JPH0422228Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an expansion valve used to control the amount of refrigerant supplied to an evaporator of an air conditioning refrigeration system for a vehicle such as a passenger car.

In order to make the refrigeration system smaller, vehicle expansion valves are required to be easy to install without restrictions on installation positions, lightweight and compact, have high controllability, and do not generate noise.

Conventionally, this type of expansion valve has a pressure difference between the refrigerant pressure in the temperature sensing part A and the refrigerant pressure in the chamber C introduced through the pressure equalization hole 8 from the end B of the pressure equalization hole 8, as shown in FIG. Due to the fluctuation, the actuating rod 3 and the valve body 4 move up and down via the diaphragm 2, and the valve body 4 moves away from and approaches the valve seat 5, so that the flow flows from the first flow path 6 to the second flow path 7. The temperature of the evaporator is controlled by controlling the amount of refrigerant and adiabatically expanding it, but in such an expansion valve, the pressure equalizing hole 8 is provided on the side of the valve body 9, so the valve seat When the refrigerant flows from the first flow path 6 to the second flow path 7, it expands adiabatically due to the small gap between the valve body 4 and the valve seat 5, and this effect causes significant pressure fluctuations around the refrigerant. Since this fluctuating pressure exerts an unstable effect on the diaphragm 2 through the pressure equalization hole 8, the valve body 4 does not always come into contact with and separate from the valve seat 5 normally, and in severe cases, it causes vibration and noise. Cause.

The technical problem to be solved by this proposal is to provide a pressure equalizing hole that penetrates the center of the actuating rod and the valve body, one end of which opens into the valve chamber, and the other end of which opens toward the temperature sensing part. By providing a slot in the part in contact with the diaphragm, the valve body can be brought into contact with and separated from the valve seat correctly during refrigerant control, thereby eliminating the generation of vibration noise.

In order to solve the above technical problems, this proposal takes the following technical measures.

In other words, the present invention includes a valve body that is provided with a first passage through which refrigerant flows, a valve seat communicating with this passage, and a second passage; a temperature sensing section having a diaphragm operated by the first flow path and the second flow path;
an actuating rod that is provided in a passage communicating with the second passage and has one end in contact with the diaphragm and the other end a valve body that slides within the valve chamber of the second passage and is biased toward the valve seat by a spring; A pressure equalizing hole is provided that penetrates through the center of the actuating rod and the valve body, one opening into the valve chamber and the other opening toward the temperature-sensing section, and a slot is provided in the portion of the actuating rod that contacts the diaphragm. , the operating rod is provided with a sealing member to seal the passage and the temperature sensing section.

Now, when the outlet temperature of the evaporator becomes high, the diaphragm in the temperature sensing part moves and moves the valve body together with the operating rod against the elasticity of the spring to open the passage. For this reason, the high-pressure refrigerant flowing in the first flow path undergoes adiabatic expansion and flows into the second flow path, and further flows to the evaporator to achieve desired temperature control.

Also, when the outlet temperature of the evaporator becomes low, the diaphragm moves in the opposite direction to the above, moving the actuating rod toward the diaphragm, and the elasticity of the spring moves the valve body in the opposite direction, blocking the valve chamber and the passage. . Therefore, the refrigerant to the evaporator is cut off, and a predetermined temperature control is performed.

According to the present invention, the pressure equalizing hole penetrates through the center of the actuating rod and the valve body, and one side is provided in the valve chamber and the other side is opened on the temperature-sensing part side. Pressure fluctuations due to adiabatic expansion that occur when refrigerant flows into the passage do not affect the pressure equalization hole, and therefore have a stable effect on the diaphragm, and the valve body moves normally against the valve seat and does not cause noise. There isn't.

Next, an embodiment of the expansion valve of the present invention will be described with reference to FIG. The first flow path 11 has one end communicating with a compressor (not shown) and through which the refrigerant passes, and the other end thereof communicates with a passage 13 of the valve body 12 . Further, the other end of the second flow path 14, whose one end communicates with an evaporator (not shown), also communicates with the passage 13.

A temperature sensing portion 15 is provided at one end of the valve body 12. Reference numeral 16 indicates a lid of this temperature sensing portion, and 17 indicates a diaphragm provided between this lid and the valve body. And the temperature sensing part is chamber 18 and chamber 19 by a diaphragm.
It is divided into. The chamber 18 contains a temperature-sensitive tube and a capillary 20 installed near the outlet of the evaporator (not shown).
communicated through.

Reference numeral 21 denotes an operating rod, and a valve body 22 is formed integrally with the operating rod at the bottom in the figure. A valve seat 23 is provided in the communication portion between the second flow path 14 and the passage 13, and the valve body 22 is opposed to the valve seat 23.

A pressure equalizing hole 24 is provided in the center of the actuating rod 21 and the valve body 22 in the vertical direction, one of which opens toward the valve chamber, and the other opens toward the temperature sensing section. A slot 26 is provided in the portion of the large diameter portion 25 at the upper end of the actuating rod 21 that is in contact with the diaphragm 17, so that a portion of the refrigerant flowing from the first flow path 11 to the second flow path 14 flows through the pressure equalization hole 24.
Therefore, it is made to act evenly on the lower surface of the diaphragm 17 through this slot 26.

Reference numeral 27 denotes a sealing member provided at the intermediate portion of the actuating rod 21, and its action is in contact with the inner periphery of the passage 13.

Reference numeral 28 denotes a valve chamber provided in the second flow path, and the valve body 22 slides within this valve chamber. 29 is the valve chamber 28
By rotating the adjusting member screwed therein, the elasticity of the spring 30 provided between the adjusting member and the valve body 22 is adjusted.

Next, we will discuss the effect.

If the temperature at the evaporator outlet increases now, the temperature sensing part 15
The temperature at the outlet of the evaporator is transmitted through the capillary 20, and since the high-pressure refrigerant in the first flow path 11 is blocked by the seal member 27, the pressure in the chamber 19 is evaporated through the pressure equalization hole 24. The pressure in the chamber 18 becomes higher than the pressure in the chamber 19, and the diaphragm 17 is deflected downward in the figure, causing the actuating rod 21 to be deflected downward as well.

Therefore, the valve body 22 is deviated in the same direction against the elasticity of the spring 30 and separated from the valve seat 23.

Therefore, the high-pressure, high-temperature refrigerant in the first flow path 11 adiabatically expands through the valve seat and the second flow path 14, becomes low-pressure and low-temperature, reaches the evaporator, and performs predetermined temperature control.

Next, when the outlet temperature of the evaporator decreases, contrary to the above, the pressure in the chamber of the temperature sensing section 15 becomes lower than the pressure in the chamber 19, so that the diaphragm 17 is deviated upward in the figure, and the spring 30 is The elasticity closes the valve body 22 against the valve seat 23 and similarly deflects the valve stem 21 upward. When the valve body 22 closes, the high-pressure, high-temperature refrigerant in the first flow path 11 is cut off and is not introduced into the evaporator, thereby controlling the inside of the evaporator to a predetermined temperature.

In such a control operation, the valve body 22 is pressed against the valve seat 23.
When they are separated from each other, the refrigerant passes through the pressure equalization hole 24 provided at the center of the valve body and valve stem 21, passes through the slot 26 in the large diameter portion 25 of the valve stem, and applies stable pressure to the lower surface of the diaphragm 17. The movement of the body 22 into and out of contact with the valve seat 23 is normal, and no vibration occurs, so no noise is generated.

Moreover, since the sliding range of the sealing member 27 relative to the valve body is small, only a small amount of machining and finishing is required within the valve body, which also has the advantage of being easy to assemble and being manufactured at low cost.

[Brief explanation of the drawing]

Figure 1 is a schematic vertical cross-sectional view of a conventional expansion valve, and Figure 2 is a schematic vertical cross-sectional view of a conventional expansion valve.
The figure is a similar longitudinal sectional view of the expansion valve of the present invention. 11...first flow path, 12...valve body, 13...
...Passage, 14...Second channel, 15...Temperature sensing section,
17...diaphragm, 21...operating rod, 22...
... Valve body, 24 ... Pressure equalization hole, 26 ... Sliding, 2
7... Seal member, 28... Valve chamber, 30... Spring.

Claims (1)

[Scope of utility model registration request] A valve body having a first passage through which a refrigerant flows, a valve seat communicating with the valve seat, and a second passage, and a valve body provided in the valve body and operated by fluctuations in evaporation pressure and evaporation temperature of the refrigerant above and below the valve body. A temperature-sensing section having a diaphragm, and a passageway that communicates with the first flow path and the second flow path, one end of which is in contact with the diaphragm, and the other end of which slides within the valve chamber of the second flow path. It consists of an actuating rod having a valve body that is biased toward the valve seat side by a spring, and a uniform shaft that passes through the center of the actuating rod and the valve body, with one side opening into the valve chamber and the other side opening toward the temperature sensing section. An expansion valve comprising a pressure hole, a slot in a portion of an actuating rod that contacts a diaphragm, and a sealing member provided between the passage and the actuating rod.