JPH027346Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in an expansion valve that maintains a constant load on the evaporator by changing the amount of refrigerant supplied to the evaporator according to the cooling capacity of the evaporator that forms part of the cooling cycle.

Generally, as shown in Fig. 1, a cooling cycle consists of a compressor 1 and a condenser 2 that cools and condenses the gaseous refrigerant that has become high-pressure and high-temperature in the compressor 1 and returns it to a high-pressure liquid. , a liquid tank (liquid receiver) 3 that separates the refrigerant into gas and liquid, removes moisture and dust from the refrigerant, and allows the refrigerant to be smoothly supplied into the system; It consists of an expansion valve 4 for cooling the air, and an evaporator 6 for exchanging heat between the refrigerant and air to remove heat from the air and cool the air.

Here, the expansion valve 4 adjusts the amount of refrigerant flowing inside the evaporator 6 according to the cooling capacity of the evaporator 6, and adjusts the amount of refrigerant such that the output of the evaporator 6 just finishes evaporating and completely turns into gas. It will be necessary to supply. Therefore, traditionally, the second
As shown in the figure, the temperature change of the refrigerant at the outlet of the evaporator is detected as a pressure change using the temperature sensing cylinder 5, and the difference between the pressure change of the temperature sensing medium of the temperature sensing cylinder 5 and the refrigerant pressure at the evaporator inlet ( The refrigerant flow rate is controlled based on the difference between the pressure at the evaporator outlet (internal equation) or the pressure at the evaporator outlet (external equation) to maintain the opening degree of the ball valve, that is, the set heating degree.

By the way, with such conventional expansion valves, when the engine speed is suddenly increased while the valve is being throttled without requiring much refrigerant, and the refrigerant flow rate is rapidly changing while the valve is being throttled, the peak There is a possibility that this high-pitched sound may be generated momentarily (for a few seconds). This noise is similar to the sound of metal colliding, so
This is thought to occur because the valve body and valve stem collide with the throat portion of the valve hole or the inner wall of the valve hole. In other words, in conventional expansion valves, it is difficult to accurately position the valve body in the center of the valve hole, and the gap between the valve hole and the valve body is not always constant, so the pressure around the valve body is balanced. There is a risk of damaging the When a sudden change in flow rate occurs, the pressure imbalance that occurs around the valve body causes the valve body to vibrate, and this vibration further aggravates the vibration of the valve body, eventually causing the valve body to collide with the valve hole. It is thought that it vibrates as much as possible. This self-excited vibration becomes a problem in the normal operating range of the expansion valve; during cool-down, when a large amount of refrigerant is required, the valve is in its most open state, so even if there is a sudden change in flow, the valve body collides with the main body, producing noise. There is no problem.

The purpose of this invention is to provide an expansion valve that does not generate metallic noise even when the refrigerant flow rate changes rapidly in the normal operating range. By interposing the valve body, vibrations of the valve body caused by loss of pressure balance are damped, and the valve body is prevented from colliding with the throat portion of the valve hole.

The configuration of the present invention will be explained in detail below based on an embodiment shown in the drawings and FIGS. 3 to 5.

The expansion valve 4 has the same basic structure as the conventional one, and has a high pressure side flow path 12 communicating with the liquid tank 3.
and a low pressure side flow path 13 communicating with the evaporator 6 and a valve hole 8 communicating these, in the valve body 11,
The ball valve 7, which moves along the valve hole 8 by the action of the diaphragm 9, opens and closes the flow path to adjust the amount of refrigerant. The diaphragm 9 is connected to the temperature of the refrigerant at the outlet of the evaporator 6 detected by the temperature sensing tube 5 (this is replaced by the pressure change P ₁ of the temperature sensing medium), and the diaphragm is controlled by the pressure equalization pipe (not shown). It operates based on changes in the refrigerant pressure P ₂ introduced to the lower part of 9. The movement of this diaphragm 9 is
It is transmitted via the actuating rod 10 to the spring retainer 14 to which the ball valve 7 is attached. Since the ball valve 7 is supported by a spring retainer 14 that is pushed up by a coil spring (force P ₃ ) 15, the above-mentioned 3.
Move to a position where the three forces P ₁ , P ₂ , and P ₃ are balanced.
Incidentally, the pressing force of the spring presser 14 is appropriately adjusted by an adjusting screw 16.

The ball valve 7, which is a valve body, is fixed to a spring holder 14 and moves together with the spring holder 14. This fixing method is to fix the ball valve 7 directly to the spring holder 14 itself by spot welding, or fit the adjustment rod 17 to which the ball valve 7 is spot welded into the C-shaped spring holder 14 and tighten it to make it detachable. Fix it. At this time, if a knurl is cut in the spring holder 14 and the adjustment rod 17, the tightening can be made more securely.

an operating rod 10 that controls the movement of a spring retainer 14 that supports the ball valve 7 and presses it toward the valve hole 8;
are attached to the diaphragm 9 to transmit its movement, and in this embodiment, three are provided. Further, an elastic body 18 surrounding the ball valve 7 is fitted into the actuating rod 10.

The elastic body 18 is made of rubber or synthetic resin, for example, and has high elasticity so as to attenuate vibrations and not generate sound during a collision. As shown in FIGS. 3 to 5, the elastic body 18 may have various shapes such as a cylinder, an O-ring, or a disk, but the main thing is that the
It is sufficient if it is interposed between the ball valve 7 and the ball valve 7 and suppresses the lateral vibration of the ball valve 7. Further, the elastic body 18 may not come into contact with the ball valve 7 from the beginning, but may come into contact only when the valve is throttled to the extent that noise is generated. For example, the third
When using the cylindrical elastic body 18 as shown in Figures A and B, the elastic body 18 is separated from the ball valve 7 when the valve is opened to the maximum, but when the valve starts to close, the elastic body 18 is separated from the ball valve 7. The elastic body is crushed between the valve body 11 and expands into a barrel shape, and presses the ball valve 7 to integrate it with the spring retainer 40, the actuating rod 10, and the valve body 11. Therefore, even if pressure imbalance occurs around the ball valve 7, the ball valve 7 attached to the valve body 11 via the elastic body 18 will not vibrate, and the ball valve 7 will not vibrate before the elastic body 18 is pressed. Even if vibration occurs, the vibration is damped by colliding with the elastic body 18. Note that the flow path area of the expansion valve 4 is partially narrowed due to the presence of the elastic body 18;
This will not be a problem if the opening area is taken into consideration in advance when designing.

On the other hand, the ball valve 7 may be always held between the elastic bodies 18. For example, a rubber ring 18 or an O-ring (not shown) as shown in FIG. 4 is fitted onto the actuating rod 10 to surround the ball valve 7.

Furthermore, not only the ball valve 7 itself is directly held between the elastic bodies 18 and integrated with the actuating rod 10, but also the elastic body 18 may be interposed between the adjusting rod 17 that supports the ball valve 7 and the actuating rod 10. be. However, even in this case, the adjustment rod 17 constitutes a part of the valve body, and the valve body and the actuating rod 10
There is no change in the fact that the elastic body 18 is interposed between the two. The elastic body 18 of this embodiment is not attached to each actuating rod 10 individually, but
Attach it as a part. For example, as shown in FIGS. 5A and 5B, a configuration may be adopted in which three flanges each protrude from an annular portion surrounding the adjustment rod 17. In this case, in order to ensure a refrigerant flow path, it is necessary to remove unnecessary portions of the flange except for the portion surrounding the actuating rod 10.

As described above, in the expansion valve 4 of the present invention, since the elastic body 18 is interposed between the valve body 7 and the actuating rod 10,
Even if the pressure balance around the valve body is lost due to sudden fluctuations in the refrigerant flow, the operating rod 10
The valve body 7, which is elastically supported, has a small amount of displacement and does not develop into self-excited vibration. In addition, the elastic body 18 and the valve body 7
Even if they are not in direct contact with each other, the vibrating valve body 7 is damped by colliding with the elastic body 18, and since it is not a metal-to-metal collision, no metal noise is generated.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram of a cooling cycle, Fig. 2 is a central vertical sectional view showing an example of a conventional expansion valve, and Fig. 3 is a sectional view partially showing an example of an expansion valve of the present invention.
B shows the valve in the most open state, and B shows the valve in the throttled state. FIG. 4 is a partially sectional view showing another embodiment of the expansion valve of the present invention. FIG. 5 similarly shows another embodiment of the expansion valve, where A is a sectional view partially showing the expansion valve, and B is a sectional view taken along the line -- in FIG. 5A. 4... Expansion valve, 7... Ball valve as valve body, 8
... Valve hole, 9 ... Diaphragm, 10 ... Operating rod, 11 ... Valve body, 14 ... Spring holder, 18 ...
...Elastic body.

Claims (1)

[Scope of utility model registration request] A valve body is fixed to a spring holder that is pressed by the force of a spring toward a valve hole that communicates a high-pressure side flow path and a low-pressure side flow path, and the valve body contacts the spring holder and works in conjunction with the diaphragm to move the spring holder. 1. An expansion valve having an operating rod to be controlled, characterized in that an elastic body is interposed between the valve element and the operating rod to suppress lateral vibration of the valve element.