JPS5913175A - Fluid control valve - Google Patents

Abstract

PURPOSE:To improve a response characteristic for a change of pressure in a valve device opened and closed in accordance with the displacement of a pressure responsive element such as bellows or the like, by constituting the device such that a ball valve is adsorbed by a permanent magnet secured to the pressure responsive element. CONSTITUTION:In a fluid control valve 1 provided to a refrigerating circuit, its high pressure inlet 7 is connected to a condenser 3, and high pressure outlet 8 is connected to a capillary tube 4, while a low pressure inlet 9 and a low pressure outlet 10 are respectively connected to suction lines 6 connected to a discharge side of a compressor 2. The inside of this fluid control valve 1 is separated into high and low pressure sides by a bellows 13, and a high pressure valve device 11 and a low pressure valve device 12 are provided in the control valve 1. Then the low pressure valve device 12 is constituted by a housing 14 and a ball valve 15, and the ball valve 15 is attractively held by a permanent magnet 16 secured to the upper end of said bellows 13. In this way, a follow up characteristic of the ball valve 15 for the displacement of the bellows 13 is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a fluid control valve that opens and closes a valve device in response to the displacement of a pressure responsive element (hereinafter referred to as bellows) such as a bellows that is displaced in response to changes in fluid pressure.

Page 2 An example of this type of fluid control valve has already been filed by the present applicant. There is a patent application No. 56-187640 entitled "Fluid control valve for refrigeration equipment", which is designed to cut the superheat gas flowing into the evaporator when the cycling operation of a refrigeration equipment employing a rotary compressor is stopped. A pressure-responsive element (hereinafter referred to as a bellows) is displaced to open and close a valve device provided at the outlet of the capacitor. As shown in FIG.
A letter bellows 106 is hermetically soldered inside the casing 106 of the fluid control valve 1oO forming the valve seat 104 of No. 3, and a coil spring 1o that urges the bellows 106 upward in the figure.
7. Further holding the lower end of the coil spring 107 and the bellows 106
a retainer 108 that restricts excessive movement of the diranjar 10, which slides within the guide portion 105a of the casing 105, and has a valve body 1o9 at the top and a convex portion 1o9b at the bottom.
9. Then, the recess 10 of the bellows 106
6a and the plunger lower convex portion 109'b page 3 are connected and supported by sizing processing with a centripetal gap 106b provided. This configuration is the third
As shown in the figure, even if the lower part of the bellows 106 is inclined, the plunger 109 is slidably held with the same axis as the guide part 106a, and can be centripetal to the valve device 104. As is well known, spring members such as the bellows 106 and the coil spring 107 are difficult to manufacture with accurate parallelism and require this kind of centripetal mechanism. As a fluid control valve, the larger the differential pressure ΔP between the outside and the outside of the bellows 106 for displacing the bellows 106, the greater the effect, but in order to ensure operation, it is better to reduce ΔP.

However, as described above, if the gap 1o6b is provided for the centripetal mechanism, as shown in FIG. + Conversely, when closing the valve device 104, the lower surface of the convex portion 109b of the plunger 109 is pushed up by the lower surface of the bellows recess 106a, as shown in FIG. In other words, the differential pressure Δ
The relationship between P and the flow rate Q of the valve device 104 is shown in Figure 6. When increasing the differential pressure ΔP, the flow rate is indicated by the solid line in the figure, and conversely, when decreasing the differential pressure ΔP indicates the flow rate characteristics shown by the dashed-dotted line in the figure. That is, the differential pressure ΔP at which the valve device 104 opens is A, and the differential pressure ΔP at which the valve device 104 closes is B. Therefore, the A pressure is inevitably determined to ensure operation, and the B pressure is lowered.As a result, the original purpose of the fluid control valve 100, which is to cut off the superheat gas after the cycling operation is stopped. Valve device 104 for
This has the disadvantage that the time it takes for the circuit to close is extended, and the effectiveness is reduced.

Since the bellows 106 and the plunger 109 are sandwiched and held, the plunger 109 can be held parallel to the sliding axis even if the lower surface of the bellows 106 is inclined. However, as is well known, the bellows 106 and the coil spring 107
Springy members such as the above are particularly prone to buckling when compressed, and when used in this kind of fluid control valve 1oO, page 5, eccentricity due to buckling occurs as shown in FIG. Due to this eccentricity, the plunger 109 is held by the lower convex portion 1 held by the rose 106.
09b is displaced laterally (lower arrow in the figure), and the plunger 109 abuts the lower end of the guide 105a at approximately the center and is supported by this point.
The valve body 109a at the tip 9 is biased and displaced in a direction opposite to the eccentric direction described above (arrow above in the figure). When closing, valve body 1
' 09 a and the valve seat 104 only come into contact at the biasing pot position, and as a result, the valve device 103 is forced to become unable to close as shown in Fig. 6. The valve device 10'3 cannot be closed, and the superheat gas cannot be cut. Although it is conceivable to use a method to extremely improve the sliding accuracy and restrict the inclination of the plunger '109, this method has the drawback of increasing the number of processing and assembly steps. ' In view of the above, the present invention opens and closes the valve device by fixing a permanent magnet to the bellows and magnetically attaching the ball valve to the flat surface of the bellows, and the bellows and ball valve are separated. By doing so, the above drawbacks will be improved.
1□.

It is good.

Two embodiments of the present invention will be explained below with reference to the drawings.The 4' fluid control valve 2 is...
: 3 is a condenser, 4 is a capillary tube, 5 is an evaporator, 6 is a suction line, and the high pressure inlet lower and high pressure outlet 8 of the fluid control valve 1 are connected between the condenser 3 and the capillary tube 4, and also the low pressure inlet. 9-□
A refrigeration circuit is constructed by intervening the low-pressure holes 10 and 10 in a part of the suction line 6, respectively.

The fluid control valve 1 has a high pressure valve device 11 and a low pressure valve device 12 inside.
The high pressure and low pressure are separated by keeping the bellows 13□ airtight. The high-pressure valve device 11 is composed of a valve seat 14a at the tip, a screw portion 14b formed on the outer periphery, and a ball valve 15 and a ball valve 15, with a threaded portion 14b formed on the outer periphery and a high-pressure outlet 8 held on the upper surface. A permanent magnet 16 (hereinafter referred to as magnet) is fixed in the recess 13a, and the ball valve 1 made of magnetic material is attached.
5 is magnetically attached. Naturally, the magnetic force of the magnet 16 is caused by the pressure difference between the front and rear of the high pressure valve device 11.
The attraction force to the valve seat 14a is greater than that of the bellows 13 and the pole valve 16, and non-magnetic materials such as copper or copper alloy are used for the parts other than the bellows 13 and the pole valve 16. An outer surface convex portion 13d of the tip recess 13a, which is a contact portion between the bellows 13 and the ball valve 16, is formed in a plane perpendicular to the sliding axis of the ball valve 16.

The ball valve 16 has a substantially cylindrical portion 17a in the upper part of the casing 17.
The inner diameter of this cylindrical portion 17a is slightly larger than that of the ball valve 15, so that the ball valve 16 can slide. Further, a screw is formed on the inner surface of the upper end of the cylindrical portion 17a,
The threaded portion 14b of the housing 14 is screwed together.

The low pressure valve device 12 has a valve seat 19 formed in the center of the upper surface of the low pressure housing 18, and holds a low pressure inlet 9 in the center of the lower part.

A groove 18a is formed on the outer periphery of the upper part of the low pressure housing 18, and a plurality of stoppers 21.2 are engaged with the groove 18a and positioned with a slight gap around the outer periphery of the disc-shaped leaf valve 2o.
1, the stoppers 21 and 21 extend above the leaf valve 2o, with each tip facing downward to the center, and configured so that a certain gap is created between the tip and the leaf valve 2o. .

In other words, the low pressure valve device 12 is a check valve mechanism, and the leaf valve 2
When o floats upward, it is held at the tip of each stopper 21.21, and when it moves, each stopper 21.2
It slides inside the shaft of 1 and seals with the valve seat 19.

The bellows 13 is held by a boss 22 and a cap 23. In other words, the boss 22 has the upper end of the central hole 22a approximately the same as the outer circumference 13b of the opening of the bellows 13, and this hole 2
The cap 23 has nine holes in the center, and the gap between the lower part of the boss center hole 22a and the lower end of the taper 23b of the cab 23 is the opening of the bellows 13. Part 13b
The wall thickness is slightly smaller than that of the Therefore, the opening 1 of the bellows 13 is located in the central hole 22a of the boss 22.
3b facing the bellows 13 and press-fitting the cap 23 allows the bellows 13 to be held airtight. A recess 13c immediately above the opening 13b of the bellows 13 is formed to have a smaller size than the opening 13b. boss 22
A recess 22b is formed around the entire circumference of the casing 17, and after being inserted into the casing 17, the casing 17 is expanded to fit along the recess 22b, thereby airtightly separating the inside of the casing 17 with the boss 22. ing.

The urging force of the high pressure valve device 170 and the ball valve 15 is the bellows 13
The bellows 1 is attached to the casing 17 by taking advantage of its spring properties.
After retaining the boss 22 that holds the bellows 13, the ball valve 15 is housed, the screwing position of the threaded portion 14b of the housing 14 is adjusted, and the bellows 13 is compressed to obtain a biasing force. After setting force 10 to the specified force, housing 14 and casing 1
7 is brazed airtightly.

Next, the operation of the above configuration will be explained.

While the rotary compressor 2 is in operation, the condenser 3 and high pressure valve device 11 are at high pressure, and the evaporator 6 suction line 6 and low pressure valve device 12 are at low pressure.
A pressure difference is generated between the inside and outside of the bellows 13, and the bellows 13 is compressed downward. At this time, the ball valve 16 is attracted to the valve seat 14a by the attraction force caused by the pressure difference before and after the high-pressure valve device 11. However, since the magnetic attraction force by the magnet 16 is greater than this attraction force, the magnetic force of the magnet 16 causes the bellows 13 to be attracted to the valve seat 14a. The ball valve 16 magnetically attached to the tip 13a also moves downward as the bellows 13 is compressed, and the high-pressure valve device 11 is opened.In other words, the ball valve 16 moves as if it were fixed to the bellows 13. It is. On the other hand, in the low pressure valve device 12, the leaf valve 2o is blown up to the tip of the stopper 21 by the refrigerant circulating in the refrigeration device, and the refrigerant gas flows through the gap between the outer periphery of the leaf valve 2o and the casing 17, and normal operation is performed.
16- It's been a long time.

Next, when the rotary compressor 2 is stopped, the circulation of the refrigerant is stopped. As a result, the force that blows up the leaf valve 2o disappears, and the leaf valve decreases and is seated and sealed on the valve seat 19.

At this time, the gas refrigerant and refrigerating machine oil exist in a separated state in the low-pressure circuit, and although the refrigerating machine oil is also attached to the leaf valve 2o, it is only in contact with the stopper 21 and 21 at one point at the tip of each leaf valve 2o. Adsorption by refrigerating machine oil does not occur, and the leaf valve 20 partially falls at the same time as the engine stops. After that, high pressure gas flows into the low pressure valve device 12 from the rotary compressor 2,
The pressure difference between the inside and outside of the bellows 13 is approximate, but it expands due to the expansion force of the rose 13 itself, and the ball valve 16 is also displaced upward, closing the high pressure valve device 11. The contact portion 1sa of the i-bellows 13 with the ball valve 15 is formed in a plane perpendicular to the sliding axis of the ball valve 16 and is magnetically attached, so that Even if some buckling deformation etc. occurs, it will not work.

- The ball valve 16 is movable on the plane of the outer surface convex portion 13d, and since this plane is perpendicular to the axial direction, the ball valve 16
The force applied to the ball valve 15 is always applied only in the axial direction, and the ball valve 15 is always applied perpendicularly to the center of the valve seat 14a to ensure reliable sealing.

As is clear from the above description, the fluid control valve according to the present invention includes a pressure-responsive element and a valve device within a non-magnetic body, a permanent magnet is fixed to the pressure-responsive element, and the valve device has a substantially cylindrical shape. A valve seat is formed in the center of the upper surface of the shaped guide, and a ball valve made of a magnetic material having a diameter slightly smaller than the inner diameter of the guide is accommodated, and the ball valve is held magnetically by a permanent magnet fixed to the pressure responsive element. Therefore, when the pressure-responsive element is compressed due to a pressure change, the magnetically attached ball valve follows the compression of the pressure-responsive element in the same way as the ball valve that is fixed to the pressure-responsive element. Therefore, the displacement start pressure of the pressure responsive element and the valve opening pressure of the valve device match. Conversely, when the pressure-responsive element expands, it directly pushes up the ball valve, so the opening/closing valve pressure of the valve device becomes the same as the displacement pressure of the pressure-responsive element. -It is possible to quickly convert the pressure change into the operation of the valve device, and the effect of cutting off superheat gas, for example, can be maximized.

Ru. Furthermore, by forming the magnetically attached surfaces of the pressure-responsive element and the ball valve into a plane, the ball valve can move on this plane even if buckling deformation occurs in the pressure-responsive element. It is biased against the valve seat and enables reliable sealing.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a fluid control valve and a piping diagram of a refrigeration system showing an embodiment of the present invention, and Fig. 2 is an enlarged sectional view of the main part of Fig. 1 during operation, a is when open, b is 3 shows the main part of a fluid control valve showing a conventional example; FIGS. 4a and b are enlarged sectional views of the main part during operation of FIG. FIG. 6 is a cross-sectional view showing a situation during operation of the conventional example, and FIG. 6 is a pressure characteristic diagram of the conventional example. 1... Fluid control valve, 11... Valve device,
13...Pressure responsive element (bellows), 13a.
...Tip recess, 15...Ball valve, 17
...Body (casing), page 14 17a...Inner tube (guide), 16...
- Permanent magnet, 13d... Convex portion on outer surface. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 Figure 4

Claims (2)

[Claims] (1) A pressure-responsive element and a valve device are provided in a non-magnetic body, a permanent magnet is fixed to the pressure-responsive element, and the valve device has a valve seat formed in the center of the upper surface of the approximately cylindrical guide. A fluid control valve in which a ball valve made of a magnetic material having a diameter slightly smaller than the inner diameter of the guide is housed, and the ball valve is magnetically held by a permanent magnet fixed to the pressure responsive element. (2) The permanent magnet is fixed to a recess inside the pressure-responsive element, and the four outer surface projections are formed into a flat surface, and the ball valve is held magnetically on the flat surface of the projection. The fluid control valve according to item 1.