U.S. patent application number 11/407352 was filed with the patent office on 2007-10-04 for reciprocating compressor.
Invention is credited to Tsuyoshi Ohyama, Hideaki Tsukamoto, Ryuji Watanabe.
Application Number | 20070231167 11/407352 |
Document ID | / |
Family ID | 38559204 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070231167 |
Kind Code |
A1 |
Tsukamoto; Hideaki ; et
al. |
October 4, 2007 |
Reciprocating compressor
Abstract
A reciprocating compressor is disclosed which has a valve
construction using plural discharge ports, plural reed valves and
plural valve backers to lower the discharge resistance and improve
the compression efficiency. The reciprocating compressor (1000) has
within a closed vessel (900) a reciprocating compressing section
(300) for compressing a required fluid, the reciprocating
compressing section (300) comprising a discharge unit for
discharging the fluid and a valve assembly (500) for opening and
closing the discharge unit, with a plurality of discharge ports
(522A, 522B) being formed in the valve assembly, the valve assembly
(500) comprising valve members (560), the valve members (560)
comprising reed valves (530A, 530B) disposed correspondingly to the
discharge ports (522A, 522B) and valve backers (540A, 540B)
disposed respectively on back sides of the reed valves, a valve
seat (520) having a recess for receiving the valve members therein,
and valve members fixing means for urging end sides of the valve
members to fix the valve members elastically to fixing portions
(523A, 523B) of the recess.
Inventors: |
Tsukamoto; Hideaki;
(Saitama-ken, JP) ; Watanabe; Ryuji; (Gunma-ken,
JP) ; Ohyama; Tsuyoshi; (Gunma-ken, JP) |
Correspondence
Address: |
WEINGARTEN, SCHURGIN, GAGNEBIN & LEBOVICI LLP
TEN POST OFFICE SQUARE
BOSTON
MA
02109
US
|
Family ID: |
38559204 |
Appl. No.: |
11/407352 |
Filed: |
April 19, 2006 |
Current U.S.
Class: |
417/571 |
Current CPC
Class: |
F04B 39/1073
20130101 |
Class at
Publication: |
417/571 |
International
Class: |
F04B 39/10 20060101
F04B039/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2006 |
JP |
2006-099550 |
Claims
1. A reciprocating compressor having within a closed vessel a
reciprocating compressing section for compressing a required fluid,
said reciprocating compressing section comprising a discharge unit
for discharging said fluid and a valve assembly for opening and
closing said discharge unit, with a plurality of discharge ports
being formed in said valve assembly, said valve assembly comprising
valve members, said valve members comprising reed valves disposed
correspondingly to said discharge ports and valve backers disposed
respectively on back sides of said reed valves, a valve seat having
a recess for receiving said valve members therein, and valve
members fixing means for urging end sides of said valve members to
fix said valve members elastically to fixing portions of said
recess.
2. The reciprocating compressor according to claim 1, wherein: said
reed valves are each formed in a shape comprising fulcrum portions
projecting to both sides in the associated one of said fixing
portions, an intermediate portion projecting in a perpendicular or
oblique direction with respect to a line joining said fulcrum
portions, and a lid portion for closing the associated one of said
discharge ports, said lid portion lying on the side opposite to
said fulcrum portions with respect to said intermediate portion,
said fulcrum portions, said intermediate portion and said lid
portion being integral with one another, and said valve backers are
each formed in a shape comprising the same fulcrum portions as
those of each said reed valve, an intermediate portion having a
gradually narrowing portion projecting in an oblique direction with
respect to a line joining said fulcrum portions, and an opposite
end portion narrower than said lid portion of each said reed valve,
said fulcrum portions, said intermediate portion and said opposite
end portion being integral with one another.
3. The reciprocating compressor according to claim 2, wherein said
reed valves are disposed in such a manner that said lid portions of
said reed valves are positioned centrally and said fulcrum portions
of one of said reed valves and said fulcrum portions of the other
reed valve are positioned outside said lid portions, and said valve
backers are disposed in such a manner that said intermediate
portions of said valve backers are positioned in directions
different from each other with respect to said line joining said
fulcrum portions.
4. The reciprocating compressor according to claim 2, wherein said
valve members fixing means is formed in a shape comprising fixing
portions for fixing said fulcrum portions of said valve members to
said fixing portions of said recess and a spring portion for
connecting said fixing portions of said valve members fixing means
with each other and for urging said fulcrum portions of said valve
members elastically to said fixing portions of said recess, said
fixing portions and said spring portion being integral with each
other.
5. The reciprocating compressor according to claim 3, wherein said
valve members fixing means is formed in a shape comprising fixing
portions for fixing said fulcrum portions of said valve members to
said fixing portions of said recess and a spring portion for
connecting said fixing portions of said valve members fixing means
with each other and for urging said fulcrum portions of said valve
members elastically to said fixing portions of said recess, said
fixing portions and said spring portion being integral with each
other.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a reciprocating compressor
to be used, for example, for compressing a refrigerant in a home
refrigerator. Particularly, the present invention is concerned with
an improvement of a valve assembly portion which is for opening and
closing a discharge unit in a compressing section.
[0003] 2. Description of the Prior Art
[0004] A reciprocating compressor of this type has such a schematic
construction as FIG. 1 which illustrates a compressor 1000.
[0005] In FIG. 1, the compressor 1000 comprises an assembly.
According to the construction of this assembly, a motor section 200
is driven by electric power fed from a power dispatching section
100 which supplies electric power 101. A reciprocating compressing
section 300 is connected to the motor section 200 to compress a
refrigerant fluid which is introduced from an intake path 601 in an
intake section 600 through a valve assembly 500. The refrigerant
fluid thus compressed is discharged from a discharge path 701 in a
discharge section 700. The assembly thus constructed is mounted and
accommodated in the interior of a closed vessel 900 elastically by
means of a buffer/support section 800.
[0006] Further, there is provided a construction whereby
lubricating oil 401 stored in the bottom of the closed vessel 900
is circulated for lubrication to a mechanical kinetic portion
between the motor section 200 and the reciprocating compressing
section 300 by means of an oil feeder 400. Various proposals have
been made about concrete structures of various portions in the
above construction of the compressor (see Japanese Patent
Publication No. H04(1992)-4894).
[0007] Since a piston reciprocates at a high speed of about 3,000
rpm, various improvements have been made in connection with the
construction of the valve assembly 500. For example, there has been
proposed a construction using a valve assembly, the valve assembly
being provided with a thick plate as a restriction piece having an
appropriate divergent angle, the restriction piece being disposed
on a back side of a reed valve which is for opening and closing a
discharge port, whereby not only the degree of opening of the reed
valve is restricted but also the return speed of the reed valve is
increased to improve the compressing efficiency (see Japanese
Utility Model Publication No. H02(1990)-25986).
[0008] There also has been proposed a construction using a valve
assembly wherein a reed valve and a plate spring as a restriction
piece superimposed on a back side of the reed valve are disposed
within a recess of a valve seat, and about half of a portion which
covers a discharge port of the reed valve is covered with the
restriction piece, whereby the reed valve opens while having a
twisted surface, a fluid discharge direction is set toward an
outlet by the twisted surface, and the closing speed is increased
by a return stress of twist (see U.S. Pat. No. 4,723,896).
[0009] However, all of the above conventional valve assemblies
adopt a valve construction comprising one discharge port, one reed
valve for opening and closing the discharge port, and one
restriction piece disposed on the back side of the reed valve.
Therefore, in a compressor provided with such a valve assembly, the
discharge resistance is still high, resulting in a lowering of the
compression efficiency, and thus there has been room for
improvement.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide a
reciprocating compressor using a valve construction provided with
plural discharge ports, reed valves and restriction/repulsion
pieces (hereinafter referred to as "valve backers"), thereby
decreasing the discharge resistance and improving the compression
efficiency.
[0011] For achieving the above-mentioned object, in one aspect of
the present invention there is provided a reciprocating compressor
having within a closed vessel a reciprocating compressing section
for compressing a required fluid, the reciprocating compressing
section comprising a discharge unit for discharging the fluid and a
valve assembly for opening and closing the discharge unit, with a
plurality of discharge ports being formed in the valve assembly,
the valve assembly comprising valve members, the valve members
comprising reed valves disposed correspondingly to the discharge
ports and valve backers disposed respectively on back sides of the
reed valves, a valve seat having a recess for receiving the valve
members therein, and valve members fixing means for urging end
sides of the valve members to fix the valve members elastically to
fixing portions of the recess.
[0012] In a second aspect of the present invention there is
provided, in combination with the above first aspect, a
reciprocating compressor wherein the reed valves are each formed in
a shape comprising fulcrum portions projecting to both sides in the
associated one of the fixing portions, an intermediate portion
projecting in a perpendicular or oblique direction with respect to
a line joining the fulcrum portions, and a lid portion for closing
the associated one of the discharge ports, the lid portion lying on
the side opposite to the fulcrum portions with respect to the
intermediate portion, the fulcrum portions, the intermediate
portion and the lid portion being integral with one another, and
the valve backers are each formed in a shape comprising the same
fulcrum portions as those of each of the reed valves, an
intermediate portion having a gradually narrowing portion
projecting in an oblique direction with respect to a line joining
the fulcrum portions, and an opposite end portion narrower than the
lid portion of each of the reed valves, the fulcrum portions, the
intermediate portion and the opposite end portion being integral
with one another.
[0013] In a third aspect of the present invention there is
provided, in combination with the above second aspect, a
reciprocating compressor wherein the reed valves are disposed in
such a manner that the lid portions of the reed valves are
positioned centrally and the fulcrum portions of one of the reed
valves and the fulcrum portions of the other reed valve are
positioned outside the lid portions, and the valve backers are
disposed in such a manner that the intermediate portions of the
valve backers are positioned in directions different from each
other with respect to the line joining the fulcrum portions.
[0014] In a fourth aspect of the present invention there is
provided, in combination with the above second or third aspect, a
reciprocating compressor wherein the valve members fixing means is
formed in a shape comprising fixing portions for fixing the fulcrum
portions of the valve members to the fixing portions of the recess
and a spring portion for connecting the fixing portions of the
valve members fixing means with each other and for urging the
fulcrum portions of the valve members elastically to the fixing
portions of the recess, the fixing portions and the spring portion
being integral with each other.
[0015] Thus, the reciprocating compressor in the above first aspect
of the present invention has within a closed vessel a reciprocating
compressing section for compressing a required fluid, the
reciprocating compressing section comprising a discharge unit for
discharging the fluid and a valve assembly for opening and closing
the discharge unit, with a plurality of discharge ports being
formed in the valve assembly, the valve assembly comprising valve
members, the valve members comprising reed valves disposed
correspondingly to the discharge ports and valve backers disposed
respectively on back sides of the reed valves, a valve seat having
a recess for receiving the valve members therein, and valve members
fixing means for urging end sides of the valve members to fix the
valve members elastically to fixing portions of the recess.
[0016] With the valve members fixing means, the valve members can
be fixed elastically to the fixing portions of the recess.
Moreover, with the elasticity of the valve backers, restriction and
repulsive return of the reed valves are performed to afford an
effect of enhancing the efficiency of a pressurizing operation.
Further, since the valve assembly adopted uses a valve construction
provided with plural discharge ports and also provided
correspondingly with reed valves and valve backers, there is
attained an outstanding effect such that it is possible to lower
the discharge resistance and improve the compression
efficiency.
[0017] According to the reciprocating compressor in the above
second aspect of the present invention, in combination with the
above first aspect, the reed valves are each formed in a shape
comprising fulcrum portions projecting to both sides in the
associated one of the fixing portions, an intermediate portion
projecting in a perpendicular or oblique direction with respect to
a line joining the fulcrum portions, and a lid portion for closing
the associated one of the discharge ports, the lid portion lying on
the side opposite to the fulcrum portions with respect to the
intermediate portion, the fulcrum portions, the intermediate
portion and the lid portion being integral with one another, and
the valve backers are each formed in a shape comprising the same
fulcrum portions as those of each of the reed valves, an
intermediate portion having a gradually narrowing portion
projecting in an oblique direction with respect to a line joining
the fulcrum portions, and an opposite end portion narrower than the
lid portion of each of the reed valves, the fulcrum portions, the
intermediate portion and the opposite end portion being integral
with one another.
[0018] By disposing the fulcrum portions in the fixing portions of
the recess through the valve members fixing means, it is possible
to fix the valve members easily and positively. Besides, the reed
valves when opened can each be allowed to perform such a motion as
the letter S being stretched obliquely and the head portion
twisted. In resistance to such a cubically complicated way of
bending an internal stress is stored in the reed valves themselves
and the valve backers, and with the resulting repulsive force it is
possible to further increase the reed valve return speed, thus
affording a further outstanding effect that the compression
efficiency can be further improved.
[0019] According to the reciprocating compressor in the above third
aspect of the present invention, in combination with the above
second aspect, the reed valves are disposed in such a manner that
the lid portions of the reed valves are positioned centrally and
the fulcrum portions of one of the reed valves and the fulcrum
portions of the other reed valve are positioned outside the lid
portions, and the valve backers are disposed in such a manner that
the intermediate portions of the valve backers are positioned in
directions different from each other with respect to the line
joining the fulcrum portions.
[0020] Since the reed valves open while being bent in opposite
directions, the collision of refrigerant gases discharged from the
reed valves is diminished and the discharge resistance is made
still lower, thus affording a further outstanding effect that the
compression efficiency can be further improved.
[0021] According to the reciprocating compressor in the above
fourth aspect of the present invention, in combination with the
above second or third aspect, the valve members fixing means is
formed in a shape comprising fixing portions for fixing the fulcrum
portions of the valve members to the fixing portions of the recess
and a spring portion for connecting the fixing portions of the
valve members fixing means with each other and for urging the
fulcrum portions of the valve members elastically to the fixing
portions of the recess, the fixing portions and the spring portion
being integral with each other.
[0022] There can be obtained a further outstanding effect that the
valve members can be fixed to the aforesaid recess easily and
positively by one valve members fixing means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a block diagram showing an entire construction
common to both a reciprocating compressor according to an
embodiment of the present invention and the prior art;
[0024] FIG. 2 is a sectional view showing an entire construction of
the embodiment of the present invention in an exploded state;
[0025] FIG. 3 is a perspective view partly in section, showing an
entire construction of the embodiment of the present invention in
an assembled state of various constituent portions;
[0026] FIG. 4 is an enlarged diagram showing principal portions of
FIG. 2 in detail;
[0027] FIG. 5 is an explanatory diagram showing an assembled state
of various portions related to a valve assembly used in the
embodiment of the present invention;
[0028] FIG. 6(A) is an explanatory plan view showing an assembled
state of various portions related to the valve assembly in the
embodiment of the present invention, FIG. 6(B) is an explanatory
plan view showing in detail principal portions of reed valves and
valve backers shown in FIG. 6(A), and FIG. 6(C) is an explanatory
plan view showing a state in which valve backers are disposed on
back sides of the reed valves respectively;
[0029] FIG. 7 is an explanatory sectional view taken on line A-A in
FIG. 6(A); and
[0030] FIG. 8 is an explanatory diagram showing a state in which a
valve backer is disposed on the back side of a reed valve.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0031] A reciprocating compressor according to an embodiment of the
present invention will be described in detail hereinunder with
reference to the accompanying drawings.
[0032] FIG. 1 is a block diagram showing an entire construction
common to both a reciprocating compressor according to an
embodiment of the present invention, FIG. 2 is a sectional view
showing an entire construction of the embodiment of the present
invention in an exploded state, FIG. 3 is a perspective view partly
in section, showing an entire construction in an assembled state of
various constituent portions, FIG. 4 is an enlarged diagram showing
principal portions of FIG. 2 in detail, FIG. 5 is an explanatory
diagram showing an assembled state of various portions related to a
valve assembly used in the embodiment of the present invention,
FIG. 6(A) is an explanatory plan view showing an assembled state of
various portions related to the valve assembly in the embodiment of
the present invention, FIG. 6(B) is an explanatory plan view
showing in detail principal portions of reed valves and valve
backers shown in FIG. 6(A), and FIG. 6(C) is an explanatory plan
view showing a state in which valve backers are disposed on back
sides of the reed valves respectively, FIG. 7 is a sectional view
taken on line A-A in FIG. 6(A), and FIG. 8 is an explanatory
diagram showing a state in which a valve backer is disposed on the
back side of a reed valve.
[0033] Functional portions represented by reference numerals are
assembled by combinations indicated with fine lines and chain lines
and are mounted and fixed or engaged using set screws and retaining
springs. In the accompanying drawings, portions of the same
reference numerals represent portions having the same functions,
and portions of the same reference numerals as in FIG. 1 represent
portions having the same functions as those of the portions of the
same reference numerals illustrated in FIG. 1.
[0034] In FIGS. 1 to 3, a stator 210, a rotor 220, a rotatable
shaft 230 and a bearing 240 are assembled together to constitute a
motor section 200, which is connected to a power dispatching
section 100. A buffer/support section 800 is constituted by a
helical spring or the like.
[0035] A crescent balancing plate 231 is integrally formed at a
lower end portion of the rotatable shaft 230 in the motor section
200 and an eccentric pin 310 is disposed on the side opposite to
the crescent balancing plate 231, thereby constituting a motion
mechanism for making the eccentric pin 310 perform a motion which
describes a circular path.
[0036] A motion mechanism which is driven by the eccentric pin 310
to create a linear reciprocating motion is constituted within a
T-shaped crank tube 330, and a piston 340 reciprocates within a
cylinder bore of a cylinder 350 to effect a compression action. A
reciprocating compressing section 300 is constituted by the
portions from the eccentric pin 310 to the cylinder 350.
[0037] A valve assembly 500, which is mounted in contact with the
cylinder 350, is mainly composed of a gasket 551, an intake-side
valve member 510, a valve seat 520, two reed valves 530, two valve
backers 540, valve members fixing means 570, and a gasket 550.
These portions are sandwiched in between an end face 352 of the
cylinder 350 which constitutes the reciprocating compressing
section 300 and an end face 713 of a head muffler member 710 which
constitutes a discharge section 700, and are then fixed with screws
for assembly. Thus, the portions in question are held grippingly
and fixed between the end face 352 of the cylinder 350 and the
muffler member 710 of the discharge section 700.
[0038] The reference numeral 600 denotes an intake section. A
refrigerant fluid introduced from an intake path 601 passes through
a muffler (not shown) provided with a filter for filtering
admixtures, etc. received in a conduit of an object of utilization,
further passes through a resonance chamber, and is introduced into
the valve assembly 500.
[0039] As the solvent used in this embodiment there is used an HFC
refrigerant, e.g., R134a.
[0040] On the other hand, the refrigerant fluid after compression
passes through the valve assembly 500 and then through plural
mufflers 720 having resonance chambers adapted to resonate with a
fluid vibration of a different frequency for deadening a sound,
then passes through a path extending from a discharge pipe (not
shown) to a discharge path 701. In this way there is constituted a
discharge section 700.
[0041] After assembly of the above constituent portions, an upper
vessel 920 of a closed vessel 900 is fitted in a lower vessel 910
in a hermetically sealed state, whereby there is provided an
integrated, hermetically sealed, reciprocating compressor 1000, as
shown in FIG. 3. In this state, lubricating oil 401 is charged
through a charging pipe 402 into the lower vessel 910. An oil
feeder 400 is constituted so as to suck up the lubricating oil 401
by high-speed rotation of the rotatable shaft 230 and circulate it
to various constituent portions.
[0042] Numeral 360 denotes an intra-case discharge pipe for
discharging a portion of the compressed refrigerant into the closed
vessel 900 to increase the internal pressure to a high level.
[0043] Next, detailed portions of the valve assembly 500 will be
described below with reference to FIGS. 4 to 8.
[0044] As shown in FIG. 4, the valve assembly 500, which is mounted
in contact with the cylinder 350, is mainly composed of a gasket
551, an intake-side valve member 510, a valve seat 520, two reed
valves 530A, 530B, two valve backers 540A, 540B, valve members
fixing means 570, and a gasket 550.
[0045] These portions are sandwiched in between the end face 352 of
the cylinder 350 which constitutes the reciprocating compressing
section 300 and the end face 713 of the muffler 710 which
constitutes the discharge section 700, and are then fixed with
screws and assembled. Further, an intake path extending along an
arrow from the right to the left in FIG. 4 and a discharge path
extending along an arrow from the left to the right in the same
figure are formed.
[0046] More specifically, there are provided two discharge ports
522A and 522B from which the refrigerant is discharged with a
high-speed reciprocating motion of the piston 340 within the
cylinder 350. The reed valves 530A and 530B are for opening and
closing the discharge ports 522A and 522B and the valve backers
540A and 540B, which are for restriction and repulsion of openings
of the reed valves 530A and 530B, are disposed respectively on back
sides of the reed valves 530A and 530B to constitute valve members
560. The valve members 560 are received in predetermined positions
(523A, 523B) of a recess 523 formed in the valve seat 520.
Thereafter, end sides of the valve members 260 are urged by the
valve members fixing means 570 to fix the valve members elastically
to predetermined fixing portions (523A, 523B) of the recess 523
(see FIGS. 5 to 7).
[0047] The gasket 551 is interposed between the cylinder 350 and
the intake-side valve element 510 and is formed by forming a resin
plate, e.g., a fiber-filled butyl rubber plate, into the
illustrated shape. The gasket 551 is provided on its outer
periphery with a peripheral edge portion for closing the peripheral
portion between it and the cylinder 350, as well as the intake-side
valve element 510, and is also provided with an intake/discharge
passage 551A.
[0048] The intake-side valve member 510 comprises a reed valve 511,
the reed valve 511 being formed by forming a slit near the center
of a planar plate spring, e.g., a stainless steel plate spring
having both surfaces polished, and discharge holes 512A and 512B
formed outside a base portion of the reed valve 511, the discharge
holes 512A and 512B being a little larger than the discharge ports
522A and 522B of the valve seat 520.
[0049] The reed valves 530A and 530B are each formed by forming a
planar plate spring, e.g., a thin stainless steel plate spring
having both surfaces polished, into the illustrated shape.
According to this shape, as shown in FIG. 6(B), two fulcrum
portions 531 and 532 projecting to both sides are formed at one end
corresponding to a lead valve fixing portion 535, an intermediate
portion 533 extends along a center line (y) which is perpendicular
to a center line (x) joining the two fulcrums, and a lid portion
534 having a diameter able to close the associated one of the
discharge ports 522A and 522B is formed at an opposite end opposite
to the one end with respect to the intermediate portion 533.
[0050] As shown in FIGS. 5 to 7, the reed valves 530A and 530B are
disposed in the predetermined fixing portions (523A, 523B) of the
recess 523 in such a manner that the lid portions 534 of the reed
valves 530A and 530B are positioned centrally, while the fulcrum
portions 531 and 532 of one reed valve 530A and the fulcrum
portions 531 and 532 of the other reed valve 530B are positioned
outside the lid portions 534. The valve backers 540A and 540B are
disposed in such a manner that intermediate portions 543 of the
valve backers 540A and 540B are positioned in different directions
with respect to lines joining fulcrum portions 541 and 542 of the
valve backers 540A and 540B.
[0051] A description will now be given about the valve backer 540A.
According to the shape of the valve backer 540A, as shown in FIGS.
6(A) to 6(C), the intermediate portion 543 extends along a center
line (z) which is oblique at an angle of .theta. relative to a
center line (y) perpendicular to a center line (x) joining the
fulcrum portions 541 and 542, and an opposite end portion 544 is
formed on an opposite end side opposite to the fulcrum portions
side with respect to the intermediate portion 543. FIG. 6(C) shows
a state in which the valve backers 540A and 540B are disposed on
back sides of the reed valves 530A and 530B respectively.
[0052] By so disposing the valve backers 540A and 540B, the reed
valves 530A and 530B are lifted from below and bend in opposite
directions and open in the illustrated state by virtue of a
discharge pressure. Consequently, the collision between the
refrigerant gas discharged from the reed valve 530A and that
discharged from the reed valve 530B is diminished, whereby it is
possible to further lower the discharge resistance and improve the
compression efficiency.
[0053] The valve backers 540A and 540B are each formed by forming a
planar plate spring, e.g., a thin stainless steel plate spring
having both sides polished, into the illustrated shape. As is the
case with the reed valves 530A and 530B, two fulcrum portions 541
and 542 projecting to both sides are formed at one end
corresponding to a valve backer fixing portion 549 and an
intermediate portion 543 extends in an oblique direction at a
predetermined angle of .theta. as noted above relative to a line
joining the two fulcrums, the intermediate portion 543 extending so
as to become narrower gradually from base portions of the fulcrum
portions 541 and 542 and form a tip end 544 on the opposite end
side, the tip end 544 having a width of about half of the lid
portion 534 in each of the reed valves 530A and 530B. The valve
backer fixing portion 549 including the fulcrum portions 541 and
542 and the tip end 544 are formed so that their surfaces are
parallel to each other, while the intermediate portion 543 is
formed in a shape having surfaces curved along quadratic curves
with a small curvature on a side 543-1 close to the valve backer
fixing portion 549 and a large curvature on a side 543-2 close to
the tip end 544.
[0054] According to this shape of the valve backers 540A and 540B,
when the reed valves 530A and 530B are lifted from below in the
illustrated state by virtue of a discharge pressure, they are
deformed with elastic deformation of the valve backers 540A and
540B and along the shape of the valve backers. Moreover, the
smaller width of the tip end 544 permits the reed valves 530A and
530B to be twisted more easily.
[0055] The valve members fixing means 570 is formed by forming a
thick metallic plate, e.g., a stainless steel plate spring, into
the illustrated shape and is made up of fixing portions 570A and
570B for fixing the fulcrum portions 531, 532, 541 and 542 of the
valve members 560 to the fixing portions 523A and 523B of the
recess 523 and a spring portion 570C for connecting the fixing
portions 570A and 570B with each other and for urging the fulcrum
portions 531, 532, 541 and 542 of the valve members 560 elastically
to the fixing portions 523A and 523B of the recess 523, the fixing
portions 570A, 570B and the spring portion 570C being integral with
each other.
[0056] The fixing portions 570A and 570B of the valve members
fixing means 570 are mounted from above the fulcrum portions 531,
532, 541 and 542 to the fixing portions 523A and 523B of the recess
523. In this way the valve members 560 can be fixed easily and
positively by one valve members fixing means 570.
[0057] In this state, the valve assembly 500 is sandwiched and
fixed between the end face 352 of the cylinder 350 and the head
muffler member 710 in the discharge section 700, whereby the valve
members 560 are prevented from dislodgment under vibration or the
like.
[0058] The valve seat 520 is formed by forming a rather thick
metallic plate, e.g., a stainless steel plate into the illustrated
shape, which is in conformity with the profile of the fulcrum
portions 531 and 532 of the reed valves 530A and 530B. According to
the shape of the valve seat 520 there is formed a recess 523, the
recess 523 comprising fixing portions 523A and 523B as a first
recess in which the fulcrum portions 531, 532, 541, 542 of the reed
valves 530A, 530B and the valve backers 540A, 540B enter in a
mutually superimposed state and a second recess in which the other
portions than the fulcrum portions of the reed valves 530A, 530B
and the valve backers 540A, 540B enter, the first and the second
recess being contiguous to each other. Further, discharge ports
522A and 522B are formed in the second recess in positions
corresponding to the lid portions 534 of the reed valves 530A and
530B.
[0059] In the valve seat 520, the recess 523 is formed by stamping
and both surfaces thereof are finished by polishing. The discharge
ports 522A and 522B are formed with peripheral rib-like faces 522C,
which are finished by polishing to form contact faces for the reed
valves 530A and 530B. Further, an intake port 521 is formed in the
planar portion free of the recess 523 in a position corresponding
to the reed valve 511 of the intake-side valve member 510.
[0060] The gasket 550 is interposed between the valve seat 520 and
the head muffler member 710 in the discharge section 700 and it is
formed by forming a resin plate, e.g., a fiber-filled butyl rubber
plate, into the illustrated shape. The gasket 550 is provided with
a peripheral edge portion for closing the peripheral portion
between the valve seat 520 and the head muffler member 710 and is
also provided with a partitioning portion 554 for partition between
an intake-side small chamber 558 and a discharge-side small chamber
559.
[0061] The head muffler member 710 in the discharge section 700 is
formed by forming a rather thick metallic plate, e.g., a stainless
steel plate, into the illustrated shape, in which a hole as a
passage (not shown) leading to the discharge path 701 is
formed.
[0062] The above constituent elements, that is, all of the gasket
551, intake-side valve member 510, valve seat 520, reed valves
530A, 530B, valve backers 540A, 540B, valve members fixing means
570, gasket 550, and head muffler member 710, are demagnetized to
prevent mutual tacking in operation.
[0063] As shown in FIG. 6(A), the valve seat 520, the reed valve
530A (530B), and the valve backer 540A (540B), when assembled, are
superimposed one on another in plan.
[0064] In the section of FIG. 6(A), that is, in a longitudinal
section taken along the center of the reed valve 530A and that of
the reed valve 530B, principal portions are as shown in FIG. 7. In
the section of FIG. 6(A) taken on line A-A, the shape of the reed
valves 530A, 530B and that of the valve backers 540A, 540B are in a
pressure-free state. Further, in the valve members 560 constituted
by the reed valves 530A, 530B and the valve backers 540A, 540B, the
reed valve fixing portions 535 and the valve backer fixing portions
549 at one ends including the fulcrum portions 531, 532, 541 and
542 are held down by the valve members fixing means 570.
[0065] Since the valve backers 540A and 540B are disposed in the
illustrated fashion, when the compressed fluid is discharged from
the discharge ports 522A and 522B and a discharge pressure is
imposed on the reed valves 530A and 530B, the reed valves are
lifted from below in the illustrated state by virtue of the
discharge pressure and exhibit a complicated way of bending in
opposite directions.
[0066] This bending is a three-dimensionally complicated way of
bending as if a cobra raised it head and twisted its neck, that is,
a way of bending as if the letter S were drawn out thinly and the
head thereof twisted. Consequently, an internal stress resistive to
the bending is stored in the reed valves 530A, 530B and the valve
backers 540A, 540B.
[0067] When a change is made from the discharge pressure to a
counter pressure in this state, a restoring force which acts to
correct the bending of the reed valves 530A, 530B and close the
discharge ports 522A, 522B appears as a strong repulsive force due
to the internal stress against the foregoing three-dimensionally
complicated way of bending and acts as a force to straighten the
foregoing S-bend. Consequently, the reed valves 530A and 530B
perform such an abrupt operation as their tip portions, i.e., lid
portions 534 are thrown against the discharge ports 522A and 522B.
As a result, the reed valves 530A and 530B close the discharge
ports 522A and 522B earlier than the counter pressure and operate
so that the amount of the fluid returning to the discharge ports
522A and 522B under the counter pressure can be diminished to the
extreme degree.
[0068] Thus, in such a closed type reciprocating compressor 1000,
the valve members 260 can be fixed to the fixing portions 523A and
523B of the recess 523 easily and positively by the valve members
fixing means 570 and restriction and repulsive return of the reed
valves 530A and 530B are performed with the elasticity of the valve
backers 540A and 540B to afford an effect of enhancing the
efficiency of the pressurizing operation. Further, since the valve
assembly 500 is of a valve construction including two discharge
ports 522A, 522B, two reed valves 530A, 530B and two valve backers
540A, 540B, the discharge resistance is further lowered and the
compression efficiency is improved. Consequently, when the
reciprocating compressor 1000 is used as a compressor in a
refrigerator, the coefficient of performance in the refrigerator is
improved.
[0069] The above embodiment is for explaining the present invention
and neither limits the claimed invention nor restricts the scope of
claims. The constructions of various constituent portions in the
present invention are not limited to those described in the above
embodiment, but various modifications may be made within the
technical scope described in the claims.
[0070] According to the reciprocating compressor of the present
invention, the valve members can be fixed to the fixing portions of
the recess in the valve seat easily and positively by one valve
members fixing means. Besides, restriction and repulsive return of
the reed valves are performed with the elasticity of the valve
backers to afford an effect of enhancing the efficiency of the
pressurizing operation. Moreover, since the valve assembly used a
valve construction provided with plural discharge ports, plural
reed valves and plural valve backers, the discharge resistance is
further lowered and the compression efficiency is improved. When
the reciprocating compressor is used as a compressor in a
refrigerator, there is obtained an outstanding effect that the
coefficient of performance in the refrigerator is improved. Thus,
the reciprocating compressor of the present invention is high in
its industrial utility.
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