U.S. patent application number 13/697420 was filed with the patent office on 2013-04-18 for variable-capacity compressor.
This patent application is currently assigned to KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. The applicant listed for this patent is Yuji Hashimoto, Hiroyuki Nakaima, Kazuhiro Nomura, Yasushi Watanabe. Invention is credited to Yuji Hashimoto, Hiroyuki Nakaima, Kazuhiro Nomura, Yasushi Watanabe.
Application Number | 20130094941 13/697420 |
Document ID | / |
Family ID | 44991665 |
Filed Date | 2013-04-18 |
United States Patent
Application |
20130094941 |
Kind Code |
A1 |
Hashimoto; Yuji ; et
al. |
April 18, 2013 |
VARIABLE-CAPACITY COMPRESSOR
Abstract
Variable displacement compressor is provided with a displacement
control valve (2) that can change an opening degree of supplying
passage (44, 46) between a valve seat (VS) and a valve body (VB),
thereby changing the pressure in a crank chamber (9). The
displacement control valve (2) is accommodated within a control
valve chamber (5c) in a rear housing (5) and fixed in place by
means of a circlip (50). A cutout (50g) is formed between the
displacement control valve (2) and the circlip (50) and/or between
the circlip (50) and the rear housing (5). A clearance (C) formed
by the cutout (50g) and the like inhibits the transmission of
vibrations caused by impacts between the valve seat (VS) and the
valve body (VB). This makes the variable displacement compressor
quiet, reduces costs by obviating the need for additional
components, and results in excellent durability.
Inventors: |
Hashimoto; Yuji;
(Kariya-shi, JP) ; Nomura; Kazuhiro; (Kariya-shi,
JP) ; Nakaima; Hiroyuki; (Kariya-shi, JP) ;
Watanabe; Yasushi; (Kariya-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hashimoto; Yuji
Nomura; Kazuhiro
Nakaima; Hiroyuki
Watanabe; Yasushi |
Kariya-shi
Kariya-shi
Kariya-shi
Kariya-shi |
|
JP
JP
JP
JP |
|
|
Assignee: |
KABUSHIKI KAISHA TOYOTA
JIDOSHOKKI
Kariya-shi, Aichi-ken
JP
|
Family ID: |
44991665 |
Appl. No.: |
13/697420 |
Filed: |
May 16, 2011 |
PCT Filed: |
May 16, 2011 |
PCT NO: |
PCT/JP2011/061200 |
371 Date: |
November 12, 2012 |
Current U.S.
Class: |
415/119 |
Current CPC
Class: |
F04B 27/1081 20130101;
F04B 27/1804 20130101; F04B 27/0891 20130101; F16F 15/02 20130101;
F04B 39/0044 20130101; F16F 15/085 20130101; F04D 29/00 20130101;
F04B 27/1036 20130101; F04B 27/14 20130101; F16B 21/183 20130101;
F04B 27/0852 20130101; F04B 39/14 20130101; F04B 27/0821 20130101;
F04B 27/0873 20130101 |
Class at
Publication: |
415/119 |
International
Class: |
F04D 29/00 20060101
F04D029/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 15, 2010 |
JP |
2010-112713 |
Claims
1. A variable displacement compressor comprising: a housing
including a suction chamber, a crank chamber, a discharge chamber,
and a control valve chamber; and a displacement control valve
accommodated in the control valve chamber and fixed to the housing
by a circlip, which is engaged with an engagement groove of the
housing, wherein the displacement control valve includes a valve
seat and a valve body arranged in a passage connecting the
discharge chamber and the crank chamber or a passage connecting the
crank chamber and the suction chamber, the valve body is
accommodated in a valve case, an external signal is input to a coil
to change an opening degree of the passage between the valve seat
and the valve body so that pressure of the crank chamber can be
changed, and the coil is protected by a cover; vibration generated
by impact between the valve seat and the valve body is transmitted
through a path extending from the valve seat via the valve case and
the circlip to the housing, the variable displacement compressor
being characterized in that at least one of the circlip, the cover,
and the engagement groove includes a cutout or a recess in the
path, and a clearance defined by the cutout or the recess forms a
means for suppressing transmission of the vibration.
2. The variable displacement compressor according to claim 1,
wherein the circlip includes a C-shaped engagement portion, which
engages with the engagement groove, and a wide portion, which is
formed at two ends of the engagement portion and has a fitting hole
into which pliers is fitted; the engagement portion includes the
cutout formed in a widthwise direction to avoid contact with the
displacement control valve; and the vibration transmitting
suppressing means is the clearance defined by the cutout.
3. The variable displacement compressor according to claim 1,
wherein the circlip includes an opposing surface that opposes the
displacement control valve; the displacement control valve includes
an end surface that opposes the opposing surface; the end surface
includes the recess that avoids contact with the opposing surface;
and the vibration transmitting suppressing means is the clearance
defined by the recess.
4. The variable displacement compressor according to claim 1,
wherein the circlip includes an opposing surface that opposes the
displacement control valve; the displacement control valve includes
an end surface that opposes the opposing surface; the opposing
surface includes the recess that avoids contact with the end
surface; and the vibration transmitting suppressing means is the
clearance defined by the recess.
5. The variable displacement compressor according to claim 1,
wherein the engagement groove is defined by a first engagement
surface and a second engagement surface that are spaced apart by an
equal distance in a circumferential direction; the circlip includes
a first surface and a second surface spaced apart by an equal
distance in the circumferential direction to engage with the
engagement groove; at least one of the first surface and the second
surface includes a recess for avoiding contact with the first
engagement surface and the second engagement surface; and the
vibration transmitting suppressing means is the clearance defined
by the recess.
6. The variable displacement compressor according to claim 1,
wherein the engagement groove is defined by a first engagement
surface and a second engagement surface that are spaced apart by an
equal distance in a circumferential direction; the circlip includes
a first surface and a second surface spaced apart by an equal
distance in the circumferential direction to engage with the
engagement groove; at least one of the first engagement surface and
the second engagement surface includes the recess so that the
distance between the first engagement surface and the second
engagement surface is greater than the thickness of the circlip to
avoid contact with the first surface and the second surface; and
the vibration transmitting suppressing means is the clearance
defined by the recess.
7. The variable displacement compressor according to claim 1,
wherein the vibration transmitting suppressing means is a means for
attenuating vibration transmitted in at least either one of between
the displacement control valve and the circlip and between the
circlip and the housing.
8. The variable displacement compressor according to claim 7,
wherein the cover is sealed by an O-ring, and the vibration
attenuating means is the recess formed in a circumference of the
cover closer to an opening of the control valve chamber than the
O-ring.
9. The variable displacement compressor according to claim 7,
wherein the engagement groove is defined by a first engagement
surface and a second engagement surface spaced apart by an equal
distance in a circumferential direction; the circlip is elastically
deformable; the distance between the first engagement surface and
the second engagement surface of the engagement groove is greater
than the thickness of the circlip so that the circlip elastically
deforms to obtain the clearance between the first engagement
surface and the second engagement surface; and the vibration
attenuating means is the clearance.
Description
TECHNICAL FIELD
[0001] The present invention relates to a displacement control
valve.
BACKGROUND ART
[0002] A conventional variable displacement compressor includes a
suction chamber, crank chamber, discharge chamber, and control
valve chamber that are arranged in a housing. A displacement
control valve is accommodated in the control valve chamber by way
of an O-ring, and the displacement control valve is fixed by a
circlip. A valve seat and a valve body are arranged in a passage
that connects the discharge chamber and the crank chamber and
extends through the displacement control valve. The displacement
control valve, for example, changes an opening degree of the
passage between the valve seat and the valve body through pulse
width modulation (PWM) control to change the pressure of the crank
chamber.
[0003] The variable displacement compressor is employed in an air
conditioning device of a vehicle. For example, when the opening
degree of the passage is increased by the PWM control during
acceleration of the vehicle, high pressure refrigerant gas can
easily be supplied from the discharge chamber to the crank chamber
thereby decreasing displacement. On the other hand, when the
opening degree of the passage is decreased by the PWM control
during deceleration of the vehicle, the supply of high pressure
refrigerant gas from the discharge chamber to the crank chamber is
restricted thereby increasing displacement. In this manner, the
variable displacement compressor can vary displacement in
accordance with the vehicle speed and the like.
[0004] In the variable displacement compressor, for example,
depending on an input signal of the PWM control, small impacts may
repetitively occur between the valve seat and valve body. The
vibration caused by the impacts is transmitted to a case of the
displacement control valve. Although the vibration is not
transmitted to the housing of the variable displacement compressor
through the O-ring, the vibration is transmitted to the housing of
the variable displacement compressor through the circlip. As a
result, the variable displacement compressor and components and the
like of a refrigerant circuit, which is connected to the variable
displacement compressor, produce abnormal noise. This tendency
becomes strong especially when the input signal (frequency) is
small.
[0005] Like the variable displacement compressor disclosed in
patent document 1, the circlip may be made of a vibration absorbing
alloy. In such a case, the circlip suppresses vibration and
restricts the transmission of vibration thereby realizing
quietness.
PRIOR ART DOCUMENT
Patent Document
[0006] Patent Document 1: Japanese Laid-Open Patent Publication No.
2007-71114
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0007] However, the variable displacement compressor of the prior
art described above uses a circlip that is made of a special
vibration absorbing alloy. This raises costs.
[0008] Thus, as shown in FIGS. 15 and 16, a displacement control
valve 90 and a conventional circlip 91 may be arranged to sandwich
a rubber sheet 92. In the drawings, reference character 93 denotes
a housing of a variable displacement compressor, and reference
character 90a denotes a cover located at a rear end of the
displacement control valve 90. A terminal and the like formed in
the cover 90a to supply power to a coil is not shown in the
drawings. In this case, the sheet 92 absorbs vibration and
restricts the transmission of the vibration to the circlip 91 and
the housing 93 for the quietness.
[0009] However, even in this compressor, the sheet 92 adds to the
number of assembling steps and increases the component price
thereby inevitably raising costs. Further, the sheet 92 may
deteriorate when the compressor is used for a long period. This may
adversely affect the quietness and the sealing between the housing
93 and the displacement control valve 90.
[0010] It is an object of the present invention to provide a
variable displacement compressor that can realize quietness and
have superior durability, while lowering costs by eliminating the
need for additional components.
Means for Solving the Problem
[0011] One aspect of the present invention is a variable
displacement compressor including a housing including a suction
chamber, a crank chamber, a discharge chamber, and a control valve
chamber. A displacement control valve is accommodated in the
control valve chamber and fixed to the housing by a circlip, which
is engaged with an engagement groove of the housing. The
displacement control valve includes a valve seat and a valve body
arranged in a passage connecting the discharge chamber and the
crank chamber or a passage connecting the crank chamber and the
suction chamber. The valve body is accommodated in a valve case. An
external signal is input to a coil to change an opening degree of
the passage between the valve seat and the valve body so that
pressure of the crank chamber can be changed. The coil is protected
by a cover. Vibration generated by impact between the valve seat
and the valve body is transmitted through a path extending from the
valve seat via the valve case and the circlip to the housing. At
least one of the circlip, the cover, and the engagement groove
includes a cutout or a recess in the path. A clearance defined by
the cutout or the recess forms a means for suppressing transmission
of the vibration.
[0012] In a first embodiment, the circlip includes a C-shaped
engagement portion, which engages with the engagement groove, and a
wide portion, which is formed at two ends of the engagement portion
and has a fitting hole into which pliers is fitted. The engagement
portion includes the cutout formed in a widthwise direction to
avoid contact with the displacement control valve. The vibration
transmitting suppressing means is the clearance defined by the
cutout.
[0013] In a further embodiment, the circlip includes an opposing
surface that opposes the displacement control valve. The
displacement control valve includes an end surface that opposes the
opposing surface. The end surface includes the recess that avoids
contact with the opposing surface. The vibration transmitting
suppressing means is the clearance defined by the recess.
[0014] In a further embodiment, the circlip includes an opposing
surface that opposes the displacement control valve. The
displacement control valve includes an end surface that opposes the
opposing surface. The opposing surface includes the recess that
avoids contact with the end surface. The vibration transmitting
suppressing means is the clearance defined by the recess.
[0015] In a further embodiment, the engagement groove is defined by
a first engagement surface and a second engagement surface that are
spaced apart by an equal distance in a circumferential direction.
The circlip includes a first surface and a second surface spaced
apart by an equal distance in the circumferential direction to
engage with the engagement groove. At least one of the first
surface and the second surface includes a recess for avoiding
contact with the first engagement surface and the second engagement
surface. The vibration transmitting suppressing means is the
clearance defined by the recess.
[0016] In a further embodiment, the engagement groove is defined by
a first engagement surface and a second engagement surface that are
spaced apart by an equal distance in a circumferential direction.
The circlip includes a first surface and a second surface spaced
apart by an equal distance in the circumferential direction to
engage with the engagement groove. At least one of the first
engagement surface and the second engagement surface includes the
recess so that the distance between the first engagement surface
and the second engagement surface is greater than the thickness of
the circlip to avoid contact with the first surface and the second
surface. The vibration transmitting suppressing means is the
clearance defined by the recess.
[0017] In a further embodiment, the vibration transmitting
suppressing means is a means for attenuating vibration transmitted
in at least either one of between the displacement control valve
and the circlip and between the circlip and the housing.
[0018] In a further embodiment, the cover is sealed by an O-ring,
and the vibration attenuating means is the recess formed in a
circumference of the cover closer to an opening of the control
valve chamber than the O-ring.
[0019] In a further embodiment, the engagement groove is defined by
a first engagement surface and a second engagement surface spaced
apart by an equal distance in a circumferential direction. The
circlip is elastically deformable. The distance between the first
engagement surface and the second engagement surface of the
engagement groove is greater than the thickness of the circlip so
that the circlip elastically deforms to obtain the clearance
between the first engagement surface and the second engagement
surface. The vibration attenuating means is the clearance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a cross-sectional view of a variable displacement
compressor according to first to eighth embodiments.
[0021] FIG. 2 is a cross-sectional view of a displacement control
valve according to the first to eighth embodiments.
[0022] FIG. 3 is an enlarged cross-sectional view showing the main
part of the variable displacement compressor in the first
embodiment.
[0023] FIG. 4 is a cross-sectional view taken along line IV-IV in
FIG. 3.
[0024] FIG. 5 is a plan view showing a circlip of the variable
displacement compressor in the second embodiment.
[0025] FIG. 6 is a cross-sectional view of the compressor in the
second embodiment corresponding to FIG. 4.
[0026] FIG. 7 is an enlarged cross-sectional view showing the main
part of the variable displacement compressor in the third
embodiment.
[0027] FIG. 8 is a bottom view of the displacement control valve in
the compressor of the third embodiment.
[0028] FIG. 9 is a cross-sectional view taken along line IX-IX in
FIG. 7.
[0029] FIG. 10 is an enlarged cross-sectional view showing the main
part of the variable displacement compressor in the fourth
embodiment.
[0030] FIG. 11 is an enlarged cross-sectional view showing the main
part of the variable displacement compressor in the fifth
embodiment.
[0031] FIG. 12 is an enlarged cross-sectional view showing the main
part of the variable displacement compressor in the sixth
embodiment.
[0032] FIG. 13 is an enlarged cross-sectional view showing the main
part of the variable displacement compressor in the seventh
embodiment.
[0033] FIG. 14 is an enlarged cross-sectional view showing the main
part of the variable displacement compressor in the eighth
embodiment.
[0034] FIG. 15 is an enlarged cross-sectional view showing the main
part of a variable displacement compressor in a comparative
example.
[0035] FIG. 16 is a cross-sectional view of the compressor in the
comparative example of FIG. 15 taken alone line XIV-XIV in FIG.
15.
DETAILED DESCRIPTION OF THE INVENTION
[0036] First to eighth embodiments of the present invention will
now be described with reference to the drawings.
First Embodiment
[0037] As shown in FIG. 1, a variable displacement compressor
according to a first embodiment is provided with a cylinder block 1
including a plurality of cylinder bores 1a. The cylinder bores 1a
are concentrically arranged at equal angular intervals and extend
parallel to one another in the cylinder block 1. The cylinder block
1 is held between a front housing 3 and a rear housing 5 and
fastened in this state. A crank chamber 9 is defined in the
cylinder block 1 and the front housing 3.
[0038] The front housing 3 includes a shaft hole 3a, and the
cylinder block 1 includes a shaft hole 1b. The shaft holes 3a and
1b rotatably receive a drive shaft 11 with a shaft seal 9a and
bearings 9b and 9c. A pulley 13 is arranged on the front housing 3
by way of a bearing 3b, and the pulley 13 is fixed to the drive
shaft 11. A belt 13c, which is driven by an engine or a motor of a
vehicle, runs about the pulley 13. An electromagnetic clutch may be
used instead of the pulley 13.
[0039] In the crank chamber 9, a lug plate 15 is press-fitted to
the drive shaft 11, and bearings 9d and 9e are arranged between the
lug plate 15 and the front housing 3. A swash plate 17 is fitted to
the drive shaft 11. A spring 19, which decreases a tilt angle of
the swash plate 17 about the drive shaft 11, is arranged between
the lug plate 15 and the swash plate 17. In the crank chamber 9, a
circlip 11a is fixed to the drive shaft 11, and a return spring 21
is arranged to the circlip 11a facing toward the swash plate 17. A
link mechanism 23, which supports the swash plate 17 in a tiltable
manner, couples the lug plate 15 and the swash plate 17. In the
present specification, the term circlip is analogous to snap
ring.
[0040] Each cylinder bore 1a accommodates a piston 25 that is
movable back and forth. Shoes 27a and 27b, which form a pair, are
arranged between each piston 25 and the swash plate 17. The pairs
of the shoes 27a and 27b convert the wobbling movement of the swash
plate 17 into a reciprocating movement of the pistons 25.
[0041] A valve unit 29 is arranged between the cylinder block 1 and
the rear housing 5. A compression chamber 31 is formed between the
piston 25 of each cylinder bore 1a and the valve unit 29. The valve
unit 29 draws refrigerant from a suction chamber 5a into the
compression chamber 31 when the piston 25 is in the suction stroke,
encloses the refrigerant in the compression chamber 31 when the
piston 25 is in the compression stroke, and discharges the
refrigerant in the compression chamber 31 to a discharge chamber 5b
when the piston 25 is in the discharge stroke.
[0042] The rear housing 5 includes the suction chamber 5a, which is
located inward in the radial direction, and the discharge chamber
5b, which is annular and located outward in the radial direction. A
bleeding passage 42 connects the crank chamber 9 and the suction
chamber 5a. Supplying passages 44 and 46 connect the crank chamber
9 and the discharge chamber 5b. The rear housing 5 includes a
control valve chamber 5c defined by a cylindrical cavity. The
control valve chamber 5c accommodates a displacement control valve
2, which is in communication with the suction chamber 5a through a
pressure detection passage 48 and which is in communication with
the supplying passages 44 and 46.
[0043] As shown in FIG. 2, the displacement control valve 2
includes a first case 4 and a second case 10 that form a valve
case, which serves as a shell. An upper end portion of the first
case 4 defines a detection chamber 4a, and a lower end portion of
the first case 4 defines a valve chamber 4b. A side surface of the
first case 4 includes a suction port 4c that opens the detection
chamber 4a to the exterior. The suction port 4c, which is in
communication with the suction chamber 5a (refer to FIG. 1) through
the pressure detection passage 48, is supplied with suction
pressure Ps. The detection chamber 4a may be formed to supply the
detection chamber 4a with flow rate differential pressure. An
adjustment screw 6 is fastened to the upper end of the first case
4, and the detection chamber 4a is defined by the first case 4 and
the adjustment screw 6.
[0044] A tubular fixed steel core 8 is fixed to the lower end of
the first case 4. The first case 4 and the fixed steel core 8
define the valve chamber 4b. The side surface of the first case 4
includes a crank port 4d that opens the valve chamber 4b to the
exterior. The crank port 4d is in communication with the crank
chamber 9 (refer to FIG. 1) through the supplying passage 44 and is
supplied with crank chamber pressure Pc.
[0045] The first case 4 also includes a shaft hole 4e, which
extends in the axial direction. The shaft hole 4e communicates the
detection chamber 4a and the valve chamber 4b. The side surface of
the first case 4 includes a discharge port 4f that opens the shaft
hole 4e to the exterior and extends in the radial direction. The
discharge port 4f is in communication with the discharge chamber 5b
(refer to FIG. 1) through the supplying passage 46 and is supplied
with discharge pressure Pd.
[0046] The second case 10, which is tubular, is fixed to the lower
end of the first case 4, and a coil 12 is fixed around the fixed
steel core 8 in the second case 10. An input signal for the PWM
control, which is an external signal, is input to the coil 12
through a terminal (not shown). In the present embodiment, the side
at which the coil 12 is arranged is referred to as the lower end
side, and the opposite side is referred to as the upper end
side.
[0047] A shaft hole 8a extends through the fixed steel core 8
coaxially with the shaft hole 4e. A movable steel core 14 is
located at a lower side of the fixed steel core 8. A rod 16, which
is fixed to an upper end of the movable steel core 14, extends
upward through the shaft hole 8a, the valve chamber 4b, and the
shaft hole 4e and into the detection chamber 4a.
[0048] A bellows 18 is accommodated in the detection chamber 4a.
The bellows 18 includes an upper end fixed to the adjustment screw
6 and a lower end fixed to the rod 16. The lower end of the bellows
18 is urged upward by a spring 20, which is arranged between the
bellows 18 and the first case 4.
[0049] The upper part of the rod 16 includes a small diameter
portion 16a that extends over the shaft hole 4e and the valve
chamber 4b. The portion above the small diameter portion 16a of the
rod 16 has a diameter that is sufficient for sealing the shaft hole
4e while allowing for movement of the rod 16, and the small
diameter portion 16a has a smaller diameter than this upper
portion.
[0050] A valve seat VS extends around the shaft hole 4e of the
valve chamber 4b. The rod 16 includes a valve body VB, which faces
the valve seat VS, below the small diameter portion 16a. A spring
washer 24 is fixed to the rod 16 in the valve chamber 4b, and a
push spring 26 is arranged between the spring washer 24 and the
first case 4. In the present embodiment, the valve seat VS is
formed integrally with the first case 4, and the rod including the
valve body VB extends through the first case 4 and the second case
10.
[0051] A flange 28 is fixed to the lower end of the second case 10,
and a cover 30 is fixed to the lower end of the flange 28 to
conceal the movable steel core 14. The cover 30 is made of resin
such as nylon in which glass fiber is dispersed. Part of the coil
12 is insert molded to the cover 30 in a state connected to the
terminal (not shown). The cover 30 prevents lubricating oil and the
like from collecting on the coil 12 and the terminal.
[0052] As shown in FIG. 3, a wall surface of the control valve
chamber 5c in the rear housing 5 includes an engagement groove 40
for engagement with a circlip 50. The engagement groove 40 is
annular and has a uniform depth from the wall surface of the
control valve chamber 5c. The engagement groove 40 includes a first
engagement surface 40a, which is located at an inner far side, and
a second engagement surface 40b, which is located at an outer side.
The first engagement surface 40a has a tapered shape, the second
engagement surface 40b is orthogonal to an axis of the control
valve chamber 5c, and the first engagement surface 40a and the
second engagement surface 40b are spaced apart by an equal distance
in the circumferential direction.
[0053] The displacement control valve 2 is accommodated in the
control valve chamber 5c of the compressor by way of five O-rings
2a to 2e. The O-rings 2a to 2d seal passages from one another that
are in communication with the displacement control valve 2. The
O-ring 2e functions to seal and prevent the entrance of refrigerant
from the exterior and absorb vibration transmitted in the radial
direction of the displacement control valve 2. The circlip 50 is
engaged with the engagement groove 40. The circlip 50 uses a
widely-circulated material, for example, carbon steel (S-C
material), spring steel (SK material), and stainless steel (SUS
material). In this state, each of the O-rings 2a to 2e is forced
against the wall surface of the control valve chamber 5c. Thus, the
cover 30 of the displacement control valve 2 is in contact with the
circlip 50.
[0054] As shown in FIG. 4, the circlip 50 includes a C-shaped
engagement portion 50a, which engages the engagement groove 40,
wide portions 50b and 50c formed on the two ends of the engagement
portion 50a, and a wide portion 50d formed at the middle of the
engagement portion 50a and projecting inward in the radial
direction opposing the wide portions 50b and 50c. Fitting holes
50e, 50f, which a pliers is fitted to reduce the diameter, extend
through the wide portions 50b and 50c.
[0055] The circlip 50 shown in FIG. 4 differs from the conventional
circlip 91 shown in FIG. 16 in that the engagement portion 50a is
narrow excluding the wide portions 50b to 50d. More specifically,
the engagement portion 50a includes a cutout 50g, which avoids
contact with the cover 30 of the displacement control valve 2,
defined at an inner side of the C-shaped main body. The cutout 50g
defines a clearance C that serves as a vibration transmitting
suppressing means and a contact area reducing means. That is, the
cutout 50g reduces the contact area between the cover 30 and the
circlip 91 and lowers the rigidity of the cover 30. This decreases
the spring constant and shifts the resonance frequency to a low
frequency thereby lowering the peak frequency and suppressing the
transmission of vibration.
[0056] As shown in FIG. 3, the circlip 50 includes a first surface
50h, which faces the first engagement surface 40a and the cover 30,
and a second surface 50i, which faces the second engagement surface
40b. The first surface 50h and the second surface 50i engage the
first engagement surface 40a and the second engagement surface 40b,
respectively. The first surface 50h and the second surface 50i are
parallel. The first surface 50h, which is an opposing surface
opposing the cover 30, can contact the cover 30 at the locations of
the wide portions 50b to 50d but cannot contact the cover 30 at the
location of the engagement portion 50a. Thus, the parts of the
first surface 50h at the wide portions 50b to 50d serves as contact
surfaces that come into contact with the cover 30. The cover 30
includes a surface 30a that contacts the first surface 50h or the
second surface 50i where the wide portions 50b to 50d are
located.
[0057] In a vehicle air conditioner, the above compressor has the
discharge chamber 5b, which is shown in FIG. 1, connected to a
condenser. The condenser is connected by an expansion valve to an
evaporator, and the evaporator is connected to the suction chamber
5a. When the drive shaft 11 is driven and rotated by an engine or
the like, the refrigerant in the suction chamber 5a is compressed
in the compression chambers 31 and discharged to the discharge
chamber 5b with a displacement corresponding to the tilt angle of
the swash plate 17.
[0058] During this operation, for example, when the vehicle is
accelerated and the PWM control increases the opening degree
between the valve seat VS and the valve body VB shown in FIG. 2,
high pressure refrigerant gas is easily supplied in from the
discharge chamber 5b to the crank chamber 9 through the discharge
port 4f, the shaft hole 4e, the valve chamber 4b, and the crank
port 4d. This decreases the displacement. On the other hand, when
the speed of the vehicle is constant and the PWM control decreases
the opening degree between the valve seat VS and the valve body VB,
the supply of high pressure refrigerant gas from the discharge
chamber 5b to the crank chamber 9 is restricted. This increases the
displacement. Thus, in the compressor, the displacement is varied
in accordance with the vehicle speed and the like.
[0059] In this compressor, an input signal of the PWM control is
transmitted to the coil 12 and transmitted by the rod 16 to the
valve body VB. Thus, when the opening degree of the valve seat VS
and the valve body VB is small, the valve body VB impacts the valve
seat VS a number of times. The vibration generated by the impact of
the valve seat VS and the valve body VB in the displacement control
valve 2 is transmitted over a path extending through the case 10
from the valve seat VS to the rear housing 5.
[0060] However, in this compressor, the clearance C formed by the
cutout 50g shown in FIGS. 3 and 4 is arranged in the path and
suppresses the transmission of the vibration generated by the
impact of the valve seat VS and the valve body VB. This restricts
the transmission of the vibration to the rear housing 5 and
accomplishes noise reduction.
[0061] This compressor does not employ a sheet, which is an
additional member that increases the number of assembling steps and
increases the cost of components. Further, the circlip 50 is made
of a typical SUS. Thus, the compressor lowers cost. In particular,
in the compressor, the rear housing 5 includes the engagement
groove 40, which is normal, and only the shape of the circlip 50 is
special. Thus, costs are subtly increased. The compressor does not
employ a rubber sheet that may deteriorate when used over a long
period. Thus, quietness and sealing can be achieved over a long
period.
[0062] Accordingly, the compressor reduces noise, lowers cost, and
has superior durability.
Second Embodiment
[0063] A compressor of a second embodiment employs a circlip 51
shown in FIGS. 5 and. 6. In the circlip 51, an engagement portion
51a includes a small diameter portion 51b and a large diameter
portion 51c that are successively bent. Fitting holes 51f and 51g
used to reduce the diameter are formed in wide portions 51d and
51e. The parts of the small diameter portion 51b bent toward the
large diameter portion 51c forms a cutout 51h that avoids contact
with the cover 30 of the displacement control valve 2. The
clearance C formed by the cutout 51h serves as the vibration
transmitting suppressing means and the contact area reducing means.
That is, the cutout 50h reduces contact between the cover 30 and
the circlip 51 and suppresses the transmission of vibration.
Otherwise, the structure is the same as the first embodiment.
[0064] The second embodiment has the same advantages as the first
embodiment.
Third Embodiment
[0065] As shown in FIGS. 7 to 9, a compressor of a third embodiment
employs a novel cover 31 while employing the conventional circlip
91 shown in FIG. 15 and FIG. 16. As shown in FIG. 8, recesses 31b
and 31c are arranged at two opposite sides of a surface 31a of the
cover 31 facing the circlip 91. The recesses 31b and 31c avoid
contact between the cover 31 and the circlip 91. A clearance C
formed by the two recesses 31b and 31c serves as the vibration
transmitting suppressing means and the contact area reducing means.
That is, the recesses 31b and 31c reducing the contact area between
the cover 31 and the circlip 91 and suppress the transmission of
vibration. Otherwise, the structure is the same as the first
embodiment.
[0066] The third embodiment also has the same advantages as the
first embodiment. In particular, in the compressor of the third
embodiment, the conventional circlip 91 is employed, and only the
shape of the cover 31 of the displacement control valve 2 is
special. Thus, costs are subtly increased.
Fourth Embodiment
[0067] As shown in FIG. 10, a compressor of a fourth embodiment
employs a novel circlip 52 while employing the conventional cover
30 and the engagement groove 40 shown in FIGS. 1 to 4. A plurality
of recesses 52b are arranged in a circumferential direction in a
surface 52a, which comes into contact with the cover 30, at one
side of the circlip 52. The recesses 52b avoid contact between the
cover 30 and the circlip 52. A clearance C formed by each recess
52b serves as the vibration transmitting suppressing means and the
contact area reducing means. That is, the recesses 52b reduce the
contact area between the cover 30 and the circlip 52 and between
the circlip 52 and the rear housing 5. This suppresses the
transmission of vibration. Otherwise, the structure is the same as
the first embodiment.
[0068] The fourth embodiment also has the same advantages as the
first embodiment. In particular, in the compressor of the fourth
embodiment, the conventional displacement control valve 2 is
employed, and only the shape of the circlip 52 is special. Thus,
costs are subtly increased.
Fifth Embodiment
[0069] As shown in FIG. 11, in a compressor of a fifth embodiment,
a circlip 53 has a second surface 53a facing the second engagement
surface 40b of the engagement groove 40 on the side opposite to the
surface that comes into contact with the cover 30. A plurality of
recesses 53b are arranged in the circumferential direction in the
second surface 53a. The recesses 53b avoid contact between the
circlip 53 and the rear housing 5. A clearance C formed by each
recess 53b serves as the vibration transmitting suppressing means
and the contact area reducing means. That is, the recesses 53b
reduce the contact area between the circlip 53 and the rear housing
5 and suppresse the transmission of vibration. Otherwise, the
structure is the same as the fourth embodiment.
[0070] The fifth embodiment also has the same advantages as the
fourth embodiment.
Sixth Embodiment
[0071] As shown in FIG. 12, a compressor of a sixth embodiment
employs a novel engagement groove 41 while employing the
conventional cover 30 shown in FIGS. 1 to 4 and the conventional
circlip 91 shown in FIGS. 15 and 16. The engagement groove 41 is
defined by a first engagement surface 41a, which is located at the
inner side (upper end side) of the control valve chamber 5c, and a
second engagement surface 41b, which is located at the open side
(lower end side). A plurality of recesses 41c are arranged in the
circumferential direction in the second engagement surface 41b. In
the portion where the recesses 41c are arranged, the distance
between the first engagement surface 41a and the second engagement
surface 41b is greater than the thickness of the circlip 91. The
recesses 41c avoid contact between the circlip 91 and the rear
housing 5. A clearance C formed by each recess 41c serves as the
vibration transmitting suppressing means and the contact area
reducing means. That is, the recesses 41c reduce the contact area
between the circlip 91 and the rear housing 5 and suppress the
transmission of the vibration. Otherwise, the structure is the same
as the first embodiment.
[0072] The sixth embodiment has the same advantages as the first
embodiment. In particular, in the compressor of the sixth
embodiment, only the shape of the engagement groove 41 is special.
Thus, costs are subtly increased.
Seventh Embodiment
[0073] As shown in FIG. 13, a compressor of a seventh embodiment
employs a novel cover 32 while employing the conventional
engagement groove 40 shown in FIGS. 1 to 4 and the conventional
circlip 91 shown in FIGS. 15 and 16. The circumferential part of
the cover 32 includes a clearance 32a extending in the
circumferential direction and arranged closer to the opening of the
control valve chamber 5c than the O-ring 2e. The clearance 32a,
which is formed by a recess, serves as the vibration transmitting
suppressing means and the vibration attenuating means. That is,
when the cover 32, which defines the clearance, transmits
vibration, the clearance 32a deforms and attenuates the vibration.
This suppresses the transmission of vibration between the cover 32
and the circlip 91. A contact surface 32b of the cover 32 contacts
the circlip 91. Otherwise, the structure is the same as the first
embodiment.
[0074] The seventh embodiment has the same advantages as the first
embodiment. In particular, in the compressor of the seventh
embodiment, the clearance 32a attenuates the vibration transmitted
from the displacement control valve 2 to the circlip 91. In this
case, only the shape of the cover 32 for the displacement control
valve 2 is special. Thus, costs are subtly increased.
Eighth Embodiment
[0075] As shown in FIG. 14, a compressor of an eighth embodiment
employs a new circlip 54 while employing the conventional
engagement groove 40 and cover 30 shown in FIGS. 1 to 4. The
circlip 54 has a thickness that is less than that of the
conventional circlip 91, smaller than the distance between the
first engagement surface 40a and the second engagement surface 40b
of the engagement groove 40, and allows for elastic deformation to
obtain clearances 54a and 54b between the engagement surfaces 40a
and 40b. The clearances 54a and 54b serve as the vibration
transmitting suppressing means and the vibration attenuating means.
That is, the clearances 54a and 54b attenuate the vibration
transmitted in at least either one of between the cover 32 and the
circlip 91 and between the circlip 91 and the rear housing 5. This
suppresses the transmission of the vibration between the
components. Otherwise, the structure is the same as the first
embodiment.
[0076] The eighth embodiment has the same advantages as the first
embodiment. In particular, the compressor of the eighth embodiment
is only required to employ the circlip 54 that is elastically
deformable in the thicknesswise direction. Thus, costs are subtly
increased.
[0077] The present invention has been described through the first
to eighth embodiments. However, the present invention is not
limited to the first to eighth embodiments, which may be modified
within the scope of the invention.
[0078] For instance, the displacement control valve 2 may include a
bleeding passage 42 that connects the crank chamber 9 and the
suction chamber 5a of the variable displacement compressor.
* * * * *