Automatic temperature and humidity regulation – Thermostatic – With pressure control
Reexamination Certificate
2003-02-14
2004-11-30
Tapolcai, William E. (Department: 3744)
Automatic temperature and humidity regulation
Thermostatic
With pressure control
C062S222000, C062S296000, C251S367000, C137S375000
Reexamination Certificate
active
06824068
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an expansion valve that constitutes a refrigerating cycle, and more specifically, to an expansion valve capable of excluding noise produced therein.
2. Description of the Prior Art
There are various types of expansion valves. In widely used expansion valves, a valving element is opposed from the upper-stream side to an orifice that is formed by constricting the middle of a high-pressure refrigerant passage through which a high-pressure refrigerant is fed into an evaporator. The valving element is opened and closed according to the temperature and pressure of a low-pressure refrigerant that is delivered from the evaporator.
An example of the expansion valves of this type is used in a refrigerating cycle of an automotive air conditioner or the like. As shown in
FIG. 10
, the refrigerating cycle comprises a refrigerant compressor
2
that is driven by means of an engine, a condenser
3
connected to the discharge side of the refrigerant compressor
2
, and a receiver
4
connected to the condenser
3
. The refrigerating cycle further comprises an expansion valve
5
, which adiabatically expands a liquid refrigerant from the receiver
4
into a vapor-liquid refrigerant, and an evaporator
6
connected to the valve
5
.
A valve body
5
a
of the expansion valve
5
is formed having a high-pressure-side passage
5
b
into which the liquid refrigerant flows and a low-pressure-side passage
5
c
through which the vapor-liquid refrigerant flows out. The high- and low-pressure-side passages
5
b
and
5
c
communicate with each other by means of an orifice
7
. A valve chamber
8
d
is provided with a valving element
8
for adjusting the flow rate of the refrigerant that passes through the orifice
7
.
The expansion valve body
5
a
is penetrated by a low-pressure refrigerant passage
5
d
. A plunger
9
a
is slidably located in the passage
5
d
. The plunger
9
a
is driven by means of a temperature sensing drive element
9
that is fixed on the top of the valve body
5
a
. The drive element
9
is divided into two parts, an upper gastight chamber
9
c
and a lower gastight chamber
9
c
′, by a diaphragm
9
d
. A disc portion
9
e
on the upper end of the plunger
9
a
abuts against the diaphragm
9
d
. A tube fixing hole
9
g
is formed in the central portion of a top lid
9
f
of the temperature sensing drive element
9
. A capillary tube
9
h
is attached to the hole
9
g
.
At the lower part of the expansion valve body
5
a
, a compression coil spring
8
a
is located in the valve chamber
8
d
. The spring
8
a
causes a support member
8
c
to press the valving element
8
in the valve-closing direction. The valve chamber
8
d
is defined by an adjust screw
8
b
that mates with the valve body
5
a
and is kept gastight by means of an O-ring
8
e
. An operating rod
9
b
abuts against the lower end of the plunger
9
a
. The rod
9
b
causes the valving element
8
to move in the valve-opening direction as the plunger
9
a
slides.
The plunger
9
a
in the temperature sensing drive element
9
transmits temperature in the low-pressure refrigerant passage
5
d
to the upper gastight chamber
9
c
. Pressure in the chamber
9
c
changes according to this temperature. If the temperature is high, for example, the pressure in the chamber
9
c
increases, so that the diaphragm
9
d
presses down the plunger
9
a
. Thereupon, the valving element
8
moves in the valve-opening direction to increase the flow rate of the refrigerant that passes through the orifice
7
, thereby lowering the temperature of the evaporator
6
.
If the temperature is low, on the other hand, the pressure in the upper gastight chamber
9
c
lowers, so that the force of the diaphragm
9
d
to press down the plunger
9
a
is reduced, and the valving element
8
is moved in the valve-closing direction by means of the compression coil spring
8
a
that urges the element
8
in the same direction. Thereupon, the flow rate of the refrigerant that passes through the orifice
7
lowers, and the temperature of the evaporator
6
rises.
Thus, the expansion valve
5
moves the valving element
8
to change the opening area of the orifice
7
according to the temperature change in the low-pressure refrigerant passage
5
d
, thereby adjusting the temperature of the evaporator
6
. In the expansion valve
5
of this type, the opening of the orifice
7
, which adiabatically expands the liquid refrigerant into the vapor-liquid refrigerant, is set in a manner such that the spring load of the variable-load compression coil spring
8
a
, which presses the valving element
8
in the valve-closing direction, is adjusted by means of the adjust screw
8
b.
In the expansion valve
5
shown in
FIG. 10
, the capillary tube
9
h
is attached to the tube fixing hole
9
g
of the temperature sensing drive element
9
.
FIG. 11
shows another example of the expansion valve
5
. In this example, a sealing plug
9
i
is attached in place of the tube
9
h
to the hole
9
g
. The expansion valve body
5
a
is in the form of a column having a square cross section. Thin-walled portions
5
e
are formed individually on the opposite sides of the bottom portion of the body
5
a
, and bolt holes
5
f
are bored near the low-pressure refrigerant passage
5
d.
The expansion valve
5
shown in
FIG. 10
is a temperature-type expansion valve that detects the outlet temperature of the evaporator
6
(temperature of the low-pressure refrigerant passage
5
d
) and transmits it to the temperature sensing drive element
9
of the valve
5
. If the expansion valve of this type is used in a refrigeration system of an air conditioner of an automobile, for example, in general, the automobile is left for a while under relatively high-load conditions related to the outside and inside air temperatures. If the refrigerating cycle (air-cooling operation) is then started, the liquid refrigerant is fed into the evaporator at a high rate, since the opening of the expansion valve is wide. Possibly, therefore, noise may be produced when the refrigerant passes through the expansion valve.
In some cases, moreover, the high-pressure refrigerant that is fed into the expansion valve may be subjected to pressure fluctuation on the upper-stream side in the refrigerating cycle. This pressure fluctuation is transmitted to the valve by the medium of the high-pressure refrigerant. Thereupon, in the expansion valve shown in
FIG. 10
, the refrigerant may possibly produce noise as it expands. When the pressure fluctuation of the refrigerant on the upper-stream side is transmitted to the valving element, the operation of the valving element may become unstable. In this case, vibration of the valving element may possibly produce noise.
Accordingly, a sound insulating case has been proposed as a measure to tackle the above problems of the prior art (Japanese Patent Application Laid-open No. 2002-29251). It is attached to the outside of an expansion valve lest noise leak out. Since this sound insulating case has a complicated shape, however, its manufacturing cost is high, and its attachment to the expansion valve is very troublesome.
OBJECT AND SUMMARY OF THE INVENTION
The object of the present invention is to provide an expansion valve, which can be easily fitted with sound insulating members having simple construction and has excellent sound insulating and vibration-proof effects.
According to a first aspect of the invention, there is provided an expansion valve comprising two case members of the same shape attached to an expansion valve body through sound insulating members.
Each case member has retaining portions and retainable portions arranged at the upper and lower parts thereof, the retaining portion of one case member being capable of engaging the retainable portion of the other case member, and the retainable portion of the one case member being capable of engaging the retaining portion of the other case member.
The outer surface of each case member is flat.
According to a second aspect
Minowa Masakatsu
Watanabe Kazuhiko
Yano Masamichi
Ali Mohammad M.
Fujikoki Corporation
Rader & Fishman & Grauer, PLLC
Tapolcai William E.
LandOfFree
Expansion valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Expansion valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Expansion valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3351290