JP2000320700A - Three-port valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent ports from simultaneous communication during switching of a three-port valve and besides to reduce the number of fluid reservoirs and seal spots. SOLUTION: Passages 21 and 41 on the output side of two two-port valves 2 and 4 communicating with a common port P are caused to communicate with respective individual ports to form a three-port valve. The two-port valves 2 and 4 are constituted such that valve elements 24 and 44 are driven by pilot fluids Pa and Pb in pressure chambers 31 and 51 exerted on pistons 27 and 47, and the two-port valve consists of a pilot drive valve to felease respective valve seats 23 and 43. Besides, the pressure chamber 33 of the two-port valve 2 is caused to communicate with the pressure chamber 51 for the pilot fluid Pb of the trwo-port valve 4 and during a feed of the pilot fluid Pb, the two-port valve 2 is closed by a fluid pressure fed to the pressure chamber 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-port valve used as a divider valve or a selector valve, and more particularly to a three-port valve which eliminates inconvenience caused by simultaneous communication of three ports.

[0002]

2. Description of the Related Art A conventional three-position three-port valve generally used as shown in FIG. 5 switches a flow direction of a fluid from an inlet P to an outlet A or B. In this type of three-port switching valve, when a signal Pa or Pb for switching a flow path is applied, there is a moment, though instantaneously, at which the inlet P and the outlets A and B simultaneously communicate within the switching valve, In such a case, there is a possibility that the signal is output from the inlet to both the outlets A and B, so that there is a problem depending on the use of the switching valve. In order to avoid this problem, two 2-port valves may be used as shown in FIG. 6. However, in this case, if the signals Pa and Pb are simultaneously applied for some reason, a similar problem may occur. Will occur.

Further, as shown in FIG. 8, if a signal Pa is applied to a 3-port valve in a state where a 3-port valve and a 2-port valve are combined and a signal Pb is not applied to a 2-port valve, the outlet B
, And is output only from the exit A. In this case, even if the signal Pb is added, there is no output from the exit B,
Output from exit A only. When the signal Pb is added without adding the signal Pa, the signal is output from the outlet B. Therefore, the problem of simultaneous communication when a signal is erroneously output can be solved. However, when controlling the flow of liquids or gases such as paints and chemicals, it is necessary to reduce the number of liquid pools (gas pools) and locations where the fluids are sealed as much as possible. We cannot meet this requirement.

[0004]

SUMMARY OF THE INVENTION The technical problem of the present invention is to solve such a problem so that even if a signal is erroneously output, the ports are not connected simultaneously and no problem occurs.
To provide a port valve. Another technical problem of the present invention is that the ports do not communicate simultaneously.
An object of the present invention is to provide a three-port valve which has a small number of fluid reservoirs and seal portions to control the flow of a fluid such as paint or chemicals. Another technical object of the present invention is to provide a three-port valve suitable for use as a divider valve or a selector valve.

[0005]

According to a three-port valve of the present invention for solving the above-mentioned problems, one of the flow paths is connected to a common port P.
A three-port valve in which the other flow passages of the two two-port valves that communicate with each other communicate with individual ports A and B, respectively.
The above two-port valve is constituted by a pilot drive valve that opens each valve seat by driving the valve body by pilot fluid pressure, and a pilot fluid that drives the valve body in a direction to close the valve seat in one of the two-port valves. And a pressure chamber of a pilot fluid for driving a valve body in a direction to open a valve seat of the other two-port valve through a communication flow path.

In the above three-port valve, the two two-port valves are urged in a direction to open the valve bodies by a pilot fluid acting on the pistons connected to the respective valve bodies, and the pistons are provided with valves. It can be constituted by a pilot drive valve that applies a spring force sufficiently smaller than the force exerted by the pilot fluid by the spring force in the body closing direction.

In the three-port valve having the above configuration,
When one of the two-port valves is opened by the action of the pilot fluid Pa, the fluid from the port P common to the two two-port valves flows out from the outlet-side port A of the one two-port valve, and the other two ports. Set the valve element of the valve to pilot fluid P
When the pilot fluid is opened by the action of b, the pilot fluid pressure acts together with the biasing force of the spring in a direction to close the valve element of the one two-port valve, and whether the pilot fluid Pa is supplied to the one two-port valve or not. Regardless of this, the valve element of the two-port valve is closed, and even if there is an output from port A, it is stopped. Therefore, even if the pilot fluid Pa is added to the one two-port valve while the other two-port valve is opened with the pilot fluid Pb, the two-port valve does not open. Although the description has been made on the assumption that the three-port valve is used as a divider valve, it is needless to say that the three-port valve can be operated as a selector valve.

[0008]

1 and 2 show a third embodiment of the present invention.
1 shows a first embodiment of a port valve. The three-port valve of the first embodiment includes two two-port valves 2 and 4 in a valve body 1.
, The valve body 1
Consists of a main valve body 10 through which a fluid whose direction is to be switched flows and a pilot body 11, 12 of a pilot drive section for opening and closing the two two-port valves 2, 4. , 4 are connected to a common inlet port P, respectively, and the other flow paths (output sides) 22, 42 of the two-port valves 2, 4 are connected to each other. Each of them is communicated with an individual outlet port A, B. The outlet side port B communicates with the output flow path 5 penetrating the main valve body 10.

The two two-port valves 2 and 4 constituting the three-port valve have valve bodies 24 and 44 for opening and closing valve seats 23 and 43 provided in respective flow passages. The rods 25 and 45 are made to penetrate the diaphragms 26 and 46 in a sealed state, thereby forming the diaphragms 26 and 4.
6 is isolated from the flow path of the fluid flowing through the respective valve seats 23, 43, and at the ends of the valve rods 25, 45, the cylinders 29, 49 formed in the pilot bodies 11, 12 are provided. Piston 2 slidably fitted in
7, 47 are provided. The piston 27 of the two-port valve 2 has a piston packing 28 made of an O-ring around the piston 27, whereas the piston 47 of the other two-port valve 4 has a V or U-shaped cross section around the piston. A one-way seal piston packing 48 is provided.

In the above two two-port valves, the valve element 24,
A piston 27 connected to the piston 44 via valve stems 25 and 45;
47 defines pressure chambers 31 and 51 communicating with the pilot ports 30 and 50 in the cylinders 29 and 49, and the pistons 2 are formed in the pressure chambers 31 and 51.
The pressure of the pilot fluids Pa and Pb acting on the valves 7 and 47 urges the respective valve elements 24 and 44 in the opening direction, while the pistons 27 and 47 and the inner end faces of the cylinders 29 and 49 Between them, springs 32, 52 for biasing the valve bodies 24, 44 in the closing direction are interposed, and these two two-port valves 2, 4 are configured as pilot drive valves. The urging force of the springs 32, 52 is applied to the pilot fluid P in the pressure chambers 31, 51.
a, a force sufficiently smaller than the acting force of Pb.
4.

In the two-port valves 2 and 4, the valve bodies 24 and 44 are driven by the pressures of the pilot fluids Pa and Pb supplied and discharged through the pilot ports 30 and 50, respectively, to open the respective valve seats 23 and 43. However, a pressure chamber 33 facing the pressure chamber 31 for driving the valve element 24 in a direction to close the valve seat 23 in one of the two-port valves 2, and a pilot fluid in the other two-port valve 4. Pb pressure chamber 51 and pilot body 1
The communication between the first and the second 12 is established by a communication channel 7 that communicates with a seal 8 interposed therebetween.

When the pressure chamber 33 of the two-port valve 2 is communicated with the pressure chamber 51 of the other two-port valve 4 through the communication flow path 7, the pressure chamber 33 is closer to the pilot port 50 side than the pressure chamber 51. It is desirable to connect the communication flow path 7, so that the pilot port 50 connects the pressure chamber 33 of the two-port valve 2 to the pressure chamber 33 of the two-port valve 2, particularly when there is a restricting portion or the like that delays the flow of fluid at the inlet of the pressure chamber 51. The pilot fluid Pb of the two-port valve 2 can quickly flow.
The pressure chamber 51 of the piston 47 in the two-port valve 4
Since the chamber 53 on the opposite side does not allow a pilot fluid or the like to flow therein, the piston packing 48 can be a one-way seal. As shown, the head of the piston 47 in the two-port valve 4 is
2 and the valve stem 4 of the two-port valve 4
5 for manual operation.

In the three-port valve of the first embodiment having the above configuration, the pilot port 3 of one of the two-port valves 2
0, the valve seat 23 of the two-port valve is opened by driving the valve element 24 by the action of the pilot fluid Pa.
Fluid from the port P common to the two-port valve 4 is output from the outlet port A of the two-port valve 2, and the supply of the pilot fluid Pb to the pilot port 50 of the other two-port valve 4 causes When the valve seat 43 is opened by driving the valve body 44 by the action of the pilot fluid Pb,
The fluid from the port P is output to the output flow path 5 through the outlet port B of the two-port valve 4.

In the operation of the two-port valve 4, the pressure chamber 33 in one two-port valve 2 and the other two-port valve 2
Since the pressure chamber 51 of the port valve 4 is connected to the pressure chamber 51 by the communication flow path 7, the pressure of the pilot fluid Pb from the pilot port 50 flows into the pressure chamber 33 of the two-port valve 2, and the pilot fluid Pb The valve body 24 of the two-port valve 2 together with the urging force of the spring 32 provided in the room
Acts in the direction of closing.

The pilot port 50 of the two-port valve 4
Is supplied to the pressure chamber 33 of the two-port valve 2, the pilot fluid Pb is supplied to the piston 2.
7 is larger than the area where the pilot fluid acts on the piston 27 in the pressure chamber 31, and the urging force of the spring 32 also acts on the piston 27 from the pressure chamber 33 side. Regardless of whether the pilot fluid Pa is supplied to the second pressure chamber 31 or not, the valve element 24 of the two-port valve 2 is closed, and even if there is an output from the port A, it stops. Therefore, when the two-port valve 4 is opened by the pilot fluid Pb, the pilot port 3 of the two-port valve 2 is opened.
Even if the pilot fluid Pa is added to 0, the 2-port valve 2
But never open.

FIG. 3 shows a second embodiment of the three-port valve according to the present invention. The three-port valve according to the second embodiment includes two three-port valves 61 and 62 having the same configuration as the three-port valve according to the first embodiment in FIGS.
0 is integrated, and the output flow path 5 is provided with a common and joined structure, which is convenient for use in a mode described below with reference to FIG. Therefore, port B
Each of the three-port valves 61 and 62 has the same structure or operation as that of the first embodiment except that the fluid output from the first embodiment is led out through the common output flow path 6. The same reference numerals as in the first embodiment denote the same parts, and a description thereof will be omitted.

FIG. 4 illustrates a mode of use suitable for the above-described three-port valve, in particular, the three-port valve of the second embodiment shown in FIG.
A case is shown in which the valve bodies 1 in a number of three-port valves are connected to each other by connecting the output flow paths 6 to each other so that different-color paints are selectively supplied from the three-port valves 61 and 62. In these three-port valves 61 and 62, the paint flowing out of the output side port A is returned to the paint tank by the control of the pilot fluids Pa and Pb, while being sent from the port B to the output flow path 6. The paint thus applied is sent out through a paint passage 63 connected to the paint ejection side. In the figure, reference numeral 64 denotes a supply valve of a solvent for cleaning the paint adhered to the flow path, and reference numeral 65 denotes a supply valve of air. The three-port valve of the first embodiment can be used in a similar manner. Further, it goes without saying that the above-described three-port valves are not limited to use in such an aspect.

[0018]

According to the three-port valve of the present invention described above in detail, when the signal is erroneously output, the respective ports are simultaneously communicated, as in the above-described conventional three-port valve, causing a problem. In addition, such a three-port valve can be configured with a small number of fluid reservoirs and sealing portions, and a three-port valve suitable for controlling the flow of a fluid such as paint or chemicals can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a three-port valve according to the present invention.

FIG. 2 is a sectional view taken along a line XX in FIG.

FIG. 3 is a sectional view showing a second embodiment of the three-port valve according to the present invention.

FIG. 4 is a configuration diagram illustrating a mode of use of a three-port valve according to the present invention.

FIG. 5 is an explanatory diagram showing a configuration of a conventional general three-position three-port valve by a symbol mark.

FIG. 6 is an explanatory diagram showing the case where two 2-port valves have the same function as the 3-position 3-port valve in FIG. 5 by using symbol marks.

FIG. 7 is an explanatory diagram showing a case where a combination of a three-port valve and a two-port valve has a function similar to that of the three-position three-port valve in FIG. 5 by a symbol mark.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve body 2, 4 2 port valve 7 Communication flow path 21, 41 Flow path 23, 43 Valve seat 24, 44 Valve body 27, 47 Piston 30, 50 Pilot port 31, 51 Pressure chamber 32, 52 Spring 33 Pressure chamber P Inlet port A, B Outlet port Pa, Pb Pilot fluid

Continued on the front page F term (reference) 3H056 AA01 BB47 BB50 CA02 CB02 CD01 CD03 GG02 GG04 3H067 AA01 AA32 BB03 BB14 CC47 CC60 DD02 DD12 DD33 FF07 FF17 GG02 GG12 GG28

Claims (2)

[Claims] 1. A three-port valve in which one flow path communicates with a common port and the other flow path communicates with individual ports of two two-port valves. A pilot drive valve that opens each valve seat by driving the valve body by fluid pressure; a pilot fluid pressure chamber that drives the valve body in a direction to close the valve seat in one of the two-port valves; 3. A three-port valve, wherein a communication passage communicates with a pressure chamber of a pilot fluid that drives a valve body in a direction to open a valve seat of the port valve. 2. The two-port valve in the three-port valve according to claim 1, which is urged in a direction to open the valve bodies by a pilot fluid acting on pistons connected to the respective valve bodies, A three-port valve, comprising a pilot drive valve for applying a spring force sufficiently smaller than the force exerted by the pilot fluid to the piston by a spring force in a direction to close the valve element.