Information
-
Patent Grant
-
6488487
-
Patent Number
6,488,487
-
Date Filed
Friday, May 4, 200123 years ago
-
Date Issued
Tuesday, December 3, 200221 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Freay; Charles G.
- Gray; Michael K.
Agents
-
CPC
-
US Classifications
Field of Search
US
- 417 540
- 417 542
- 417 394
- 138 30
-
International Classifications
-
Abstract
The invention provides a pulsation damping device in which an offset load on a pulsation suppression diaphragm is eliminated while an air supply valve and an air discharge valve are separately and independently juxtaposed, and an extendable and contractible portion of the pulsation suppression diaphragm is always caused to be straightly extendingly and contractingly deformed in the axial direction of a device body casing, whereby the response property of the opening and closing operations of the air supply and discharge valves can be improved and the pulsation suppressing performance can be ensured.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device that is interposingly used in a liquid transporting pipe through which transported liquid such as liquid for processing a semi-conductor device is transported to various portions by a reciprocal pump, to damp pulsations generated by variations in flow quantity and pressure due to the reciprocal operation of the reciprocal pump.
2. Description of the Prior Art
A pulsation damping device of this kind is disclosed in, for example, Japanese Patent Application Laying-Open Nos. 617752 and 8-159016.
Among such disclosed devices, the pulsation damping device for a pump which is disclosed in Japanese Patent Application Laying-Open No. 6-17752 is shown in FIG.
11
. The device comprises: a sealed device body casing
60
; a liquid chamber
61
a
which is disposed in the device body casing
60
, which temporarily stores liquid transported by a reciprocal pump to exert a liquid storage function, and which then allows the liquid to flow out; and an air chamber
61
b
which is disposed in the device body casing
60
and separated from the liquid chamber
61
a
via a pulsation suppression diaphragm
62
that is configured by an extendable and contractible bellows, and which is filled with compressed air. The device is configured so that the pulsation suppression diaphragm
62
is extended and contracted by pulsations due to the discharge pressure of the pump, and the pulsations are damped by the capacity change of the liquid chamber
61
a.
In the case where the discharge pressure of the reciprocal pump is varied, the extension and contraction amount of the pulsation suppression diaphragm
62
must be restricted to a predetermined range in order to balance the liquid pressure in the liquid chamber
61
a
with the air pressure in the air chamber
61
b.
To comply with this, the following configuration is employed in the device shown in FIG.
11
. An automatic air supply valve mechanism
63
and an automatic air discharge valve mechanism
64
are disposed in the device body casing
60
. In the case where the pulsation suppression diaphragm
62
is extended from a reference value S in the direction of increasing the capacity of the liquid chamber by the liquid pressure variation in the liquid chamber
61
a,
when the diaphragm exceeds a predetermined range A, an air supply port
66
is opened by the pulsation suppression diaphragm
62
via a valve push rod
65
of the automatic air supply valve mechanism
63
, to adjust the air filling pressure of the air chamber
61
b
so as to raise the pressure. In the case where the pulsation suppression diaphragm
62
is contracted from the reference value S in the direction of decreasing the capacity of the liquid chamber, when the diaphragm exceeds a predetermined range B, an air discharge port
68
is opened by the automatic air discharge valve mechanism
64
by means of a slider
67
which abuts against a closed end face
62
a
of the pulsation suppression diaphragm
62
, to discharge the air in the air chamber
61
b
so as to lower the air filling pressure.
By contrast,
FIG. 12A
shows the pulsation damping device for a pump which is disclosed in Japanese Patent Application Laying-Open No. 8-159016, and
FIG. 12B
shows an air supply/discharge switch valve mechanism for the pump. The device uses an air chamber internal pressure adjust valve mechanism which restricts the capacity change of a liquid chamber
61
a
that is disposed in a similar manner as the liquid chamber
61
a
disclosed in Japanese Patent Application Laying-Open No. 6-17752, within a predetermined range. In the mechanism, the air supply/discharge switch valve mechanism comprising: an operating rod
69
which operates in accordance with the displacement of the closed end face
62
a
of the pulsation suppression diaphragm
62
; and a slide valve element
71
which is operated by the operating rod
69
to cause an air supply and discharge passage
70
connected to the air chamber
61
b
to selectively communicate with the air supply port
66
and the air discharge port
68
is protrudingly attached to the outside of the device body casing
60
. The valve mechanism is configured so that, when the capacity of the liquid chamber
61
a
is increased to exceed a predetermined range, the air supply port
66
communicates with the air supply and discharge passage
70
, and, when the capacity of the liquid chamber
61
a
is decreased to exceed the predetermined range, the air discharge port
68
communicates with the air supply and discharge passage
70
. The valve mechanism comprises: a cylindrical casing
72
in which the air supply port
66
, the air discharge port
68
, and the air supply and discharge passage
70
communicating with the air chamber
61
b
are formed; and the slide valve element
71
which is coaxially connected to the operating rod
69
, and which is slidably fitted into a cylinder
73
housed in the cylindrical casing
72
.
Among the above-mentioned two conventional art examples, in the former pulsation damping device disclosed in Japanese Patent Application Laying-Open No. 6-17752, as shown in
FIG. 11
, the automatic air supply valve mechanism
63
and the automatic air discharge valve mechanism
64
are disposed integrally with a lower end member
60
a
constituting a part of the device body casing
60
. When one of the valve mechanisms
63
and
64
is broken or becomes faulty, therefore, the whole device must be disassembled and repaired, or replaced with another one. In any case, the work requires much labor. Therefore, the configuration is disadvantageous in maintenance and cost. Furthermore, the device has a structure in which the air discharge port
68
of the automatic air discharge valve mechanism
64
is closed by a gravitational drop of a discharge valve element
75
. Therefore, the closing operation is unstable, and the device must be always placed so that the discharge valve element
75
in a vertical posture and the air discharge port
68
maintain their vertical positional relationship. For example, the device cannot be applied to a use in which the discharge valve element
75
has a horizontal posture, and hence the kinds of devices are restricted. Moreover, the valve push rod
65
of the automatic air supply valve mechanism
63
, and the slider
67
of the automatic air discharge valve mechanism
64
which are independently juxtaposed are in direct contact at two points with the closed end face
62
a
of the pulsation suppression diaphragm
62
configured by the bellows. One of the members, or the valve push rod
65
is in direct contact with a position which is deviated from the center portion of the closed end face
62
a.
When the pulsation suppression diaphragm
62
is extended and contracted, therefore, an offset load is applied to the diaphragm, thereby hindering the extendable and contractible portion of the pulsation suppression diaphragm
62
from being straightly deformed extendingly and contractingly in the axial direction X—X of the device body casing
60
. This impairs the response property of the automatic air supply and discharge valve mechanisms
63
and
64
, thereby causing the pulsation suppressing performance to be lowered.
In the air supply/discharge switch valve mechanism disclosed in the latter publication or Japanese Patent Application Laying-Open No. 8-159016, the configuration in which suction and discharge of air are concentrated into the single valve mechanism as shown in
FIGS. 12A and 12B
is employed. Even when the valve mechanism is broken or becomes faulty, therefore, it is not required to disassemble the whole device, and repair and replacement can be performed by detaching only the single air supply/discharge switch valve mechanism. Unlike the former device, the closing of the air supply and discharge ports
66
and
68
is not performed by the weight of the discharge valve element
75
. Therefore, the problem of the former device can be solved. By contrast, however, the device has drawbacks that the air supply/discharge switch valve mechanism itself is complicatedly structured, that it is difficult to seal the slide valve element
71
, and that the mechanism protrudes to the outside of the device body casing
60
to increase the size of the whole device, thereby making the device bulky.
SUMMARY OF THE INVENTION
The invention has been conducted in view of the above-discussed problems. It is an object of the invention to provide a pulsation damping device which can be placed and used in either of the vertical and horizontal directions, and which can be configured in a wide variety of kinds.
It is another object of the invention to provide a pulsation damping device in which maintenance of air supply and discharge valves can be easily conducted, and an air supply/discharge valve structure wherein the air supply valve and the air discharge valve are separately and independently juxtaposed is employed so that the valve structure can be more simplified, the fault frequency can be made lower, and the device can be produced more economically than the above-mentioned air supply/discharge switch valve mechanism.
It is a further object of the invention to provide a pulsation damping device in which an offset load on a pulsation suppression diaphragm configured by a bellows is eliminated while an air supply valve and an air discharge valve are separately and independently juxtaposed, and an extendable and contractible portion of the pulsation suppression diaphragm is always caused to be straightly deformed extendingly and contractingly in the axial direction of a device body casing, whereby the response property of the opening and closing operations of the air supply and discharge valves can be improved and the pulsation suppressing performance can be ensured.
The pulsation damping device of the invention will be described with reference to the accompanying drawings. The reference numerals in the figures are used in this paragraph in order to facilitate the understanding of the invention, and the use of the reference numerals is not intended to restrict the contents of the invention to the illustrated embodiments.
The invention provides a pulsation damping device comprising: a sealed device body casing
17
having a liquid chamber
20
a
which receives liquid to be transported by a reciprocal pump or the like through an inflow passage
2
, which temporarily stores the liquid, and which then allows the liquid to flow out through an outflow passage
3
, and an air chamber
20
b
which is to be filled with compressed air for suppressing pulsation; and a pulsation suppression diaphragm
18
which is disposed in the device body casing to separate the liquid chamber
20
a
and the air chamber
20
b
from each other, and which is freely extended and contracted in accordance with a balance between variations in flow quantity and pressure of the transported liquid flowing into the liquid chamber, and an air filling pressure of the air chamber, wherein the pulsation damping device includes: a valve casing
23
which is placed in the air chamber
20
b
to be opposed to a center portion of a closed end face of the pulsation suppression diaphragm
18
, the closed end face facing the air chamber
20
b,
and which has an air supply port
31
through which, when the air filling pressure of the air chamber is to be raised, the compressed air is introduced into the air chamber, and an air discharge port
32
through which, when the air filling pressure of the air chamber is to be lowered, the compressed air is discharged from the air chamber to an outside; an air supply valve
36
which is disposed in the valve casing, and which opens and closes the air supply port
31
; a spring
37
which always closingly urges the air supply valve; an air discharge valve
43
which is disposed in the valve casing
23
to be juxtaposed with the air supply valve
36
, and which opens and closes the air discharge port
32
; a spring
49
which always closingly urges the air discharge valve; an air supply/discharge valve control plate
28
which is placed to abut against the center portion of the closed end face of the pulsation suppression diaphragm
18
; an air supply valve rod pressing portion
55
which is disposed on the air supply/discharge valve control plate, and which pushes a rear end portion of a valve rod
41
of the air supply valve
36
to open the air supply valve, in accordance with that the liquid pressure of the liquid chamber is raised to overcome the air pressure of the air chamber and the pulsation suppression diaphragm
18
is extended; an air discharge valve rod pulling portion
56
which is juxtaposed with the air supply valve rod pressing portion on the air supply/discharge valve control plate
28
, which is slidably connected to a rear end portion of a valve rod
45
of the air discharge valve
43
, and which pulls the valve rod
45
to open the air discharge valve
43
, in accordance with that the liquid pressure of the liquid chamber is lowered, the air pressure of the air chamber overcomes the liquid pressure of the liquid chamber, and the pulsation suppression diaphragm
18
is contracted; and springs
57
which are interposed between the valve casing
23
and the air supply/discharge valve control plate
28
to respectively surround outer peripheries of the air supply valve rod
41
and the air discharge valve rod
45
, and which pressingly urge the air supply/discharge valve control plate
28
toward the center portion of the closed end face of the pulsation suppression diaphragm
18
.
In this case, the valve casing
23
and the air supply/discharge valve control plate
28
may be connected to each other by one, or more preferably plural guide shafts
58
which are parallel to extending and contracting directions of the pulsation suppression diaphragm
18
, and the air supply/discharge valve control plate
28
may be moved in parallel along the guide shafts.
In the thus configured pulsation damping device, in accordance with that the liquid pressure of the liquid chamber
20
a
is raised to overcome the air pressure of the air chamber
20
b
and the pulsation suppression diaphragm
18
is extended, the air supply valve rod pressing-portion
55
on the air supply/discharge valve control plate
28
pushes the rear end portion of the air supply valve rod
41
to open the air supply valve
36
, thereby supplying the air into the air chamber
20
b.
When the liquid pressure of the liquid chamber
20
a
balances with the air pressure of the air chamber as a result of the above operation, the pulsation suppression diaphragm
18
is contracted, and the air supply valve
36
is closed by the forces of the spring
37
and the air pressure.
In accordance with that the liquid pressure of the liquid chamber
20
a
is lowered, the air pressure of the air chamber
20
b
overcomes the liquid pressure of the liquid chamber, and the pulsation suppression diaphragm
18
is contracted, the air discharge valve rod pulling portion
56
on the air supply/discharge valve control plate
28
pulls the air discharge valve rod
45
to open the air discharge valve
43
, thereby discharging the air in the air chamber
20
b.
When the liquid pressure of the liquid chamber
20
a
balances with the air pressure of the air chamber
20
b
as a result of the above operation, the pulsation suppression diaphragm
18
is extended, and the air discharge valve
43
is closed by the forces of the air pressure and the spring
49
. Irrespective of variations of the discharge pressure of a reciprocal pump or the like which transports the transported liquid to the liquid chamber
20
a,
therefore, the extension and contraction amount of the pulsation suppression diaphragm
18
can be restricted within a predetermined range, and the pulsation amplitude can be suppressed to a low level.
Since the air supply and discharge valves
36
and
43
are respectively closingly urged by the functions of the springs
37
and
49
, the air supply port
31
and the air discharge port
32
can be closed stably and surely. Even when the device is placed and used in any of the vertical and horizontal directions so that the air supply valve
36
and the air discharge valve
43
have a vertical or horizontal posture, the opening and closing operations of the air supply port
31
and the air discharge port
32
are not hindered.
Although the air supply valve
36
and the air discharge valve
43
are independently juxtaposed in the valve casing
23
, the air supply valve rod pressing portion
55
for opening the air supply valve
36
, and the air discharge valve rod pulling portion
56
for opening the air discharge valve
43
abut against the center portion of the closed end face of the pulsation suppression diaphragm
18
via the air supply/discharge valve control plate
28
. In extension and contraction of the pulsation suppression diaphragm
18
, therefore, an offset load is eliminated, so that the extendable and contractible portion of the pulsation suppression diaphragm
18
is always straightly deformed extendingly and contractingly in the axial direction of the device body casing
17
. Consequently, the response property of the opening and closing operations of the air supply and discharge valves
36
and
43
is improved and the pulsation suppressing performance can be ensured.
In this case, when the valve casing
23
and the air supply/discharge valve control plate
28
are connected to each other by one, or more preferably plural guide shafts
58
which are parallel to extending and contracting directions of the pulsation suppression diaphragm
18
, the air supply/discharge valve control plate
28
can be always surely moved in parallel, and the operations in which the extendable and contractible portion of the pulsation suppression diaphragm
18
is always straightly deformed extendingly and contractingly in the axial direction of the device body casing
17
can be further ensured.
In another pulsation damping device of the invention, the valve casing
23
is detachably fittingly attached to the device body casing
17
. According to this configuration, when one of the air supply valve
36
and the air discharge valve
43
is broken or becomes faulty, repair and replacement of the valve can be easily performed by detaching only the valve casing
23
from the device body casing
17
. This is advantageous in maintenance. Furthermore, the air supply valve
36
and the air discharge valve
43
are separately and independently disposed in the single valve casing
23
. Therefore, the valve structure is simple, becomes less faulty, and can be economically produced, and the valve casing
23
can be compactly accommodated without substantially protruding to the outside of the device body casing
17
.
In a further pulsation damping device of the invention, an air driven reciprocal pump portion
4
is integrally attached to the device body casing
17
, the reciprocal pump portion
4
comprises: a pump casing
6
which is disposed integrally with one side portion of the device body casing
17
; a pump diaphragm
7
which is disposed in the pump casing
6
to be opposed to the pulsation suppression diaphragm
18
, and which is extendingly and contractingly deformable in the extending and contracting directions of the pulsation suppression diaphragm
18
; an air cylinder portion
14
which drives the pump diaphragm
7
to extend and contract the diaphragm; and a pump working chamber
9
a
in which check valves
16
a
and
16
b
are disposed inside the pump diaphragm
7
, the check valves being alternately opened and closed in accordance with extending and contracting deformation of the pump diaphragm to perform actions of sucking and discharging the liquid, and the transported liquid which is discharged from the pump working chamber
9
a
via the discharge check valve
16
b
is temporarily sent into the liquid chamber
20
a.
In the thus configured pulsation damping device, when the pump diaphragm
7
is extendingly and contractingly deformed via the air cylinder portion
14
, the suction check valve
16
a
and the discharge check valve
16
b
in the pump working chamber
9
a
are alternately opened and closed, and suction of the transported liquid from the inflow passage
2
into the pump working chamber
9
a,
and discharge of the transported liquid from the pump working chamber
9
a
to the outflow passage
3
are repeated to perform a predetermined pumping function. At this time, the transported liquid which is discharged from the pump working chamber
9
a
via the discharge check valve
16
b
flows out into the outflow passage
3
through the liquid chamber
20
a
of the pulsation damping device
5
. In this case, in a peak portion of pulsations of the discharge pressure of the discharged liquid, the pulsation suppression diaphragm
18
is moved in the direction along which the capacity of the liquid chamber is increased to absorb the pressure, and, in a valley portion of the pulsations, the pulsation suppression diaphragm
18
is moved in the direction along which the capacity of the liquid chamber is decreased to raise the pressure of the discharged liquid, thereby absorbing pulsations. As a result, the transported liquid can be flown out continuously and smoothly without producing pulsations. Since the reciprocal pump portion
4
and the pulsation damping device
5
are integrated with each other and external pipes connecting them are not required, the cost and the size of the whole can be reduced, and the installation space can be largely decreased. Since external pipes are not used, there is no fear that liquid leakage due to breakage of the pipes or the like occurs after a long term use. Since the pressure loss is very small, the pump capacity can be made small so that the pump itself can be miniaturized and the installation and occupation area of the pump can be decreased.
In a still further pulsation damping device of the invention, in the air discharge valve rod pulling portion
56
, a sleeve
48
which has a guide hole portion
48
a
in a front end portion is disposed on the air supply/discharge valve control plate
28
to be juxtaposed with the air supply valve rod pressing portion
55
, and a rear end portion of the air discharge valve rod
45
is slidably passed through the guide hole portion
48
a
of the sleeve
48
so as to be prevented from slipping off, the rear end portion having a flange
44
. According to this configuration, the air discharge valve
43
can be surely pulled and opened in accordance with the movement of the air supply/discharge valve control plate
28
which is moved followingly with the contracting operation of the pulsation suppression diaphragm
18
.
In a still further pulsation damping device of the invention, in the air discharge valve rod
45
, a root portion with respect to the air discharge valve
43
is slidably passed through a valve rod guide hole portion
47
a
of an air discharge valve rod holder
47
which is disposed in the valve casing
23
. According to this configuration, the linear movement guidance of the air discharge valve rod
45
can be surely performed.
In a still further pulsation damping device of the invention, the air supply valve rod
41
is slidably passed through a valve rod pass hole
39
of an air supply valve holder
40
which is disposed in the valve casing
23
, the valve rod pass hole
39
being formed in a rear end portion of the air supply valve holder, and a rear end portion of the air supply valve rod
41
protrudes toward a rear side of the air supply valve holder
40
. According to this configuration, the linear movement guidance of the air supply valve rod
41
can be surely performed.
In a still further pulsation damping device of the invention, a front end portion of each of the guide shafts
58
is coupled integrally with the valve casing
23
, and a rear end portion of the guide shaft
58
is slidably passed through a guide sleeve
22
fixed to the air supply/discharge valve control plate
28
so as to be prevented from slipping off, the rear end portion having a flange
58
a.
According to this configuration, the air supply/discharge valve control plate
28
can be moved in parallel stably and surely
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a longitudinal sectional front view of the whole of a pulsation damping device which is an embodiment of the invention;
FIG. 2
is a front view of an automatic air supply valve mechanism of the pulsation damping device of
FIG. 1
;
FIG. 3
is a section view taken along the line E—E of
FIG. 2
;
FIG. 4
is a section view taken along the line F—F of
FIG. 2
;
FIG. 5
is a section view of an air supply valve of the automatic air supply valve mechanism of the pulsation damping device of
FIG. 1
;
FIG. 6
is a section view of an air discharge valve of the automatic air supply valve mechanism of the pulsation damping device of
FIG. 1
;
FIG. 7
is a section view taken along the line G—G of
FIG. 3
;
FIG. 8A
is a view showing the operation of the automatic air supply valve mechanism when the liquid pressure in a pulsation suppression diaphragm of the pulsation damping device of
FIG. 1
is raised;
FIG. 8B
is a view showing the operation of a guide shaft portion of an air supply/discharge valve control plate when the liquid pressure in the pulsation suppression diaphragm of the pulsation damping device of
FIG. 1
is raised;
FIG. 9A
is a view showing the operation of the automatic air supply valve mechanism when the liquid pressure in the pulsation suppression diaphragm of the pulsation damping device of
FIG. 1
is lowered;
FIG. 9B
is a view showing the operation of the guide shaft portion of the air supply/discharge valve control plate when the liquid pressure in the pulsation suppression diaphragm of the pulsation damping device of
FIG. 1
is lowered;
FIG. 10
is a longitudinal sectional front view of the whole of a pulsation damping device which is another embodiment of the invention;
FIG. 11
is a longitudinal sectional front view of the whole of a pulsation damping device which is a conventional art example;
FIG. 12A
is a longitudinal sectional front view of the whole of a pulsation damping device which is another conventional art example; and
FIG. 12B
is an enlarged longitudinal sectional front view of an air supply/discharge switch valve mechanism of the pulsation damping device shown in FIG.
12
A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the pulsation damping device of the invention will be described with reference to
FIGS. 1
to
9
.
FIG. 1
is a longitudinal sectional front view of the whole of a pulsation damping device which is applied to an air driven bellows pump for a semiconductor manufacturing apparatus. In
FIG. 1
,
1
denotes a partition wall of the device body in which an inflow passage
2
and an outflow passage
3
for liquid transported by the pump are formed. A reciprocal pump portion
4
and a pulsation damping device
5
are integrally disposed on both the sides of the partition wall
1
so as to be opposed to each other, respectively.
A bottomed cylindrical pump casing
6
is formed continuously with one side portion of the partition wall
1
. A bottomed cylindrical pump diaphragm
7
configured by a bellows or a diaphragm which is extendingly and contractingly deformable in the axial direction X—X of the pump casing
6
is disposed in the pump casing
6
(in the illustrated example, the diaphragm is configured by a bellows). An opening peripheral edge
7
a
of the pump diaphragm
7
is airtightly pressingly fixed to one side face of the partition wall
1
by an annular fixing plate
8
. According to this configuration, the inner space of the pump casing
6
is hermetically partitioned into a pump working chamber
9
a
inside the pump diaphragm
7
, and a pump operating chamber
9
b
outside the pump diaphragm
7
.
A cylinder body
12
in which a piston body
11
that is fixedly coupled via a coupling member
10
to a closed end member
7
b
of the pump diaphragm
7
is slidably housed is fixed to the outside of a bottom wall portion
6
a
of the pump casing
6
. Pressurized air which is fed from a pressurized air supplying device (not shown) such as a compressor is supplied to the interior of the cylinder body
12
, or the pump operating chamber
9
b
via air holes
13
a
and
13
b
formed in the cylinder body
12
and the bottom wall portion
6
a
of the pump casing
6
, thereby configuring an air cylinder portion
14
which drives the pump diaphragm
7
so as to extend and contract. Proximity sensors
25
a
and
25
b
are attached to the air cylinder portion
14
, and a sensor sensing plate
26
is attached to the piston body
11
. In accordance with the reciprocal motion of the piston body
11
, the sensor sensing plate
26
alternately approaches the proximity sensors
25
a
and
25
b,
whereby the supply of the pressurized air which is fed from the pressurized air supplying device (not shown), into the cylinder body
12
, and that into the pump operating chamber
9
b
are automatically switched over.
A suction port
15
a
and a discharge port
15
b
which are opened in the pump working chamber
9
a
communicate with the inflow passage
2
and the outflow passage
3
, respectively. A suction check valve
16
a
and a discharge check valve
16
b
which are alternately opened and closed in accordance with extending and contracting operations of the pump diaphragm
7
are disposed in the suction port
15
a
and the discharge port
15
b,
respectively. The above-mentioned components constitute the reciprocal pump portion
4
.
On the other hand, a bottomed cylindrical device body casing
17
is disposed in the other side portion of the partition wall
1
so as to be coaxial with the pump casing
6
. In the device body casing
17
also, a bottomed cylindrical pulsation suppression diaphragm
18
configured by a bellows or a diaphragm which is extendingly and contractingly deformable in the axial direction X—X of the device body casing
17
is disposed so as to be opposed to the pump diaphragm
7
in the pump portion
4
(in the illustrated example, the diaphragm is configured by a bellows). An opening peripheral edge
18
a
of the pulsation suppression diaphragm
18
is airtightly pressingly fixed to the other side face of the pertition wall
1
by an annular fixing plate
19
. According to this configuration, the inner space of the device body casing
17
is partitioned into a liquid chamber
20
a
which is formed inside the pulsation suppression diaphragm
18
, and which temporarily stores the liquid that is to be discharged via the discharge check valve
16
b
in the pump portion
4
and a communication passage
21
formed in the thickened portion of the partition wall
1
, and an air chamber
20
b
which is formed outside the pulsation suppression diaphragm
18
, and which is to be filled with compressed air for suppressing pulsation.
The above-mentioned components constitute the pulsation damping device
5
which causes pulsation due to the discharge pressure of the liquid discharged from the pump working chamber
9
a
of the pump portion
4
, to be absorbed and damped by a change in the capacity of the liquid chamber
20
a
due to extending and contracting deformation of the pulsation suppression diaphragm
18
.
An automatic pressure adjusting mechanism configured by an automatic air supply valve mechanism
33
and an automatic air discharge valve mechanism
34
is disposed in the air chamber
20
b
of the pulsation damping device
5
.
In the automatic pressure adjusting mechanism, an opening
27
is formed in the vicinity of the center of an air chamber closing wall
17
a
of the device body casing
17
. A valve casing
23
in which air supply and discharge valves are incorporated is fitted into the opening
27
. A flange
23
a
attached to the outer periphery of the rear end of the valve casing
23
is detachably fastened to the bottom wall
17
a
by bolts
24
or the like. By contrast, an air supply/discharge valve control plate
28
is placed so as to abut against a center portion of a closed end face
18
b
of the pulsation suppression diaphragm
18
facing the air chamber
20
b
of the pulsation suppression diaphragm
18
, so as to be opposed to the valve casing
23
.
As shown in
FIGS. 2 and 3
, an air supply port
31
and an air discharge port
32
are formed in the front end face of the valve casing
23
so as to be juxtaposed. The automatic air supply valve mechanism
33
is disposed in the air supply port
31
. When the capacity of the liquid chamber
20
a
is increased to exceed a predetermined range, the air supply valve mechanism supplies air of a pressure which is equal to or higher than the maximum pressure of the transported liquid, into the air chamber
20
b,
thereby raising the filling pressure in the air chamber
20
b.
The automatic air discharge valve mechanism
34
is disposed in the air discharge port
32
. When the capacity of the liquid chamber
20
a
is decreased to exceed the predetermined range, the automatic air discharge valve mechanism
34
discharges air from the air chamber
20
b
to lower the filling pressure in the air chamber
20
b.
In the automatic air supply valve mechanism
33
, as shown in
FIG. 3
, an internal thread hole
29
is formed in the rear end face of the valve casing
23
so as to communicate with the air supply port
31
, and an air supply valve holder
40
which holds an air supply valve
36
and a valve rod
41
integrated therewith is screwingly fixed to the internal thread hole
29
via an O-ring
80
. In the air supply valve holder
40
, an air supply valve chamber
35
is formed in a front end portion which is screwed into the internal thread hole
29
, a valve seat
38
is formed on the inner bottom of the air supply valve chamber
35
, and a valve rod pass hole
39
is formed in a rear end portion so as to communicate with the air supply valve chamber
35
in the same axis. A plurality of communication holes
30
which enable the air supply valve chamber
35
and the air chamber
20
b
to communicate with each other via the valve rod pass hole
39
are formed in the outer periphery of the rear end portion of the air supply valve holder
40
. This formation of the communication holes
30
can improve the response property of the air chamber
20
b
with respect to a pressure change.
In the air supply valve holder
40
, the air supply valve
36
is incorporated into the air supply valve chamber
35
so as to be movable along the axial direction, and the valve rod
41
is passed through the valve rod pass hole
39
. A rear end portion of the valve rod
41
protrudes toward the rear side of the air supply valve holder
40
. The valve rod pass hole
39
is formed into a stepped shape having a larger diameter portion
39
a
which has an inner diameter that is larger than the outer diameter of the valve rod
41
to form a communication gap between the portion and the valve rod
41
, and a guide hole portion
39
b
which is slightly larger than the outer diameter of the valve rod
41
so as to be in sliding contact with the valve rod
41
without leaving a substantial gap therebetween. The valve rod
41
of the air supply valve
36
is slidingly guided by the guide hole portion
39
b,
thereby enabling the air supply valve
36
to be straightly moved in the air supply valve chamber
35
in the axial direction.
In the air supply valve chamber
35
, the air supply valve
36
is always urged by a spring
37
so as to be in the closing position where the valve is closely in contact with the valve seat
38
. The air supply valve
36
is airtightly in contact with the valve seat
38
via an O-ring
50
. As shown in
FIG. 5
, the O-ring
50
is attached to the air supply valve
36
so as to be prevented from slipping off, with being fitted into an arcuate groove
51
which is formed in an edge portion of the rear end face of the valve.
Under the condition where the pulsation suppression diaphragm
18
is in a reference position in a mean pressure state of the liquid pressure in the liquid chamber
20
a,
the air supply valve element
36
is in close contact with the valve seat
38
of the valve rod holder
40
to close the air supply port
31
, and an end portion
41
a
of the valve rod
41
which faces the air chamber
20
b
is separated from the closed end face
18
b
of the pulsation suppression diaphragm
18
by a predetermined stroke.
In the automatic air discharge valve mechanism
34
, as shown in
FIG. 3
, an air discharge valve chamber
42
having a circular section, and an internal thread portion
52
having an inner diameter which is larger than the inner diameter of the air discharge valve chamber
42
are formed on the rear end face of the valve casing
23
so as to communicate with the air discharge port
32
in the same axis. An air discharge valve
43
having a shape in which flat faces
43
a
are formed in opposing portions on the circumference as shown in
FIG. 7
is incorporated into the air discharge valve chamber
42
so as to be movable in the axial direction. An air discharge valve rod
45
is integrally coupled with the air discharge valve
43
. The air discharge valve rod
45
is passed through and held by a valve rod guide hole portion
47
a
at the center of an air discharge valve rod holder
47
which is screwingly fixed to the internal thread portion
52
, so as to be slidable in the axial direction. In the air discharge valve rod holder
47
, a plurality of communication holes
46
through which the air discharge valve chamber
42
and the air chamber
20
b
communicate with each other are formed on the same circle centered at the valve rod guide hole portion
47
a.
A spring
49
through which the discharge valve rod
45
is passed is interposed between the air discharge valve
43
and the air discharge valve rod holder
47
. The air discharge valve
43
is always urged by the spring
49
so as to be in the closing position where the valve is closely in contact with a valve seat
42
a
of the air discharge valve chamber
42
. The air discharge valve
43
is airtightly in contact with the valve seat
42
a
via an O-ring
53
. As shown in
FIG. 6
, the O-ring
53
is attached to the air discharge valve
43
so as to be prevented from slipping off, with being fitted into an arcuate groove
54
which is formed in an edge portion of the front end face of the valve.
Under the condition where the pulsation suppression diaphragm
18
is in the reference position, the air discharge valve
43
closes the air discharge port
32
, and a flange
44
in the rear end of the air discharge valve rod
45
is separated from the inner face of the closed end face
48
a
of the slider
48
by a predetermined stroke.
On the other hand, the air supply/discharge valve control plate
28
which is placed so as to abut against the center portion of the closed end face
18
b
of the pulsation suppression diaphragm
18
is formed into a disk-like shape, an air supply valve rod pressing portion
55
is recessedly formed in the front face of the plate, and a sleeve
48
constituting an air discharge valve rod pulling portion
56
is fittingly fixed with being juxtaposed with the air supply valve rod pressing portion
55
. A guide hole portion
48
a
which is slightly larger than the outer diameter of the air discharge valve rod
45
so as to be in sliding contact with the valve rod
45
without leaving a substantial gap therebetween. A rear end portion of the air discharge valve rod
45
and having the flange
44
is passed through and coupled to the guide hole portion
48
a
so as to be slidable and prevented from slipping off. The air discharge valve rod
45
is slidingly guided by the guide hole portion
48
a,
so as to be straightly movable in the axial direction. The sleeve
48
may be formed integrally with the air supply/discharge valve control plate
28
.
Springs
57
each formed by a compression coil spring are interposed between the air supply valve rod pressing portion
55
of the air supply/discharge valve control plate
28
and the air supply valve holder
40
, and between the sleeve
48
and the rear end face of the air discharge valve rod holder
47
, so as to surround the outer peripheries of the air supply valve rod
41
and the air discharge valve rod
45
. The air supply/discharge valve control plate
28
is pressingly urged by the springs
57
toward the center portion of the closed end face
18
b
of the pulsation suppression diaphragm
18
.
As shown in
FIG. 4
, the air supply/discharge valve control plate
28
and the valve casing
23
are connected to each other by one, or more preferably plural guide shafts
58
which are parallel to the extending and contracting directions of the pulsation suppression diaphragm
18
. In each of the guide shafts
58
, the front end portion is fasteningly fixed to the rear end face of the valve casing
23
by a nut
59
via a washer
59
a,
and the rear end portion having a flange
58
a
is passed through and coupled to a guide sleeve
22
which is embeddedly fixed to the front end face of the air supply/discharge valve control plate
28
, so as to be prevented from slipping off and slidable in the axial direction. In the front end portion of each of the guide sleeves
22
, a guide hole portion
22
a
which is slidingly contacted with the corresponding guide shaft
58
without leaving a substantial gap therebetween is formed. The rear end portions of the guide shafts
58
are passed through the guide hole portions
22
a,
thereby enabling the air supply/discharge valve control plate
28
to be straightly moved in parallel with the extending and contracting directions of the pulsation suppression diaphragm
18
under guidance of the guide shafts
58
. The guide sleeves
22
may be formed integrally with the air supply/discharge valve control plate
28
.
Next, the operation of the thus configured pulsation damping device for the pump will be described.
The pressurized air which is fed from the pressurized air supplying device (not shown) such as a compressor is supplied to the interior of the cylinder body
12
of the air cylinder portion
14
in the reciprocal pump portion
4
, via the air hole
13
b,
to move the piston body
11
and the coupling member
10
in the direction x in
FIG. 1
, thereby extending the pump diaphragm
7
in the direction x in FIG.
1
. The transported liquid in the inflow passage
2
is sucked into the pump working chamber
9
a
via the suction check valve
16
a.
When the pressurized air is supplied into the pump operating chamber
9
b
of the air cylinder portion
14
via the air hole
13
b
and air is discharged through the air hole
13
b
to cause the pump diaphragm
7
to be contracted in the direction y in
FIG. 1
, the transported liquid which has been sucked into the pump working chamber
9
a
is discharged via the discharge check valve
16
b.
When the pump diaphragm
7
of the reciprocal pump portion
4
is driven via the air cylinder portion
14
so as to be extended and contracted as described above, the suction check valve
16
a
and the discharge check valve
16
b
are alternately opened and closed, so that suction of the liquid from the inflow passage
2
into the pump working chamber
9
a,
and discharge of the liquid from the pump working chamber
9
a
into the outflow passage
3
are repeated to conduct a predetermined pumping action. When the transported liquid is fed to a predetermined portion by the operation of the reciprocal pump portion
4
, the pump discharge pressure generates pulsations due to repetition of peak and valley portions.
The transported liquid discharged from the pump working chamber
9
a
of the pump portion
4
via the discharge check valve
16
b
is passed through the communication passage
21
and then sent into the liquid chamber
20
a
in the pulsation damping device
5
. The liquid is temporarily stored in the liquid chamber
20
a,
and thereafter discharged into the outflow passage
3
. When the discharge pressure of the transported liquid is in a peak portion of a discharge pressure curve, the transported liquid causes the pulsation suppression diaphragm
18
to be extended so as to increase the capacity of the liquid chamber
20
a,
and hence the pressure of the liquid is absorbed. At this time, the flow quantity of the transported liquid flowing out from the liquid chamber
20
a
is smaller than that of the liquid supplied from the reciprocal pump portion
4
.
When the discharge pressure of the transported liquid comes to a valley portion of the discharge pressure curve, the pressure of the transported liquid becomes lower than the filling pressure of the air chamber
20
b
which is compressed by extension of the pulsation suppression diaphragm
18
, and hence the pulsation suppression diaphragm
18
is contracted. At this time, the flow quantity of the liquid flowing out from the liquid chamber
20
a
is larger than that of the transported liquid flowing from the reciprocal pump portion
4
into the liquid chamber
20
a.
This repeated operation, i.e., the capacity change of the liquid chamber
20
a
causes the pulsation to be absorbed and suppressed.
When the discharge pressure of the reciprocal pump portion
4
is varied in the increasing direction during such an operation, the capacity of the liquid chamber
20
a
is increased by the transported liquid, with the result that the liquid pressure of the liquid chamber
20
a
overcomes the pressure of the air chamber
20
b
and the pulsation suppression diaphragm
18
is extended. In accordance with the extension of the pulsation suppression diaphragm
18
, as shown in
FIGS. 8A and 8B
, the air supply/discharge valve control plate
28
is pushed in the direction of the valve casing
23
by the center portion of the closed end face
18
b
of the pulsation suppression diaphragm
18
. As a result, the air supply valve
36
which has been closed by the spring
37
is opened by pushing the rear end portion of the air supply valve rod
41
with the air supply valve rod pressing portion
55
of the air supply/discharge valve control plate
28
, and the compressed air is supplied into the air chamber
20
b
through the air supply port
31
, with the result that the filling pressure of the air chamber
20
b
is raised. In accordance with the rise of the filling pressure in the air chamber
20
b,
the pulsation suppression diaphragm
18
is contracted. Then, the air supply valve rod pressing portion
55
of the air supply/discharge valve control plate
28
does not push the rear end portion of the air supply valve rod
41
, and the air supply valve
36
is set to the closing state by the spring
37
and the pressure of the compressed air in the air chamber
20
b,
so as to balance with the liquid pressure in the liquid chamber
20
a.
When the pulsation suppression diaphragm
18
is extended by a degree which is greater than the predetermined stroke, the closed end face
18
b
strikes against a stopper wall
17
c
of the device body casing
17
which protrudes into the air chamber
20
b,
whereby excessive extending deformation of the pulsation suppression diaphragm
18
is restricted, so that the diaphragm can be prevented from being damaged.
By contrast, when the discharge pressure of the reciprocal pump portion
4
is lowered, the capacity of the liquid chamber
20
a
is reduced by the transported liquid, and the pressure in the air chamber
20
b
the liquid pressure in the liquid chamber
20
a,
so that the pulsation suppression diaphragm
18
is contractingly deformed. As shown in
FIGS. 9A and 9B
, this contracting deformation of the pulsation suppression diaphragm
18
causes the air supply/discharge valve control plate
28
to, in accordance with the movement of the closed end face
18
b
of the pulsation suppression diaphragm
18
in the contracting direction, be moved in the same direction while receiving the urging force of the springs
57
. The air discharge valve rod
45
which is coupled to the discharge valve rod pulling portion
56
of the air supply/discharge valve control plate
28
is pulled in the same direction, whereby the discharge valve
43
is changed to the opening state. Therefore, the compressed air in the air chamber
20
b
is discharged to the atmosphere through the air discharge port
32
to lower the filling pressure in the air chamber
20
b.
In accordance with the reduction of the filling pressure in the air chamber
20
b,
the pulsation suppression diaphragm
18
is extended. Then, the air supply/discharge valve control plate
28
is pushed by the center portion of the closed end face
18
b
of the pulsation suppression diaphragm
18
, and the air discharge valve
43
is caused to close the air discharge port
32
by the urging action of the spring
49
. As a result, the filling pressure in the air chamber
20
b
is fixed to the adjusted state.
As described above, when a liquid pressure is applied to the pulsation suppression diaphragm
18
, the compressed air is sucked or discharged until balance with the pressure is attained, whereby pulsations are efficiently absorbed and the amplitude of pulsations is suppressed to a low level, irrespective of variation of the discharge pressure of the pump working chamber
9
a
of the reciprocal pump portion
4
.
In this way, the air supply valve
36
and the air discharge valve
43
which are separately and independently disposed in the valve casing
23
are subjected to the valve-opening control in accordance with extension and contraction of the pulsation suppression diaphragm
18
, via the air supply valve rod pressing portion
55
and the air discharge valve rod pulling portion
56
on the air supply/discharge valve control plate
28
. Since the air supply/discharge valve control plate
28
is placed so as to always abut against the center portion of the closed end face
18
b
of the pulsation suppression diaphragm
18
, no offset load is applied to the pulsation suppression diaphragm
18
even when the air supply valve
36
and the air discharge valve
43
are juxtaposed separately and independently in the valve casing
23
. Therefore, the pulsation suppression diaphragm
18
is always straightly extendingly and contractingly deformed in the axial direction X—X of the device body casing
17
, whereby the response performance of the opening and closing operations of the air supply and discharge valves
36
and
43
can be improved and the performance of reducing pulsations can be ensured. The air supply/discharge valve control plate
28
can be always enabled to be moved in parallel stably and surely by the guiding action of the guide shafts
58
. Consequently, the air supply and discharge valves
36
and
43
can faithfully perform the opening and closing operations corresponding to extension and contraction of the pulsation suppression diaphragm
18
, via the air supply/discharge valve control plate
28
.
FIG. 10
is a longitudinal sectional front view of the whole of a pulsation damping device for a pump which is another embodiment of the invention. In the embodiment, the pulsation damping device
5
is independently configured as an accumulator with being separated from a pump. The liquid chamber
20
a
which receives and temporarily stores liquid transported by a pump (not shown) that is placed in another position, through the inflow passage
2
, and which then allows the liquid to flow out from the outflow passage
3
is formed in a lower portion of the sealed device body casing
17
. The air chamber
20
b
is formed in an upper portion of the device body casing
17
. The liquid chamber
20
a
and the air chamber
20
b
are separated from each other by the pulsation suppression diaphragm
18
. The valve casing
23
in which mechanisms that are identical with the automatic air supply valve mechanism
33
and the automatic air discharge valve mechanism
34
of the above-described embodiment are disposed is detachably fitted and fastened to the opening
27
of an upper wall
17
b
of the device body casing
17
, by bolts
24
or the like. The air supply/discharge valve control plate
28
is placed so as to abut against the center portion of the closed end face
18
b
of the pulsation suppression diaphragm
18
. The pulsation damping device
5
, the automatic air supply valve mechanism
33
, and the automatic air discharge valve mechanism
34
are configured and operate in the same manner as those of the above-described embodiment, and hence their description is omitted.
Claims
- 1. A pulsation damping device comprising: a sealed device body casing having a liquid chamber which receives liquid to be transported by a reciprocal pump or the like through an inflow passage, which temporarily stores the liquid, and which then allows the liquid to flow out through an outflow passage, and an air chamber which is to be filled with compressed air for suppressing pulsation; and a pulsation suppression diaphragm which is disposed in said device body casing to separate said liquid chamber and said air chamber from each other, and which is freely extended and contracted in accordance with a balance between variations in flow quantity and pressure of the transported liquid flowing into said liquid chamber, and an air filling pressure of said air chamber, wherein said pulsation damping device includes:a valve casing which is placed in said air chamber to be opposed to a center portion of a closed end face of said pulsation suppression diaphragm, said closed end face facing said air chamber, and which has an air supply port through which, when the air filling pressure of said air chamber is to be raised, the compressed air is introduced into said air chamber, and an air discharge port through which, when the air filling pressure of said air chamber is to be lowered, the compressed air is discharged from said air chamber to an outside; an air supply valve which is disposed in said valve casing, and which opens and closes said air supply port, and a spring which always closingly urges said air supply valve; an air discharge valve which is disposed in said valve casing to be juxtaposed with said air supply valve, and which opens and closes said air discharge port, and a spring which always closingly urges said air discharge valve; an air supply/discharge valve control plate which is placed to abut against the center portion of said closed end face of said pulsation suppression diaphragm; an air supply valve rod pressing portion which is disposed on said air supply/discharge valve control plate, and which pushes a rear end portion of a valve rod of said air supply valve to open said air supply valve, in accordance with that the liquid pressure of said liquid chamber is raised to overcome the air pressure of said air chamber and said pulsation suppression diaphragm is extended; an air discharge valve rod pulling portion which is juxtaposed with said air supply valve rod pressing portion on said air supply/discharge valve control plate, which is slidably connected to a rear end portion of a valve rod of said air discharge valve, and which pulls said valve rod to open said air discharge valve, in accordance with that the liquid pressure of said liquid chamber is lowered, the air pressure of said air chamber overcomes the liquid pressure of said liquid chamber, and said pulsation suppression diaphragm is contracted; and springs which are interposed between said valve casing and said air supply/discharge valve control plate to respectively surround outer peripheries of said air supply valve rod and said air discharge valve rod, and which pressingly urge said air supply/discharge valve control plate toward the center portion of said closed end face of said pulsation suppression diaphragm.
- 2. A pulsation damping device according to claim 1, wherein said valve casing and said air supply/discharge valve control plate are connected to each other by a guide shaft which is parallel to extending and contracting directions of said pulsation suppression diaphragm, and said air supply/discharge valve control plate is moved in parallel along said guide shaft.
- 3. A pulsation damping device according to claim 2, wherein said guide shaft is disposed in a plural number.
- 4. A pulsation damping device according to claim 1, wherein said valve casing is detachably attached to said device body casing.
- 5. A pulsation damping device according to claim 2, wherein said valve casing is detachably attached to said device body casing.
- 6. A pulsation damping device according to claim 3, wherein said valve casing is detachably attached to said device body casing.
- 7. A pulsation damping device according to claim 1, wherein an air driven reciprocal pump portion is integrally attached to said device body casing, said reciprocal pump portion comprises: a pump casing which is disposed integrally with one side portion of said device body casing; a pump diaphragm which is disposed in said pump casing to be opposed to said pulsation suppression diaphragm, and which is extendingly and contractingly deformable in the extending and contracting directions of said pulsation suppression diaphragm; an air cylinder portion which drives said pump diaphragm to extend and contract said diaphragm; and a pump working chamber in which check valves are disposed inside said pump diaphragm, said check valves being alternately opened and closed in accordance with extending and contracting deformation of said pump diaphragm to perform actions of sucking and discharging the transported liquid, and the transported liquid which is discharged from said pump working chamber via said discharge check valve is temporarily sent into said liquid chamber.
- 8. A pulsation damping device according to claim 2, wherein an air driven reciprocal pump portion is integrally attached to said device body casing, said reciprocal pump portion comprises: a pump casing which is disposed integrally with one side portion of said device body casing; a pump diaphragm which is disposed in said pump casing to be opposed to said pulsation suppression diaphragm, and which is extendingly and contractingly deformable in the extending and contracting directions of said pulsation suppression diaphragm; an air cylinder portion which drives said pump diaphragm to extend and contract said diaphragm; and a pump working chamber in which check valves are disposed inside said pump diaphragm, said check valves being alternately opened and closed in accordance with extending and contracting deformation of said pump diaphragm to perform actions of sucking and discharging the transported liquid, and the transported liquid which is discharged from said pump working chamber via said discharge check valve is temporarily sent into said liquid chamber.
- 9. A pulsation damping device according to claim 3, wherein an air driven reciprocal pump portion is integrally attached to said device body casing, said reciprocal pump portion comprises: a pump casing which is disposed integrally with one side portion of said device body casing; a pump diaphragm which is disposed in said pump casing to be opposed to said pulsation suppression diaphragm, and which is extendingly and contractingly deformable in the extending and contracting directions of said pulsation suppression diaphragm; an air cylinder portion which drives said pump diaphragm to extend and contract said diaphragm; and a pump working chamber in which check valves are disposed inside said pump diaphragm, said check valves being alternately opened and closed in accordance with extending and contracting deformation of said pump diaphragm to perform actions of sucking and discharging the transported liquid, and the transported liquid which is discharged from said pump working chamber via said discharge check valve is temporarily sent into said liquid chamber.
- 10. A pulsation damping device according to claim 4, wherein an air driven reciprocal pump portion is integrally attached to said device body casing, said reciprocal pump portion comprises: a pump casing which is disposed integrally with one side portion of said device body casing; a pump diaphragm which is disposed in said pump casing to be opposed to said pulsation suppression diaphragm, and which is extendingly and contractingly deformable in the extending and contracting directions of said pulsation suppression diaphragm; an air cylinder portion which drives said pump diaphragm to extend and contract said diaphragm; and a pump working chamber in which check valves are disposed inside said pump diaphragm, said check valves being alternately opened and closed in accordance with extending and contracting deformation of said pump diaphragm to perform actions of sucking and discharging the transported liquid, and the transported liquid which is discharged from said pump working chamber via said discharge check valve is temporarily sent into said liquid chamber.
- 11. A pulsation damping device according to claim 5, wherein an air driven reciprocal pump portion is integrally attached to said device body casing, said reciprocal pump portion comprises: a pump casing which is disposed integrally with one side portion of said device body casing; a pump diaphragm which is disposed in said pump casing to be opposed to said pulsation suppression diaphragm, and which is extendingly and contractingly deformable in the extending and contracting directions of said pulsation suppression diaphragm; an air cylinder portion which drives said pump diaphragm to extend and contract said diaphragm; and a pump working chamber in which check valves are disposed inside said pump diaphragm, said check valves being alternately opened and closed in accordance with extending and contracting deformation of said pump diaphragm to perform actions of sucking and discharging the transported liquid, and the transported liquid which is discharged from said pump working chamber via said discharge check valve is temporarily sent into said liquid chamber.
- 12. A pulsation damping device according to claim 6, wherein an air driven reciprocal pump portion is integrally attached to said device body casing, said reciprocal pump portion comprises: a pump casing which is disposed integrally with one side portion of said device body casing; a pump diaphragm which is disposed in said pump casing to be opposed to said pulsation suppression diaphragm, and which is extendingly and contractingly deformable in the extending and contracting directions of said pulsation suppression diaphragm; an air cylinder portion which drives said pump diaphragm to extend and contract said diaphragm; and a pump working chamber in which check valves are disposed inside said pump diaphragm, said check valves being alternately opened and closed in accordance with extending and contracting deformation of said pump diaphragm to perform actions of sucking and discharging the transported liquid, and the transported liquid which is discharged from said pump working chamber via said discharge check valve is temporarily sent into said liquid chamber.
- 13. A pulsation damping device according to claim 1, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, and a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange.
- 14. A pulsation damping device according to claim 2, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, and a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange.
- 15. A pulsation damping device according to claim 3, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, and a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange.
- 16. A pulsation damping device according to claim 4, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, and a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange.
- 17. A pulsation damping device according to claim 5, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, and a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange.
- 18. A pulsation damping device according to claim 6, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, and a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange.
- 19. A pulsation damping device according to claim 1, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange, and a root portion of said air discharge valve rod with respect to said air discharge valve is slidably passed through a valve rod guide hole portion of an air discharge valve rod holder which is disposed in said valve casing.
- 20. A pulsation damping device according to claim 2, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange, and a root portion of said air discharge valve rod with respect to said air discharge valve is slidably passed through a valve rod guide hole portion of an air discharge valve rod holder which is disposed in said valve casing.
- 21. A pulsation damping device according to claim 3, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange, and a root portion of said air discharge valve rod with respect to said air discharge valve is slidably passed through a valve rod guide hole portion of an air discharge valve rod holder which is disposed in said valve casing.
- 22. A pulsation damping device according to claim 4, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange, and a root portion of said air discharge valve rod with respect to said air discharge valve is slidably passed through a valve rod guide hole portion of an air discharge valve rod holder which is disposed in said valve casing.
- 23. A pulsation damping device according to claim 5, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange, and a root portion of said air discharge valve rod with respect to said air discharge valve is slidably passed through a valve rod guide hole portion of an air discharge valve rod holder which is disposed in said valve casing.
- 24. A pulsation damping device according to claim 6, wherein, in said air discharge valve rod pulling portion, a sleeve which has a guide hole portion in a front end portion is disposed on said air supply/discharge valve control plate to be juxtaposed with said air supply valve rod pressing portion, a rear end portion of said air discharge valve rod is slidably passed through said guide hole portion of said sleeve so as to be prevented from slipping off, said rear end portion having a flange, and a root portion of said air discharge valve rod with respect to said air discharge valve is slidably passed through a valve rod guide hole portion of an air discharge valve rod holder which is disposed in said valve casing.
- 25. A pulsation damping device according to claim 1, wherein said air supply valve rod is slidably passed through a valve rod pass hole of an air supply valve holder which is disposed in said valve casing, said valve rod pass hole being formed in a rear end portion of said air supply valve holder, and a rear end portion of said air supply valve rod protrudes toward a rear side of said air supply valve holder.
- 26. A pulsation damping device according to claim 2, wherein said air supply valve rod is slidably passed through a valve rod pass hole of an air supply valve holder which is disposed in said valve casing, said valve rod pass hole being formed in a rear end portion of said air supply valve holder, and a rear end portion of said air supply valve rod protrudes toward a rear side of said air supply valve holder.
- 27. A pulsation damping device according to claim 3, wherein said air supply valve rod is slidably passed through a valve rod pass hole of an air supply valve holder which is disposed in said valve casing, said valve rod pass hole being formed in a rear end portion of said air supply valve holder, and a rear end portion of said air supply valve rod protrudes toward a rear side of said air supply valve holder.
- 28. A pulsation damping device according to claim 4, wherein said air supply valve rod is slidably passed through a valve rod pass hole of an air supply valve holder which is disposed in said valve casing, said valve rod pass hole being formed in a rear end portion of said air supply valve holder, and a rear end portion of said air supply valve rod protrudes toward a rear side of said air supply valve holder.
- 29. A pulsation damping device according to claim 5, wherein said air supply valve rod is slidably passed through a valve rod pass hole of an air supply valve holder which is disposed in said valve casing, said valve rod pass hole being formed in a rear end portion of said air supply valve holder, and a rear end portion of said air supply valve rod protrudes toward a rear side of said air supply valve holder.
- 30. A pulsation damping device according to claim 6, wherein said air supply valve rod is slidably passed through a valve rod pass hole of an air supply valve holder which is disposed in said valve casing, said valve rod pass hole being formed in a rear end portion of said air supply valve holder, and a rear end portion of said air supply valve rod protrudes toward a rear side of said air supply valve holder.
- 31. A pulsation damping device according to claim 2, wherein a front end portion of said guide shaft is coupled integrally with said valve casing, and a rear end portion of said guide shaft is slidably passed through a guide sleeve fixed to said air supply/discharge valve control plate so as to be prevented from slipping off, said rear end portion having a flange.
- 32. A pulsation damping device according to claim 3, wherein a front end portion of each of said guide shafts is coupled integrally with said valve casing, and a rear end portion of said guide shaft is slidably passed through a guide sleeve fixed to said air supply/discharge valve control plate so as to be prevented from slipping off, said rear end portion having a flange.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2000-137572 |
May 2000 |
JP |
|
US Referenced Citations (4)
Foreign Referenced Citations (2)
Number |
Date |
Country |
6-17752 |
Jan 1994 |
JP |
8-159016 |
Jun 1996 |
JP |