U.S. patent application number 11/772885 was filed with the patent office on 2008-04-24 for refrigerating cycle device and sealed-type rotary compressor.
This patent application is currently assigned to TOSHIBA CARRIER CORPORATION. Invention is credited to Toshimasa Aoki, SHOICHIRO KITAICHI, Koji Satodate, Takeshi Tominaga.
Application Number | 20080092586 11/772885 |
Document ID | / |
Family ID | 36647533 |
Filed Date | 2008-04-24 |
United States Patent
Application |
20080092586 |
Kind Code |
A1 |
KITAICHI; SHOICHIRO ; et
al. |
April 24, 2008 |
REFRIGERATING CYCLE DEVICE AND SEALED-TYPE ROTARY COMPRESSOR
Abstract
There is provided a pressure switching mechanism that switches
one compressor mechanism in a sealed-type rotary compressor between
regular compression operation and operation stop in accordance with
the magnitude of load, and the pressure switching mechanism is
equipped with a branch pipe which includes an open/close valve at
the middle thereof and which communicates a high-pressure side of a
refrigerating cycle to a second suction pipe, an auxiliary suction
pipe connected to the suction pipe end part in an accumulator, a
check valve which is mounted on either the auxiliary suction pipe
or the suction pipe and checks a reverse flow of refrigerant into
the accumulator, and a guide pipe which mounts and holds the
suction pipe or the auxiliary pipe to the accumulator.
Inventors: |
KITAICHI; SHOICHIRO;
(Fuji-shi, JP) ; Aoki; Toshimasa; (Fuji-shi,
JP) ; Tominaga; Takeshi; (Fuji-shi, JP) ;
Satodate; Koji; (Fuji-shi, JP) |
Correspondence
Address: |
DLA PIPER US LLP
P. O. BOX 9271
RESTON
VA
20195
US
|
Assignee: |
TOSHIBA CARRIER CORPORATION
TOKYO
JP
|
Family ID: |
36647533 |
Appl. No.: |
11/772885 |
Filed: |
July 3, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP05/23031 |
Dec 15, 2005 |
|
|
|
11772885 |
Jul 3, 2007 |
|
|
|
Current U.S.
Class: |
62/498 |
Current CPC
Class: |
F04C 14/26 20130101;
F04C 23/008 20130101; F04C 29/12 20130101; F04C 18/3564 20130101;
F25B 49/022 20130101; F25B 2600/0261 20130101; F25B 31/026
20130101; F25B 1/04 20130101; F25B 2500/01 20130101; F04C 23/001
20130101; F25B 43/006 20130101 |
Class at
Publication: |
062/498 |
International
Class: |
F25B 1/04 20060101
F25B001/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 4, 2005 |
JP |
2005-000226 |
Claims
1. A refrigerating cycle device, comprising: a sealed-type rotary
compressor which houses an electric motor unit and multiple sets of
rotary compressor mechanisms connected to the electric motor unit
in a sealed casing, which suctions a refrigerant from an
accumulator provided outside the sealed casing via suction pipes,
respectively, to each of the compressor mechanisms, which
compresses the refrigerant at each compressor mechanism, and then,
discharges the refrigerant via a space in the sealed casing; a
refrigerating cycle circuit composed of this sealed-type rotary
compressor and refrigerating cycle components which are linked to
communicate via a refrigerant pipe; and pressure switching means
switching one of the compressor mechanisms in such a manner that
low-pressure gas is guided to the compressor mechanism in the
sealed-type rotary compressor to allow it to conduct regular
compression operation or high-pressure gas is guided thereto to
allow it to stop compression operation in accordance with the
magnitude of load, wherein the pressure switching means comprises:
a branch pipe, one end of which is connected to a high pressure
side of the refrigerating cycle via an electromagnetic open-close
valve and the other end of which is connected to a suction pipe
which communicates the accumulator to the other compressor
mechanism; an auxiliary suction pipe connected to an end part
protruding to the inside of the accumulator of the suction pipe; a
check valve which is mounted on the auxiliary suction pipe or the
suction pipe and which checks reverse flow of refrigerant to the
accumulator; and a guide pipe which mounts and holds the suction
pipe or the auxiliary suction pipe to the accumulator.
2. The refrigerating cycle device according to claim 1, wherein the
suction pipe includes an end connector unit bulge-forming processed
to connect the branch pipe, and an extended tube part to mount the
check valve, and the auxiliary suction pipe is integrally linked to
the extended tube part.
3. The refrigerating cycle device according to claim 1, wherein the
suction pipe has a bent part protruded downward from a connection
portion with the compressor mechanism.
4. The refrigerating cycle device according to claim 2, wherein the
suction pipe has a bent part protruded downward from a connection
portion with the compressor mechanism.
5. A sealed-type rotary compressor which houses an electric motor
unit and multiple sets of rotary compressor mechanisms to be
connected to this electric motor unit in a sealed housing, which
suctions a refrigerant from an accumulator provided outside the
sealed casing via suction pipes, respectively, to each of the
compressor mechanisms, and which compresses the refrigerant in each
compressor mechanism, and then, discharges the refrigerant via a
space in the sealed casing, the compressor comprising pressure
switching means having: a branch pipe, one end of which is
connected to a high pressure side of the refrigerating cycle via an
electromagnetic open-close valve and the other end of which is
connected to a suction pipe which communicates the accumulator to
the other compressor mechanism; an auxiliary suction pipe connected
to an end part protruding to the inside of the accumulator of the
suction pipe; a check valve which is mounted on the auxiliary
suction pipe or the suction pipe and which checks reverse flow of
refrigerant to the accumulator; and a guide pipe which mounts and
holds the suction pipe or the auxiliary suction pipe to the
accumulator.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a Continuation Application of PCT Application No.
PCT/JP2005/023031, filed Dec. 15, 2005, which was published under
PCT Article 21(2) in Japanese.
[0002] This application is based upon and claims the benefit of
priority from prior Japanese Patent Application No. 2005-000226,
filed Jan. 4, 2005, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a refrigerating cycle
device equipped with a sealed-type rotary compressor that switches
one of multiple compressor mechanisms to operate or stop operating
in accordance with the magnitude of load, and the sealed-type
rotary compressor.
[0005] 2. Description of the Related Art
[0006] A general sealed-type rotary compressor is configured in an
in-casing high-pressure type, in which an electric motor and a
rotary-type compressor mechanism that is linked to this electric
motor are housed in a sealed casing, and gas compressed at the
compressor mechanism is temporarily discharged into the sealed
casing.
[0007] The compressor mechanism has an eccentric roller housed in a
cylinder chamber formed in a cylinder, and the head end edge of a
vane constantly comes elastically into contact with the
circumferential surface of the eccentric roller. The cylinder
chamber is divided into two chambers by the vane, and a suction
unit communicates with one chamber, while a discharge unit
communicates with the other chamber. A suction pipe is connected to
the suction unit and the discharge unit is open to the sealed
casing.
[0008] In recent years, a two-cylinder-type sealed rotary
compressor, with two sets of compressor mechanisms set above and
below, has been standardized. In this kind of a compressor, if
there can be provided a compressor mechanism which constantly
carries out compression operation and a compressor mechanism which
can switch between compression operation and operation stop in
accordance with the magnitude of load, the specifications are
advantageously expanded.
[0009] For example, Jpn. Pat. Appln. KOKAI Publication No. 1-247786
(Patent Document 1) discloses a technique related to a compressor
having two cylinder chambers and equipped with high-pressure
introducing means for forcibly separating and holding a vane of
either one of the cylinder chambers from a roller as required and
pressurizing the cylinder chamber to interrupt compression
action.
[0010] In addition, Japanese Patent No. 2803456 (Patent Document 2)
discloses a technique related to a compressor having a bypass
passage serving as means for introducing high pressure from a
sealed container to a suction pipe, in which in one cylinder
chamber a vane is brought in contact with a roller by the action of
an elastic member even at the time of off-cylinder operation in
which no compression action takes place and a compression chamber
is constantly partitioned by the vane.
BRIEF SUMMARY OF THE INVENTION
[0011] Note that, the compressor according to Patent Document 1 is
functionally excellent, but in order to configure high-pressure
introducing means, it includes a high-pressure introducing hole
which communicates one cylinder chamber with the sealed casing, a
two-stage restriction mechanism provided to a refrigerating cycle,
and a bypass refrigerant pipe which is branched from the
intermediate portion of this restriction mechanism, which
communicates with a vane chamber of one side, and which is equipped
with an electromagnetic open-close valve in the middle portion
thereof.
[0012] That is, boring processing to provide the high-pressure
introducing means to the compressor is required, and at the same
time, the restrictor on the refrigerating cycle must be made into a
two-stage restrictor. Furthermore, a bypass refrigerant pipe must
be connected between this two-stage restrictor and the cylinder
chamber to increase complication of the configuration, which
adversely affects the cost.
[0013] Furthermore, in the compressor according to Patent Document
2, a bypass pipe connection process to bypass the discharge side
and the suction side to the sealed container must be performed, and
this adversely affects the cost. Further, because the vane is
constantly brought elastically in contact with the roller even
during the off-cylinder operation, there occurs a failure that the
efficiency is lowered due to the presence of a little compression
work or sliding loss.
[0014] In both techniques, when the high-pressure introducing means
is operated and high pressure is introduced to a predetermined
compressor mechanism, there is a fear that the high-pressure
refrigerant flows backward from the suction pipe connected to the
compressor to an accumulator. However, no specific structure to
prevent backflow is described in either Patent Document.
[0015] The present invention is made on the basis of the above
situation and an object of the present invention is to provide a
refrigerating cycle device which has pressure switching means to
one compressor mechanism that forms a sealed-type rotary compressor
to enable switching between compression operation and operation
stop in accordance with the magnitude of load, and which prevents
backflow of the refrigerant to the accumulator and prevents
detrimental thermal effect in providing the pressure switching
means to secure reliability, and the sealed-type rotary
compressor.
[0016] The present invention has been achieved in order to satisfy
the object, and comprises: a sealed-type rotary compressor which
houses an electric motor unit and multiple sets of rotary
compressor mechanisms connected to the electric motor unit in a
sealed casing, which suctions a refrigerant from an accumulator
provided outside the sealed casing via suction pipes, respectively,
to each of the compressor mechanisms, which compresses the
refrigerant at each compressor mechanism, and then, discharges the
refrigerant via a space in the sealed casing; a refrigerating cycle
circuit composed of this sealed-type rotary compressor and
refrigerating cycle components which are linked to communicate via
a refrigerant pipe; and pressure switching means switching one of
the compressor mechanisms in such a manner that low-pressure gas is
guided to the compressor mechanism in the sealed-type rotary
compressor to allow it to conduct regular compression operation or
high-pressure gas is guided thereto to allow it to stop compression
operation in accordance with the magnitude of load, wherein the
pressure switching means comprises: a branch pipe, one end of which
is connected to a high pressure side of the refrigerating cycle via
an electromagnetic open-close valve and the other end of which is
connected to a suction pipe which communicates the accumulator to
the other compressor mechanism; an auxiliary suction pipe connected
to an end part protruding to the inside of the accumulator of the
suction pipe; a check valve which is mounted on the auxiliary
suction pipe or the suction pipe and which checks reverse flow of
refrigerant to the accumulator; and a guide pipe which mounts and
holds the suction pipe or the auxiliary suction pipe to the
accumulator.
[0017] And a sealed-type rotary compressor which houses an electric
motor unit and multiple sets of rotary compressor mechanisms to be
connected to this electric motor unit in a sealed housing, which
suctions a refrigerant from an accumulator provided outside the
sealed casing via suction pipes, respectively, to each of the
compressor mechanisms, and which compresses the refrigerant in each
compressor mechanism, and then, discharges the refrigerant via a
space in the sealed casing, the compressor comprising pressure
switching means having: a branch pipe, one end of which is
connected to a high pressure side of the refrigerating cycle via an
electromagnetic open-close valve and the other end of which is
connected to a suction pipe which communicates the accumulator to
the other compressor mechanism; an auxiliary suction pipe connected
to an end part protruding to the inside of the accumulator of the
suction pipe; a check valve which is mounted on the auxiliary
suction pipe or the suction pipe and which checks reverse flow of
refrigerant to the accumulator; and a guide pipe which mounts and
holds the suction pipe or the auxiliary suction pipe to the
accumulator.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0018] FIG. 1 is a longitudinal cross-sectional view of a
sealed-type rotary compressor and configuration diagram of a
refrigerating cycle according to a first embodiment of the present
invention.
[0019] FIG. 2 is an explodes perspective view of a first cylinder
and a second cylinder according to the embodiment.
[0020] FIG. 3A is a front view with part of a second suction pipe
partially shown in a cross section according to the embodiment.
[0021] FIG. 3B is a side view of the second suction pipe.
[0022] FIG. 4A is a front view showing the second suction pipe, a
disassembled check valve and auxiliary suction pipe partially cut
away.
[0023] FIG. 4B is a front view showing the reassembled condition of
the second suction pipe, the check valve and the auxiliary suction
pipe partially cut away.
[0024] FIG. 4C is a front view of part of a branch pipe according
to the embodiment.
[0025] FIG. 5 is a front view of a subassembly according to the
embodiment.
[0026] FIG. 6A is an exploded view of an accumulator according to
the embodiment.
[0027] FIG. 6B is an assembled view of the accumulator according to
the embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Referring now to drawings, an embodiment of the present
invention will be described in detail as follows.
[0029] FIG. 1 is a cross-sectional view of a sealed-type rotary
compressor C which configures a refrigerating cycle device and
configuration diagram of a refrigerating cycle circuit R.
[0030] First of all, the sealed-type rotary compressor C will be
described. The reference number 1 designates a sealed casing. A
compressor mechanism 2 is provided at a lower part of this sealed
casing 1, and an electric motor unit 3 is provided at the upper
part. These electric motor unit 3 and compressor mechanism 2 are
linked via a rotary shaft 4.
[0031] For example, a brushless DC synchronous motor (or an AC
motor or commercial motor) is used for the electric motor unit 3,
which is configured with a stator 5 fixed to the inner surface of
the sealed casing 1 and a rotor 6 arranged inside this stator 5
with a predetermined clearance and having the rotary shaft 4
inserted thereto. The electric motor unit 3 is electrically
connected to an inverter which varies the operating frequency and a
control unit which controls the inverter (both not
illustrated).
[0032] The compressor mechanism 2 is equipped with a first cylinder
8A and a second cylinder 8B arranged vertically via an intermediate
partition board 7 at the bottom of the rotary shaft 4. These first
and second cylinders 8A and 8B are set in such a manner that they
differ from each other in profile and dimensions and have the same
inner diameter.
[0033] The size of the outer diameter of the first cylinder 8A is
formed to be slightly larger than the size of the inner diameter of
the sealed casing 1 and press-fitted to the inner circumferential
surface of the sealed casing 1, and positioned and fixed by welding
from the outside of the sealed casing 1. A main bearing 9 is laid
on the top surface part of the first cylinder 8A, and is mounted
and fixed to the cylinder 8A via a fixing bolt together with a
valve cover "a". A sub-bearing 11 is laid on the bottom surface
part of the second cylinder 8B, and is mounted and fixed to the
first cylinder 8A via a fixing bolt together with a valve cover
"b".
[0034] The sizes of the outer diameter of the intermediate
partition board 7 and the sub-bearing 11 are larger to some extent
than the size of the inner diameter of the second cylinder 8B, and
the inner diameter position of the cylinder 8B deviates from the
cylinder center. Consequently, part of the outer circumference of
the second cylinder 8B protrudes in the radial direction from the
outer diameter of the intermediate partition board 7 and the
sub-bearing 11.
[0035] On the other hand, the rotary shaft 4 has its midway part
and bottom end part rotatably pivoted between the main bearing 9
and the sub-bearing 11. Furthermore, the rotary shaft 4 passes
through the inside of each of the cylinders 8A and 8B and is
equipped integrally with two eccentric parts 4a and 4b formed with
nearly 180.degree. phase difference provided. The eccentric parts
4a and 4b have the same diameter and are assembled to be located in
the inner diameter portions of the cylinders 8A and 8B. Eccentric
rollers 13a and 13b having the same diameter are fitted to the
circumferential surfaces of the eccentric parts 4a and 4b.
[0036] The first cylinder 8A and the second cylinder 8B have the
top and bottom surfaces partitioned by the intermediate partition
board 7, main bearing 9, and sub-bearing 11, and a first cylinder
chamber 14a and a second cylinder chamber 14b are formed in the
cylinders 8A and 8B, respectively. The cylinder chambers 14a and
14b are formed to have the same diameter and height, and the
eccentric rollers 13a and 13b are eccentrically rotatably housed
therein, respectively.
[0037] The size of height of each of the eccentric rollers 13a and
13b is formed to be the same as the size of height of each of the
cylinder chambers 14a and 14b. Consequently, the eccentric rollers
13a and 13b have a 180.degree. phase difference with each other,
but are set to the identical excluded volume by eccentrically
rotating in the cylinder chambers 14a and 14b.
[0038] FIG. 2 is a perspective view that shows the first cylinder
8A and the second cylinder 8B in a disassembled condition.
[0039] Vane chambers 22a and 22b which communicate with the
cylinder chambers 14a and 14b are provided to the cylinders 8A and
8B. In the vane chambers 22a and 22b, vanes 15a and 15b are
protrudably and retractably housed with respect to the cylinder
chambers 14a and 14b. The vane chambers 22a and 22b include vane
housing grooves 23a and 23b in which both sides of the vanes 15a
and 15b can slidably move and longitudinal hole portions 24a and
24b provided integrally with the vane housing grooves 23a and 23b
and housing rear end portions of the vanes 15a and 15b.
[0040] A lateral hole 25 that communicates the outer
circumferential surface and the vane chamber 22a is provided to the
first cylinder 8A, in which a spring member 26 is housed. The
spring member 26 is a compression spring which is allowed to
intervene between the back-side end face of the vane 15a and the
inner circumferential surface of the sealed casing 1, imparts an
elastic force (back pressure) to the vane 15a, and brings this head
end edge in contact with the eccentric roller 13a.
[0041] Although no member other than the vane 15b is housed in the
vane chamber 22b on the second cylinder 8B side, the head end edge
of the vane 15b is brought in contact with and released from the
eccentric roller 13b in accordance with the setting environment for
the vane chamber 22b as discussed later and the action of the
pressure switching mechanism (means) K later discussed. The head
end edge of each of the vanes 15a and 15b is formed in a semicircle
as seen in the planar view, and can make line contact with
circular-form circumferential walls, as seen in the planar view, of
the eccentric rollers 13a and 13b, irrespective of the rotating
angle of the eccentric roller 13a.
[0042] In the event that the eccentric rollers 13a and 13b
eccentrically rotate along the inner circumferential wall of the
cylinder chambers 14a, 14b, the vanes 15a and 15b make
reciprocating motion along the vane housing grooves 23a and 23b,
and at the same time, make the vane rear end portion free to
advance and retract from the longitudinal hole portions 24a and
24b. As described above, from the relationship between the
dimensions and profile of the second cylinder 8B and the outer
diameter dimensions of the intermediate partition board 7 and the
sub-bearing 11, part of the profile of the second cylinder 8B is
exposed to the inside of the sealed casing 1.
[0043] The portion exposed to the sealed casing 1 is designed to
correspond to the vane chamber 22b, and therefore, the vane chamber
22b and the rear end portion of the vane 15b are directly subject
to pressure inside the casing. In particular, the second cylinder
8B and the vane chamber 22b are of a fixed structure by itself and
are not subject to any influence even if pressure inside the casing
is exerted, but because the vane 15b is slidably housed in the vane
chamber 22b and the rear end portion thereof is located in the
longitudinal hole portion 24b of the vane chamber 22b, the vane 15b
is directly subject to the pressure inside the casing.
[0044] Furthermore, the head end portion of the vane 15b faces the
second cylinder chamber 14b and the vane head end portion is
subject to the pressure inside the cylinder chamber 14b. After all,
the vane 15b is configured to move in the direction from larger
pressure to smaller pressure in accordance with the magnitude of
pressures to which the head end portion and the rear end portion
are subjected.
[0045] Fixing holes or screw holes through which the fixing bolts
are inserted or threadably inserted are provided to each of the
cylinders 8A and 8B, and a circular-arc form gas passage hole 27 is
provided to the first cylinder 8A only. In particular, a holding
mechanism 10, which energizes the vane 15b in the direction to
separate the vane 15b from the eccentric roller 13b by the force
smaller than the differential pressure between the suction pressure
guided to the cylinder chamber 14b and the pressure inside the
sealed casing 1 guided to the vane chamber 22b, is provided in the
vane chamber 22b on the second cylinder 8B side.
[0046] For the holding mechanism 10, any of permanent magnet,
electromagnet, or elastic body may be used. To discuss further, the
holding mechanism 10 energizes and holds the vane 15b in the
direction to separate the vane 15b from the eccentric roller 13b
with the force smaller than the differential pressure between the
suction pressure exerted to the second cylinder chamber 14b and the
pressure inside the sealed casing 1 exerted to the vane chamber
22b.
[0047] By providing a permanent magnet as the holding mechanism 10,
the holding mechanism magnetically absorbs the vane 15b constantly
by a predetermined force. Alternatively, an electromagnet may be
provided in place of the permanent magnet and magnetic absorption
may be conducted as required. Alternatively, the holding mechanism
10 is made to be an extension spring, which is an elastic body. One
end portion of the extension spring may be allowed to latch on the
rear end portion of the vane 15b and pulled and energized
constantly with predetermined elastic force.
[0048] Again as shown in FIG. 1, a refrigerant pipe 18 which is a
discharge port of compressed gas is connected to the top end of the
sealed casing 1 that configures the sealed-type rotary compressor
C. An outdoor heat exchanger 20 and an electronic expansion valve
21 which is an expansion mechanism are connected to this
refrigerant tube 18 via a four-way switching valve 19 and connected
to an accumulator 17 via an indoor heat exchanger 22, thereby
configuring the refrigerating cycle circuit R.
[0049] A first suction pipe 16a and a second suction pipe 16b which
communicate with the sealed-type rotary compressor C are connected
to the accumulator 17 bottom portion. The first suction pipe 16a
passes through the sealed casing 1 and the first cylinder 8A side
part and directly communicates with the inside of the first
cylinder chamber 14a. The second suction pipe 16b passes through
the second cylinder 8B side part via the sealed casing 1 and
directly communicates with the inside of the second cylinder
chamber 14b.
[0050] In the refrigerating cycle circuit R configured in this way,
the pressure switching mechanism (means) K to switch operation of
the sealed-type rotary compressor C is provided. Now, the pressure
switching mechanism K will be described in detail as follows.
[0051] The pressure switching mechanism K is equipped with a branch
pipe 30, and an electromagnetic open-close valve 31 is provided to
the midway portion thereof. The branch pipe 30 includes a first
branch pipe 30A whose one end is connected to the midway part of
the refrigerant pipe 18 that allows the compressor C to communicate
with the four-way switching valve 19 and the other end connected to
the electromagnetic open-close valve 31, and a second branch pipe
30B whose one end is connected to the electromagnetic open-close
valve 31 and the other end connected to the midway part of the
second suction pipe 16b that allows the second cylinder chamber 14b
to communicate with the accumulator 17. The midway part of the
second branch pipe 30B is provided to and supported by the
accumulator 17 via a supporting tool 32.
[0052] The electromagnetic open-close valve 31 has its opening and
closing controlled in accordance with electrical signals from the
control unit. That is, the electromagnetic open-close valve 31
conducts the refrigerant from the refrigerant pipe 18 to the second
suction pipe 16b via the branch pipe 30 or interrupts circulation
of the refrigerant.
[0053] The other end part of the second branch pipe 30B is
connected to an end connector 33 provided in the midway part of the
second suction pipe 16b. The second suction pipe 16b itself is
inserted to the guide pipe 34 mounted on the accumulator 17, and
connection processing such as brazing is provided at the bottom end
c of the guide pipe 34.
[0054] The auxiliary suction pipe 35, the second suction pipe 16b
in the accumulator 17 penetrated portion, and the guide pipe 34 are
formed perpendicularly with one another, and the auxiliary suction
pipe 35 is placed side by side with the first suction pipe 16a in
the accumulator 17 and are adjusted so that the top end positions
(height) thereof are aligned with each other.
[0055] A check valve 36 is inserted and mounted in the second
suction pipe 16b. The check valve 36 has functions to allow a
refrigerant flow from the auxiliary suction pipe 35 to the end
connector 33 portion between the second suction pipe 16b and the
branch pipe 30 as described later and conversely, block a
refrigerant flow from the second suction pipe 16b to the
accumulator 17 via the auxiliary suction pipe 35.
[0056] In this way, the pressure switching mechanism K is
configured by the second suction pipe 16b connected to the second
cylinder chamber 14b, branch pipe 30, electromagnetic open-close
valve 31, guide pipe 34, auxiliary suction pipe 35, and check valve
36. As discussed later, in accordance with the switching action of
the pressure switching mechanism K, low-pressure suction pressure
or high-pressure discharge pressure is guided to the second
cylinder chamber 14b equipped to the second cylinder 8B.
[0057] By the way, the configuration and assembly of the pressure
switching mechanism K, assembly of the accumulator 17, and mounting
of the pressure switching mechanism K to the accumulator 17 will be
described later in further detail.
[0058] Next discussion is made on the action of the refrigerating
cycle device with the above-mentioned sealed-type rotary compressor
C.
[0059] (1) In the event that regular operation (full-capacity
operation) is selected:
[0060] After closing the electromagnetic valve 31 which composes
the pressure switching mechanism K, operating signals are sent to
the electric motor unit 3 via an inverter, and the rotary shaft 4
is rotary-driven. In the compression mechanism 2, the eccentric
rollers 13a and 13b eccentrically rotate in the cylinder chambers
14a and 14b, respectively. Because in the first cylinder 8A, the
vane 15a is pressed and energized constantly elastically by the
spring member 26, the head end edge of the vane 15a slidably comes
in contact with the circumferential wall of the eccentric roller
13a and divides the first cylinder chamber 14a into two, a suction
chamber and a compression chamber.
[0061] The inner circumferential surface rotary contact position of
the cylinder chamber 14a of the eccentric roller 13a aligns with
the vane housing groove 23a, and the space capacity of this
cylinder chamber 14a is maximized with the vane 15a at the most
retracted position. The refrigerant gas is suctioned from the
accumulator 17 into the first cylinder chamber 14a via the first
suction pipe 16a and the first cylinder chamber 14a is filled with
the refrigerant gas. With the eccentric rotation of the eccentric
roller 13a, the rotary contact position of the eccentric roller to
the inner circumferential surface of the first cylinder chamber 14a
moves, and the volume of the partitioned compression chamber of the
cylinder chamber 14a decreases. That is, the gas previously guided
to the first cylinder chamber 14a is gradually compressed.
[0062] When the rotary shaft 4 continues to rotate, the compression
chamber volume of the first cylinder chamber 14a is further reduced
and the gas is compressed, and the gas pressure is increased to a
specified level, a discharge valve not illustrated is opened. The
high-pressure gas is discharged into and fills the inside of the
sealed casing 1 via the valve cover "a". The high pressure gas is
discharged from the refrigerant pipe 18 at the upper part of the
sealed casing and is guided to, for example, the outdoor heat
exchanger 20 via the four-way switching valve 19.
[0063] On the other hand, because the electromagnetic open-close
valve 31 is closed in the pressure switching mechanism K, no
discharge pressure (high pressure) is guided to the second cylinder
chamber 14b. Low-pressure evaporated refrigerant gas-liquid
separated at the accumulator 17 is guided to the second cylinder
chamber 14b via the auxiliary suction pipe 35, the check valve 37,
and the second suction pipe 16b.
[0064] Consequently, the second cylinder chamber 14b reaches the
suction pressure (low-pressure) atmosphere, while the vane chamber
22b is exposed to the inside of the sealed casing 1 and is under
the discharge pressure (high pressure). In the above-mentioned vane
15b, the head end portion thereof is placed under the low-pressure
conditions, the rear end portion under the high-pressure
conditions, and the differential pressure exists between the front
and rear end portions.
[0065] By the influence of this differential pressure, the head end
portion of the vane 15b is pressed and energized against the
holding force of the holding mechanism 10 so as to be in sliding
contact with the eccentric roller 13b. That is, the compression
action takes place in the second cylinder chamber 14b as well, in
exactly the same manner as that conducted by the spring member 26
which presses and energizes the vane 15a on the first cylinder
chamber 14a side.
[0066] After all, in the sealed-type rotary compressor C,
compression action is carried out in both the first cylinder
chamber 14a and the second cylinder chamber 14b. The high-pressure
gas discharged from the sealed casing 1 via the refrigerant pipe 18
is guided to the outdoor heat exchanger 20 to be condensed and
liquefied, adiabatically expanded by the electronic expansion valve
21, deprives heat-exchanged air of evaporative latent heat at the
indoor heat exchanger 23, and carries out cooling function. The
refrigerant after evaporation is guided to the accumulator 17,
gas-liquid separated, and again suctioned from the first and second
suction pipes 16b and 16b into relevant cylinder chambers 14a and
14b in the compressor C and circulate in the above-mentioned
route.
[0067] (2) In the event that special operation (halved-capacity
operation) is chosen:
[0068] When special operation (operation to halve the capacity) is
chosen, the electromagnetic open-close valve 31 of the pressure
switching mechanism K is opened. When the electric motor unit 3 is
conducted and the rotary shaft 4 is rotary-driven, in the first
cylinder chamber 14a, regular compression action takes place as
described above, the sealed casing 1 is filled with discharged
high-pressure gas and high pressure is achieved inside the
casing.
[0069] Part of the high-pressure gas discharged from the
refrigerant pipe 18 is diverted to the branch pipe 30 and is
directly introduced into the second cylinder chamber 14b via the
opened electromagnetic open-close valve 31 and the second suction
pipe 16b. Meanwhile, part of the high-pressure refrigerant tries to
flow backward from the second suction tube 16b in the accumulator
17 direction, but the reverse flow to the accumulator 17 is
prevented by the check valve 36.
[0070] While the second cylinder chamber 14b is under the discharge
pressure (high-pressure) atmosphere, the vane chamber 22b still
remains under the same high-pressure condition as that in the
casing. Consequently, the vane 15b equipped to the second cylinder
chamber 14b has both front and back ends subjected to influence of
high pressure, and there is no differential pressure between the
front and back ends. The vane 15b maintains the stop condition
without moving at the position separated from the roller 13b outer
circumferential surface and no compression action takes place in
the second cylinder chamber 14b. After all, compression action in
the first cylinder chamber 14a only is effective, and operation
with the capacity halved is conducted.
[0071] Furthermore, since the inside of the second cylinder chamber
14b is under high pressure, no leak of compressed gas from the
sealed casing 1 to the second cylinder chamber 14b occurs and no
loss caused by the leakage occurs, either. Consequently, operation
with the capacity halved is enabled without degrading the
compression efficiency.
[0072] For example, as compared to the case in which the rotating
speed is adjusted so that the capacity with the excluded volume of
the compressor mechanism 2 is halved, adopting the above-mentioned
halved-capacity operation can conduct the halved-capacity operation
with the same high rotating speed as that of regular operation
maintained and the improved compression efficiency can be
obtained.
[0073] The minimum capacity by minimum rotating speed established
by the lubricity in the compression mechanism 2 can be lowered by
varying the excluded volume to half, and the minimum capacity can
be expanded to provide a refrigerating cycle device that enables
finely-tuned temperature and humidity control. In the compressor R,
with a simple construction only by omitting the spring member that
energizes the vane 15b, the volume can be varied, advantageous cost
is achieved, superb manufacturing capability is achieved, and high
efficiency is achieved.
[0074] When the maximum capacity is required, the predetermined
capacity is secured by two-cylinder operation, and a wide range of
capacity can be secured with one compressor. That is, by
controlling the opening and closing of the electromagnetic
open-close valve 31 in accordance with the operation mode, the
required capacity can be easily obtained.
[0075] Next, the configuration and assembly of pressure switching
mechanism K, assembly of the accumulator 17, and mounting of the
pressure switching mechanism K to the accumulator 17 will be
discussed in detail as follows.
[0076] FIG. 3 is a partial sectional view and bottom view of the
second suction valve 16b; FIG. 4, a view to explain the
configuration and the assembly of the second suction pipe 16b,
auxiliary suction pipe 35, and check valve 36; FIG. 5, an enlarged
view of the assembled second suction pipe 16b, auxiliary suction
pipe 35 and check valve 35; and FIG. 6, an assembly illustration of
the accumulator 17 and partial sectional view of the assembled
accumulator 17.
[0077] First of all, the second suction pipe 16b will be described
with reference to FIG. 3.
[0078] The second suction pipe 16b includes a portion connected too
the accumulator 17 via the guide pipe 34 and a portion communicated
with the second cylinder chamber 14b that passes through the sealed
casing 1 and is formed in the second cylinder 8B. The portion
connected to the accumulator 17 is directed perpendicularly and the
portion communicated with the second cylinder chamber 14b is
directed horizontally, and the midway part is folded nearly at
90.degree..
[0079] A bent portion 37 is formed at the portion of the second
suction pipe 16b folded at 90.degree.. The bent portion 37
protrudes (distance: H) downwards from the portion extended in the
horizontal direction to be formed in an R shape, and the end
connector 33 is provided to this bent portion 37. The end-connector
33 is located in a range distributed 45.degree. each up and down
with the line L as a center drawn in the horizontal direction from
the bend center point O of the bent portion 37.
[0080] That is, as the processing sequence, the second suction pipe
16b is in a straight state in the beginning, and at first, the end
connector 33 is formed, for example, by bulging or burring using
oil pressure. As shown in FIG. 3B only, a stepped portion 33d
formed at the base end of the end connector 33 is formed by
post-processing after providing the end connector 33.
[0081] Next, the second suction pipe 16b is bent and the bent
portion 37 is formed. At this time, providing the end connector 33
at the above-mentioned location can prevent effects at the time of
processing the bent portion 37 from being exerted to the end
connector 33 and no deformation occurs.
[0082] In addition, the portion of the second suction pipe 16b
extended in the perpendicular direction is formed into an expanded
pipe, and this expanded pipe portion 38 is located at the position
separated at least by .alpha. (2 mm) from the top end of the end
connector 33. The expanded pipe portion 38 can be formed by bulging
simultaneously with the end connector 33, and carrying out pipe
expanding with the size .alpha. separated can prevent effects at
the time of pipe expanding from being exerted to the end connector
33 and no deformation occurs.
[0083] By forming this kind of second suction pipe 16b and mounting
it to the accumulator 17 together with the bent portion 37, the
accumulator 17 fixing position can be lowered by the protruded
portion H only. That is, the mounting height of the accumulator 17
integrally assembled with the compressor C can be reduced to
achieve compactness.
[0084] In particular, as shown in FIG. 4A, the check valve 36
includes a ball-form valve disc 40, a valve holder 41 that houses
this valve disc 40, and a valve casing 42 which hold the valve
holder 41 and whose bottom end part composes a valve seat portion
k. The valve holder 41 is formed by folding a thin sheet material,
and at the bottom end thereof, a valve hole not illustrated is
provided. The valve disc 40 is housed in the valve holder 41
displaceably only in the vertical direction and opens and closes
the valve hole in accordance with its position.
[0085] The top end of the valve holder 41 is opened and is equipped
with a leaf part f folded inwards. This leaf part f is hooked on a
latch portion g mounted on the side of the valve casing 42, and the
valve holder 41 is suspended to the valve casing 42. The check
valve 36 configured in this way has its dimensions set in such a
manner that it can be inserted into the expanded pipe portion 38
formed in the second suction pipe 16b in a tight state.
[0086] A positioning stepped portion h, in which a bottom end m
subject to pipe expanding of the auxiliary suction pipe 35 is
inserted, is provided to the top end portion of the valve casing 42
and a hole portion i is further provided thereto in a linked
manner. Consequently, in the valve casing 42, the hole portion i is
penetrated and provided along the center axis that encompasses the
top-end positioning stepped portion h to the bottom end face. By
the way, in FIG. 4A, the horizontal portion of the second suction
pipe 16b is illustrated in a straight form and the bent portion 37
is omitted.
[0087] As shown in FIG. 4B, the preassembled check valve 36 is
housed in the expanded pipe portion 38 of the second suction pipe
16b, and the bottom end m of the auxiliary suction pipe 35 is
connected to the top end of the expanded pipe portion 38.
Specifically, the valve disc 40 is inserted in the valve holder 41
and the valve holder 41 is latched to the valve casing 42 to
assemble the check valve 36, and the pipe-expanded bottom end m of
auxiliary suction pipe 35 is inserted to the positioning stepped
portion h of the valve casing 42.
[0088] Then, the check valve 36 is inserted from the top end of the
expanded pipe portion 38 of the second suction pipe 16b. As
described above, since the outer diameter of the check valve 36 and
the inner diameter of the expanded pipe portion 38 are set to the
tight dimensions, the check valve 36 does not drop straight to the
bottom end of the expanded pipe portion 38. When the top end of the
check valve 36 and the top end of the second suction pipe 16b are
aligned to each other, insertion of the check valve 36 into the
expanded pipe portion 38 is stopped.
[0089] Thereafter, high-frequency brazing will be performed to the
connection d where the top end of the expanded pipe portion 38, the
top end of the check valve 36, and the bottom end m of the
auxiliary suction pipe 35 are located at the same position.
Consequently, the top end of the second suction pipe 16b, the top
end of the check valve 36, and the bottom end m of the auxiliary
suction pipe 35 are integrally linked.
[0090] In order to prevent thermal deformation caused by brazing of
the valve seat portion k of the valve casing 42 in the check valve
36, it is preferable to perform brazing while cooling by immersing
the lower part of the brazed portion (linked portion d) in water,
or by other cooling means. For the cooling means, in addition to
water immersion, water or inert gas may be allowed to flow to the
inside.
[0091] As shown in FIG. 4C, a second branch pipe 30B is prepared.
Almost all the portion of the second branch pipe 30B is in the
vertical state, and it is slanted at the bottom and is bent in the
horizontal direction at the bottom end portion. This horizontal end
part is inserted into the end connector 33 provided in the second
suction pipe 16B and connected by high-frequency brazing.
[0092] In this case, since the stepped portion 33d is formed in the
end connector 33, by inserting the end portion of the second branch
pipe 30B into the end connector 33 and by striking it against the
stepped portion 33d, the second branch pipe 30B can be positioned
and brazed without occurrence of dislocation.
[0093] Since the location of the end connector 33 in the second
suction pipe 16b is separated far away from the valve seat portion
k of the check valve 36 which has already been assembled in the
expanded pipe portion 38, no thermal effect is exerted at the time
of brazing the second branch pipe 30B to the end connector 33. Note
that, in the event that any thermal effect is suspected, it is
desirable to carry out brazing while inert gas such as nitrogen gas
is allowed to flow inside.
[0094] By the foregoing processing and formation, as shown in FIG.
5, there is obtained a sub-assembly 43 which houses the check valve
36 in the second suction pipe 16b and connects to integrate the
auxiliary suction pipe 35 with the second branch pipe 30B as
described above.
[0095] On the other hand, the accumulator 17 is configured with a
top cup 17A and a bottom cup 17B which are integrally connected
after fitting a filter assembly 45 into a nearly intermediate
portion in the axial direction as shown in FIGS. 6A and 6B. The
refrigerant pipe 18 extended from the compressor C via
refrigerating cycle component devices such as the outdoor heat
exchanger 20 is connected to the top cup 17A. The first suction
pipe 16a and the guide pipe 34 are mounted on the bottom cup 17B
with part of these pipes inserted in the accumulator 17.
[0096] That is, the first suction pipe 16a is formed by being bent
nearly in an L form of a vertical portion and a horizontal portion.
The straight portion passes through the bottom cup 17B and the top
end portion is extended to the filter assembly 45 inside the
accumulator 17. The portion protruding downwards from the bottom
cup 17B is extended in the horizontal direction towards the
compressor C.
[0097] The guide pipe 34 is partially inserted into the inside of
the accumulator 17 and another part is protruded downwards from the
accumulator 17. A top end opening portion n in the accumulator 17
is bent inwards in advance to restrict the opening amount.
[0098] The refrigerant pipe 18, the first suction pipe 16a, and the
guide pipe 34 are all brazed to the accumulator 17 along the
circumferential surface of the penetrated portion of the
accumulator 17, and the sealed condition of the accumulator is not
impaired. This completes assembly of the accumulator 17.
[0099] The sub-assembly 43 including the second suction pipe 16b
and the like is brought face-to-face to the lower part of the guide
pipe 34 in the assembled accumulator 17, and with the top end of
the auxiliary suction pipe 35 applied to the bottom end of the
guide pipe 34, the auxiliary suction pipe 35 is inserted into the
guide pipe 34.
[0100] By moving the sub-assembly 43 upwards as it is, the whole
auxiliary suction pipe 35 is inserted into the guide pipe 34, and
the brazed positions d of the auxiliary suction pipe 35, the check
valve 36, and the second suction pipe 16b are brought in contact
with the restricted top-end opening portion n of the guide pipe 34,
thereby restricting further elevation.
[0101] In the accumulator 17, the auxiliary suction pipe 35 stands
upright vertically, and is parallel to the first suction pipe 16a,
and the top end positions of the two pipes are nearly aligned. In
addition, the expanded pipe portion 38 of the second suction pipe
16b is fitted in the guide pipe 34 and the bottom end of the guide
pipe 34 and the bottom end position of the expanded pipe portion 38
are nearly aligned.
[0102] With the position of the sub-assembly 43 tentatively held,
the bottom end of the guide pipe 34 and the bottom end of the
expanded pipe portion 38 are brazed along the circumferential
surfaces (portion of the reference character c of FIG. 1). The
second suction pipe 16b (sub-assembly 43) is mounted on the
accumulator 17 via the guide pipe 34, and assembly of the second
suction pipe 16b equipped with the check valve 36 to the
accumulator 17 is completed. It is preferable to separate the
brazed position and the valve seat portion k of the check valve 36
by 10 mm or more, and more preferably 20 mm or more. In addition,
it is preferable to braze with inert gas such as nitrogen gas
allowed to flow inside to prevent oxidation and at the same time to
achieve cooling.
[0103] Because the check valve 36 is fabricated independently from
the accumulator 17, the check valve 36 is not subject to the effect
of direct heat when the accumulator 17 is assembled. Furthermore,
since the check valve 36 is separated from the brazed position d
between the second suction pipe 16b and the auxiliary suction pipe
35 as well as from the brazed position of the end connector 33
provided to the second branch pipe 30B and the second suction pipe
16b, the check valve 36 is subject to only a small heat effect, and
it is possible to braze while cooling by cooling means.
Consequently, high assembly accuracy can be maintained for the
check valve 36 and the check valve 36 can be operated in a
remarkably smooth manner.
[0104] Note that, although the expanded pipe portion 38 is formed
in the second suction pipe 16b to house the check valve 36 in the
embodiment, the present invention is not limited to this, and a
configuration to house the check valve in the auxiliary suction
pipe 35 may be adopted. In addition, one end of the first branch
pipe 30A may be connected to the sealed casing.
[0105] Furthermore, the present invention is not limited to the
above-mentioned embodiment as it is, but in the working stages, the
constituent elements may be modified and embodied without departing
from the spirit and the scope of the invention. It is possible to
form various inventions by suitably combining multiple constituent
elements disclosed in the above-mentioned embodiment.
[0106] According to the present invention, various advantages are
exhibited, such that operation can be switched in accordance with
the sizes of load to expand the range of use, the reverse flow of
refrigerant to the accumulator can be reliably prevented to improve
the refrigerating cycle efficiency, and the detrimental thermal
effects can be prevented to thereby maintain the reliability.
* * * * *