, and the terminal members 81
connected to the electric load 20 and fixedly disposed at the
locations corresponding to the central portion of the movable
contact-supporting member 74 are connected to the common contacts
53. With such arrangement, the electric cords 82, 83 and 84 leading
to the first and second power source terminal members 77 and 78 and
the load terminal members 81 can be easily arranged in such a
manner that a wiring line is distributed for each of the electric
cords 82, 83 and 84.
[0082] To connect the electric cords 82, 83 and 84 to the terminal
members 77, 78 and 81, the terminal members 77, 78 and 81 are
provided with the insertion bores 85 for insertion of the electric
cords 82, 83 and 84 and with the threaded bores 86 having the axis
perpendicular to the insertion bores 85, respectively. The retainer
87 made of a conductive material is comprised of the following
plates integrally connected to one another to form the
substantially U-shape in cross section: the clamping plate 89
inserted into the insertion bore 85 for clamping each of the
electric cords 82, 83 and 84 between the clamping plate 89 and the
inner surface of the insertion bore 85, the plate 90 opposed to the
outer surface of each of the terminal members 77, 78 and 81 and
having the insertion bore 92, and the connecting plate 91
connecting the one ends of the clamping plate 89 and the opposed
plate 90. The tip end of the bolt 88 inserted through the insertion
bore 92 and threadedly screwed in the threaded bore 86 is in
abutment against the clamping plate 89.
[0083] Therefore, the turning movement of the clamping plate 89
about the axis of the threaded bore 86 is inhibited only by
inserting the clamping plate 89 into the insertion bore 85, and
each of the electric cords 82, 83 and 84 can be clamped at one end
thereof between the clamping plate 89 and the inner surface of the
insertion bore 85 in the simple structure in which the tip end of
the bolt 88 is put into abutment against the clamping plate 89,
while preventing the occurrence of the twisting of the electric
cords 82, 83 and 84 and the damaging of their strands. Thus, it is
possible to reliably maintain the electric connection of the
electric cords 82, 83 and 84 to the terminal members 77, 78 and
81.
[0084] Moreover, it is possible to release the threaded engagement
of the bolt 88 in the threaded bore 86 to withdraw the bolt 88 from
the opposed plate 90. Therefore, the eyelet-type terminal 101
inserted between the opposed plate 90 and the outer surface of each
of the terminal members 77, 78 and 81 can be clamped between the
opposed plate 90 and the outer surface of each of the terminal
members 77, 78 and 81 by tightening the bolt 88, and can be
electrically connected to each of the terminal members 77, 78 and
81.
[0085] The insertion bore 85 is provided in each of the terminal
members 77, 78 and 81 with its opposite ends opened, and the tip
end of the bolt 88 can be put into abutment against the clamping
plate 89 capable of being inserted into the insertion bore 85 from
any of axial directions. Therefore, the electric cords 82, 83 and
84 can be electrically connected to the terminal members 77, 78 and
81 from any of the axial directions in selecting the direction of
insertion of the clamping plate 89 and each of the electric cords
82, 83 and 84 into the insertion bore 86.
[0086] The accommodation box 21 for accommodation of the automatic
switchover device 15 is comprised of the box body 22 formed into
the bottomed quadrilateral tubular shape with one end closed and
the other end opened, and the lid member 23 which can open and
close the opening 42 in the box body 22. The box body 22 comprises
the four first, second, third and fourth side-plates 24, 25, 26 and
27 forming the quadrilateral tubular shape upon the connection of
them, and the base plate 28 which commonly and detachably connects
one ends of the side-plates 24, 25, 26 and 27. A plate to be bored
or the like is not required as in the prior art and hence, the box
body 22 can be formed by a reduced number of special parts and at a
reduced number of assembling steps.
[0087] Moreover, each of the side-plates 24, 25, 26 and 27 is
detachably connected to the other adjacent to side-plates 24, 25,
26, 27 so that when one or more of the side plates 24, 25, 26 and
27 selected to be provided with the electric cord leading-out bore
95, 96, 97, e.g., the side-plates 24 and 25, are removed for
boring, it is possible to avoid that such removal affects the
connection of the other side-plates to one another as well as the
connection of the other side-plates to the base plate 28.
[0088] Therefore, depending on the situation of a place for setting
the accommodation box 21, only the side-plate selected to be
provided with the electric cord leading-out bores 95, 96, 97 for
leading-out the electric cords 82, 83, 84 leading to the automatic
switchover device 15 can be removed without affecting the other
parts of the box body 22, and then subjected to a boring treatment
for providing the electric cord leading-out bores 95, 96, 97.
Depending on the situation of a place for setting the accommodation
box 21, positions of the electric cord leading-out bore 95, 96, 97
can be determined as desired.
[0089] The side-plates 24, 25, 26 and 27 and the base plate 28 are
disconnectably connected to one another and hence, if the box body
22 is disassembled into the four side-plates 24, 25, 26 and 27 and
the base plate 28 when the accommodation box 21 is transported, a
space required for such transportation can be reduced, leading to
an enhanced transporting efficiency.
[0090] Further, the switching unit 16 and the control unit 17
constituting the automatic switchover device 15 are mounted
separately to the box body 22 and the lid member 23 in such an
arrangement that the superposition of the switching unit 16 and the
control unit 17 is avoided in a state in which the opening 42 in
the box body 22 is closed by the lid member 23. Thus, it is easy to
ensure a space required for wiring of the automatic switchover
device 15 within the accommodation box 21. In addition, it is
possible to enhance the packaging density in the accommodation box
21 and to increase the degree of freedom of determination of the
positions for provision of the electric cord leading-out bores 95,
96 and 97.
[0091] The lid member 23 of the accommodation box 21 is provided
with the display means 105, the displaying state of which is
controlled by the control unit 17. The control unit 17 is
configured to control the switching operation of the switching unit
16 to supply the electric power output from the engine generator 19
to the electric load 20 upon completion of the warming operation
after lapse of the set time from the starting of the engine
generator 19 in response to the occurrence of the power failure of
the regular power source system 18, and to control the display
means 105 to display the set time upon starting of the engine
generator 19.
[0092] Therefore, when the engine generator 19 is started as a
result of the power failure of the regular power source system 18,
the time required for the warming of the engine generator 19 is
displayed on the display means 105. Even if there is a delay until
the electric power is supplied to the electric load 20 after the
starting of the engine generator 19, it is possible to allow a user
to recognize that the engine generator 19 is being warmed and
hence, it is possible to eliminate a possibility that the user has
a feeling of mistrust that the automatic switchover device 15 has
broken down.
[0093] Moreover, the set time can be changed by the set-time
changing means 103 and hence, the warming time for the engine
generator 19 can be determined at an appropriate value depending on
the situation of operation of the engine generator 19, and to
appropriately display the warming time in accordance with the
change in set time.
[0094] The control unit 17 controls the display means 105 to
display the decreasing of the set time in a counting-down manner
with the lapse of time after the starting of the engine generator
19. Thus, it is possible for the user to appropriately grasp the
time taken until the electric power is supplied to the electric
load 20, thereby providing a sense of relief.
[0095] Further, the control unit 17 controls the display means 105
to display the cumulative operational time of the engine generator
19 in the case other than during the warming operation of the
engine generator 19. Therefore, it is possible to easily construct
a system designed to enable the operator to appropriately grasp the
timing for carrying out the maintenance of the engine generator 19,
and moreover, designed to provide an emergent displaying upon the
occurrence of the power failure of the regular power source system
18 so that the user does not have a feeling of mistrust.
[0096] Although the embodiment of the present invention has been
described in detail, it will be understood that the present
invention is not limited to the above-described embodiment, and
various modifications in design may be made without departing from
the spirit and scope of the invention defined in claims.
* * * * *