U.S. patent application number 14/640254 was filed with the patent office on 2015-10-01 for variable displacement type swash plate compressor.
This patent application is currently assigned to KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. The applicant listed for this patent is KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. Invention is credited to Shohei FUJIWARA, Kei NISHII, Masaki OTA, Takahiro SUZUKI, Shinya YAMAMOTO.
Application Number | 20150275874 14/640254 |
Document ID | / |
Family ID | 54066920 |
Filed Date | 2015-10-01 |
United States Patent
Application |
20150275874 |
Kind Code |
A1 |
OTA; Masaki ; et
al. |
October 1, 2015 |
VARIABLE DISPLACEMENT TYPE SWASH PLATE COMPRESSOR
Abstract
The valve body has a first valve part and a second valve part.
The first valve part has an end surface seal part that is brought
into contact with a seat part of a first valve seat part and closes
a bleed passage. The second valve part has an external surface seal
part that enters the second valve hole and closes the supply
passage. When the opening degree of the first valve part is
maximum, the seal length of the external surface seal part along
the moving direction of the valve body is shorter than the distance
between the end surface seal part and the seat part along the
moving direction of the valve body.
Inventors: |
OTA; Masaki; (Kariya-shi,
JP) ; SUZUKI; Takahiro; (Kariya-shi, JP) ;
YAMAMOTO; Shinya; (Kariya-shi, JP) ; NISHII; Kei;
(Kariya-shi, JP) ; FUJIWARA; Shohei; (Kariya-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA TOYOTA JIDOSHOKKI |
Kariya-shi |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA TOYOTA
JIDOSHOKKI
Kariya-shi
JP
|
Family ID: |
54066920 |
Appl. No.: |
14/640254 |
Filed: |
March 6, 2015 |
Current U.S.
Class: |
417/222.1 |
Current CPC
Class: |
F04B 27/1804 20130101;
F04B 2027/1813 20130101; F04B 2027/1822 20130101; F04B 2027/1827
20130101 |
International
Class: |
F04B 27/18 20060101
F04B027/18; F04B 27/10 20060101 F04B027/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 25, 2014 |
JP |
2014-061832 |
Claims
1. A variable displacement type swash plate compressor comprising:
a housing; a rotation shaft; a swash plate, which is housed in the
housing and rotates by obtaining driving force from the rotation
shaft, and an inclination angle of the swash plate relative to the
rotation shaft varies; a piston, which is engaged with the swash
plate; a movable body, which is coupled to the swash plate and
changes the inclination angle of the swash plate; a control
pressure chamber, which is partitioned by the movable body and in
which the movable body moves in an axial direction of the rotation
shaft to change the inclination angle of the swash plate based on
change of a pressure inside the control pressure chamber due to
introduction of a refrigerant gas into the control pressure
chamber; and a capacity control valve that controls a pressure in
the control pressure chamber, the piston reciprocally moving by
stroke according to the inclination angle of the swash plate,
wherein the capacity control valve comprises: a valve body that
reciprocally moves by operation of an electromagnetic solenoid; a
first valve seat part that has a first valve hole, which forms a
part of a bleed passage from the control pressure chamber to a
suction pressure region; and a second valve seat part that has a
second valve hole, which forms a part of a supply passage from a
discharge pressure region to the control pressure chamber, the
valve body has: a first valve part, which has an end surface seal
part that closes the bleed passage by moving into contact with the
first valve seat part; and a second valve part that has an external
surface seal part, which closes the supply passage by entering the
second valve hole, and when an opening degree of the first valve
part is maximum, a seal length of the external surface seal part
along a moving direction of the valve body is shorter than a
distance between the end surface seal part and the first valve seat
part.
2. The variable displacement type swash plate compressor according
to claim 1, wherein the valve body has a projecting part that
projects from the end surface seal part toward the first valve seat
part and also enters the first valve hole and closes the bleed
passage, and when the projecting part has entered the first valve
hole, the second valve part opens.
3. The variable displacement type swash plate compressor according
to claim 1, wherein the second valve seat part is a separate body
from a valve housing of the capacity control valve, a biasing
member is provided between the first valve seat part and the second
valve seat part in the valve housing, and the biasing member biases
the second valve seat part toward a step part of the valve
housing.
4. The variable displacement type swash plate compressor according
to claim 3, wherein the valve body has an external surface enlarged
part that increases in size in a tapered manner from the external
surface seal part to the end surface seal part.
5. The variable displacement type swash plate compressor according
to claim 3, wherein the first valve seat part is a separate body
from the valve housing, the first valve seat part is press-fitted
to a press fitting part of the valve housing, and before the first
valve seat part is press-fitted to the press fitting part, a length
of the biasing member is a free length.
6. The variable displacement type swash plate compressor according
to claim 3, further comprising: a press-fit member that is
press-fitted to a press fitting part of the valve housing, wherein
the first valve seat part is a separate body from the valve
housing, the first valve seat part, the biasing member and the
second valve seat part are arranged between the step part and the
press-fit member, and before the press-fit member is press-fitted
to the press fitting part, a length of the biasing member is a free
length.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a variable displacement
type swash plate compressor in which a piston reciprocally moves by
stroke according to an inclination angle of a swash plate.
[0002] Japanese Laid-Open Patent Publication No. 1-190972 discloses
a variable displacement type swash plate compressor of which an
inclination angle of the swash plate is changeable by a movable
body. According to this compressor, when a refrigerant gas has been
introduced into the control pressure chamber within a housing, the
pressure in the control pressure chamber is changed. By this
arrangement, the movable body moves in the axial direction of the
rotation shaft and changes the inclination angle of the swash
plate.
[0003] Specifically, when the pressure in the control pressure
chamber has become high and has approached the pressure in the
discharge pressure region, the movable body moves toward one end
part of the rotation shaft, and increases the inclination angle of
the swash plate. As a result, the stroke of the piston becomes
large, and a discharge capacity increases. On the other hand, when
the pressure in the control pressure chamber has become low and has
approached the pressure in the suction pressure region, the movable
body moves toward the other end part of the rotation shaft and
decreases the inclination angle of the swash plate. As a result,
the stroke of the piston becomes small, and the discharge capacity
decreases. The variable displacement type swash plate compressor
further includes a capacity control valve that controls the
pressure in the control pressure chamber.
[0004] The variable displacement type swash plate compressor has a
throttle in the middle of the supply passage from the discharge
pressure region to the control pressure chamber. The throttle can
decrease the flow quantity of the refrigerant gas that is supplied
from the discharge pressure region to the control pressure chamber.
Accordingly, the inclination angle of the swash plate can be
maintained at an intermediate angle between a maximum inclination
angle and a minimum inclination angle. Consequently, the compressor
can be efficiently operated in the intermediate discharge
quantity.
[0005] However, as the compressor has the throttle in the middle of
the supply passage when an operation command in the maximum
discharge capacity is transmitted from the control computer, a
pressure in the control pressure chamber cannot be instantly
approached to a pressure in the discharge pressure region.
Therefore, the inclination angle of the swash plate cannot be
instantly changed to the maximum inclination angle, and it takes
time until the compressor is operated in the maximum discharge
capacity.
[0006] Further, the refrigerant gas that is supplied from the
discharge pressure region to the control pressure chamber via the
supply passage is a compressed refrigerant gas. Therefore, during
the operation of the compressor, when the flow quantity of the
refrigerant gas supplied to the control pressure chamber increases,
the operation efficiency of the compressor decreases.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a variable
displacement type swash plate compressor that can instantly change
the inclination angle of the swash plate to a maximum inclination
angle while maintaining operation efficiency.
[0008] In order to solve the above problem, according to a first
aspect of the present invention, there is provided a variable
displacement type swash plate compressor that includes: a housing;
a rotation shaft; a swash plate, which is housed in the housing and
rotated by driving force from the rotation shaft, and the
inclination angle of the swash plate relative to the rotation shaft
varies; a piston, which is engaged with the swash plate; a movable
body, which is coupled to the swash plate and changes the
inclination angle of the swash plate; a control pressure chamber
which is partitioned by the movable body and in which the movable
body moves in an axial direction of the rotation shaft to change
the inclination angle of the swash plate based on change of a
pressure inside the control pressure chamber due to introduction of
a refrigerant gas into the control pressure chamber; and a capacity
control valve that controls a pressure in the control pressure
chamber, wherein the piston reciprocally moves by stroke according
to the inclination angle of the swash plate. The capacity control
valve includes: a valve body that reciprocally moves by operation
of an electromagnetic solenoid; a first valve seat part that has a
first valve hole which forms a part of a bleed passage from the
control pressure chamber to a suction pressure region; and a second
valve seat part that has a second valve hole which forms a part of
a supply passage from a discharge pressure region to the control
pressure chamber. The valve body has: a first valve part which has
an end surface seal part that closes the bleed passage by moving
into contact with the first valve seat part; and a second valve
part that has an external surface seal part which closes the supply
passage by entering the second valve hole. When an opening degree
of the first valve part is maximum, a seal length of the external
surface seal part along a moving direction of the valve body is
shorter than a distance between an end surface seal part and a
first valve seat part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side sectional view of a double-headed piston
type swash plate compressor according to an embodiment of the
present invention;
[0010] FIG. 2 is a sectional view of a capacity control valve when
an inclination angle of a swash plate is a minimum inclination
angle;
[0011] FIG. 3 is a sectional view of the capacity control valve
when the inclination angle of the swash plate is a maximum
inclination angle;
[0012] FIG. 4 is a side sectional view of the double-headed piston
type swash plate compressor when the inclination angle of the swash
plate is a maximum inclination angle;
[0013] FIG. 5 is a graph showing a relationship between
displacement of a valve body and opening degrees of a first valve
part and a second valve part;
[0014] FIG. 6A is a partially enlarged sectional view showing a
state before a first valve seat part is press-fitted to a press
fitting part;
[0015] FIG. 6B is a partially enlarged sectional view showing a
state that a second valve seat part and an external surface
enlarged part are in contact with each other;
[0016] FIG. 7A is a partially enlarged sectional view showing a
state that a swash plate of a capacity control valve according to
other example is at a minimum inclination angle;
[0017] FIG. 7B is a partially enlarged sectional view showing a
state that the swash plate is at a maximum inclination angle;
[0018] FIG. 8 is a graph showing a relationship between
displacement of a valve body and opening degrees of a first valve
part and a second valve part;
[0019] FIG. 9A is a partially enlarged sectional view of a capacity
control valve according to other example; and
[0020] FIG. 9B is a partially enlarged sectional view showing a
state before a press-fit member is press-fitted to a press fitting
part.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Hereinafter, a variable displacement type swash plate
compressor according to an embodiment of the present invention will
be described with reference to FIG. 1 to FIG. 6B by taking an
example of a compressor that is used in a vehicle air conditioner.
In the following description, a front and rear direction and an up
and down direction will be defined respectively as shown in FIG.
1.
[0022] As shown in FIG. 1, a housing 11 of a variable displacement
type swash plate compressor 10 includes a first cylinder block 12,
a second cylinder block 13, a front housing 14 joined to the front
end of the first cylinder block 12, and a rear housing 15 joined to
the rear end of the second cylinder block 13. The first cylinder
block 12 is arranged in front of the second cylinder block 13 and
is joined to the second cylinder block 13.
[0023] A first valve/port forming body 16 is arranged between the
front housing 14 and the first cylinder block 12. A second
valve/port forming body 17 is arranged between the rear housing 15
and the second cylinder block 13.
[0024] A suction chamber 14a and a discharge chamber 14b are
partitioned between the front housing 14 and the first valve/port
forming body 16. The discharge chamber 14b is arranged at the outer
periphery side of the suction chamber 14a. A suction chamber 15a
and a discharge chamber 15b are partitioned between the rear
housing 15 and the second valve/port forming body 17. A pressure
adjusting chamber 15c is formed in the rear housing 15. The
pressure adjusting chamber 15c is arranged in a center part of the
rear housing 15, and the suction chamber 15a is arranged at an
outer periphery side of the pressure adjusting chamber 15c. The
discharge chamber 15b is arranged at an outer periphery side of the
suction chamber 15a. The discharge chambers 14b and 15b are
connected to each other via a discharge passage not shown. The
discharge passage is connected to an external refrigerant circuit
not shown. The discharge chambers 14b and 15b are discharge
pressure regions.
[0025] The first valve/port forming body 16 has a suction port 16a
that is communicated with the suction chamber 14a, and a discharge
port 16b that is communicated with the discharge chamber 14b. The
second valve/port forming body 17 has a suction port 17a that is
communicated with the suction chamber 15a, and a discharge port 17b
that is communicated with the discharge chamber 15b. The suction
port 16a and 17a have suction valve mechanisms not shown. The
discharge ports 16b and 17b have discharge valve mechanisms not
shown.
[0026] A rotation shaft 21 having a center axial line L is
rotationally supported in the housing 11. Both ends in the
longitudinal direction of the rotation shaft 21 are arranged toward
the front and rear direction of the housing 11. A front end of the
rotation shaft 21 is inserted through an axial hole 12h which is
formed on the first cylinder block 12, and the front end is also
arranged in the front housing 14. The rear end of the rotation
shaft 21 is inserted through an axial hole 13h which is formed on
the second cylinder block 13, and the rear end is also arranged in
the pressure adjusting chamber 15c.
[0027] The front end of the rotation shaft 21 is rotationally
supported to the axial hole 12h of the first cylinder block 12. The
rear end of the rotation shaft 21 is rotationally supported to the
axial hole 13h of the second cylinder block 13. A lip seal type
shaft seal device 22 is arranged between the front housing 14 and
the rotation shaft 21. An engine E of a vehicle as an external
driving source is work-coupled to the front end of the rotation
shaft 21 via a power transmission mechanism PT. The power
transmission mechanism PT is a normally transmission type
clutchless mechanism that is configured by combining a belt and a
pulley.
[0028] A crank chamber 24 partitioned by the first cylinder block
12 and the second cylinder block 13 is formed in the housing 11. A
swash plate 23 having an insertion hole 23a is housed in the crank
chamber 24. The swash plate 23 is installed on the rotation shaft
21 by inserting the rotation shaft 21 through the insertion hole
23a. The swash plate 23 can rotate by obtaining driving force from
the rotation shaft 21 and can also tilt with respect to the axis of
the rotation shaft 21.
[0029] A plurality of first cylinder bores 12a is formed on the
first cylinder block 12. The plurality of first cylinder bores 12a
extends in the axial direction of the first cylinder block 12 and
is also arranged around the rotation shaft 21. FIG. 1 shows only
one first cylinder bore 12a. Each of the plurality of first
cylinder bores 12a is communicated with the suction chamber 14a via
the suction port 16a and is communicated with the discharge chamber
14b via the discharge port 16b. A plurality of second cylinder
bores 13a is formed on the second cylinder block 13. The plurality
of second cylinder bores 13a extends in the axial direction of the
second cylinder block 13 and is also arranged around the rotation
shaft 21. FIG. 1 shows only one second cylinder bore 13a. Each of
the plurality of second cylinder bores 13a is communicated with the
suction chamber 15a via the suction port 17a and is communicated
with the discharge chamber 15b via the discharge port 17b. The
first cylinder bore 12a and the second cylinder bore 13a are
respectively arranged to form a pair in the front and rear
direction. In the first cylinder bore 12a and the second cylinder
bore 13a that form the pair, double-headed pistons 25 as pistons
are housed reciprocally in the front and rear direction.
[0030] Each double-headed piston 25 is engaged with the outer
peripheral part of the swash plate 23 via a pair of shoes 26. When
the rotation shaft 21 has rotated, rotational motion of the swash
plate 23 is transformed into reciprocal linear motion of the
double-headed pistons 25 via the shoes 26. In each first cylinder
bore 12a, the first compression chamber 20a is partitioned by the
double-headed pistons 25 and the first valve/port forming body 16.
In each second cylinder bore 13a, the second compression chamber
20b is partitioned by the double-headed pistons 25 and the second
valve/port forming body 17.
[0031] A first large diameter hole 12b having a larger diameter
than that of the axial hole 12h and being continuous with the axial
hole 12h is formed on the first cylinder block 12. The first large
diameter hole 12b is communicated with the crank chamber 24. The
crank chamber 24 and the suction chamber 14a are communicated with
each other by a suction passage 12c that passes through the first
cylinder block 12 and the first valve/port forming body 16.
[0032] A second large diameter hole 13b having a larger diameter
than that of the axial hole 13h is formed on the second cylinder
block 13 as well as being continuous with the axial hole 13h. The
second large diameter hole 13b is communicated with the crank
chamber 24. The crank chamber 24 and the suction chamber 15a are
communicated with each other by a suction passage 13c that passes
through the second cylinder block 13 and the second valve/port
forming body 17.
[0033] A suction opening 13s is formed on the peripheral wall of
the second cylinder block 13. The suction opening 13s is connected
to the external refrigerant circuit. The refrigerant gas is
suctioned into the crank chamber 24 from the external refrigerant
circuit via the suction opening 13s, and is thereafter suctioned
into the suction chamber 14a via the suction passage 12c and into
the suction chamber 15a via the suction passage 13c. Therefore, the
pressures in the suction chambers 14a and 15a and the pressure in
the crank chamber 24 become substantially equal, and the suction
chambers 14a and 15a and the crank chamber 24 become a suction
pressure region.
[0034] An annular flange part 21f is installed in a protruding
manner on the outer peripheral surface of the rotation shaft 21.
The flange part 21f is arranged in the first large diameter hole
12b. A first thrust bearing 27a is installed near the front end of
the rotation shaft 21. The first thrust bearing 27a is arranged
between the flange part 21f and the first cylinder block 12. A
cylindrical supporting member 39 is press-fitted to the vicinity of
the rear end of the rotation shaft 21. An annular flange part 39f
is provided installed in a protruding manner from the outer
peripheral surface of the supporting member 39. The flange part 39f
is arranged in the second large diameter hole 13b. The second
thrust bearing 27b is arranged between the flange part 39f and the
second cylinder block 13.
[0035] An annular fixed body 31 is fixed to the rotation shaft 21.
Therefore, the fixed body 31 can rotate together with the rotation
shaft 21. The fixed body 31 is arranged between the flange part 21f
and the swash plate 23. A bottomed cylindrical movable body 32 is
arranged between the flange part 21f and the fixed body 31. The
movable body 32 can move to the fixed body 31 in the axial
direction of the rotation shaft 21.
[0036] The movable body 32 is formed by a circular annular bottom
part 32a and a cylinder part 32b. An insertion hole 32e through
which the rotation shaft 21 is inserted is formed on the bottom
part 32a. The cylinder part 32b extends from the outer peripheral
edge of the bottom part 32a along the axial direction of the
rotation shaft 21. The inner peripheral surface of the cylinder
part 32b can slide to the outer peripheral edge of the fixed body
31. Therefore, the movable body 32 can rotate together with the
rotation shaft 21 by the fixed body 31. The interface between the
inner peripheral surface of the cylinder part 32b and the outer
peripheral edge of the fixed body 31 is sealed by a seal member 33.
The interface between the insertion hole 32e and the rotation shaft
21 is sealed by a seal member 34. A control pressure chamber 35 is
partitioned between the fixed body 31 and the movable body 32.
[0037] A first shaft inner passage 21a is formed in the rotation
shaft 21. The first shaft inner passage 21a extends along the axial
direction of the rotation shaft 21. The rear end of the first shaft
inner passage 21a is opened to the pressure adjusting chamber 15c.
A second shaft inner passage 21b is formed on the rotation shaft
21. The second shaft inner passage 21b extends along the radial
direction of the rotation shaft 21. The lower end of the second
shaft inner passage 21b is communicated with the front end of the
first shaft inner passage 21a. The upper end of the second shaft
inner passage 21b is opened to the control pressure chamber 35.
Therefore, the control pressure chamber 35 and the pressure
adjusting chamber 15c are communicated with each other via the
first shaft inner passage 21a and the second shaft inner passage
21b.
[0038] In the crank chamber 24, a lug arm 40 is arranged between
the swash plate 23 and the flange part 39f. The lug arm 40 is
formed in approximately an L shape. A weight part 40a is formed at
the upper end of the lug arm 40. The upper end of the weight part
40a passes through a groove part 23b of the swash plate 23 and
projects to the front of the swash plate 23.
[0039] A first pin 41 that is arranged to cross the groove part 23b
is installed on the swash plate 23. The upper end of the lug arm 40
is coupled to the vicinity of the upper end of the swash plate 23
by the first pin 41. Therefore, the vicinity of the upper end of
the lug arm 40 is supported to the swash plate 23 so as to be able
to swing around a first swing center M1 as an axis core of the
first pin 41. The vicinity of the lower end of the lug arm 40 is
coupled to the supporting member 39 by a second pin 42. Therefore,
the vicinity of the lower end of the lug arm 40 is supported to the
supporting member 39 so as to be able to swing around a second
swing center M2 as an axis core of the second pin 42.
[0040] A coupling part 32c projects from the front end of the
cylinder part 32b of the movable body 32 toward the swash plate 23.
An insertion hole 32h through which a third pin 43 is inserted is
formed on the coupling part 32c. An insertion hole 23h through
which the third pin 43 is inserted is formed near the lower end of
the swash plate 23. The third pin 43 couples between the coupling
part 32c of the movable body 32 and the lower end of the swash
plate 23.
[0041] The pressure in the control pressure chamber 35 is
controlled by the supply of the refrigerant gas from the discharge
chamber 15b to the control pressure chamber 35 and the discharge of
the refrigerant gas from the control pressure chamber 35 to the
suction chamber 15a. That is, the refrigerant gas that is supplied
to the control pressure chamber 35 is a control gas that controls
the pressure in the control pressure chamber 35. The movable body
32 moves to the fixed body 31 in the axial direction of the
rotation shaft 21, based on a pressure difference between the
pressure in the control pressure chamber 35 and the pressure in the
crank chamber 24. An electromagnetic system capacity control valve
50 that controls the pressure in the control pressure chamber 35 is
installed in the rear housing 15. The capacity control valve 50 is
electrically connected to a control computer 50c. An air
conditioner switch 50s is signal-connected to the control computer
50c.
[0042] As shown in FIG. 2, a valve housing 50h of the capacity
control valve 50 has a first housing 51 having a cylindrical shape
and a second housing 52 having a cylindrical shape. An
electromagnetic solenoid 53 is housed in the first housing 51. The
second housing 52 is installed in the first housing 51. The
electromagnetic solenoid 53 has a fixed iron core 54 and a variable
iron core 55. The variable iron core 55 is pulled to the fixed iron
core 54 based on excitation by current supply to a coil 53c. That
is, electromagnetic force of the electromagnetic solenoid 53 acts
to pull the variable iron core 55 toward the fixed iron core 54.
The electromagnetic solenoid 53 operates by receiving conduction
control of the control computer 50c, specifically, by receiving
duty ratio control. A spring 56 is arranged between the fixed iron
core 54 and the variable iron core 55. The spring 56 biases the
variable iron core 55 to a direction of separating the variable
iron core 55 from the fixed iron core 54.
[0043] A driving force transmitting rod 57 is installed on the
variable iron core 55. The driving force transmitting rod 57 can
move together with the variable iron core 55. The fixed iron core
54 has a small diameter part 54a and a large diameter part 54b
having a larger diameter than that of the small diameter part 54a.
The small diameter part 54a is arranged at the inner side of the
coil 53c. The large diameter part 54b projects from the opening of
the first housing 51 at the opposite side of the variable iron core
55. A concave part 54c is formed on the end surface of the large
diameter part 54b at the opposite side of the small diameter part
54a. A step part 541c is formed on the inner wall of the concave
part 54c. The second housing 52 is fitted to and fixed to the
concave part 54c in the state that the second housing 52 is brought
into contact with the step part 541c.
[0044] A housing chamber 59 is formed at the opposite side of the
electromagnetic solenoid 53 in the second housing 52. A pressure
sensing mechanism 60 is housed in the housing chamber 59. The
pressure sensing mechanism 60 includes a bellows 61, a pressure
receiving body 62 that is joined to the upper end of the bellows
61, a coupled body 63 that is coupled to the lower end of the
bellows 61, and a spring 64 that is laid in the bellows 61. The
pressure receiving body 62 is press-fitted to the opening of the
second housing 52 at the opposite side of the first housing 51. The
spring 64 biases the coupled body 63 to a direction of separating
the coupled body 63 away from the pressure receiving body 62.
[0045] A stopper 62a is formed on the pressure receiving body 62.
The stopper 62a projects from the lower surface of the pressure
receiving body 62 toward the coupled body 63. A stopper 63a is
formed on the coupled body 63. The stopper 63a projects from the
upper surface of the coupled body 63 toward the stopper 62a of the
pressure receiving body 62. The stopper 62a of the pressure
receiving body 62 and the stopper 63a of the coupled body 63 define
a shortest length of the bellows 61.
[0046] A valve chamber 65 is formed between the housing chamber 59
in the second housing 52 and the first housing 51. The valve
chamber 65 is communicated with the housing chamber 59. The
diameter of the valve chamber 65 is smaller than the diameter of
the housing chamber 59. A supply chamber 66 is formed between the
valve chamber 65 in the second housing 52 and the first housing 51.
The supply chamber 66 is communicated with the valve chamber 65.
The diameter of the supply chamber 66 is smaller than the diameter
of the valve chamber 65. A step part 52f is formed between the
valve chamber 65 and the supply chamber 66 in the second housing
52.
[0047] An annular first valve seat part 71 is arranged near the
housing chamber 59 in the valve chamber 65. The first valve seat
part 71 is a separate body from the second housing 52. A first
valve hole 71h is formed at the center of the first valve seat part
71. The first valve hole 71h communicates between the valve chamber
65 and the housing chamber 59. An annular second valve seat part 72
is arranged near the supply chamber 66 in the valve chamber 65. The
second valve seat part 72 is a separate body from the second
housing 52. A second valve hole 72h is formed at the center of the
second valve seat part 72. The second valve hole 72h communicates
between the valve chamber 65 and the supply chamber 66.
[0048] A biasing spring 73 as a biasing member is arranged between
the first valve seat part 71 and the second valve seat part 72 in
the valve chamber 65. The biasing spring 73 biases the second valve
seat part 72 toward the step part 52f of the second housing 52. The
second valve seat part 72 is positioned by being pressed to the
step part 52f by the biasing spring 73. The first valve seat part
71 is press-fitted to the inner surface of the valve chamber 65
near the housing chamber 59. Therefore, the inner surface of the
valve chamber 65 near the housing chamber 59 forms a press fitting
part 65a to which the first valve seat part 71 is press-fitted.
[0049] A rear pressure chamber 67 is partitioned between the
concave part 54c of the fixed iron core 54 and the lower surface of
the second housing 52. The rear pressure chamber 67 and the housing
chamber 59 are communicated with each other via a communication
passage 52r that is formed on the second housing 52.
[0050] A valve body 74 is housed in the second housing 52. The
valve body 74 extends from the housing chamber 59 to the rear
pressure chamber 67. The valve body 74 has a first valve part 75
and a second valve part 76. Both the first valve part 75 and the
second valve part 76 are housed in the valve chamber 65. The first
valve part 75 has an end surface seal part 75s. The end surface
seal part 75s is brought into contact with a seat part 71e as an
end surface of the first valve seat part 71 around the first valve
hole 71h. The first valve part 75 has an annular projecting part
75f. The projecting part 75f projects above the end surface seal
part 75s and also enters the first valve hole 71h. The second valve
part 76 has an external surface seal part 76s that enters the
second valve hole 72h.
[0051] The valve body 74 has an annular external surface enlarged
part 74a. The external surface enlarged part 74a is formed to
increase in size in in a tapered manner and to be inclined
conically from the external surface seal part 76s toward the end
surface seal part 75s. The valve body 74 has a reduced-diameter
part 74b having a smaller diameter than that of the external
surface seal part 76s. The reduced-diameter part 74b is arranged in
the supply chamber 66. The valve body 74 further has an
enlarged-diameter part 74c having a larger diameter than that of
the reduced-diameter part 74b. The enlarged-diameter part 74c is
continuous with the reduced-diameter part 74b. The
enlarged-diameter part 74c projects into the rear pressure chamber
67 by moving beyond the bottom part of the second housing 52. An
annular first working surface 741, which has the form of a step, is
formed between the external surface seal part 76s and the
reduced-diameter part 74b of the valve body 74. A second working
surface 742, which has the form of an annular step, is formed
between the reduced-diameter part 74b and the enlarged-diameter
part 74c of the valve body 74. The pressure receiving surface of
the first working surface 741 is the same as the pressure receiving
surface of the second working surface 742.
[0052] The upper end of the driving force transmitting rod 57
projects into the rear pressure chamber 67 by moving beyond the
fixed iron core 54. The upper end of the driving force transmitting
rod 57 is brought into contact with the enlarged-diameter part 74c
of the valve body 74.
[0053] A rod 74e projects from the upper end surface of the valve
body 74 that faces the housing chamber 59. The upper end of the rod
74e is separably coupled to the coupled body 63. A return spring 77
is arranged between the projecting part 75f and the coupled body
63. The return spring 77 biases the valve body 74 toward the
electromagnetic solenoid 53.
[0054] A communication hole 521 that is communicated with the
housing chamber 59 is formed in the second housing 52. A
communication hole 522 that is communicated with the valve chamber
65 is formed in the second housing 52. A communication hole 523
that communicates with the supply chamber 66 is formed in the
second housing 52. The housing chamber 59 is communicated with the
suction chamber 15a via the communication hole 521 and the passage
81. The valve chamber 65 is communicated with the pressure
adjusting chamber 15c via the communication hole 522 and the
passage 82. Therefore, the second shaft inner passage 21b, the
first shaft inner passage 21a, the pressure adjusting chamber 15c,
the passage 82, the communication hole 522, the valve chamber 65,
the first valve hole 71h, the housing chamber 59, the valve chamber
521, and the passage 81 form a bleed passage that extends from the
control pressure chamber 35 to the suction chamber 15a.
[0055] The supply chamber 66 is communicated with the discharge
chamber 15b via the communication hole 523 and the passage 83. The
discharge chamber 15b is communicated with the control pressure
chamber 35 via the passage 83, the communication hole 523, the
supply chamber 66, the second valve hole 72h, the valve chamber 65,
the communication hole 522, the passage 82, the pressure adjusting
chamber 15c, the first shaft inner passage 21a, and the second
shaft inner passage 21b. Therefore, the passage 83, the
communication hole 523, the supply chamber 66, the second valve
hole 72h, the valve chamber 65, the communication hole 522, the
passage 82, the pressure adjusting chamber 15c, the first shaft
inner passage 21a, and the second shaft inner passage 21b form a
supply passage from the discharge chamber 15b to the control
pressure chamber 35.
[0056] The bellows 61 expands and contracts in a moving direction
of the valve body 74 by sensing the pressure applied to the bellows
61 in the housing chamber 59 and the pressure applied to the
enlarged-diameter part 74c of the valve body 74 in the rear
pressure chamber 67. Expansion and contraction of the bellows 61
positions the valve body 74 and contributes to the control of the
opening degrees of the first valve part 75 and the second valve
part 76. The opening degrees of the first valve part 75 and the
second valve part 76 are determined by the balance between the
electromagnetic force generated by the electromagnetic solenoid 53,
the biasing force of the spring 56, and the biasing force of the
pressure sensing mechanism 60.
[0057] The first valve part 75 is in the closed valve state for
closing the bleed passage when the projecting part 75f enters the
first valve hole 71h. On the other hand, the first valve part 75 is
in the opened valve state for opening the bleed passage when the
projecting part 75 exits from the first valve hole 71h. The second
valve part 76 is in the closed valve state for closing the supply
passage when the external surface seal part 76s enters the second
valve hole 72h. On the other hand, the second valve part 76 is in
the opened valve state for opening the supply passage when the
external surface seal part 76s exits from the second valve hole
72h.
[0058] In the variable displacement type swash plate compressor 10,
in the state in which the air conditioner switch 50s has been
turned off and current to the electromagnetic solenoid 53 has been
stopped, the variable iron core 55 is separated from the fixed iron
core 54 by the spring 56, and the valve body 74 is moved toward the
electromagnetic solenoid 53 by the return spring 77. Accordingly,
the end surface seal part 75s is separated from the seat part 71e,
and the projecting part 75f can exit from the first valve hole 71h.
In this state, the end surface seal part 75s is most separated from
the seat part 71e and the opening degree of the first valve part 75
is maximum.
[0059] At this time, the external surface seal part 76s enters the
second valve hole 72h, so that the interface between the external
surface seal part 76s and the second valve hole 72h is sealed. A
seal length L1 of the external surface seal part 76s along the
moving direction of the valve body 74 is shorter than a distance L2
between the end surface seal part 75s and the seat part 71e along
the moving direction of the valve body 74. In the present
embodiment, when the opening degree of the first valve part 75 is
maximum, the seal length L1 is the same as a distance L3 along the
moving direction of the valve body 74 between the projecting part
75f and the first valve seat part 71. Further, because the pressure
receiving surface of the first working surface 741 is the same as
the pressure receiving surface of the second working surface 742,
the valve body 74 is suppressed from moving by sensing the pressure
of the refrigerant gas supplied to the supply chamber 66.
[0060] An increase in the opening degree of the first valve part 75
causes an increase in the flow quantity of the refrigerant gas that
is discharged from the control pressure chamber 35 to the suction
chamber 15a via the second shaft inner passage 21b, the first shaft
inner passage 21a, the pressure adjusting chamber 15c, the passage
82, the communication hole 522, the valve chamber 65, the first
valve hole 71h, the housing chamber 59, the communication hole 521,
and the passage 81. As a result, the pressure in the control
pressure chamber 35 approaches the pressure in the suction chamber
15a.
[0061] As shown in FIG. 1, when the pressure in the control
pressure chamber 35 approaches the pressure in the suction chamber
15a and the pressure difference between the pressure in the control
pressure chamber 35 and the pressure in the crank chamber 24 has
become small, the swash plate 23 pulls the movable body 32 by the
compression reaction force from the double-headed pistons 25 that
operates to the swash plate 23, and the movable body 32 moves to
set the bottom part 32a closer to the fixed body 31. Then, the
swash plate 23 swings around the first swing center M1. Following
this vibration, the lug arm 40 swings around the first vibration
center M1 and around the second swing center M2 respectively, and
the lug arm 40 approaches the flange part 39f of the supporting
member 39. Consequently, the inclination angle of the swash plate
23 becomes small, the stroke of the double-headed pistons 25
becomes small, and the discharge capacity decreases. When the
inclination angle of the swash plate 23 has reached a minimum
inclination angle, the lug arm 40 is brought into contact with the
flange part 39f of the supporting member 39. When the lug arm 40
has been brought into contact with the flange part 39f, the
inclination angle of the swash plate 23 is maintained at a minimum
inclination angle.
[0062] As shown in FIG. 3, in the variable displacement type swash
plate compressor 10, when the air conditioner switch 50s has been
turned on and a current has been supplied to the electromagnetic
solenoid 53, the variable iron core 55 is pulled to the fixed iron
core 54 against the spring force of the spring 56 by the
electromagnetic force of the electromagnetic solenoid 53. Then, the
driving force transmitting rod 57 presses the valve body 74 against
the spring force of the return spring 77.
[0063] When the valve body 74 has been pressed by the driving force
transmitting rod 57, the projecting part 75f enters the first valve
hole 71h, and the external surface seal part 76s exits from the
second valve hole 72h. When the valve body 74 has been further
pressed, the end surface seal part 75s is brought into contact with
the seat part 71e, and the quantity of the external surface seal
part 76s that exits from the second valve hole 72h becomes maximum.
This causes decrease in the flow quantity of the refrigerant gas
that is discharged from the control pressure chamber 35 to the
suction chamber 15a via the second shaft inner passage 21b, the
first shaft inner passage 21a, the pressure adjusting chamber 15c,
the passage 82, the communication hole 522, the valve chamber 65,
the first valve hole 71h, the housing chamber 59, the communication
hole 521, and the passage 81. Then, the refrigerant gas is supplied
from the discharge chamber 15b to the control pressure chamber 35
via the passage 83, the communication hole 523, the supply chamber
66, the second valve hole 72h, the valve chamber 65, the
communication hole 522, the passage 82, the pressure adjusting
chamber 15c, the first shaft inner passage 21a, and the second
shaft inner passage 21b. As a result, the pressure in the control
pressure chamber 35 approaches the pressure in the discharge
chamber 15b.
[0064] As shown in FIG. 4, when the pressure in the control
pressure chamber 35 approaches the pressure in the discharge
chamber 15b and the pressure difference between the pressure in the
control pressure chamber 35 and the pressure in the crank chamber
24 has become large, the movable body 32 moves to separate the
bottom part 32a from the fixed body 31 while pulling the swash
plate 23. Then, the swash plate 23 swings in the direction opposite
to the direction at the time of reduction in the inclination angle
of the inclination angle 23, around the first swing center M1.
Then, the lug arm 40 swings in the direction opposite to the
direction at the time of reduction in the inclination angle of the
swash plate 23 around the first swing center M1 and around the
second swing center M2, respectively, and the lug arm 40 is
separated from the flange part 39f of the supporting member 39.
Accordingly, the inclination angle of the swash plate 23 becomes
large, the stroke of the double-headed pistons 25 becomes large,
and the discharge capacity increases. When the inclination angle of
the swash plate 23 has reached the maximum inclination angle, the
movable body 32 is brought into contact with the flange part 21f.
When the movable body 32 has been brought into contact with the
flange part 21f, the inclination angle of the swash plate 23 is
maintained at the maximum inclination angle.
[0065] Next, the operation of the variable displacement type swash
plate compressor 10 will be described with reference to FIG. 5 to
FIG. 6A.
[0066] A solid line in FIG. 5 expresses a relationship between
displacement of the valve body 74 and opening degrees of the first
valve part 75 and the second valve part 76 according to the present
embodiment. A two-dot chain line in FIG. 5 expresses a relationship
between displacement of the valve body 74 and opening degrees of
the first valve part 75 and the second valve part 76 according to a
comparative example. In the comparative example, the first valve
part 75 does not have the projecting part 75f, and the second valve
part 76 has an end surface seal part that closes the supply passage
by being brought into contact with the end surface of the second
valve seat part 72 around the second valve hole 72h.
[0067] As shown in FIG. 5, in the present embodiment, the opening
degree of the second valve part 76 when the first valve part 75 is
moving to the seat part 71e from the state of a maximum opening
degree of the first valve part 75 is smaller than the opening
degree in the comparative example. As a result, during the
operation of the variable displacement type swash plate compressor
10, the flow quantity of the refrigerant gas supplied to the
control pressure chamber 35 becomes small.
[0068] Then, when the end surface seal part 75s of the first valve
part 75 has been brought into contact with the seat part 71e, the
external surface seal part 76s of the second valve part 76 exits
from the second valve hole 72h, and the opening degree of the
second valve part 76 becomes maximum. Accordingly, as the flow
quantity of the refrigerant gas supplied from the discharge chamber
15b to the control pressure chamber 35 via the supply passage
increases, the inclination angle of the swash plate 23 is instantly
changed to the maximum inclination angle. As a result, the variable
displacement type swash plate compressor 10 is operated in the
maximum discharge capacity.
[0069] FIG. 6A shows a state that the second valve seat part 72 is
mounted on the step part 52f of the second housing 52, the valve
body 74 is housed in the second housing 52, and the biasing spring
73 is mounted on the second valve seat part 72. In this state, the
first valve seat part 71 is press-fitted to the press fitting part
65a. Before the first valve seat part 71 is press-fitted to the
press fitting part 65a, the length of the biasing spring 73 is a
free length. When the first valve seat part 71 has been
press-fitted to the press fitting part 65a, biasing force that
presses the second valve seat part 72 to the step part 52f occurs
in the biasing spring 73.
[0070] FIG. 6B shows a state that the valve body 74 is being
pressed toward the bottom part of the second housing 52 in the
state that the first valve seat part 71 has been press-fitted to
the press fitting part 65a and the second valve seat part 72 has
been pressed to the step part 52f by the biasing spring 73. In this
state, the external surface enlarged part 74a is in contact with
the inner surface of the second valve hole 72h and the axis of the
second valve seat part 72 coincides with the axis of the valve body
74. As a result, leakage of the refrigerant gas between the second
valve hole 72h and the external surface seal part 76s of the second
valve part 76 can be suppressed.
[0071] Accordingly, in the present embodiment, the following
effects can be obtained.
[0072] (1) The valve body 74 has the first valve part 75 and the
second valve part 76. The first valve part 75 has the end surface
seal part 75s that is brought into contact with the seat part 71e
of the first valve seat part 71 and closes the bleed passage. The
second valve part 76 has the external surface seal part 76s that
enters the second valve hole 72h and closes the supply passage.
When the opening degree of the first valve part 75 is maximum, the
seal length L1 of the external surface seal part 76s along the
moving direction of valve body 74 is shorter than the distance L2
between the end surface seal part 75s and the seat part 71e along
the moving direction of the valve body 74. According to this
configuration, as compared with the above comparative example, the
opening degree of the second valve part 76 when the first valve
part 75 is moving to the seat part 71e from the state of a maximum
opening degree of the first valve part 75 can be made small. As a
result, during the operation of the variable displacement type
swash plate compressor 10, the flow quantity of the refrigerant gas
supplied to the control pressure chamber 35 can be made small.
Further, when the end surface seal part 75s of the first valve part
75 has been brought into contact with the seat part 71e, the
external surface seal part 76s of the second valve part 76 exits
from the second valve hole 72h, and the opening degree of the
second valve hole 76 becomes maximum. Accordingly, because the flow
quantity of the refrigerant gas that is supplied from the discharge
chamber 15b to the control pressure chamber 35 via the supply
passage increases, the inclination angle of the swash plate 23 can
be instantly changed to the maximum inclination angle. As a result,
the inclination angle of the swash plate 23 can be instantly
changed to a maximum inclination angle while maintaining the
operation efficiency of the variable displacement type swash plate
compressor 10.
[0073] (2) The valve body 74 has the projecting part 75f that
projects from the end surface seal part 75s. The projecting part
75f enters the first valve hole 71h and closes the bleed passage.
When the projecting part 75f has entered the first valve hole 71h,
the second valve part 76 is opened. According to this
configuration, as compared with the case where the valve body 74
does not have the projecting part 75f, the timing when the bleed
passage is closed during the operation of the variable displacement
type swash plate compressor 10 can be made earlier. Therefore, the
discharge quantity of the refrigerant gas from the control pressure
chamber 35 to the suction chamber 15a via the bleed passage can be
made small. As a result, it is possible to decrease the flow
quantity of the refrigerant gas that is supplied from the discharge
chamber 15b to the control pressure chamber 35 via the supply
passage in order to set the inclination angle of the swash plate 23
to a maximum inclination angle. Accordingly, the operation
efficiency of the variable displacement type swash plate compressor
10 improves.
[0074] (3) The second valve seat part 72 is a separate body from
the second housing 52. Further, the biasing spring 73 is arranged
between the first valve seat part 71 and the second valve seat part
72 in the second housing 52. The biasing spring 73 biases the
second valve seat part 72 toward the step part 52f of the second
housing 52. According to this configuration, as compared with the
case where the second valve seat part 72 has been integrally formed
in the second housing 52, the clearance between the second valve
hole 72h and the external surface seal part 76s of the second valve
part 76 can be easily adjusted. Accordingly, leakage of the
refrigerant gas between the second valve hole 72h and the external
surface seal part 76s of the second valve part 76 can be
suppressed.
[0075] (4) The valve body 74 has the external surface enlarged part
74a. The external surface enlarged part 74a is formed to have a
tapered shape from the external surface seal part 76s to the end
surface seal part 75s. According to this configuration, by
contacting the external surface enlarged part 74a with the inner
surface of the second valve hole 72h in the state that the second
valve seat part 72 has been housed in the second housing 52, the
axis of the second valve seat part 72 and the axis of the valve
body 74 coincide with each other. That is, centering of the second
valve seat part 72 and the valve body 74 can be performed easily.
Consequently, leakage of the refrigerant gas between the second
valve hole 72h and the external surface seal part 76s of the second
valve part 76 can be suppressed.
[0076] (5) The first valve seat part 71 is a separate body from the
second housing 52. Further, the first valve seat part 71 is
press-fitted to the press fitting part 65a of the second housing
52. Before the first valve seat part 71 is press-fitted to the
press fitting part 65a, the length of the biasing spring 73 is a
free length. According to this configuration, in press-fitting the
first valve seat part 71 to the press fitting part 65a, the biasing
force of the biasing spring 73 does not act on the first valve seat
part 71. Therefore, the first valve seat part 71 can be easily
press-fitted to the press fitting part 65a.
[0077] (6) In the variable displacement type swash plate compressor
10 that employs the double-headed pistons 25, the crank chamber 24
cannot be made to function as a control pressure chamber for
changing the inclination angle of the swash plate 23, unlike the
variable displacement type swash plate compressor that employs a
single-headed piston. In this respect, in the above variable
displacement type swash plate compressor 10, the inclination angle
of the swash plate 23 is changed by changing the pressure of the
control pressure chamber 35 that is partitioned by the movable body
32. The control pressure chamber 35 has a space smaller than that
of the crank chamber 24. Therefore, the quantity of the refrigerant
gas that is introduced into the control pressure chamber 35 can be
small, and the operation efficiency of the variable displacement
type swash plate compressor 10 improves.
[0078] The above embodiment may be also changed as follows.
[0079] As shown in FIG. 7A and FIG. 7B, the projecting part 75f may
be omitted from the end surface seal part 75s. A valve body 74A
becomes in the closed valve state for closing the bleed passage, by
bringing the end surface seal part 75s of the first valve part 75
into contact with the seat part 71e. The valve body 74A becomes in
the opened valve state for opening the bleed passage, by separating
the end surface seal part 75s from the seat part 71e.
[0080] A solid line in FIG. 8 expresses a relationship between
displacement of the valve body 74A and opening degrees of the first
valve part 75 and the second valve part 76 according to the present
embodiment. A two-dot chain line in FIG. 8 expresses a relationship
between displacement of the valve body 74A and opening degrees of
the first valve part 75 and the second valve part 76 in the
comparative example. In the comparative example, the second valve
part 76 has the end surface seal part that closes the supply
passage by being brought into contact with the end surface of the
second valve seat part 72 around the second valve hole 72h.
[0081] As shown in FIG. 8, when the first valve part 75 is moving
toward the seat part 71e from the state of a maximum opening degree
of the first valve part 75, the opening degree of the second valve
part 76 is smaller than the opening degree in the comparative
example. As a result, during the operation of the variable
displacement type swash plate compressor 10, the flow quantity of
the refrigerant gas supplied to the control pressure chamber 35
becomes small.
[0082] Then, when the end surface seal part 75s of the first valve
part 75 has been brought into contact with the seat part 71e, the
external surface seal part 76s of the second valve part 76 exits
from the second valve hole 72h, and the opening degree of the
second valve hole 76 becomes maximum. Accordingly, because there is
the increase in the flow quantity of the refrigerant gas supplied
from the discharge chamber 15b to the control pressure chamber 35
via the supply passage, the inclination angle of the swash plate 23
is instantly changed to the maximum inclination angle. As a result,
the variable displacement type swash plate compressor 10 is
operated in the maximum discharge capacity.
[0083] As shown in FIG. 9A, an annular press-fit member 78 may be
further press-fitted to the press fitting part 65a. Further, the
first valve seat part 71 may not be press-fitted to the press
fitting part 65a. The first valve seat part 71, the biasing spring
73, and the second valve seat part 72 are arranged between the step
part 52f and the press-fit member 78.
[0084] As shown in FIG. 9B, before the press-fit member 78 is
press-fitted to the press fitting part 65a, the length of the
biasing spring 73 may be a free length. According to this
configuration, in press-fitting the press-fit member 78 to the
press fitting part 65a, the biasing force of the biasing spring 73
does not work on the press-fit member 78. Therefore, the press-fit
member 78 can be easily press-fitted to the press fitting part
65a.
[0085] When the press-fit member 78 is press-fitted to the press
fitting part 65a, the first valve seat part 71 is installed on the
press-fit member 78 in the state of being urged against the
press-fit member 78 by the biasing spring 73. In this case, in
order to install the first valve seat part 71, the first valve seat
part 71 need not be press-fitted to the press fitting part 65a.
Therefore, the axis of the first valve seat part 71 and the axis of
the valve body 74 easily coincide with each other without having
the first valve seat part 71 constrained by the second housing
52.
[0086] Before the first valve seat part 71 is press-fitted to the
press fitting part 65a, the length of the biasing spring 73 may not
be a free length, and the first valve seat part 71 may be energized
by the biasing spring 73.
[0087] The external surface enlarged part 74a may be omitted from
between the external surface seal part 76s and the end surface seal
part 75s of the valve body 74.
[0088] The second valve seat part 72 may be integrally formed with
the second housing 52.
[0089] The driving force transmitting rod 57 may be integrally
formed with the valve body 74.
[0090] The housing chamber 59 may be communicated with the suction
chamber 14a via the communication hole 521 and the passage 81. That
is, it is sufficient that the bleed passage from the control
pressure chamber 35 to the suction pressure region has been
formed.
[0091] The discharge chamber 14b and the control pressure chamber
35 may be communicated with each other via the passage 83, the
communication hole 523, the supply chamber 66, the second valve
hole 72h, valve chamber 65, communication hole 522, the passage 82,
pressure adjusting chamber 15c, the first shaft inner passage 21a,
and the second shaft inner passage 21b.
[0092] The driving force may be obtained from the external driving
source via a clutch.
[0093] The variable displacement type swash plate compressor 10 may
be a single-head piston type swash plate compressor that employs a
single-headed piston.
* * * * *