|
Patent Abstract
An expansion valve 1 integrated with a solenoid valve includes a
valve body 10 and a valve chamber 20 formed inside the valve body
10 to which a high-pressure refrigerant is introduced. A valve member
30 forms a throttle flow path between a valve seat 40, and controls
the amount of refrigerant flowing therethrough. The valve body 30
is operated by the movement of a stopper member 80 of a power element
60 via an actuating rod 100. The high-pressure refrigerant acts
on a surface 80a of the stopper member 80 opposite to a diaphragm
70 via a pressure equalizing passage 12, a connecting chamber 22
of a solenoid valve 200, and a pressure equalizing passage 14. The
stopper member 80 is sealed between the guide member 90, so that
the high-pressure refrigerant does not act directly on the diaphragm.
Patent Claims
What is claimed is:
1. An expansion valve integrated with a solenoid valve, comprising:
a valve body; an inlet refrigerant flow path provided inside said
valve body into which is introduced a high-pressure-side refrigerant;
a valve chamber formed inside said valve body into which said refrigerant
flowing through said inlet refrigerant flow path enters; a throttle
flow path with a valve seat disposed inside said valve chamber;
a valve member for adjusting the opening of said throttle flow path;
a valve member actuating mechanism provided to said valve body for
displacing said valve member; an outlet refrigerant flow path formed
inside said valve member, said outlet refrigerant flow path providing
refrigerant being decompressed and expanded inside said throttle
flow path to an evaporator; and a solenoid valve assembled integrally
to said valve body, including a valve member provided so as to open
and close said outlet refrigerant flow path; wherein said valve
member actuating mechanism is provided with a housing, a diaphragm
provided inside said housing, a stopper member, and a guide member
for leading the high-pressure-side refrigerant to said stopper member.
2. The expansion valve integrated with a solenoid valve according
to claim 1, wherein said guide member is a stepped pipe-shaped member
provided with a large diameter portion for slidably supporting said
stopper member, and a small diameter portion press-fitted into said
valve body.
Patent Description
FIELD OF THE INVENTION
[0001] The present invention is related to an expansion valve integrated
with a solenoid valve, which is preferably used, for example, in
an air-conditioning device for automobiles in which the refrigeration
cycle is provided to both the front side and the rear side of the
automobile interior.
DESCRIPTION OF THE RELATED ART
[0002] Conventionally, expansion valves integrated with solenoid
valves such as those disclosed in Japanese Patent Laid-Open Publication
No. 10-73345 (Pages 4 through 8, FIG. 2) and Japanese Patent Laid-Open
Publication No. 11-182983 (Pages 4 through 7, FIG. 2) are known.
[0003] The expansion valve integrated with a solenoid valve disclosed
in these documents are equipped with a throttle flow path for decompressing
and expanding a high-pressure-side refrigerant, a valve member for
adjusting the opening of the throttle flow path, a valve member
actuating mechanism for displacing the valve member, and an outlet
refrigerant flow path for providing the refrigerant decompressed
and expanded in the throttle flow path to an evaporator, wherein
the outlet refrigerant flow path is opened and closed by the valve
member of the solenoid valve, and when the valve member of the solenoid
valve is closed, the valve member of the throttle flow path is closed
by a diaphragm operating mechanism that operates the valve member
by utilizing the refrigerant pressure between the valve member of
the solenoid valve and the throttle flow path.
[0004] However, in the conventional expansion valve integrated
with a solenoid valve, the high-pressure-side refrigerant is lead
towards the under surface of the diaphragm constituting the diaphragm
operating mechanism when the solenoid valve is closed, so that the
high-pressure-side refrigerant pressure of the refrigeration cycle
is provided to the diaphragm. Therefore, the diaphragm operating
mechanism is required to have high strength. Under such conditions,
measures such as forming the diaphragm using stainless steel material
with high compressive strength or increasing the thickness of the
housing of the diaphragm operating mechanism are considered.
[0005] Consequently, the conventional expansion valve integrated
with a solenoid valve suffers from problems such as high cost and
large size.
SUMMARY OF THE INVENTION
[0006] The present invention aims to solve the problems mentioned
above, by providing an expansion valve integrated with a solenoid
valve that does not introduce the high-pressure-side refrigerant
to the diaphragm operating mechanism when the solenoid valve is
closed.
[0007] The expansion valve integrated with a solenoid valve of
the present invention is basically equipped with a valve body; an
inlet refrigerant flow path provided inside the valve body into
which a high-pressure-side refrigerant is introduced; a valve chamber
formed inside the valve body into which the refrigerant flowing
from the inlet refrigerant flow path enters; a throttle flow path
with a valve seat disposed inside the valve chamber; a valve member
for adjusting the opening of the throttle flow path; a valve member
actuating mechanism provided to the valve body for displacing the
valve member; an outlet refrigerant flow path formed inside the
valve member, said outlet refrigerant flow path providing refrigerant
being decompressed and expanded inside the throttle flow path to
an evaporator; and a solenoid valve assembled integrally to said
valve body, including a valve member provided so as to open and
close the outlet refrigerant flowpath. The valve member actuating
mechanism mentioned above is provided with a housing, a diaphragm
provided inside the housing, a stopper member, and a guide member
for leading the high-pressure-side refrigerant to the stopper member.
[0008] Also, the guide member is a stepped pipe-shaped member provided
with a large diameter portion for slidably supporting the stopper
member, and a small diameter portion press-fitted into the valve
body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a cross-sectional view of the expansion valve
integrated with a solenoid valve of the present invention; and
[0010] FIG. 2 is a view illustrating the major components of the
expansion valve integrated with a solenoid valve of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] FIG. 1 is a cross-sectional view of the expansion valve
integrated with a solenoid valve of the present invention, and FIG.
2 is a view showing the major components of the present invention.
[0012] The expansion valve integrated with a solenoid valve denoted
as a whole by reference number 1 includes a valve body 10 made of
aluminum alloy and the like, and is provided with a valve chamber
20 to which a high-pressure refrigerant flows in and which is formed
on one end of the entire valve.
[0013] A spherical valve member 30 is provided to the interior
of the valve chamber 20, for opening and closing the refrigerant
flow path formed between the valve member and a valve seat 40 located
on the valve body 10. The valve member 30 is supported by a supporting
member 32, and the supporting member 32 is supported by a nut member
36 via a spring 34. The nut member 36 is provided with a screw portion
36a and a hexagonal hole 37, and is fitted to the valve body 10
using a wrench and the like. The space between the nut member 36
and the valve chamber 20 is sealed with a sealing member 38.
[0014] The refrigerant passing through a throttle flow path formed
between the valve member 20 and the valve seat 40 travels toward
an evaporator through a passage 42. The refrigerant returning from
the evaporator is sent toward a compressor through a passage 50.
[0015] A valve member actuating device 60, hereinafter referred
to as a power element, for operating the valve member 30 includes
a housing 62, and a diaphragm 70 interposed inside the housing 62.
An actuating chamber 72 defined by the diaphragm 70 is filled with
actuating fluid, and is sealed by a plug 74.
[0016] The housing 62 of the power element 60 includes a screw
portion 64, and is screwed onto the valve body 10.
[0017] The surface of the diaphragm 70 opposite to the actuating
chamber comes into contact with a stopper member 80.
[0018] The stopper member 80 is supported slidably by the interior
of a pipe-shaped guide member 90, which is press-fitted into the
valve body 10.
[0019] A seal member 82 is fitted to the stopper member 80, sealing
the space between the stopper member 80 and the guide member 90.
[0020] A solenoid valve 200 includes a coil 210. Electricity is
fed to the coil 210 via a cord 212. When electricity is fed to the
coil 210, magnetic force is generated at a suction member 230.
[0021] A plunger 220 is pressed against a pilot valve 240 at all
times by a spring 232. When electricity is supplied to the coil
210, the plunger 220 is pulled toward the suction member 230 resisting
against the force provided by the spring 232. At this point, a projection
222 on the leading end of the plunger 220 opens the central hole
of the pilot valve 240.
[0022] The high-pressure refrigerant flowing toward the valve chamber
20 reaches a connecting chamber 22 through a pressure equalizing
passage 12. When the central hole of the pilot valve 240 is opened
under such condition, the high-pressure refrigerant actuates the
pilot valve in the opening direction, and the high-pressure refrigerant
flows into a passage 42 leading to the evaporator.
[0023] The high-pressure refrigerant inside the connecting chamber
22 is sent into the interior of the guide member 90 through a sloped
passage 14, acts on a surface 80a of the stopper member 80, and
pushes up the diaphragm 70 via the stopper member 80. With this
action, the valve member 30 comes into contact with the valve seat
40, thereby closing the valve.
[0024] With the operation mentioned above, the disadvantages caused
by the high-pressure refrigerant being sent to the evaporator in
large amounts during initiation can be avoided.
[0025] In the structure of the present expansion valve integrated
with a solenoid valve, the high-pressure refrigerant acts on the
surface 80a of the stopper member 80, and not directly on the diaphragm
70.
[0026] Therefore, the load acting on the housing 62 of the power
element 60 is reduced.
[0027] FIG. 2 illustrates the major components of the expansion
valve integrated with a solenoid valve of the present invention.
The power element 60 is of the structure where the diaphragm 70
is interposed inside the housing 62, and where the stopper member
80 is assembled therein.
[0028] The stopper member 80 is provided with a ring groove 81
for receiving a seal member.
[0029] The guide member 90 is a stepped member including a large
diameter portion 90a for guiding the stopper member 80 and a small
diameter portion 90b having a leading end that is press-fitted into
the valve body, and is made of steel or the like.
[0030] The expansion valve integrated with a solenoid valve of
the present invention is structured so that the high-pressure refrigerant
acting on the actuating device (power element) for operating the
valve member provides pressure to the stopper member of the diaphragm,
and not directly to the diaphragm.
[0031] With the structure mentioned above, the load provided to
the operating device is reduced, and the durability of the members
is improved. |