U.S. patent application number 10/579868 was filed with the patent office on 2009-05-07 for hermetic compressor.
Invention is credited to Terumasa Ide, Tomio Maruyama, Tsuyoshi Matsumoto, Masakazu Yamaoka.
Application Number | 20090116985 10/579868 |
Document ID | / |
Family ID | 35811668 |
Filed Date | 2009-05-07 |
United States Patent
Application |
20090116985 |
Kind Code |
A1 |
Matsumoto; Tsuyoshi ; et
al. |
May 7, 2009 |
Hermetic compressor
Abstract
A hermetic compressor including a discharge valve system in a
cylinder. A discharge valve system includes a discharge reed having
an opening/closing portion and a discharge reed holding portion, a
spring reed having a movable portion and a spring reed holding
portion, and a stopper having a regulation portion and a stopper
holding portion. The discharge reed, the spring reed and the
stopper are fixed in this order to a pedestal of a valve plate. At
a spring reed bending portion provided in a movable portion, the
movable portion is bent toward the direction of the valve seat and
the tip portion is brought into contact with the plate contact
portion. Space is provided between the movable portion of the
spring reed and the opening/closing portion of the discharge reed,
and both are not brought into close contact with each other. Thus,
delay in closing discharge reed can be prevented and deterioration
of the refrigerating capacity can be suppressed.
Inventors: |
Matsumoto; Tsuyoshi;
(Kanagawa, JP) ; Ide; Terumasa; (Kanagawa, JP)
; Maruyama; Tomio; (Kanagawa, JP) ; Yamaoka;
Masakazu; (Kanagawa, JP) |
Correspondence
Address: |
RATNERPRESTIA
P.O. BOX 980
VALLEY FORGE
PA
19482
US
|
Family ID: |
35811668 |
Appl. No.: |
10/579868 |
Filed: |
December 8, 2005 |
PCT Filed: |
December 8, 2005 |
PCT NO: |
PCT/JP2005/022992 |
371 Date: |
May 18, 2006 |
Current U.S.
Class: |
417/440 |
Current CPC
Class: |
F04B 39/1073
20130101 |
Class at
Publication: |
417/440 |
International
Class: |
F04B 23/00 20060101
F04B023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 8, 2004 |
JP |
2004-355157 |
Claims
1. A hermetic compressor comprising a hermetic container that
accommodates a compressing element and oil, the compressing element
comprising: a cylinder; a piston reciprocating in the cylinder; and
a valve plate that seals an opening end of the cylinder and has a
discharge valve system at the outer side of the cylinder; the
discharge valve system comprising: a discharge hole formed in the
valve plate; a valve seat provided on the outer side of the valve
plate around the discharge hole; a pedestal formed substantially in
the same height as the valve seat on the outer side of the valve
plate; a plate contact portion formed at a position higher than the
valve seat on the outer side of the valve plate; a discharge reed
made of a plate spring material and including an opening/closing
portion covering the discharge hole in a way capable of opening and
closing thereof and a discharge reed holding portion fixed to the
pedestal; a spring reed made of a plate spring material, which
includes a spring reed holding portion fixed to the pedestal and a
movable portion and is provided at the outer side of the discharge
reed; and a stopper including a stopper holding portion fixed to
the pedestal and a regulation portion and is provided at the outer
side of the spring reed; wherein the spring reed has a spring reed
bending portion and a tip portion in the movable portion, the
spring reed is bent toward a direction of the valve seat at the
spring reed bending portion, and the tip portion is brought into
contact with the plate contact portion.
2. The hermetic compressor according to claim 1, wherein the
discharge reed includes a discharge reed bending portion between
the discharge reed holding portion and the opening/dosing portion;
and the discharge reed is bent toward a direction of the valve seat
at the discharge reed bending portion.
3. The hermetic compressor according to claim 2, wherein a concave
portion whose bottom surface is lower than the valve seat and the
pedestal is formed between the valve seat and the pedestal on the
outer surface of the valve plate, and a position of the discharge
reed bending portion is provided at the outer side of the concave
portion.
4. The hermetic compressor according to any of claims 1 to 3,
wherein the stopper has a stopper contact portion bending toward
the side of the spring reed in the regulation portion.
5. A hermetic compressor comprising: a cylinder; a piston
reciprocating in the cylinder; and a valve plate that seals an
opening end of the cylinder and has a discharge valve system at the
outer side of the cylinder; the discharge valve system comprising:
a valve seat provided on the outer side of the valve plate around a
hole penetrating through the valve plate; a pedestal formed in the
same height as the valve seat on the outer side of the valve plate;
a plate contact portion formed at a higher position than the valve
seat on the outer side of the valve plate; a first plate spring
fixed to the pedestal at one end and being capable of covering the
hole at another end; a second plate spring provided at the outer
side of the first plate spring, fixed to the pedestal at one end
and reaching the plate contact portion at another end, and bent
toward the direction of the valve seat in a middle portion; and a
stopper fixed to the pedestal at one end and covering the second
plate spring.
6. The hermetic compressor according to claim 5, wherein a concave
portion whose bottom surface is lower than the valve seat and the
pedestal is formed between the valve seat and the pedestal on the
outer surface of the valve plate, and the second spring is bent at
a point outer side of the concave portion.
Description
TECHNICAL FIELD
[0001] The present invention relates to a hermetic compressor used
in a refrigerator with freezer, etc.
BACKGROUND ART
[0002] As a conventional hermetic compressor, for example, Japanese
Patent Unexamined Publication No. 2002-195160 discloses a
compressor equipped with a discharge valve system, which reduces
noise during operation and improves energy efficiency by reducing
loss at the time of opening and closing of a discharge reed.
[0003] Hereinafter, a conventional hermetic compressor is described
with reference to drawings.
[0004] FIG. 7 and FIG. 8 are a sectional view and a plan view
showing a conventional hermetic compressor, respectively. FIG. 9
and FIG. 10 are a side-sectional view and an exploded view showing
a discharge valve system of a conventional hermetic compressor,
respectively.
[0005] In FIGS. 7 to 10, hermetic container 1 includes discharge
tube 2 and suction tube 3 connected to a cooling system (not
shown). Furthermore, hermetic container 1 stores oil 4 in its
bottom portion, accommodates motor element 7 composed of stator 5
and rotor 6 and compressor element 8 driven by motor element 7. The
inside of hermetic container 1 is filled with refrigerant 9.
[0006] Next, a main configuration of compressor element 8 is
described.
[0007] Cylinder 10 includes substantially cylindrical compressing
chamber 11 and bearing 12. Valve plate 13 has discharge valve
system 14 at the outer side of cylinder 10 so as to close
compressing chamber 11. Head 15 covers valve plate 13. Suction
muffler 16 is opened in hermetic container 1 at one end and
communicates to compressing chamber 11 at another end. Crank shaft
17 has main shaft 18 and eccentric shaft 19, which is supported by
bearing 12 of the cylinder and to which rotor 6 is press-fitted and
fixed. Piston 20 is inserted into compressing chamber 11 in a way
in which it can sidably reciprocate and connected to eccentric
shaft 19 via connecting rod 21.
[0008] Next, discharge valve system 14 provided on compressor
element 8 is described referring to FIG. 9.
[0009] Valve plate 13 has concave portion 22 at the outer side of
cylinder 10. Concave portion 22 is provided with discharge hole 23
communicating to cylinder 10 and valve seat 24 formed so as to
surround discharge hole 23. Valve plate 13 is provided with
pedestal 25 formed on substantially the same plane as valve seat
24. Discharge reed 26, spring reed 27 and stopper 28 are fixed to
pedestal 25 by rivet 29 in this order.
[0010] Discharge reed 26 is formed of a tongue-shaped plate spring
material. Discharge reed 26 includes discharge reed holding portion
30 fixed to pedestal 25 and opening/closing portion 31 for opening
and closing valve seat 24.
[0011] Spring reed 27 is formed of a tongue-shaped plate spring
material. Spring reed 27 includes spring reed holding portion 32
fixed to pedestal 25 and movable portion 33, and has bending
portion 34 in the vicinity of the root of opening/closing portion
31 of discharge reed 26.
[0012] Stopper 28 includes stopper holding portion 35 fixed to
pedestal 25 and regulation portion 36 for regulating the movement
of discharge reed 26. Regulation portion 36 of stopper 28 is formed
substantially parallel in a cross sectional view to a plane
including valve seat 24 and pedestal 25.
[0013] Movable portion 33 of spring reed 27 is adjusted by
adjusting a bending angle of bending portion 34 so as to have
predetermined space between movable portion 33 and opening/closing
portion 31 of discharge reed 26 and between movable portion 33 and
regulation portion 36 of stopper 28.
[0014] Hereinafter, an operation of the above-configured hermetic
compressor is described.
[0015] When electricity is supplied to motor element 7, rotor 6 is
rotated and crank shaft 17 is driven to rotate. At this time, an
eccentric rotation movement of eccentric shaft 19 is transmitted to
piston 20 via connecting rod 21, and thereby piston 20 reciprocates
in compressing chamber 11.
[0016] Following the reciprocating movement of piston 20,
refrigerant 9 in hermetic container 1 is sucked from suction
muffler 16 into compressing chamber 11 and at the same time, low
pressure refrigerant 9 flows into hermetic container 1 from a
cooling system (not shown) though suction tube 3. Refrigerant 9
sucked into compressing chamber 11 is compressed and then
discharged into head 15 by way of discharge valve system 14 of
valve plate 13. Furthermore, high pressure gas discharged into head
15 is discharged from discharge tube 2 into a cooling system (not
shown).
[0017] However, there is a problem in a conventional hermetic
compressor that refrigerating capacity and efficiency vary
easily.
SUMMARY OF THE INVENTION
[0018] The present invention relates to a hermetic compressor
having a cylinder provided with a discharge valve system. The
discharge valve system includes a discharge reed having an
opening/closing portion and a discharge reed holding portion; a
spring reed having a movable portion and a spring reed holding
portion; and a stopper having a regulation portion and stopper
holding portion. The discharge reed, the spring reed and the
stopper are fixed to a pedestal of a valve plate in this order. In
a spring reed bending portion provided in the movable portion, the
movable portion is bent toward the direction of a valve seat. The
tip portion of the movable portion is brought into contact with a
plate contact portion. Space is provided between the movable
portion of the spring reed and the opening/closing portion of the
discharge reed, so that the both portions are not brought into
close contact with each other with oil, thus preventing the delay
in closing of the discharge reed. Furthermore, since the distance
of the space is stabilized in a state in which the tip portion is
brought into contact with the plate contact portion, an effect of
stabilizing the spring property of the discharge valve system is
obtained.
[0019] The hermetic compressor of the present invention can prevent
the discharge reed and the spring reed from being brought into dose
contact with each other and stabilize the spring property of the
discharge valve system. Therefore, the present invention can
provide a stable hermetic compressor with high energy
efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a sectional view showing a hermetic compressor in
accordance with an exemplary embodiment of the present
invention.
[0021] FIG. 2 is a plan view showing a hermetic compressor in
accordance with an exemplary embodiment of the present
invention.
[0022] FIG. 3 is a side sectional view showing a discharge valve
system when it is closed in accordance with an exemplary embodiment
of the present invention.
[0023] FIG. 4 is an exploded view showing a discharge valve system
in accordance with an exemplary embodiment of the present
invention.
[0024] FIG. 5 is a side sectional view showing a discharge valve
system when it is opened in accordance with an exemplary embodiment
of the present invention.
[0025] FIG. 6 is a graph showing a spring property of a discharge
valve system in accordance with an exemplary embodiment of the
present invention.
[0026] FIG. 7 is a sectional view showing a conventional hermetic
compressor.
[0027] FIG. 8 is a plan view showing a conventional hermetic
compressor.
[0028] FIG. 9 is a side sectional view showing a discharge valve
system of a conventional hermetic compressor.
[0029] FIG. 10 is an exploded view showing a discharge valve system
of a conventional hermetic compressor.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] The present inventors have found that in a conventional
hermetic compressor, right after the hermetic compressor starts to
be operated, a phenomenon sometimes occurs, in which a lower
refrigerating capacity as compared with a usual refrigerating
capacity is maintained for a relatively long time. The present
inventors have succeeded in elucidating the mechanism of discharge
reed 26 and spring reed 27 by analyzing the behaviors thereof.
Therefore, firstly, the mechanism is described with reference to
FIGS. 7 to 10. In FIG. 9, the direction in which the discharge reed
is closed is represented by "In" direction to cylinder 10 and the
direction in which the discharge reed is opened is represented by
"Out" direction to cylinder 10.
[0031] At the starting time of the hermetic compressor when this
low refrigerating capacity phenomenon easily occur, oil 4 together
with refrigerant 9 returns from a refrigerating cycle (not shown).
Then, since oil 4 together with refrigerant 9 is compressed and
discharged, much oil 4 intervenes between discharge reed 26 and
spring reed 27.
[0032] Furthermore, in general, when a hermetic compressor starts
to be operated, a suction pressure is high, refrigerant 9 with a
relatively high density is compressed and discharged until the
pressure in hermetic container 1 is reduced, and large load is
applied to opening/dosing portion 31 of discharge reed 26. On the
other hand, since the displacement of opening/closing portion 31 of
discharge reed 26 is regulated by regulation portion 36 of stopper
28, opening/closing portion 31 of discharge reed 26 is strongly
pressed by high density refrigerant 9 toward movable portion 33 of
spring reed 27 that is disposed between opening/dosing portion 31
of discharge reed 26 and regulation portion 36 of stopper 28.
[0033] Since large pressing load is applied as mentioned above,
opening/closing portion 31 of discharge reed 26 and movable portion
33 of spring reed 27 are brought into dose contact with each other
by oil 4. That is to say, discharge reed 26 and spring reed 27 are
integrated with each other and carry out an opening/dosing
operation as if one thick sheet of discharge reed carries out the
opening/dosing operation.
[0034] Herein, movable portion 33 of spring reed 27 is bent toward
the opening direction ("Out" direction) of discharge reed 26 at
bending portion 34. As a result, the spring force of spring reed 27
acts in the opening direction ("Out" direction) opposite to dosing
direction ("In" direction) in which discharge reed 26 is closed, so
that discharge reed 26 is pulled toward the opening direction
("Out" direction) and thus timing of dosing is delayed.
[0035] As a result, when piston 20 shifts to the suction stroke in
compressing chamber 11 after the upper dead center, the opening
time of discharge reed 26 is longer. During the time, inside
compressing chamber 11, high pressure refrigerant flows backward
and substantial displacement volume of the piston is decreased.
Consequently, a low refrigerating capacity phenomenon occurs.
[0036] During the occurrence of this low refrigerating capacity
phenomenon, the efficiency of a hermetic compressor is bad.
Consequently, power consumption is increased and at the same time,
cooling of refrigerating equipment on which this hermetic
compressor is mounted is decelerated.
[0037] Furthermore, since the space between movable portion 33 of
spring reed 27 and opening/closing portion 31 of discharge reed 26
is adjusted by adjusting a bending angle of bending portion 34 of
spring reed 27, the space between movable portion 33 of spring reed
27 and opening/dosing portion 31 of discharge reed 26 varies
easily. When discharge reed 26 is opened, the displacement varies
easily until discharge reed 26 is brought into contact with spring
reed 27. That is to say, an inflection point, in which the spring
force of discharge reed 26 shifts to the synthetic spring force of
discharge reed 26 and spring reed 27, varies, thus causing
variation in the spring property.
[0038] Therefore, it is thought that the opening amount and dosing
timing of discharge reed 26 easily vary, and as a result,
refrigerating capacity and efficiency may vary.
[0039] The present invention has been made based on the elucidation
of the mechanism of the above-mentioned low refrigerating capacity
phenomenon, and the present invention provides a stable hermetic
compressor in which delay in closing of a discharge reed hardly
occurs and energy efficiency is high.
[0040] The hermetic compressor of the present invention includes a
valve plate having a discharge valve system at the outer side of a
cylinder. The discharge valve system includes a discharge hole
formed in the valve plate; a valve seat provided around the
discharge hole on the outer side of the valve plate; a pedestal
formed in substantially the same height as that of the valve seat
on the outer side of the valve plate; a plate contact portion
formed on the valve plate at a position that is higher than the
valve seat on the outer side of the valve plate; a discharge reed
made of a plate spring material having the opening/closing portion
covering the discharge hole in a way of capable of opening and
closing thereof, a spring reed made of a plate spring material
provided at the outer side of the discharge reed; and a stopper
provided at the outer side of the spring reed. The spring reed has
a spring reed bending portion and a tip portion in the movable
portion. In the spring reed bending portion, the spring reed is
bent toward the direction of the valve seat and the tip portion
thereof is brought into contact with the plate contact portion.
[0041] Even when oil intervenes between the discharge reed and the
spring reed and excessive load is applied to the discharge reed at
the starting time, etc., since space is formed with respect to the
discharge reed in the position corresponding to the discharge reed
opening/closing portion, close contact due to the intervening oil
can be prevented. Furthermore, since the distance of the space is
stabilized in a state which is brought into contact with the plate
contact portion, the spring property of the discharge valve system
can be stabilized. Thus, a stable hermetic compressor with high
energy efficiency can be provided.
[0042] Hereinafter, an exemplary embodiment of the present
invention is described with reference to drawings.
Exemplary Embodiment
[0043] FIG. 1 and FIG. 2 are a sectional view and a plan view
showing a hermetic compressor in accordance with an exemplary
embodiment of the present invention, respectively. FIG. 3 is a side
sectional view showing a discharge valve system when it is closed
in accordance with the exemplary embodiment of the present
invention; FIG. 4 is an exploded view showing the discharge valve
system; FIG. 5 is a side sectional view showing the discharge valve
system when it is opened; and FIG. 6 is a graph showing a spring
property of the discharge valve system. In FIGS. 1 and 2, the
direction in which the discharge reed is closed is represented by
"In" direction to the cylinder and the direction in which the
discharge reed is opened is represented by "Out" direction to the
cylinder.
[0044] In FIGS. 1 to 6, hermetic container 101 includes discharge
tube 102 and suction tube 103 connected to a cooling system (not
shown) and stores oil 104 in its bottom portion. Furthermore,
hermetic container 101 accommodates motor element 107 composed of
stator 105 and rotor 106 and compressor element 108 driven by motor
element 107. The inside of hermetic container 101 is filled with
refrigerant 109. It is preferable that refrigerant 109 to be used
is refrigerant that measures with environmental problem of recent
years and is other than specified chlorofluorocarbons. For example,
R134a, natural refrigerant R600a, and the like, are preferable as
refrigerant 109.
[0045] Next, a main configuration of compressor element 108 is
described.
[0046] Cylinder 110 includes substantially cylindrical compressing
chamber 111 and bearing 112. Valve plate 113 has discharge valve
system 114 on the outer side of cylinder 110 (side of "Out") so as
to close compressing chamber 111. Head 115 covers valve plate 113.
Suction muffler 116 is opened in hermetic container 101 at one end
and communicates to compressing chamber 111 at another end. Crank
shaft 117 has main shaft 118 and eccentric shaft 119, which is
supported by bearing 112 of cylinder 110 and press-fitted and fixed
into stator 105. Piston 120 is inserted into compressing chamber
111 in a way in which it can sidably reciprocate and connected to
eccentric shaft 119 via connecting rod 121.
[0047] Next, discharge valve system 114 provided on compressor
element 108 is described referring to FIG. 3.
[0048] Valve plate 113 has recess 122 at the outer side of cylinder
110 (side of "Out"). Recess 122 is provided with discharge hole 123
penetrating through valve plate 113 and communicating to cylinder
110, and with valve seat 124 surrounding discharge hole 123. Valve
plate 113 is further provided with pedestal 125 formed on the side
of "Out" in substantially the same plane as valve seat 124, and
with plate contact portion 126. Plate contact portion 126 is formed
substantially parallel to a plane including valve seat 124 and
pedestal 125 in the cross sectional view.
[0049] Discharge reed 127, spring reed 128 and stopper 129 are
fixed to pedestal 125 by rivet 130 in this order. Discharge reed (
as a first plate spring) 127 is formed of a tongue-shaped plate
spring material and includes discharge reed holding portion 131
fixed to pedestal 125 and opening/closing portion 132 for opening
and dosing the valve seat 124.
[0050] Spring reed (as a second plate spring) 128 is formed of a
tongue-shaped plate spring material and includes spring reed
holding portion 133 fixed to pedestal 125 and movable portion 134.
Movable portion 134 is bent toward the direction of valve seat 124
("In" direction) at spring reed bending portion 135 provided in
movable portion 134. Tip portion 136 is brought into contact with
plate contact portion 126 of the valve plate.
[0051] Stopper 129 includes stopper holding portion 137 fixed to
pedestal 125 and regulation portion 138 for regulating the movement
of discharge reed 127. Regulation portion 138 of stopper 129 is
formed substantially parallel to a plane including valve seat 124
and pedestal 125. That is to say, the surface of regulation portion
138 is substantially parallel to valve seat 124 and pedestal
125.
[0052] Height of plate contact portion 126 provided in valve plate
113 is set so that movable portion 134 of spring reed 128 has space
between movable portion 134 and opening/closing portion 132 of
discharge reed 127 and between movable portion 134 and regulation
portion 138 of stopper 129 stably.
[0053] Opening/dosing portion 132 of discharge reed 127 is bent
toward the direction of valve seat 124 at discharge reed bending
portion 139.
[0054] Between valve seat 124 and pedestal 125, a portion that is
deeper than pedestal 125 is provided as clearance groove 140.
Discharge reed bending portion 139 is located in a region of
clearance groove 140 at the outer side of clearance groove 140.
That is to say, a concave portion formed on the surface of valve
plate 113 forms clearance groove 140 and the bottom surface of the
concave portion is formed lower in height than valve seat 124 and
pedestal 125.
[0055] Regulation portion 138 of stopper 129 is provided at the tip
with stopper contact portion 141 formed of a surface that bends
toward spring reed 128. Stopper contact portion 141 is formed
substantially parallel to a plane including valve seat 124 and
pedestal 125. That is to say, stopper contact portion 141 is
substantially parallel to plate contact portion 126.
[0056] Hereinafter, an operation and effect of the above-configured
hermetic compressor is described.
[0057] When electricity is supplied to motor element 107, rotor 106
is rotated and crank shaft 117 is driven to rotate. At this time,
an eccentric rotation movement of eccentric shaft 119 is
transmitted to piston 120 via connecting rod 121, and thereby
piston 120 reciprocates in compressing chamber 111.
[0058] Following the reciprocating movement of piston 120,
refrigerant 109 in hermetic container 101 is sucked from suction
muffler 116 into compressing chamber 111 and at the same time, low
pressure refrigerant 109 flows into hermetic container 101 from a
cooling system (not shown) though suction tube 103. Refrigerant 109
sucked into compressing chamber 111 is compressed and then
discharged into head 115 by way of discharge valve system 114 of
valve plate 113. Furthermore, high pressure gas discharged into
head 115 is discharged from discharge tube 102 into a cooling
system (not shown).
[0059] Herein, at the starting time of a hermetic compressor, oil
104 together with refrigerant 109 returns from a refrigerating
cycle (not shown). Then, since oil 104 together with refrigerant
109 is compressed and discharged, much oil 104 intervenes between
discharge reed 127 and spring reed 128.
[0060] Furthermore, in general, when a hermetic compressor started
to be operated, a suction pressure is high. Therefore, refrigerant
109 with a relatively high density is compressed and discharged
until the pressure of hermetic container 1 is reduced, and large
load is applied to opening/dosing portion 132 of discharge reed
127.
[0061] On the other hand, since the displacement of opening/closing
portion 132 of discharge reed 127 is regulated by regulation
portion 138 of stopper 129, opening/closing portion 132 of
discharge reed 127 is strongly pressed by high density refrigerant
109 toward movable portion 134 of spring reed 128 disposed between
opening/dosing portion 132 of discharge reed 127 and regulation
portion 138 of stopper 129. As a result, opening/closing portion
132 of discharge reed 127 and movable portion 134 of spring reed
128 tend to be brought into close contact with each other with oil
104.
[0062] However, in the first exemplary embodiment, since spring
reed bending portion 135 is formed in movable portion 134 of spring
reed 128, even when spring reed 128 is pressed to the "Out" side,
between opening/closing portion 132 of discharge reed 127 and
movable portion 134 of spring reed 128, as shown in FIG. 5, space
142 is formed. Since space 142 exists, even if movable portion 134
of spring reed 128 and opening/closing portion 132 of discharge
reed 127 are brought into close contact with each other, they can
easily be peeled off from each other. That is to say, the close
contact is not continued and spring reed 128 and discharge reed 127
are not operated integrally. Therefore, delay in closing can be
prevented.
[0063] As a result, a low refrigerating capacity phenomenon caused
by the backflow of high pressure refrigerant into compressing
chamber 111 can be prevented.
[0064] When spring reed 128 is not pressed toward the "Out" side,
as shown in FIG. 3, tip portion 136 of spring reed 128 is brought
into contact with plate contact portion 126 provided in valve plate
113. Therefore, movable portion 134 of spring reed 128 can have
space stably between movable portion 134 and opening/closing
portion 132 of discharge reed 127. When discharge reed 127 opens in
the "Out" direction, the displacement until it is brought into
contact with spring reed 128 becomes stable. That it to say, it is
possible to suppress variation in the inflection points at which
the spring force of discharge reed 127 shifts to the synthetic
spring force of discharge reed 127 and spring reed 128, thus
stabilizing the spring property.
[0065] As a result, variation in opening amount of discharge reed
127 and closing timing is suppressed and thus the refrigerating
capacity and efficiency can be stabilized.
[0066] Therefore, it is possible to provide a stable hermetic
compressor having small variation and high energy efficiency.
[0067] Furthermore, since opening/closing portion 132 of discharge
reed 127 is bent toward valve seat 124 at discharge reed bending
portion 139, spring force for pressing to valve seat 124 is applied
to opening/closing portion 132 of discharge reed 127.
[0068] Therefore, opening/closing portion 132 of discharge reed 127
can be prevented from floating from valve seat 124, and thus more
excellent sealing property can be maintained. Thus, it is possible
to provide a hermetic compressor with higher energy efficiency.
[0069] Furthermore, between valve seat 124 and pedestal 125, a
recess portion that is deeper than pedestal 125 is provided as
clearance groove 140. Since discharge reed bending portion 139 is
located corresponding to the outer side of clearance groove 140, it
is possible to prevent clearance groove 140 from being pressed by
pedestal 125 and spring force of spring reed 128. As a result, the
force by which opening/closing portion 132 of discharge reed 127 is
pressed to valve seat 124 can be obtained stably. Sealing property
between opening/closing portion 132 and valve seat 124 is improved.
Thus, efficiency can be further improved.
[0070] Furthermore, according to the exemplary embodiment,
regulation portion 138 of stopper 129 is provided with stopper
contact portion 141 bending toward spring reed 128. Therefore, even
after spring reed 128 is brought into contact with stopper contact
portion 141, discharge reed 127 can be further displaced. As a
result, the spring property of discharge reed 127 has two
inflection points as shown in FIG. 6, three stages of properties
can be obtained.
[0071] In FIG. 6, first inflection point P1 corresponds to a point
at which opening/closing portion 132 of reed 127 is brought into
contact with movable portion 134 of spring reed 128. After first
inflection point P1 and before second inflection point P2,
synthetic spring force of opening/dosing portion 132 of spring reed
127 and movable portion 134 of spring reed 128 can be obtained.
[0072] Second inflection point P2 corresponds to a point at which
movable portion 134 of spring reed 128 is brought into contact with
stopper contact portion 141 of stopper 129. After second inflection
point P2, a supporting mechanism of the spring reed is changed from
cantilever type to dual support type, so that the spring force is
further increased.
[0073] As mentioned above, since two inflection points and three
stages of properties are obtained, as the opening amount of
discharge reed 127 becomes larger, the spring force works more
strongly and the closing speed is increased. Thus, even in a high
circulation region in which discharge reed 127 opens largely, few
delay in closing occurs. It is possible to provide a hermetic
compressor with high energy efficiency.
INDUSTRIAL APPLICABILITY
[0074] As mentioned above, the present invention can provide a
stable hermetic compressor having high energy efficiency in which
the delay in dosing of discharge reed hardly occurs even in a case
where the circulation amount of refrigerant is relatively large.
Therefore, the hermetic compressor in accordance with the present
invention can be used for refrigerating and air-conditioning
equipment using CO.sub.2 refrigerant.
REFERENCE MARKS IN THE DRAWINGS
[0075] 101 hermetic container
[0076] 104 oil
[0077] 108 compressor element
[0078] 110 cylinder
[0079] 113 valve plate
[0080] 114 discharge valve system
[0081] 120 piston
[0082] 122 recess
[0083] 123 discharge hole
[0084] 124 valve seat
[0085] 125 pedestal
[0086] 126 plate contact portion
[0087] 127 discharge reed
[0088] 128 spring reed
[0089] 129 stopper
[0090] 130 rivet
[0091] 131 discharge reed holding portion
[0092] 132 opening/closing portion
[0093] 133 spring reed holding portion
[0094] 134 movable portion
[0095] 135 spring reed bending portion
[0096] 136 tip portion
[0097] 137 stopper holding portion
[0098] 138 regulation portion
[0099] 139 discharge reed bending portion
[0100] 140 clearance groove (concave portion)
[0101] 141 stopper contact portion
[0102] 142 space
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