Refrigeration – Refrigeration producer – With refrigerant treater
Reexamination Certificate
1999-07-06
2001-03-06
Tapolcai, William E. (Department: 3744)
Refrigeration
Refrigeration producer
With refrigerant treater
C062S503000
Reexamination Certificate
active
06196019
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an accumulator used in a refrigerant cycle for an automobile air conditioner or the like.
2. Description of the Related Art
One example of a conventional accumulator is shown in FIG.
15
. The accumulator includes a U-shaped suction pipe
204
provided in a tank
201
for separating refrigerant evaporated in an evaporator (not shown) into gaseous refrigerant and liquid refrigerant. A defroster
220
in the shape or an umbrella or a reversed-cup is also provided in the tank
210
for an effective separation of gaseous refrigerant and liquid refrigerant, even in a case where the accumulator vibrates or swings. Also provided in the tank
201
is a dryer unit
202
to dehydrate the refrigerant. The dryer unit
202
has a specific configuration so as to avoid the suction pipe
204
. At the bottom portion of the tank
201
, an oil returning opening (not shown) is provided in order to return lubricant oil to a compressor (not shown). A filter having a specific structure is provided in the suction pipe
204
at the bottom portion thereof.
As explained above, a conventional accumulator is composed of many parts including the suction pipe
204
, the defroster
220
, the dryer unit
202
, and the filter. Further, each of these parts has a complicated and peculiar shape and/or structure, which causes an increase in a manufacturing cost of the accumulator.
The conventional accumulator has other drawbacks that a refrigerant pressure loss in the accumulator is relatively large because the refrigerant passes through the U-shaped suction pipe
204
provided in the tank
201
, and the upper and opening of the suction pipe
204
is covered by a defroster
220
. The filter mounted in the suction pipe
204
also increases the loss of refrigerant pressure.
In this kind of refrigerant cycle, a certain amount of lubricant oil for lubricating a compressor (hereinafter referred to as “lubricant oil”) is added to the refrigerant. In the accumulator constituting the refrigerant cycle, the refrigerant containing the lubricant oil is separated into gaseous refrigerant, liquid refrigerant and lubricant oil. Then, the gaseous refrigerant and the lubricant oil are introduced into a compressor from the accumulator. At the same time, in the accumulator, the refrigerant is dehydrated by the dryer unit
202
disposed in the tank
201
.
Thus, an accumulator has various functions including a refrigerant-separate-function for separating refrigerant into gaseous refrigerant and liquid refrigerant, a liquid-store-function for storing liquid refrigerant, a oil-supply-function for supplying a certain amount of lubricant oil to a compressor, and a dehydrate-function for removing water contained in the refrigerant cycle.
In the tank
201
, liquid refrigerant and lubricant oil are accumulated at the bottom portion of the tank
201
in a separated manner such that a liquid refrigerant layer stays on a lubricant oil layer because the former is lighter than the latter in specific gravity. Especially, in a case where a large amount of liquid refrigerant is accumulated in the tank
201
, the lubricant oil cannot be supplied to the compressor until the liquid refrigerant forming the lower layer is completely discharged because the oil returning opening (not shown) is formed at the bottom portion of the tank
201
. As a result, the aforementioned oil-supply-function of the accumulator cannot be performed.
Furthermore, immediately after the refrigeration cycle begins to operate, the liquid refrigerant may be supplied to a compressor through the oil returning opening, which may cause trouble of the compressor.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the disadvantages of the conventional accumulator as described above.
An object of the present invention is to provide an accumulator having a reduced number of parts and a simplified structure, which can be manufactured at a low cost.
Another object of the present invention is to provide an accumulator having a structure which can decrease the loss of refrigerant pressure and improve system efficiency.
Still another object of the present invention is to provide an accumulator which can effectively supply lubricant oil, which tends to stay at a bottom portion of the accumulator, to a compressor.
According to one aspect of the present invention, an accumulator includes a tank, a refrigerant inlet and outlet ports each provided at an upper portion of the tank, and a dryer unit disposed in the tank at an intermediate portion along the direction of height of the tank. The accumulator also includes a separating wall extending upwardly from the dryer unit and dividing an upper inner space of the tank above the dryer unit into an inlet side upper space located at the refrigerant inlet port side and an outlet side upper space located at the refrigerant outlet port side. The separating wall has a plurality of apertures formed in a scattered state for communicating the inlet side upper space and the outlet side upper space with each other. Further, the accumulator includes an oil returning tube having a lower inlet opening and an upper outlet opening, wherein the oil returning tube in disposed in the tank such that the lower inlet opening and the upper outlet opening are located at a bottom portion of the tank and at the refrigerant outlet port, respectively.
As mentioned above, the upper inner space located above the dryer unit is divided into an inlet side upper space and an outlet side upper space, and these right and left upper spaces are communicated with each other through a plurality of apertures formed in the separating wall. Accordingly, when a mixture of liquid refrigerant and gaseous refrigerant is introduced into the inlet side upper space, the gaseous refrigerant flows from the inlet side upper space to the outlet side upper space through a plurality of apertures formed in the separating wall. Thus, the pressure loss of the refrigerant passing thought the accumulator can be decreased. Also, the inside structure of the accumulator can be simplified.
It is preferable that a refrigerant passing space is formed between an inner surface of the tank and the dryer unit so that refrigerant introduced into the tank through the refrigerant inlet port is arrived directly or indirectly at the bottom portion of the tank through the refrigerant passing space, whereby the refrigerant is agitated in the tank. In this case, lubricant oil and liquid refrigerant can be effectively agitated at the bottom portion of the tank, which enables to circulate the lubricant oil in the refrigeration cycle without causing a stagnation of the lubricant oil in the accumulator.
It is preferable that a ratio of a total area of the apertures formed in the separating wall to a cross-sectional area of the refrigerant inlet port falls within a range of from 1.3 to 3. In this case, the plurality of apertures formed in the separating wall can prevent a free communication between the refrigerant inlet port and the refrigerant outlet port to some degree, which enables the separating wall to function as a separator and causes the refrigerant to pass through the dryer unit.
It is preferable that a cross-sectional area of the oil returning pipe is 20 to 50% of a cross-sectional area of the refrigerant outlet port. This enables an effective pumping of the lubricant oil out of the tank.
It is preferable that the separating wall has an opening for communicating the inlet side upper space and the outlet side upper space with each other at a lower end portion of the separating wall. This prevents an accumulation of liquid refrigerant in the outlet side upper space, whereby the liquid refrigerant can be effectively prevented from being sent out of the tank through the refrigerant outlet port in case where the rotation rate of the compressor is suddenly changed when, for example, an engine connected to the compressor is in the process of starting or stopping.
Further, it is preferable that the upper outlet opening of
Fujii Takayuki
Higo Yutaka
Yamazaki Keiji
Showa Aluminum Corporation
Tapolcai William E.
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