JPH0338600Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to an expansion valve incorporated in the cooling cycle of an automobile air conditioner.

``Prior Art'' As shown in FIG. 4, a conventional expansion valve has a diaphragm 50 that is airtightly clamped at its periphery by an upper lid 51 and a lower lid 52, and the interior of the upper and lower lids is divided into two by the diaphragm. 1 and 2 airtight chambers 53 and 54 are constructed. Therefore, the temperature of the refrigerant at the outlet side of the evaporator 35 in the cooling system 30 shown in FIG. Natsute diaphragm 5
Pressure is applied to the upper side of 0. Further, the pressure in the outlet side passage 58 of the evaporator 35 is transmitted through the pressure equalizing hole 55 of the main body 57 to the second airtight chamber 54, that is, the diaphragm 50.
This diaphragm 50
Spring 2 that opposes the balance of the upper and lower receiving pressure of
3 acts on the lower surface of the diaphragm 50 from the valve 26 via the operating rod 59, and the opening degree of the valve 26 is determined by the balance of pressures in the first and second airtight chambers 53 and 54. . However, there are the following problems in response to the demand for downsizing the diaphragm 50 due to restrictions on mounting space within the hood or the like. To reduce the thickness of the diaphragm,
Due to strength and assembly limitations, the rigidity of the diaphragm increases, and a large differential pressure is required to obtain the specified opening of the valve, and in order to operate the cooling system, the flow control of the valve is reduced and the degree of superheat is adjusted. Controllability deteriorated due to adjustment. If the rigidity of the diaphragm is increased by reducing the plate diameter of the diaphragm, the repeated durability performance will be reduced.

Furthermore, there are the following problems in response to a request to change the pressure value in the first airtight chamber 53, which is affected by the heat received from the refrigerant temperature on the outlet side of the evaporator, in order to improve the efficiency of the system. (a) Even if a refrigerant different from the refrigerant in the cooling system is filled, the vapor pressure of the refrigerant is uniquely determined, so the efficiency of the system cannot be improved. ○Because the refrigerant is filled with liquid, it has a small time constant and tends to cause hunting in the expansion valve.

"Means for Solving the Problems" The present invention was developed in view of the problems mentioned above, and its structure is such that a lid is airtightly fixed to the upper part of a main body having a high-pressure side passage and a low-pressure side passage. A diaphragm is placed in the recessed chamber formed by the diaphragm, and the other end of the operating rod is in contact with the lower surface of the diaphragm, and the valve opening provided at the end of the high pressure side passage is biased from behind by a spring to seat the diaphragm. In a temperature-type automatic expansion valve that is butted against a valve, the upper and lower diaphragms are airtightly joined around the entire circumference to provide an airtight chamber inside, and the diaphragm is housed in the recessed chamber, and one diaphragm is is adhesively supported on the lid body, and a temperature sensing cylinder containing an adsorbent inside is airtightly connected to the other diaphragm and housed in the main body, and the inside of the refrigerant filling pipe penetrated through the lid body and the airtight chamber are connected. A means for solving the above-mentioned problems is to provide a structure in which the temperature sensing tube is communicated with the temperature sensing tube and the lower end of the temperature sensing tube is abutted against the upper end of the operating rod.

"Operation" Since the displacement of the diaphragm corresponding to the opening amount of the valve is divided into two diaphragms, the displacement of each diaphragm is small.As a result, the diameter of the diaphragm can be reduced, and the upper and lower diaphragms can be Since the volume of the airtight chamber provided is small, the temperature-sensitive tube that houses the adsorbent can be made smaller.

``Example'' 1 is a main body of an expansion valve, which is formed by vertically penetrating a communicating hole 3 along a center line 2 located at the center of the main body, and a concentric circle with the communicating hole 3 is formed in the upper part of the main body. A lid body 5 is airtightly fixed in a raised part 4 provided in a shape to form a recessed chamber 6 inside. An end portion of a refrigerant filling tube 8 filled with refrigerant is communicated with a convex portion 7 formed by projecting the central portion of the lid body 5 downward. 1
Reference numeral 5 denotes an airtight chamber formed by airtightly bonding the peripheries of the upper and lower diaphragms 16 and 17, and the center portion of the upper and lower diaphragms 16 is bonded and supported at the lower end of the convex portion 7. 18 is a cooling system 30, one end of which will be described later.
A first low-pressure side passage communicating with the compressor 31 and having the other end connected to the evaporator 35 side, and is formed above the main body 1. 19 is a second low-pressure side passage provided below the main body 1; 20 is a high-pressure side passage provided below the main body 1; this second low-pressure side passage 19 and the high-pressure side passage 2
0 through a valve port 21, and a communication hole 3 provided along the center line 2 connects the recessed entry chamber 6 and the first
Low pressure side passage 18, second low pressure side passage 19, and valve port 21
and communicates with the high pressure side passage 20.

23 is a valve chamber provided at the end of the high pressure side flow path 20;
A valve 24 is attached to the valve port 21 from the high pressure side, and is biased toward the valve port 21 side by a spring 25.
An adjustment lid is screwed onto the lower part of the valve chamber 23, and the pressure of the spring 25 is adjusted by rotating the lid 26 via a receiving piece 27.

28 is a temperature-sensitive cylinder containing an adsorbent 29 inside;
Airtightly fixed to the center lower surface of the lower diaphragm 17,
In addition, the temperature sensing cylinder 28 is housed in a temperature sensing cylinder accommodating portion 22 provided by expanding the upper part of the communication hole 3, and an operating rod 30 is installed between the lower end of the temperature sensing cylinder 28 and the valve 24. It is interposed and housed in the communication hole 3 so as to be able to move up and down.

Next, to explain the operation of this embodiment, first, in the cooling system 31, the high temperature, high pressure refrigerant compressed by the compressor 32 is cooled and liquefied by the condenser 33, and the liquid receiver 34 The temperature type expansion valve 35 sent through the temperature type expansion valve 35 adiabatically expands the pressure to lower the pressure, absorbs the heat of evaporation through the cooling fan (not shown), and evaporates inside the evaporator 36 to become a gas. , is sent to the compressor 32 again, and this process is repeated.

Thus, the temperature of the refrigerant at the exit side of the evaporator 36 sensed by the thermosensor 28 is transferred to the adsorbent 29 in the thermosensor, and the refrigerant gas in the thermosensor 28 is released from the adsorbent 29. Alternatively, it is adsorbed, and the temperature-equivalent pressure pressurizes the airtight chamber 15 inside the diaphragm. Further, the outlet pressure of the evaporator 36 is transmitted from the first low-pressure side passage 18 through the inside of the temperature-sensitive cylinder housing section 22 to the recessed entry chamber 6, and both pressures in the airtight chamber 15 and the recessed entry chamber 6 are transmitted to the upper and lower diaphragms 16, Pressure is applied to the inside and outside of the diaphragm 17, and the diaphragm is displaced by the differential pressure. In this case, since the upper diaphragm 16 is joined and supported by the convex portion 7 of the lid, the respective displacement positions of the upper and lower diaphragms 16 and 17 are determined by the total displacement of the temperature sensing cylinder 28 that is airtightly attached to the lower diaphragm. The operating rod 30, which is moved up and down with the displacement and abuts against the lower surface of the temperature sensing tube 28, moves the valve 24 against the spring 25, thereby determining the opening amount of the valve port 21.

"Effects of the invention" The invention has the following effects.

If the diameter of the diaphragm is made smaller, the amount of displacement in the vertical direction will be smaller, but since the two small diaphragms are closely connected around each other and one diaphragm is supported to obtain a differential pressure in the vertical direction, it is possible to reduce the displacement in the vertical direction. A displacement position equal to that can be obtained, and the diaphragm can be made smaller without changing the conventional valve structure.

By downsizing the diaphragm, the volume of the airtight chamber in the upper and lower diaphragms can be reduced, and the temperature-sensing filling method using adsorbent can be used in vehicle cooling systems with a small amount of adsorbent filling. It becomes possible to determine the characteristics of the range in which it will be used, and the temperature-sensing tube that houses this adsorbent can be made smaller, so it becomes possible to accommodate the temperature-sensing tube within the main body of the expansion valve.

When the displacement of one diaphragm and the two diaphragms, that is, the valve opening amount, are the same, the latter requires less displacement than the former, resulting in less fatigue and improving the durability of the diaphragm against repeated fatigue. can.

In a temperature sensing filling method using an adsorbent, the temperature-internal pressure value of the temperature sensing part can be set depending on the amount of adsorbent filled to improve the efficiency of the cooling system.

Since the temperature sensing method uses an adsorbent, there is a response delay due to a delay in heat transfer to the adsorbent and a delay in adsorption or release of the refrigerant, so hunting due to high-frequency temperature fluctuations in the temperature sensing part does not occur. Therefore, stable cooling system operation can be achieved.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall longitudinal sectional view, FIG. 2 is an enlarged sectional view of the main part, and FIG.
The figure is a flowchart of the cooling system, and FIG. 4 is a longitudinal sectional view of the conventional system. 6... Concave room, 15... Airtight room, 16, 17...
...Diaphragm, 28...Temperature-sensitive cylinder, 29...Adsorbent.

Claims (1)

[Scope of utility model registration request] A diaphragm is arranged in a recessed chamber formed by airtightly fixing a lid to the upper part of the main body having a high-pressure side passage and a low-pressure side passage, and the other end of the operating rod has one end in contact with the lower surface of the diaphragm. In the temperature-type automatic expansion valve, the valve port provided at the end of the high-pressure side passage is urged by a spring from the other side and abutted against the seated valve, and the entire circumference of the two upper and lower diaphragms are airtightly joined. The diaphragm, which has an airtight chamber inside, is housed in the recessed chamber, one diaphragm is adhesively supported on the lid, and the other diaphragm is airtightly fitted with a temperature-sensitive cylinder containing an adsorbent therein. An expansion valve which is connected and accommodated in a main body, and which communicates the inside of a refrigerant filling pipe attached to the lid, an airtight chamber, and a temperature sensing cylinder, and the lower end of the temperature sensing cylinder is brought into abutment with the upper end of the operating rod.