JPH04366376A - Expansion valve - Google Patents

Abstract

PURPOSE:To provide an expansion valve capable of eliminating various kinds of operation failures, such as noise by means of a new system. CONSTITUTION:There is formed a liquid refrigerant passage 7 communicating with a capacitor 2 in an expansion valve main body 6 while there is formed a mist-like refrigerant passage 8 communicating with an evaporator 5 therein. Both passages 7 and 8 communicate with a communication passage 9 which extends in a straight line. A rod hole 21 is formed in such a fashion that it may penetrate this communication passage 9. An actuating rod 24 is laid out in such a fashion that it may slide in the rod hole 21 and moves, responding to the temperature of refrigerant at the outlet of the evaporator 5. A communication hole 29 is formed on the actuating rod 24. The opening area in the communication passage 9 may vary with the movement of the actuating rod 24 so that the refrigerant from the liquid refrigerant passage 7 to the mist-like refrigerant passage 8 may be subjected to adiabatic expansion.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve used in a refrigeration cycle of a car air conditioner or the like.

0002

2. Description of the Related Art A conventional expansion valve for a refrigeration cycle is disclosed in, for example, Japanese Utility Model Application Laid-open No. 196058/1983. This expansion valve has a main body formed with a liquid refrigerant passage that communicates with the condenser and an atomized refrigerant passage that communicates with the evaporator, and the liquid refrigerant passage and the atomized refrigerant passage communicate through an orifice while bending the refrigerant passage. The orifice is provided with a valve body that is biased toward the valve closing side by a spring. This valve body is moved by an actuating rod against the biasing force of a spring. Then, by driving the refrigeration cycle,
The refrigerant condensed in the condenser is introduced into the liquid refrigerant passage, adiabatically expanded in the orifice, and atomized refrigerant is supplied from the atomized refrigerant passage to the evaporator. Further, the valve body is moved by the operating rod according to the outlet temperature of the evaporator, and the opening degree of the orifice is adjusted.

0003

However, since the operating system including the valve body and spring is always present in the refrigerant, when the refrigerant passes through the expansion valve, the refrigerant expands and its flow is refracted. In addition to the refrigerant passing sound, vibrations (abnormal noises) in the operating system are also generated. An object of the present invention is to provide an expansion valve that can eliminate various problems such as noise using a new method.

0004

[Means for Solving the Problems] The present invention provides a liquid refrigerant passage formed within an expansion valve body, communicating with a condenser, and into which refrigerant condensed in the condenser is introduced; a communication passage extending linearly from the liquid refrigerant passage; a mist refrigerant passage communicating with the other end of the refrigerant passage within the expansion valve body and supplying refrigerant to the evaporator; and a communication passage within the expansion valve body. an operating rod sliding hole formed to penetrate through the operating rod; an operating rod that is slidably disposed within the operating rod sliding hole and moves according to the refrigerant temperature at the outlet of the evaporator; The expansion valve includes an orifice hole formed in a rod and whose opening area in the communicating path is changed as the operating rod moves to adiabatically expand refrigerant from the liquid refrigerant path to the atomized refrigerant path. This is the summary.

[0005]

[Operation] The operating rod moves within the operating rod sliding hole depending on the temperature of the refrigerant at the outlet of the evaporator. As the actuating rod moves, the opening area of the orifice hole in the communication passage is changed, and the refrigerant from the liquid refrigerant passage to the atomized refrigerant passage expands adiabatically. At this time, the refrigerant passes through the communication path that extends linearly.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an expansion valve for a car air conditioner will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing a car air conditioner according to an embodiment. The car air conditioner includes a compressor 1, a condenser 2, a receiver 3, a box-type expansion valve 4, and an evaporator 5. In the box-type expansion valve 4, a liquid refrigerant passage 7 and a mist refrigerant passage 8 are formed on both left and right sides of the lower portion of the expansion valve main body 6 so as to face each other. The liquid refrigerant passage 7 and the atomized refrigerant passage 8 communicate with each other through a communication passage 9, which extends linearly.

[0007] Also, passages 7 and 8 in the expansion valve main body 6
, 9, a low pressure refrigerant passage 10 is formed so as to penetrate therethrough. One end of the low-pressure refrigerant passage 10 is connected to a compressor 1 driven by a vehicle engine, and the compressor 1 is connected to the liquid refrigerant passage 7 via a condenser 2 and a receiver 3. Further, the mist refrigerant passage 8 is connected to an evaporator 5 in the vehicle interior, and this evaporator 5 is connected to the other end of the low-pressure refrigerant passage 10.

On the other hand, a screw hole 12 is formed in the upper part of the expansion valve body 6, and a lower housing 13 is screwed into the screw hole 12 via an O-ring 14 in an airtight manner. An upper housing 16 is disposed on the lower housing 13 with a diaphragm 15 made of thin stainless steel in between, and the three members 13, 15, and 16 are fixed to each other at their peripheries. As a result, both housings 13,1
6, a diaphragm chamber (thermal chamber) 17 is provided above the diaphragm 15, and a pressure equalization chamber 18 including the inside of the screw hole 12 is provided below. Further, a pipe 19 is connected to the upper housing 16, and a refrigerant gas as a temperature responsive body is previously sealed in the diaphragm chamber 17 via the pipe 19.

A plunger hole 20a into which a temperature sensing rod 22 is inserted is formed at the inner bottom of the screw hole 12 of the expansion valve body 6, and the plunger hole 20a communicates with the low pressure refrigerant passage 10. Further, a plunger hole 20b is formed below the center of the low-pressure refrigerant passage 10 so as to face the plunger hole 20a. Further, a rod hole 21 constituting a smaller diameter operating rod sliding hole is continuously formed below the plunger hole 20b, and this rod hole 21 passes through the communication path 9. And the plunger hole 20
An aluminum temperature sensing rod 22 is fitted into the insides of a and 20b so as to be able to move up and down, and a stopper portion 22a at the upper end of the temperature sensing rod 22 is disposed within the pressure equalization chamber 18 and abuts against the lower surface of the diaphragm 15. ing. Further, the middle portion of the temperature sensing rod 22 is exposed in the low pressure refrigerant passage 10. Furthermore, the low-pressure refrigerant passage 10 and the refrigerant passages 7, 8, and 9 are maintained in a sealed state (airtight) by an O-ring 23 attached to a temperature sensing rod 22.

A stainless steel actuating rod 24 is disposed within the rod hole 21 so as to be movable up and down.
The upper end is in contact with the temperature sensing rod 22, the middle part is exposed in the communication path 9, and the lower end projects into a spring chamber 25 formed on the lower surface of the main body 6. Further, the refrigerant passages 7, 8, 9 and the spring chamber 25 are kept airtight by an O-ring 26 attached to the actuating rod 24. The spring chamber 25 is closed by an adjustment screw 27, and a compression coil spring 28 is interposed between the adjustment screw 27 and the seat 31 of the actuating rod 24. Therefore, the actuating rod 24 is urged upward by the compression coil spring 28. Further, the operating rod 24 has a communication hole 29 formed therein as an orifice hole. The overlap between the communication passage 9 and the communication hole 29 is changed at the upper and lower positions of the actuating rod 24, and the opening area of the communication hole 29 is changed.

That is, as shown in FIG. 2, when the cycle is stopped, the operating rod 24 is located upward and the communication path 9 is closed.
There is no communication hole 29 for the actuating rod 24 inside, and the communicating path 9 is blocked by the actuating rod 24 (the liquid refrigerant path 7 and the atomized refrigerant path 8 are not in communication with each other). Additionally, as shown in FIG. 3, the actuating rod 24
is located below, the operating rod 24 is located in the communication path 9.
The communicating holes 29 of
9 is fully open. Furthermore, the actuating rod 24 is shown in FIGS. 2 and 3.
At an intermediate position between the two, an intermediate opening degree is obtained depending on the position of the actuating rod 24.

Furthermore, the compression coil spring 28 can be adjusted using the adjustment screw 27.
When the set length of the actuating rod 24 changes, the pressing force applied to the actuating rod 24 changes. Next, the operation of the expansion valve configured as described above will be explained. The highly compressed refrigerant discharged from the compressor 1 is condensed in the condenser 2, passes through the receiver 3 and the liquid refrigerant passage 7 of the expansion valve 4, enters the communication passage 9, passes through the communication hole 29 of the operating rod 24, At this time, it adiabatically expands and becomes a gas-liquid two-phase refrigerant, which reaches the atomized refrigerant passage 8. Thereafter, the refrigerant is introduced into the evaporator 5 through the mist refrigerant passage 8 and vaporized to become a gas refrigerant. At this time, the evaporator 5 is cooled and used to cool the interior of the vehicle. Furthermore, the gas refrigerant discharged from the evaporator 5 returns to the compressor 1 again via the low-pressure refrigerant passage 10.

On the other hand, the temperature sensing rod 22 is always urged upward by a compression coil spring 28 via an operating rod 24. Therefore, the position of the actuating rod 24 (the opening degree of the communication hole 29) is maintained at a position where the biasing force of the compression coil spring 28, the refrigerant pressure in the pressure equalization chamber 18, and the gas pressure in the diaphragm chamber 17 are balanced. . Further, the refrigerant pressure in the pressure equalization chamber 18 is the evaporation pressure of the evaporator 5.

[0014] A temperature sensing rod 2 is installed in the low pressure refrigerant passage 10.
2 is exposed, the heat of the gas refrigerant passing through the low-pressure refrigerant passage 10 is transmitted to the diaphragm 15 via the aluminum temperature-sensing rod 22 with high thermal conductivity, and is further transferred from the diaphragm 15 to the diaphragm 15. This is transmitted to the gas in the diaphragm chamber 17, causing the gas to expand and contract. Therefore, the gas pressure in the diaphragm chamber 17 changes depending on the temperature of the refrigerant at the outlet of the evaporator 5, and the gas pressure acts on the upper surface of the diaphragm 15.

When the temperature inside the vehicle increases and the temperature of the refrigerant flowing into the low-pressure refrigerant passage 10 also increases, the gas in the diaphragm chamber 17 that has received heat through the temperature sensing rod 22 and the diaphragm 15 expands, causing the diaphragm 15 to expand. Displaced downward. This displacement is transmitted to the temperature sensing rod 22 and the operating rod 24, and the degree of opening of the communication hole 29 in the communication path 9 increases, so that the amount of refrigerant flowing toward the inlet of the evaporator 5 increases.

[0016] Furthermore, the temperature inside the vehicle decreases, and the low pressure refrigerant passage 1
When the temperature of the refrigerant passing through 0 also decreases, the diaphragm chamber 17
The gas pressure also decreases, the actuating rod 24 slides, and the degree of opening of the communication hole 29 in the communication path 9 becomes smaller, and the amount of refrigerant flowing toward the inlet of the evaporator 5 decreases. In this way, the amount of refrigerant supplied to the evaporator 5 is adjusted according to the opening degree of the communication hole 29.

As described above, in this embodiment, a liquid refrigerant passage 7 is formed in the expansion valve body 6 to communicate with the condenser 2 and into which the refrigerant condensed in the condenser 2 is introduced, and also to supply refrigerant to the evaporator 5. A mist refrigerant passage 8 was formed, and both passages 7 and 8 were communicated through a communication passage 9 extending linearly. Then, the rod hole 21 (
An operating rod 2 is formed in the rod hole 21 and moves in accordance with the refrigerant temperature at the outlet of the evaporator 5.
4 is slidably disposed, and a communication hole 29 (orifice hole) is formed in the actuation rod 24, so that as the actuation rod 24 moves, the communication path 9 opens.
The opening area within the refrigerant passage was changed so that the refrigerant from the liquid refrigerant passage 7 to the atomized refrigerant passage 8 was expanded adiabatically. Therefore, in conventional expansion valves, the operating system including the valve body and spring exists in the refrigerant, and as the refrigerant expands, its flow is bent, causing refrigerant passing noise and vibrations in the operating system.
In this embodiment, the refrigerant passages 7 and 8 communicate with each other through a communication passage 9 that extends linearly, and there is no valve element biased by a spring, so that various problems such as noise can be eliminated. .

It should be noted that the present invention is not limited to the above-mentioned embodiments. For example, in the above-mentioned embodiments, a box-type expansion valve with an integrated low-pressure refrigerant passage was described, but a type without this low-pressure refrigerant passage It may be used for expansion valves.

[0019]

As described in detail above, according to the present invention, an excellent effect can be achieved in which various problems such as noise can be solved using a new method.

[Brief explanation of drawings]

FIG. 1 is a diagram schematically showing a car air conditioner according to an embodiment.

FIG. 2 is a partially enlarged view of an expansion valve.

FIG. 3 is a partially enlarged view of the expansion valve.

[Explanation of symbols]

2 Capacitor 5 Evaporator 6 Expansion valve body 7 Liquid refrigerant passage 8 Atomized refrigerant passage 9 Communication path 21 Rod hole as operating rod sliding hole 24 Operating rod 29 Communication hole as orifice hole

Claims (1)

[Claims] 1. A liquid refrigerant passage formed within an expansion valve body, communicating with a condenser and into which refrigerant condensed in the condenser is introduced, and a liquid refrigerant passage extending linearly from the liquid refrigerant passage within the expansion valve body. a communication passage; an atomized refrigerant passage within the expansion valve body that communicates with the other end of the refrigerant passage and supplies refrigerant to the evaporator; and an atomized refrigerant passage formed within the expansion valve body so as to penetrate the communication passage. an operating rod sliding hole; an operating rod that is slidably disposed in the operating rod sliding hole and moves in accordance with the refrigerant temperature at the outlet of the evaporator; an orifice hole whose opening area in the communicating passage is changed as the liquid refrigerant passage moves, and adiabatically expands the refrigerant from the liquid refrigerant passage to the atomized refrigerant passage.