JPH045973Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an expansion valve for a cooler cycle used in automobiles.

Examples of conventional expansion valves include those shown in FIGS. 1 to 4, for example. (Refer to Japanese Unexamined Patent Publication No. 54-51140) First, the cooler cycle 1 will be explained. The cooler cycle 1 circulates refrigerant in the cycle at the discharge pressure and suction pressure of the compressor 2. converts the low-temperature, low-pressure gaseous refrigerant A into high-temperature, high-pressure gaseous refrigerant B and sends it out, exchanges heat with the outside air in the condenser 3 to become a high-temperature, high-pressure liquid refrigerant C, and removes moisture and dirt in this refrigerant C in the liquid tank 4. The expansion valve 5 converts the high temperature, high pressure liquid refrigerant C sent from the liquid tank 4 into a mist of low temperature, low pressure gas refrigerant D using the "throttling action" and sends it to the evaporator 6, where the blower It exchanges heat with cabin air sent from a source (not shown) and converts it into low temperature, low pressure gaseous refrigerant A and sends it to the compressor 2. In the figure, 7 is a pressure equalizing pipe, 8 is a temperature sensing cylinder, 9 is an inlet pipe, and 10 is an outlet pipe.

In such a cooler cycle 1, the expansion valve 5 guides the high-temperature, high-pressure liquid refrigerant C from the liquid tank 4 to the passage 13 between the valve body 11 and the valve seat 12 and throttles it, as described above, and reduces the pressure and temperature by adiabatic expansion. The diaphragm 14, the valve rod 15 for forming the valve body 11, the valve ball 16, the spring 1
It is mainly composed of 7th magnitude. The amount of opening and closing of the passage 13 is determined by the distance (S ₀ -S ₁ ) between the valve ball 16 and the valve hole 18. Furthermore, the opening and closing of the passage 13 is as follows.
Specifically, the temperature at the outlet side 30 of the evaporator 6 is controlled via the temperature sensing cylinder 8 which is in contact with the piping 31 at the outlet side 30 of the evaporator 6, and the temperature at the outlet side 30 of the evaporator 6 is controlled by a temperature sensitive chamber in which the refrigerant E is sealed. 32, the expansion and contraction of the refrigerant E inside the sensitive chamber 32 due to the temperature change is converted into the forward and backward movement of the diaphragm 14, and the forward and backward movement of the diaphragm 14 moves the valve stem 15 and the valve ball 16 in the vertical direction in the figure. This is done by moving it in the direction of arrow F.

However, in such a conventional expansion valve 5, since the movement of the valve body 11 is performed by the forward and backward movement of the diaphragm 14 as described above, the valve stroke ₁ as the amount of forward and backward movement of the diaphragm 14 is
is determined to be a constant value, and this valve stroke
As described above, the amount of opening and closing of the passage 13 is determined by the forward and backward movement of the diaphragm 14 within the range of the distance (S ₀ to _{S 1 )} corresponding to 1, and the amount of refrigerant that can flow is also determined thereby. Although a large amount of refrigerant is required to improve the performance, the amount of refrigerant that cannot be circulated is insufficient, resulting in poor cooling. In order to avoid this problem, it may be possible to use an expansion valve 5 with a large flow rate, but conversely, when the flow rate is throttled at a stable state, the flow rate changes greatly with a minute stroke of the valve, which causes a hunting phenomenon of the valve. There is a problem with it being stored away.

This invention was made by focusing on such conventional problems, and the valve body is made of a valve ball that can freely come into contact with the valve hole of the valve seat, and an upper end connected to the diaphragm and a lower end connected to the valve ball. A valve stem with a ball,
The entire valve stem, including the lower end portion that protrudes from the valve hole to the outside of the valve, is made of a shape memory alloy that changes shape depending on the temperature of the refrigerant to increase the valve stroke. The gist is that the amount of opening and closing of the passage formed between the valve ball and the valve hole of the valve seat can be controlled freely by the amount of change and the amount of forward and backward movement of the diaphragm.

This invention will be explained below based on the drawings. FIGS. 5 to 8 are diagrams showing an embodiment of this invention. In the following description, parts that are the same or similar to those of the prior art will be denoted by the same reference numerals and redundant explanation will be omitted.

20 is a valve body, which includes a valve ball 22 that can freely come into contact with the valve hole 18 portion of the valve seat 12, and a diaphragm 14 at the upper end.
The valve stem 21 is connected to the valve rod 21 and has the valve ball 22 at its lower end. Of this valve body 20, the valve stem 21 is entirely formed of a shape memory alloy. More specifically, the valve stem 21 is made of a shape memory alloy that has been subjected to shape memory treatment so that the valve stroke increases by Δ when the high temperature and high pressure liquid refrigerant C reaches a predetermined temperature (for example, 60 to 70 degrees Celsius or higher).
The entire valve including the lower end portion protruding outside the valve is formed.

As a result, the valve stroke ₂ is the sum of the valve stroke ₁ as the amount of forward and backward movement of the diaphragm 14 and the increase amount Δ (amount of change in the valve stem) due to the shape memory effect. As the "shape memory alloy" employed for this purpose, copper-based [Cu-Zn-A], titanium-nickel-based [Ti-Ni], and others can be used as appropriate, and the type of alloy is not particularly specified.
In other words, for the type of shape memory alloy, Δ is obtained before and after the shape change, and as mentioned above, the shape change Δ
and valve stroke due to diaphragm movement ₁
Valve stroke ₂ is obtained by the sum of
Distance between valve ball 22 and valve hole 18 (S ₀ ~ S ₁ ~ _{S 2} )
Anything is fine as long as it can be obtained.

Note that (S ₂ ) in the figure indicates the distance between the valve ball 22 and the valve hole 18 in the case of valve stroke ₂ .

Next, the effect will be explained.

In the cooler cycle 1, when the pressure and temperature on the high pressure side rise in the early stage of cool-down, the temperature inside the pipe 31 on the outlet side 30 of the evaporator 6 also rises, so The refrigerant E in the sensitive chamber 32 expands and lowers the diaphragm 14. Therefore, the valve body 20 also has a valve stroke corresponding to that amount.
It goes down by ₁ . As a result, the lower end portion of the valve rod 21 protrudes from the valve hole 18 to the outside of the valve, and comes into direct contact with the high-temperature, high-pressure (60 to 70° C. or higher) liquid refrigerant C outside the valve. Then, the shape memory alloy returns from the martensite phase to the austenite phase, and the valve stem 21 is deformed and elongated according to the shape memory, and the valve stroke increases by Δ. In this way, the diaphragm 14
The valve stroke ₁ due to the shape memory alloy is added to the valve stroke Δ resulting in the valve stroke _2.
Therefore, the distance S ₁ between the valve ball 16 and the valve hole 18 becomes a large distance S ₂ corresponding to the valve stroke ₂ , and
Valve body 20 [specifically, valve ball 22] and valve seat 12
The amount of opening and closing of the passage 13 between the two increases. In this way Δ
and passage ₁ over two stages of valve stroke 1
3 is set to "open", the flow rate of refrigerant increases accordingly, and as shown in FIG. 8, the cooling at the initial stage of cool-down becomes even better.

Then, as it gradually cools down, the high temperature and high pressure liquid refrigerant C
The pressure and temperature of the pipe 31 on the outlet side 30 of the evaporator 6 also decrease from the initial stage of cool-down.
The temperature inside will also drop. Due to these temperature drops, the shape memory alloy forming the valve stem 21 changes from an austenitic phase to a martensitic phase, and the valve stroke ₂ is reduced by the above-mentioned Δ and returns to the original valve stroke ₁ , causing the valve ball 22 and the valve hole to change. 1
8 is also S ₁ from S ₂ , and the distance between the valve body 20 and the valve seat 12 is
The opening/closing amount of the passage 13 between the two also returns to the previous state.

Then, the temperature drop inside the pipe 31 is transmitted to the temperature-sensitive chamber 32 via the temperature-sensitive cylinder 8, causing the refrigerant E to contract and the diaphragm 14 to retract. The stroke ₁ decreases further, and as a result the passage 13 approaches the "closed" state, hereinafter referred to as the valve stroke.
The amount of opening and closing of the passage 13 is adjusted and controlled within the range of ₁ ,
The refrigerant flow rate is adjusted as in the conventional case.

Since this invention has the content described above, it is possible to significantly increase the refrigerant flow rate at the early stage of cool-down, and has the effect of further improving the cooling performance at the early stage of cool-down.

[Brief explanation of drawings]

Fig. 1 is an overall explanatory diagram of the cooler cycle, Fig. 2 is a partially cutaway side view of a conventional expansion valve, and Figs. 3 A and B are explanatory diagrams showing the valve closed and valve open states, respectively.
Fig. 4 is a graph showing the relationship between the valve opening degree and room temperature during cool-down using a conventional expansion valve, Fig. 5 is a side view equivalent to Fig. 2 showing an embodiment of this invention, and Fig. 6 is the valve stroke. 7th side view of the valve body showing changes in
Figures A and B are explanatory diagrams showing the valve closed and valve open states corresponding to Figures 3 A and B, respectively, and Figure 8 is a graph showing the relationship between the valve opening degree and room temperature during cool-down equivalent to Figure 4. be. 1... Cooler cycle, 4... Liquid tank, 5... Expansion valve, 6... Evaporator, C...
High pressure liquid refrigerant from liquid tank, 11, 20...
...Valve body, 12... Valve seat, 13... Passage between the valve body and valve seat, 14... Diaphragm, 15, 21... Valve stem, 16, 22... Valve ball, 18... Valve hole,
₁ ... Valve stroke (amount of forward and backward movement by the diaphragm), ₂ ... Valve stroke, Δ... Amount of increase in valve stroke (amount of change in valve stem), 30... Evaporator outlet side, 32... Sensitive chamber, E... Refrigerant inside the sensitive greenhouse.

Claims (1)

[Claims for Utility Model Registration] The temperature on the evaporator outlet side is transmitted to a sealed temperature-sensitive chamber in which refrigerant is sealed, and the expansion and contraction of the refrigerant inside the temperature-sensitive chamber due to temperature changes is controlled by the movement of the diaphragm. The passage formed between the valve body and the valve hole of the valve seat is opened and closed by the forward and backward movement of the diaphragm, and the high-temperature, high-pressure liquid refrigerant from the liquid tank guided into the passage is converted into a low-temperature, low-pressure gas refrigerant. In an expansion valve for a cooler cycle to be sent to an evaporator, the valve body is connected to a valve ball that can freely come into contact with a valve hole portion of a valve seat, and a valve whose upper end is connected to the diaphragm and whose lower end is provided with the valve ball. and a shape memory alloy that causes the shape of the valve stem, including at least the lower end portion that protrudes from the valve hole to the outside of the valve when the diaphragm moves, to change shape depending on the temperature of the refrigerant to increase the valve stroke. The opening/closing amount of the passage formed between the valve ball and the valve hole of the valve seat can be freely controlled by the amount of shape change of the valve stem and the amount of movement of the diaphragm. Expansion valve for cooler cycle.