JPH0113882Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a refrigerant flow rate control valve device with an improved valve seat structure.

As a refrigerant flow control valve device, for example, one having a spherical poppet shape, the one shown in FIG. 6 is known. That is, in the figure, reference numeral 1 denotes a valve body, and this valve body 1 is provided with a flow passage 2, and when a ball valve 4 is brought into contact with and separated from a valve seat 3 of this flow passage 2, the above-mentioned flow passage 2 is opened.
is now open and closed.

However, the conventional one has a lift L of the ball valve 4.
As shown in FIG. 7, the relationship between the opening area of the flow passage 2 and the opening area of the flow passage 2 is almost proportional, or as shown in FIG. greatly and then gradually decreased,
The rate of change in the opening area of the flow path 2 was initially large and then gradually decreased.

For this reason, the flow rate change at the initial stage of opening of the flow path 2 becomes large, and the flow rate change in the flow path 2 in the refrigerant cycle increases.
At the beginning of the opening, the flow rate changes become large, making it difficult to precisely adjust the flow rate, resulting in the inconvenience that good refrigeration efficiency cannot be maintained.

This invention was made with attention to the above circumstances,
The purpose of this is, as mentioned above, that the rate of change in the lift L of the ball valve is large at the beginning of opening based on the input signal, and then gradually decreases, and the rate of change in the opening area of the flow path is large at the beginning of opening, and then It has a characteristic of gradually decreasing, and the flow rate change is large at the beginning of the valve opening.
Therefore, in order to solve the problem that precise flow rate adjustment is difficult, it is an object of the present invention to provide a refrigerant flow rate control valve device that has a simple structure and reduces the rate of change in flow rate at the initial stage of valve opening.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, 11 is a valve body connected, for example, in a refrigeration cycle, and this valve body 1
A flow path 12 is provided within the chamber 1 . A first valve seat 13 and a second valve seat 14 are formed at the outflow side end of the flow passage 12. The inner diameter φd of the first valve seat 13 is the inner diameter φD _P of the second valve seat 14.
It is said to be smaller. Further, the first valve seat 13
A ball valve 15 is moved toward and away from the second valve seat 14 to open and close the flow passage 12.
The diameter D _B of the ball valve 15 is equal to or approximately equal to the inner diameter φD _P of the second valve seat 14, and the distance x between the first and second valve seats is It is expressed as

Therefore, in the above-described configuration, when the ball valve 15 is lifted in a direction away from the first and second valve seats 13 and 14, the flow passage 12 is opened and the refrigerant is allowed to flow.

When this flow passage 12 is opened, the second valve seat 1
The relationship between the lift amount of the ball valve 15 and the opening area of the flow passage 12 with respect to the ball valve 1 is as shown in line a in FIG.
4, the opening area of the flow passage 12 gradually increases. Therefore, the rate of change in the flow rate of the refrigerant at the beginning of opening of the ball valve 15 becomes small instead of increasing as in the conventional case, and the flow rate adjustment becomes easy.

On the other hand, the refrigerant flow rate characteristic at the first valve seat 13 changes proportionally as shown by line b in FIG.

In addition, by fitting the first valve seat 13 and the ball valve 15, the flow passage 12 is reliably closed, the ball valve 15 is positioned, and the maximum passage area of the refrigerant is set. There is.

By the way, the characteristics of the element that drives the lift of the valve body are such that when the input signal is small, the valve lift increase rate is large, and when the input signal is large, the valve lift increase rate is small, that is, for example, when the ball valve 15 is When operating with a bimetal whose operating amount gradually decreases accordingly, the characteristics of the bimetal shown in Fig. 3 and the flow rate characteristics shown in Fig. 4 are combined as shown in Fig. 5, and the flow rate at the initial stage of valve opening is It can be corrected to a proportional characteristic that reduces the rate of change. In addition to bimetal, a bellows containing a fluid substance such as wax and a heater inserted therein may be used.

As explained above, in the present invention, a first valve seat and a second valve seat having an inner diameter larger than the first valve seat are provided in the flow passage within the valve body, and these first and second valve seats are provided. Since the flow passage is opened and closed by moving a ball valve toward and away from the seat, the flow rate when the flow passage begins to open can be reduced, and precise flow rate adjustment is required when the flow passage begins to open. This has the effect of making the adjustment extremely easy in some cases.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the refrigerant flow control valve device of the present invention, Fig. 2 is a graph showing its flow characteristics, and Fig. 3 is a graph showing the flow rate characteristics.
Figure 4 is a graph showing the characteristics of the drive element, Figure 4 is a graph showing the flow rate characteristics, Figure 5 is a graph combining Figures 3 and 4, and Figure 6 is a cross section showing a conventional valve device. In the figure, FIG. 7 is a graph showing the flow rate characteristics. DESCRIPTION OF SYMBOLS 11... Valve body, 12... Flow path, 13... First valve seat, 14... Second valve seat, 15... Ball valve.

Claims (1)

[Scope of utility model registration request] In a flow control valve, the characteristic of the element that drives the lift of the valve body is that when the input signal is small, the valve lift increase rate is large and when the input signal is large, the valve lift increase rate is small. a flow path provided in the flow path, a first valve seat provided in the flow path, a second valve seat having an inner diameter larger than that of the first valve seat, and a valve seat that approaches and separates from these first and second valve seats. A refrigerant flow rate control valve device comprising a ball valve that opens and closes the flow passage to reduce a rate of change in flow rate at an initial stage of valve opening.