JPS594585B2 - Switching valve device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention, Field of Industrial Application) The present invention is first used in the field of controlling the flow direction of fluids such as gases and liquids.

The present invention is directed to a refrigerant flow path in order to operate each heat exchanger alternately as a heater or a cooler in a heating and cooling system in which, for example, one compressor is selectively connected to a set of heat exchangers. It relates to switching valve devices used for switching, and in particular, so-called closed-type switching devices consisting of a combination of a pilot-operated main switching valve and a cut-off switching valve for pilot pressure switching. Regarding.

(Prior art, its problems, and technical analysis) For example, in a heat pump type air-conditioning system, a set of heat exchangers, namely an evaporator and a condenser, are connected in the direction of flow of refrigerant gas in order to change their respective roles in summer or winter. However, when switching the flow direction, the most important thing is to absolutely prevent the refrigerant gas from leaking to the outside. A closed type (closed circuit) switching valve system must be used, and this system usually consists of a pilot operated switching valve (main switching valve),
It is composed of a solenoid valve (cutting switching valve) for switching the pilot pressure.

However, in the pilot type switching valve (main switching valve) of conventional equipment, all pilot pressure must be processed in a closed type as described above, so at least the pilot pressure is processed by a three-way switching solenoid valve (cutting switching valve). The structure of the main switching valve itself was extremely complicated because the flow direction of the fluid was switched and the pilot pressure fluid was absorbed within the pilot type main switching valve.

That is, the above-mentioned prior art device is the Japanese Patent Publication No. 44-94
There is a switching valve (reversible valve) device disclosed in Publication No. 32,
The main switching valve in this device is provided with a movable valve member and six sets of pistons that are integrally connected on both sides of the movable valve member via connecting members, and a valve chamber is provided between the two pistons in the valve casing. In addition, a pilot chamber is formed on the outside of the valve chamber via both pistons, and pilot pressure fluid is alternately supplied to both pilot chambers by the operation of a switching valve to control the movable valve member in the valve chamber. However, when applying pilot pressure to the pilot chamber on one side to switch the operating state of the movable valve member,
In order to release the residual pilot pressure in the pilot chamber on the other side, this residual pressure is temporarily returned to the cutting switching valve, and from there it is discharged through a special pipe piped from the cutting switching valve to the main switching valve side. Therefore, in addition to requiring extra piping equipment, the cutting switching valve must be at least a three-way valve.As a result, not only does the side switching valve itself have a complicated and costly structure, but the entire device becomes large. It's complicated.

(Technical Problem of the Present Invention) A technical problem of the present invention is that when the operating state of the valve member (valve body) in the valve chamber is switched by applying pilot pressure to one side of both pilot chambers, the pilot chamber on the other side is In order to release the residual pilot pressure, special external piping is not required as in the past, and the residual pilot pressure can be absorbed and discharged within the pilot type switching valve (main switching valve) using the simple structure of the switching valve itself, As a result, it is possible to simplify a switching valve for pilot pressure switching, and also to simplify the structure of the switching valve device as a whole.

(Technical means) The means of the present invention taken to solve the above problems are as follows [
A] and [1 point] are shown.

[B] “The main switching valve has a valve body in the center of a rod placed inside the switching valve body, and a valve body is installed at both ends of the rod, and sliding pistons with different inner diameters are installed at both ends of the switching valve body. Seven sets of pistons that slide in chambers are provided facing each other, and each piston sliding chamber has a valve body side chamber communicating with at least the above-mentioned discharge port via the piston on the valve body side thereof, and a pilot chamber on the opposite side thereof. In addition, a small air vent gap is provided between the pilot chamber and the valve body side chamber in the large-diameter piston sliding chamber and communicates with these chambers.

” [Port] “The cutting switching valve selectively supplies pilot pressure fluid to the compartments of the large-diameter pilot chamber and the small-diameter pilot chamber, and supplies pilot pressure fluid only to the small-diameter pilot chamber. Something that can be switched.

” (action of technical means) The above technical means works as follows (see Figure 4).

That is, when the cutting switching valve 104 is first operated to supply pilot pressure fluid only to the pilot chamber 116a of the small diameter piston sliding chamber 116 as shown in FIG. Pilot room 116
The small diameter piston 113 is used to supply pilot pressure to a.
is pressed and the rod 111 moves to the left in the figure, so that the pressure fluid supplied from the pressure source through the supply port A' is directed to the right valve chamber portion 118a divided by sandwiching the valve body 114. from which it exits the output port CI and circulates, for example, through a series of heat exchangers.

From the other output port C da to the left valve chamber portion 1 of the valve chamber 118
18b, and further returns to the pressure source side from this valve chamber portion 118b through the exhaust port) and B1/.

In the above case, it is assumed that there is no residual pilot pressure in the large-diameter pilot chamber 115a initially.

Then, the operation of the switching valve 104 transfers the pilot pressure fluid to both the pilot chambers 115a on the large diameter side and the small diameter side.

116a, fluid from the pressure source flows into both pilot chambers 115a and 116a at the same time, but at this time, the difference in effective pressure receiving area between the large diameter piston 112 and the small diameter piston 113 By rod 11
1 moves to the right in the figure, thereby switching the fluid flow direction.

That is, the pressure fluid supplied from the supply port A' exits the output port c4 from the left valve chamber portion 118b, enters the right valve chamber portion 118a from the opposite output port CI', and then flows through the discharge port B. Exit and return to the pressure source.

When further switching the flow direction from this flow state, the cut-off switching valve 104 is switched to cut off the supply of pressure fluid to the pilot chamber 115a of the large-diameter piston sliding chamber 115, and the small-diameter pilot chamber 116a When pilot pressure fluid is supplied only to the small diameter side piston 113 and the small diameter side piston 113 is pressed by the pilot pressure, the large diameter side pilot chamber 1
The residual pilot pressure in the air vent 15a is vented to the valve body side chamber 115b through the air vent 4Jr gap 111 and is discharged from the discharge port B (the rod 111 moves to the left in the figure). The operating state of the main cutoff valve 103 is switched, and the direction of fluid flow is switched.

(Special effects of the present invention) In conventional devices, in order to release residual pilot pressure, the residual pressure is returned to the cutting switching valve and then discharged from the main switching valve side discharge port through special piping. On the other hand, in the present invention, in the main switching valve, a small gap is provided between the pilot chamber and the valve body side chamber in the large-diameter piston movement chamber to communicate with both chambers, thereby reducing the residual pilot pressure in the pilot chamber. Since the residual pressure is extracted into the valve body side chamber through this minute gap and discharged from the discharge port, special piping equipment for discharging the residual pressure is not required.

On the other hand, the switching of the cutting switching valve can be done by applying pilot pressure only to the small-diameter pilot chamber or by applying pilot pressure to both pilot chambers; in other words, the pilot pressure to the large-diameter piston is cut off. The above switching can be performed depending on whether the pilot pressure is cut off or not, and there is no need to change the flow direction of the pilot pressure by using at least a three-way switching valve as in the past. It is sufficient to adopt an on-off valve, which simplifies the structure of the cut-off valve itself.

Therefore, according to the present invention, the structure of the entire switching valve device can be simplified and costs can be significantly reduced.

(Example) Next, an example of the present invention will be described based on FIGS. 1 to 3.

First, in the heat pump air conditioning system shown in FIGS. 1 and 2, the general structure is as follows: a compressor 1; a main switching valve 3 to which refrigerant gas is supplied from the compressor 1 via a supply pipe 2; a condenser (acts as an evaporator in the heating state in Fig. 2), a capillary tube, (capillary) 8
and evaporator (works as a condenser in the heating state in Figure 2) 9
It consists of

The main switching valve 3 has the following configuration.

That is, the supply port A) and the discharge port B1. In the switching valve main body 10 having B2 and output ports C1 and C2,
A rod having pistons 12 and 13 sliding in piston sliding chambers 15 and 16 provided at both ends of the switching valve main body 10 at both ends, and having a valve body 14 integrally formed in the center protruding from the rod. 11 is inserted into the switching valve body 10, and a valve chamber 18 in which the valve body 14 is located is formed in the central part of the switching valve body 10. The piston sliding chamber 15 of the other piston sliding chamber 1
6, the effective pressure receiving area of the piston 12 sliding in the larger diameter piston sliding chamber 15 is larger than that of the other piston 13, and the piston sliding chamber 1
5.16 to the valve body side chamber 15 via the piston 12゜13.
b and a pilot chamber 15a, and on the larger diameter piston 12 side, a minute gap 17 is actively provided between the rod 11 at the center of the piston 12 and the piston 12 based on the design or machining tolerance. Air can be vented between the pilot chamber 15a and the valve body side chamber 15b by sandwiching the piston 12, and the valve body side chamber 15b communicates with the valve chamber 18, and also has a communication circuit with the exhaust ports B1 and B2. It becomes.

Specifically, the minute gap 17 will be explained in detail. A sleeve 19.20 is press-fitted into the center of both pistons 12.13, and a sealing material 21.22 and a retaining ring 23.24 are placed on the pilot chamber side of the piston 12.13. A unit fixed to the end face is manufactured in advance as a unit, and this is assembled into the main switching valve 30.
A locking collar 2 that fits over both ends of the rod 11 during assembly and has respective valve body side end surfaces 12a and 13a protruding from the rod 11.
5 and 26 are brought into contact and locked.

At this time, an airtight packing 27 such as an O-ring is interposed between the end face of the small diameter piston 13 on the valve body side and the locking flange 26 to provide an airtight structure. The sleeve 19 and the rod 11 are only brought into contact with the locking collar 25 so that the minute gap 17 formed between the sleeve 19 and the rod 11 due to design or machining overlap is not closed.

A supply port A to which the supply pipe 2 is connected is opened in the center of the switching valve body 10, and valve seats 28a and 28b are provided on both sides of the supply port A.
Output ports C1 and C2 are connected via the valve seats 28c and 28d on both sides, and a discharge port B1°B is connected via the valve seats 28c and 28d.
2 are opened respectively, and the output ports C□ and C2 are connected to the connecting pipes 5 and 6, and the discharge ports B□ and B21/'i are connected to the discharge pipe 29.
．． 30 respectively.

Further, piston sliding chambers 15 are provided on both end surfaces of the switching valve body 10.
, 16, pilot holes 31 and 32 communicating with the pilot chambers 15a and 16a, respectively, are opened, and these holes 31
．． 32 is a pilot pressure fluid supply pipe 33a.

34a is the connection.

On the other hand, the switching valve 4 is composed of an electromagnetic on-off valve, and includes a branch pipe 34b that communicates with the discharge port of the compressor 1 and the supply pipe 34a, and a pilot pipe that communicates with the pilot fluid supply pipe 33a of the large-diameter pilot chamber 15a. A poppet 39 that opens and closes a valve hole 38 between an inlet port 36 and an outlet port 37 is housed in the main body 35 of the main body 35. The poppet 39 is pressed by the interposed compression spring 41 to open the valve hole 38.
The hole is closed and opened when the electromagnetic coil 42 is excited.

Next, the operating state of the above embodiment will be described. FIG. 1 shows the switching state during cooling, in which the valve hole 38 of the cut-off valve 4 is closed by the poppet 39 biased by the compression spring 41.

Therefore, the pressure fluid (refrigerant gas) from the compressor 1 flows only into one pilot pressure fluid supply pipe 34a, flows into the small-diameter side pilot chamber 16a, and flows into the small-diameter side piston 13.
Press to move it to the left in the diagram.

This allows the refrigerant gas l/i from the compressor 1 to pass through the supply pipe 2 and from the supply port A to one valve chamber portion 18a.
from one output port CI through the connecting pipe 5, the condenser 1 installed outdoors, the capillary tube 8, and the evaporator 9 installed indoors, via the connecting pipe 6, and from the other output port C2. , flows into the other valve chamber portion 18b divided by sandwiching the valve body 14, exits from the valve chamber portion 18b through the discharge port B1, and circulates through the discharge pipe 29 toward the suction port side of the compressor 1.

As is well known, the indoor air is cooled by the evaporator 9vc, and the refrigerant gas absorbed there is dissipated into the outside air from the condenser 7. In the case of switching to third-order heating, as shown in Figure 2. As shown, the electromagnetic coil 42 of the switching valve 4 is energized and the poppet 39 is attracted to open the valve hole 38.

Thereby, the pressure fluid from the compressor 1 flows simultaneously from both pilot pressure fluid supply pipes 33a, 34a through the pilot holes 31, 32 into both pilot chambers 15a, 16a.

At this time, since the effective pressure receiving area of the large diameter piston 12 is larger than that of the small diameter piston 13, due to the area difference, the large diameter piston 12 overcomes the oppression of the small diameter piston 13 and moves to the right in the figure. When the heating state is switched, the refrigerant gas from the compressor 1 flows into the valve chamber portion 18b through the supply pipe 2, and from there exits through the output capo C2 and is connected to the condenser 9 installed in the door via the connecting pipe 6. Via the capillary tube 8 and the evaporator 7 installed outdoors, it flows from the other connecting pipe 5 and the output port C□ into the other divided valve chamber portion 18a via the valve body 14. It circulates from the valve chamber portion 18a through the discharge port B2 and the discharge pipe 30 to the suction port side of the compressor 1.

As is well known, the outdoor evaporator 7 obtains heat from the outside air, the condenser 9 releases the heat, and the heat is used as hot air.

Furthermore, when switching from the heating state shown in FIG. 2 to the cooling state shown in FIG. 1, the valve hole 38 of the cut-off valve 4 is closed as shown in FIG. All that is required is to cut off the flow of pressure fluid to the supply pipe 33a, but in this case, since pilot pressure is accumulated in the large-diameter pilot chamber 15a, unless this is released, the pistons 12 and 13 will be moved to the left in the figure. It is difficult to make it work.

However, as described above, a small gap 17 is provided between the rod 11 and the sleeve 19 at the center of the large-diameter piston 12 due to needle installation or processing tolerance, and the piston 12
The valve body side chamber 18b is sandwiched between the pilot chamber 15a and the valve body side chamber 18b so that air can be vented.

In addition, when switching directly from heating to cooling, the refrigerant gas is not supplied to both heating and cooling due to the function of the thermometal circuit, and the pressure in the pilot chamber 15a decreases along with the supply pipe 2. Normally, the heating state is stopped for a long period of time (in other words, in the spring), and then the air conditioning state is switched to the cooling state in the summer.

Therefore, during the above-mentioned rest period, the residual pilot pressure fluid in the pilot chamber 15a is discharged from the valve body side chamber 1 through the air venting minute gap 1γ.
8b, exits the discharge port B1 from the valve chamber portion 15b, and is discharged into the discharge pipe 29, and the pilot pressure in the pilot chamber 15a has sufficiently decreased by the time the state is switched to the cooling/heating state.

Therefore, if the pilot pressure in the pilot chamber 16a on the radial side increases, the piston 12.13 smoothly moves to the left to the state shown in FIG. 1, and the cooling state can be achieved without any inconvenience.

Note that the small diameter piston 13 is connected to the valve seat 28d,
At the same time, the pilot pressure in the pilot chamber 16a constantly presses against the locking flange 26 and strongly presses against the airtight packing 27 interposed between the two, so the pilot pressure in the pilot chamber 16a constantly leaks. It is reliably maintained without any damage.

FIG. 3 shows another embodiment of the main switching valve in the switching valve device, and in the embodiment shown in FIGS.
0 is formed of copper pipe material, and each flow path and the core valve body 10 are brazed with phosphor brazing material, but in FIG. 3, the switching valve body 10' is integrally formed of brass material, Each flow path and the switching valve main body 10' are welded, and the rod 11' in particular is formed of a straight bar material, and the locking grooves 43 are formed at appropriate intervals.
The locking flanges 25' and 26' of each piston 12' and 13' are positioned by a snap ring 44 that is locked in a locking groove 43, and the valve body 14' is also located in the center. On the side, an O-ring 46 is interposed between a pair of locking rings 45, 45, and they are clamped and fixed by snap rings 47, 47 respectively locked in locking grooves 43, 43.

In the embodiments shown in FIGS. 1 and 2, the pressure fluid from the compressor 1 is branched and supplied to both the switching valve 4, which is an electromagnetic on-off valve, and the pilot pressure fluid supply pipe 32 at the branching section 48. However, in the embodiment shown in FIG. 3, the pressure fluid is once sent to the cut-off valve 4 which is a similar electromagnetic on-off valve, and then the pilot pressure fluid supply pipe is sent from the outlet 49 which is always in communication with the inlet 36. Pilot pressure fluid is supplied to the pilot chamber 16a via 34c.

In each of the above embodiments, the switching valve device of the present invention was applied to a heat pump four-season heating and cooling system.

Of course, the present invention is not limited to this, and can also be applied to other so-called closed type fluid control systems.

[Brief explanation of the drawing]

Figures 1 and 2 show one embodiment of the switching valve device of the present invention. Figure 1 is a cross-sectional view showing the cooling state, Figure 2 is a cross-sectional view showing the heating state, and Figure 3 is a cross-sectional view showing the switching valve device of the present invention. A sectional view showing an embodiment, and FIG. 4 are explanatory views for explaining the present invention in detail. A... Supply port, A'... Supply port, B□. B2...Exhaust port, B'3. B'2...
...Exhaust port, CI, C2... Output port,
C'1tC2... Output port, 1... Compressor, 2... Supply pipe, 3...
Main switching valve, 4...Solenoid switching valve (cutting switching valve), 5
゜6...Ren pipe, 7...Condenser, 8...
...Capillary tube, 9...Evaporator, 10,10'...Switching valve body, 12,12'
, 13, 13'...Piston, 11. '11'
...Rod, 14,14'...Valve body, 1
5, 16...Piston sliding chamber, 15a. 16a... Pilot room, 'f5b, 16b.
...Anterior body lateral chamber, 17...Minute gap for air extraction, 1
8...Valve chamber, 19.20...Sleeve,
21, 22... Seal material, 23.24...
... Nut, 25, 25; 26゜26' ... Locking collar, 27 ... Airtight gasket, 29゜30...
...Discharge path, 35...Solenoid on-off valve body, 3
8... Valve hole, 39... Poppet, 40
... Valve stem, 41 ... Compression spring, 42.
... Solenoid coil, 103 ... Main switching valve,
104... Cutting switching valve, 110... Switching valve body, 111... Rod, 112...
- Large diameter side piston, 113...Diameter/JS side piston, 114...Valve body, 115... Large diameter side piston sliding chamber, 115a...Diameter Large side pilot chamber, 115b... Valve body side chamber, 116...
... Screw on the opposite side) 1 movement room. 116a... Diameter/h side pilot chamber, 116b
...Valve body side chamber, 117...Minute gap for air removal.

Claims (1)

[Claims] 1. A rod is arranged in a switching valve body in which a supply port, a discharge port, and an output port are arranged in the center, and a valve body is installed in the center of the rod, and both ends of the switching valve main body are provided at both ends. A pair of pistons are provided facing each other and slide in piston sliding chambers with different inner diameters provided on the sides, and each bistoy sliding chamber has a valve communicating with at least the discharge port on the valve body side of the piston through the piston. A main switching system having a body side chamber and a pilot chamber formed on the opposite side thereof, and a small gap for air removal communicating with these chambers between the pilot chamber and the valve body side chamber in the large-diameter piston sliding chamber. a valve; and a cutting switching valve that selectively switches between supplying pilot pressure fluid to both the large-diameter pilot chamber and the small-diameter pilot chamber and supplying pilot pressure fluid only to the small-diameter pilot chamber. A switching valve device consisting of .