Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION
AIR SUCTION DEVICE FOR TOILET DRAINAGE CHANNEL
Technical Field
The present invention relates to an air suction device for
toilet drainage channel.
Background Art
Patent Document 1 discloses one of conventional air suction
devices for toilet drainage channel. The air suction device is
provided with air suction means for sucking air from a toilet
drainage channel connected to the downstream side of a water
sealing part of a toilet body. A bypass pipe is connected to
a water supply pipe which supplies flush water into a toilet bowl
of the toilet body. The bypass pipe is provided with an ejector
generating negative pressure. The air suction means has the
ejector and a suction tank connected between the ejector and the
toilet drainage channel. The suction tank has an interior
partitioned into an outside of a bellows (a first chamber) and
an inside of the bellows (a second chamber) . The first chamber
communicates with the ejector, and the second chamber
communicates with the toilet drainage channel. A flush valve
is provided on the water supply pipe located upstream of the
bypass pipe.
Upon actuation of the flush valve in the air suction device,
the flush water is caused to flow through the water supply pipe
for a predetermined time thereby to be supplied into the toilet
bowl. Since the flush water also flows through the bypass pipe
into the ejector in this case, air in the first chamber of the
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suction tank is sucked by the ejector. As a result, the bellows
in the suction tank is expanded. Air is sucked from the toilet
drainage channel into the second chamber in the course of
expansion of the bellows. An air suction step is thus carried
out thereby to cause a siphon action.
Furthermore, the delivery of the flush water to the water
supply pipe is stopped upon lapse of a predetermined time, whereby
the supply of flush water to the toilet bowl is terminated. This
allows the water supply pipe downstream of flush valve, the bypass
pipe and the first chamber to be open to the atmosphere, whereupon
the bellows in the suction tank is contracted. Air in the second
chamber is discharged into the toilet drainage channel in the
course of contraction of the bellows. An air discharge step is
thus carried out.
No special control device is necessitated in the
conventional air suction device for toilet drainage channel
since air is sucked from the toilet drainage channel in
synchronization with the flush water supply to the toilet bowl.
Accordingly, the air suction device has a simple construction.
Patent Document 1: JP-A-H07-54388
Disclosure of the Invention
Problem to be Overcome by the Invention
However, the siphon action is caused under the condition
where an amount of flush water supplied into the toilet bowl is
small since the air suction step is carried out concurrently with
the supply of flush water into the toilet bowl in the
above-described conventional air suction device for toilet
drainage channel. Accordingly, the siphon action is weaker than
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a siphon action caused with the use of potential energy obtained
by supplying flush water into the toilet bowl so that a water
level becomes sufficiently high in the toilet bowl. In this case,
there is a possibility that sewage may insufficiently be
discharged from the toilet bowl to the toilet drainage channel.
Furthermore, the siphon action caused by execution of the
air suction step is terminated by discharging almost all flush
water in the toilet bowl into the toilet drainage channel such
that a water sealing part is broken. In this case, a breaking
sound is produced.
The present invention was made in view of the foregoing
conventional circumstances and the subject matter thereof is to
provide an air suction device for a toilet drainage channel, which
can perform good and silent toilet flushing.
The present invention provides an air suction device for
a toilet drainage channel, provided with an air suction unit which
sucks air from a toilet drainage channel connected to a downstream
side of a water sealing part of a toilet body, the air suction
unit having a negative pressure generator and a suction tank
connected between the negative pressure generator and the toilet
drainage channel, the air suction device comprising a control
device which controls execution of an air suction step in which
air is sucked from the toilet drainage channel by the suction
tank and execution of a air discharge step in which the air is
discharged into the toilet drainage channel by the suction tank,
wherein the control device executes the air suction step after
start of flush water supply to a toilet bowl of the toilet body
and the air discharge step before termination of the flush water
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supply to the toilet bowl of the toilet body.
In the above-constructed air suction device for the toilet
drainage channel according to the present invention, the air
suction is executed in the state where a water level in the toilet
bowl is sufficiently high after flush water supply to the toilet
bowl, so that a siphon action is caused. Consequently, the
siphon action is rendered stronger with the use of potential
energy obtained by a rise of the water level in the toilet bowl,
whereupon sewage can reliably be discharged into the toilet
drainage channel.
Furthermore, when the air discharge step is executed before
termination of the flush water supply to the toilet bowl, the
discharge flow is broken as the result of increase in an amount
of air in the toilet drainage channel such that the siphon action
can be terminated. In this case, no breaking sound is produced
since the water sealing part is not broken.
Consequently, the air suction device for the toilet
drainage channel according to the invention can perform good and
silent toilet flushing.
In the air suction device according to the invention, it
is preferable that the control device executes the air discharge
step while a discharge flow due to a siphon action is continuous
in the toilet drainage channel after supply of the flush water
into the toilet bowl. In this case, the siphon action can
reliably be terminated by the execution of the air discharge step.
In the air suction device according to the invention, it
is preferable that the control device executes the air drainage
step after the flush water supply to the toilet bowl has been
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interrupted and before the flush water supply to the toilet bowl
is re-started for formation of a water sealing part. In this
case, since the siphon action is reliably terminated, a water
sealing part with a predetermined water level can be formed.
In the air suction device according to the invention, it
is preferable that the suction tank has an interior partitioned
into a first chamber and a second chamber by a diaphragm movable
in an upward and/or a downward direction defined during
installation of the suction tank, and that the first chamber is
connected to the negative pressure generator and the second
chamber is connected to the toilet drainage channel.
In this case, the siphon action can stably be caused since
a predetermined amount of air is sucked from the toilet drainage
channel according to an interior volume of the suction tank.
Furthermore, the interior of the suction tank is divided into
the first and second chambers by the diaphragm, and only the
second chamber communicates with the toilet drainage channel,
whereby the flush water containing sewage, air containing a foul
odor and the like are reliably prevented from flowing into the
negative pressure generator side.
Various negative pressure generators can be used only if
these generators can generate negative pressure. For example,
a mechanical pump or the like may be used other than the ejector
which generates negative pressure by supplying flush water.
Brief Description of the Drawings
FIG. 1 is a view showing a frame format of a western flushing
toilet provided with an air suction device for a toilet drainage
channel, in accordance with embodiments 1 and 2;
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FIG. 2 is a schematic block diagram showing a control device
of the air suction device of embodiments 1 and 2;
FIG. 3 is a timing chart explaining actuation of the flushing
toilet in embodiment 1; and
FIG. 4 is a timing chart explaining actuation of the flushing
toilet in embodiment 2.
Explanation of Reference Symbols
1 === toilet body
2 === toilet bowl
4... water sealing part
5 === toilet drainage channel
30 == ejector (negative pressure generator)
80 === suction tank
200 = air suction device
C === control device
Best Mode for Carrying Out the Invention
Embodiments 1 and 2 of a western flushing toilet will be
described with reference to the drawings. The air suction device
for the toilet drainage channel in accordance with the present
invention is applied to the flushing toilet.
Embodiment 1
The western flushing toilet of embodiment 1 comprises a
toilet body 1 and a toilet flushing device S as shown in FIG.
1. A toilet seat and a toilet lid are eliminated in the drawings.
The toilet body 1 has a rim 3 formed along an upper inner
periphery of a toilet bowl 2. The toilet body 1 is formed with
an upward flow path 2b extending upward from a lower end of the
toilet bowl 2 and with a water sealing part 4 located in a lower
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interior of the toilet bowl 2. The upward flow path 2b of the
toilet body 1 is connected to a connecting pipe, in which a toilet
drainage channel 5, a dwell part 6 and a drain outlet 7 are
defined.
The toilet flushing device S comprises a flush water
supplying device 100 and an air suction device 200 for the toilet
drainage channel 5.
The flush water supplying device 100 comprises a water
conduit 10 connected to a water pipe and a first on-off valve
Vl opening and closing the water conduit 10.
The water conduit 10 communicates with a water shutoff
valve V5 of a water pipe drawn out of a floor or wall surface
of a toilet room in which the toilet body 1 is installed.
Furthermore, a strainer device 11 incorporated with a water stop
valve and a strainer and a constant flow rate valve 12 are provided
upstream of the first on-off valve Vl, and a vacuum breaker 13
is provided downstream of the first on-off valve Vl.
An ejector 30 serving as a negative pressure generator has
an inlet 31 connected to a part of the water conduit 10 located
downstream of the vacuum breaker 13. The ejector 30 has an outlet
32 to which an inlet 21 of a tank 20 is connected, so that flush
water stored in the tank 20 can be caused to flow through an outlet
22.
The tank 20 has an inflow chamber 25 communicating with
the inlet 21 and an outflow chamber 26 which has a bottom
communicating with the inflow chamber 25 and communicates with
the outlet 22. The inflow chamber 25 is provided with an
atmospheric port 23 to which the second on-off valve V2 is
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connected. The inflow chamber 25 includes a swirl chamber 29
into which flush water is discharged from a nozzle 50
communicating with the outlet 32 of the ejector 30 such that a
swirl flow is formed. To the outlet 22 is connected a delivery
pipe 40 which extends to the rim 3 of the toilet body 1.
The ejector 30 has a suction port 33 communicating with
the outside. The suction port 33 draws flush water from the
outlet 32 thereby to suck air thereinto.
The air suction device 200 of the toilet drainage channel
5 has a negative pressure storage tank 70, a suction tank 80 and
the like as will be described below.
The suction port 33 of the ejector 30 communicates, via
a first connecting pipe 110 provided with a check valve 111, with
the negative pressure storage tank 70 storing the negative
pressure. Accordingly, the ejector 30 constituting a water
supply unit of the flush water supplying device 100 is also used
for the air suction device 200.
A second connecting pipe 120 is branched from the first
connecting pipe 110 located nearer to the negative pressure
storage tank 70 than the check valve 111 is. The second
connecting pipe 120 is provided with a third on-off valve V3
located midway therethrough and communicates with the outside.
A third connecting pipe 130 is also branched from the first
connecting pipe 110 and provided with a fourth on-off valve V4
located midway therethrough. The third connecting pipe L30
communicates with the suction tank 80 which sucks air from the
toilet drainage channel 5.
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The suction tank 80 has an interior partitioned into a first
chamber 81 and a second chamber 82 by a diaphragm 83 which is
movable in an upward and/or a downward direction defined during
installation thereof. The first chamber 81 communicates with
the third connecting pipe 130, and the second chamber 82
communicates with the toilet drainage channel 5 via a suction
pipe 90.
As shown in FIG. 2, the on-off timing and the on-off period
of each of the first, second, third and fourth on-off valves V1,
V2, V3 and V4 are controlled by a control device C. Since the
second, third and fourth on-off valves V2, V3 and V4 are for use
with air, the valves V2, V3 and V4 are not subjected to a large
pressure, whereupon these valves can be rendered smaller than
on-off valves for use with water and is designed so as to be opened
and closed with a smaller force.
In the above-described western flushing toilet, the
suction device 200 of the toilet drainage channel 5 comprises
the ejector 30, the first connecting pipe 110, the check valve
111, thenegative pressure storage tank 70, the second connecting
pipe 120, the third on-off valve V3, the third connecting pipe
130, the fourth on-off valve V4, the suction tank 80, the suction
pipe 90 and the control device C. The flush water supplying
device comprises the water conduit 10, the strainer device 11,
the constant flow rate valve 12, the first on-off valve V1, the
vacuum breaker 13, the ejector 30, the nozzle 50, the tank 20,
the second on-off valve V2, the delivery pipe 40, the first
connecting pipe 110, the second connecting pipe 120, the third
on-off valve V3 and the control device C.
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Next, the operation of the toilet flushing device S
incorporated with the suction device 200 of embodiment 1 will
now be described on the basis of the construction as shown in
FIG. 1.
[Non-flushing]
In FIG. 3, the first, second, third and fourth on-off valves
V1, V2, V3 and V4 are closed during non-flushing before time tl.
In this state, flush water is stored in the tank 20. The
diaphragm 83 in the suction tank 80 is in abutment with a lower
inner wall surface of the suction tank 80.
[Toilet bowl flushing step and negative pressure storing step]
When the user operates a flushing switch for delivering
a toilet flush start signal to the control device C at time tl
in FIG. 3 after having gone to stool, the first on-off valve V1
is opened by the control device C.
As a result, flush water flowing though the connecting pipe
10 further flows through the ejector 30 into the swirl chamber
29. When the flush water flows into the ejector 30, the ejector
30 sucks air in the negative pressure storage tank 70 through
the first connecting pipe 110 and the check valve 111. The sucked
air flows into the swirl chamber 29 together with flush water.
Since the flush water is swirled in the swirl chamber 29, air
contained in the flush water is separated successfully thereby
to be stored in an upper interior of the inflow chamber 25. As
a result, negative pressure is gradually stored in the negative
pressure storage tank 70, and the water level in the inflow
chamber 25 is gradually lowered by an amount corresponding to
the air sucked from the negative pressure storage tank 70.
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Furthermore, the flush water supplied from the water
conduit 10 and the flush water stored in the tank 20 whose amount
corresponds to the amount of air sucked from the negative pressure
storage tank 70 are supplied through the delivery pipe 40 into
the rim 3. The flush water supplied into the rim 3 flows downward
while swirling along an inner surface of the toilet bowl 2,
thereby forming a swirl flow. Sewage is collected by the swirl
flow to a central part of the toilet bowl 2. Toilet paper is
unhardened and fitted with flush water, being dispersed into the
flush water.
[Air suction step]
The fourth on-off valve V4 is opened at time t2 in FIG.
3 by the control device C. As a result, the negative pressure
in the negative pressure storage tank 70 is transmitted through
the first connecting pipe 110, the third connecting pipe 130 and
the fourth on-off valve V4 to the first chamber 81 of the suction
tank 80, whereupon the pressure in the first chamber 81 becomes
negative. Furthermore, since flush water is continuously
supplied into the ejector 30, air in the first chamber 81 is also
sucked by the ejector 30. Consequently, the diaphragm 83 in the
suction tank 80 is rapidly lifted upward by the negative pressure
in the negative pressure storage tank 70 in the beginning of the
opening of the fourth on-off valve V4. Thereafter, since the
air suction by the negative pressure storage tank 70 is terminated,
the diaphragm 83 is slowly lifted upward only by the ejector 30
until the diaphragm 83 abuts against the upper inner wall surface
of the suction tank 80.
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When air in the toilet drainage channel 5 is to be sucked
into the second chamber 82 by the suction tank 80, the water level
in the toilet bowl 2 is rendered sufficiently high by the flush
water having been supplied into the toilet bowl 2 at the toilet
bowl flushing step, whereupon the water head difference between
the water level in the toilet bowl 2 and a highest portion 4a
of the water sealing part 4 is sufficiently large. As a result,
the potential energy of the flush water due to the water head
difference and air suction from the toilet drainage channel 5
cause the flush water in the toilet bowl 2 to rush into the toilet
drainage channel 5, whereby the toilet drainage channel 5 is
filled with the flush water promptly such that a strong siphon
action is produced. Accordingly, a discharge flow can promptly
be formed by a smaller amount of flush water. The filled state
of the toilet drainage channel 5 to cause the siphon action is
achieved not only by the state of the toilet drainage channel
5 completely filled with flush water but also a state where
pressure balance is maintained between the upstream side and the
downstream side of the toilet drainage channel 5 and the discharge
flow is caused, and the filled state of the toilet drainage
channel 5 includes the case where air remains in the toilet
drainage channel 5.
In this case, sewage centrally collected in the toilet bowl
2 by the swirl flow formed in the toilet bowl 2 is reliably
discharged to the toilet drainage channel 5 with the flush water
discharged to the toilet drainage channel 5 by the siphon action.
Furthermore, the toilet drainage channel 5 is disconnected
from the downstream side by the retaining portion 6 such that
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the toilet drainage channel 5 is a closed space existing between
the water sealing 4 and the retaining portion 6. Accordingly,
since a predetermined amount of air can reliably be sucked from
the toilet drainage channel 5, the siphon action can be caused.
Furthermore, the interior of the suction tank 80 is divided
by the diaphragm 83 into the first and second chambers 81 and
82, and only the second chamber 82 communicates with the toilet
drainage channel 5. Accordingly, the flush water containing
sewage, the air containing foul odor and the like are reliably
prevented from entering the negative pressure storage tank 70
or the ejector 30.
[Flush water increasing step]
The water level in the toilet bowl 2 is reduced to the height
near the lowest level 2a of the rear of the toilet bowl 2 at time
t3 in FIG. 3. In this instant of time, the third on-off valve
V3 is opened and the fourth on-off valve V4 is closed by the
control device C.
In this case, since the flush water is still being supplied
into the ejector 30, a large amount of external air flows into
the swirl chamber 29 through the third on-off valve V3, the second
connecting pipe 120 and the first connecting pipe 110.
Accordingly, the flush water in the inflow chamber 25 is forced
via the outflow chamber 26 and the delivery pipe 40 into the rim
3 by the entered external air. As a result, the water level in
the inflow chamber 25 is rapidly reduced to a large degree.
An amount of flush water supplied into the rim 3 is increased
before air flows from the toilet bowl 2 into the toilet drainage
channel 5 and the siphon action is terminated, that is, before
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the water level in the toilet bowl 2 become lower than the lowest
water level portion 2a in the rear of the toilet bowl 2. In other
words, the flush water supplied from the rim 3 is an addition
of the flush water supplied from the water conduit 10 and the
flush water stored in the tank 20. Accordingly, since an amount
of flush water supplied to the toilet bowl 2 per predetermined
time is increased, the water sealing part 4 is not broken, the
flush water in the toilet bowl 2 is swirled, and the siphon action
is continued. Furthermore, the swirl flow in the toilet bowl
2 is intensified, and the flow of flush water is increased.
Consequently, sewage remaining in the toilet bowl 2 is discharged
so as to be forced out into the toilet drainage channel 5, and
lightweight sewage floating in the flush water can be discharged
into the toilet drainage channel 5.
[Air discharge step]
The flush water supplied into the toilet bowl 2 by the flush
water increasing step is still swirled at time t4 in FIG. 3, and
the water sealing part 4 is not broken. In other words, the
discharge flow due to the siphon action is continuous. At this
time t4, the first on-off valve Vl is closed and the fourth on-off
valve V4 is opened by the control device C. As a result, the
atmospheric pressure is introduced into the first chamber 81 such
that the diaphragm 83 is lowered, since the first chamber 81 of
the suction tank 80 communicates with the outside through the
fourth on-off valve V4, the third connecting pipe 130, the first
connecting pipe 110, the second connecting pipe 120 and the third
on-off valve V3. Accordingly, since air is discharged from the
second chamber 82 into the toilet drainage channel 5, an amount
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of air is increased in the toilet drainage channel 5. For this
reason, the toilet drainage channel 5 cannot be retained in a
state completely filled with the flush water, whereby the siphon
action is terminated. That the toilet drainage channel 5 cannot
be retained in the state completely filled with the flush water
includes the case where the upstream side and the downstream side
of the toilet drainage channel 5 are kept balanced in pressure
even in the state where air remains in the toilet drainage channel
5 such that the state where the discharge flow is being caused
cannot be maintained. In this case, no noise due to the braking
of the water sealing part 4 is produced.
[Restoring step]
The first and second on-off valves V1 and V2 are opened
and the fourth on-off valve V4 is closed by the control device
C at time t5 in FIG. 3. As a result, the flush water flows into
the swirl chamber 29 while the ejector 30 is sucking air from
the outside. Air contained in the flush water is successfully
separated in the swirl chamber 29 to be discharged through the
atmospheric port 23 and the second on-off valve V2 to the outside.
Accordingly, the flush water is stored in the tank 20 until the
predetermined water level before start of the flushing is reached.
Furthermore, the siphon action has been completely terminated,
and flush water is supplied from the outflow chamber 26 through
the delivery pipe 40 to the rim 3, whereby the water sealing part
4 with a predetermined water level is formed in the toilet bowl
2 such that the toilet is restored to the initial state.
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[Opening step]
The first on-off valve Vl is closed and the fourth on-off
valve V4 is opened by the control device C at time t6 in FIG.
3. As a result, the first chamber 81 of the suction tank 80
communicates with the outside via the fourth on-off valve V4,
the third connecting pipe 130, the first connecting pipe 110,
the second connecting pipe 120 and the third on-off valve V3,
whereupon the diaphragm 83 is lowered until the diaphragm 83 abuts
against the lower inner wall surface of the suction tank 80.
Consequently, since the diaphragm 83 is returned to the
predetermined position before flushing, the subsequent flushing
can stably be executed. Thereafter, the second, third and fourth
on-off valves V2, V3 and V4 are closed by the control device C
at time t7 in FIG. 3.
Accordingly, the air suction device 200 for the toilet
drainage channel 5 in accordance with embodiment 1 carries out
toilet flushing successfully and silently.
Embodiment 2
The western flushing toilet of embodiment 2 has the same
construction as embodiment 1 and differs from the western
flushing toilet of embodiment 1 only in the operation of the
toilet flushing device S.
The difference regarding the operation of the toilet
flushing device S will be described.
As shown in FIG. 4, the first on-off valve V1 is closed
and the fourth on-off valve V4 is opened by the control device
C at time t4 a predetermined time after time t3' at which the
flush water increasing step has been terminated. As a result,
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the first chamber 81 of the suction tank 80 communicates with
the outside through the fourth on-off valve V4, the third
connecting pipe 130, the first connecting pipe 110, the second
connecting pipe 120 and the third on-off valve V3, whereupon the
atmospheric pressure is introduced into the first chamber 81 such
that the diaphragm 83 is lowered. At time t4 a predetermined
time after completion of the flush water increasing step, the
flush water supplied into the toilet bowl 2 by the flush water
increasing step is also discharged into the toilet drainage
channel 5 by the siphon action, whereupon an amount of flush water
in the toilet bowl 2 is reduced. Accordingly, when air is rushed
from the second chamber 82 into the toilet drainage channel 5,
the discharge flow established by the siphon action is
intermitted, whereby the siphon action can be terminated
immediately and reliably. Furthermore, since the water sealing
4 is not broken in this case, too, no noise due to the breaking
of the water sealing part 4 is produced. Since the other
operation of embodiment 2 is the same as that in embodiment 1,
detailed description of the other operation will be eliminated.
Consequently, the air suction device 200 for the toilet
drainage channel in accordance with embodiment 2 can achieve the
same effect of the invention in the same manner as in embodiment
1.
Although the invention has been described as embodiments
1 and 2, the invention should not be limited to the embodiments.
It is not regardless to say that the invention can be changed
suitably without departing from the gist thereof.
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Industrial applicability
The present invention is utilizable as water flushing
toilet.
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