JPS59131070A - Three-way valve - Google Patents

Abstract

PURPOSE:To improve the reliability and to reduce the cost by applying driving fluid pressure from the side of a valve body and opening and closing a small- diameter pilot valve to change a difference in pressure between two pressure chambers mounted in the valve body, and by driving a valve shaft to switch a fluid outlet port. CONSTITUTION:When a pilot valve 28 is closed, and fluid pressure is applied from a pressure introduction port 2 through a through hole 4 to the first pressure chamber 6, the second valve seat 22 and the second valve 23 are closed and the first valve seat 13 and the first valve 21 are opened, so that a fluid introduced from a fluid inlet port 8 flows to the first fluid outlet port 14. When the pilot valve 28 is opened, a fluid in the second pressure chamber 7 is discharged through a pilot valve 28 to the air, and a fluid in the first pressure chamber 6 leaks out to the interior of the second pressure chamber 7. Accordingly, a valve cylinder 20 is raised, so that the first valve 21 is brought into contact with the first valve seat 13, and the second valve 23 is separated from the second valve seat 22 to form a passageway. Thus, a fluid from the fluid inlet port 8 flows to a flow outlet port 16.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a cylindrical valve as a driving source for valve switching by introducing a constant pressure fluid from the side of a valve body and opening and closing a pilot valve provided on the outlet side of this fluid. This invention relates to a three-way valve that switches fluid from an inlet to two outlet ports by moving the valve shaft.

Conventional three-way valves operate remotely by installing a pneumatic, hydraulic, or electric drive unit at one end of the valve body to switch the fluid from the inlet to one of the two outlet ports. There are two operating methods: one is a manual operating method, and the other is a manual operating method, which is equipped with a drive unit consisting of a screw, gear mechanism, etc., but in the above method, the driving force is applied directly to the valve stem by applying pressure, magnetic force, etc. by 1 yen within the drive unit. Therefore, it is desirable to reduce the failure rate and cost due to the large number of components required for these.In addition, the weight of the drive part increases by 1°, which increases in volume as the valve size increases. There is also a need for a reduction in weight and compactness.

The present invention improves the above-mentioned drawbacks, and instead of providing a valve drive unit in the valve shaft direction, the driving fluid pressure is applied from the side of the valve body, and two pressure chambers provided on the valve body wall and the valve shaft are mutually connected. To provide a three-way valve that changes the pressure difference by opening and closing a small-diameter pilot valve, generates a driving force to a valve shaft inside a valve body, and switches an outlet.

Embodiments of the present invention will be described with reference to the drawings. On the outer periphery of the kidney jacket, there is a flange 15 connecting the pressure inlet 2, the outlet 3, and the first outlet 14, and a second outlet. A flange 17 is provided to connect the pressure inlet 2 to the first pressure chamber 6 through the through hole 4, and the outlet hole 3 to the second pressure chamber 7 through the through hole 5. are doing. A flange 9 connecting the inlet 8 to the valve body 1 is provided on one end surface of the valve body 1, and a first valve seat 13 is provided at the terminal end of the inlet 8. Further, inside the valve body 1, a second valve seat cylinder 10 and a valve cylinder 20 are provided on the same axis, and the seven flange 11 provided on the second valve seat cylinder 10 and the flange 12 provided on the valve body l are Fixation,
It's blocked. The valve cylinder 20 is composed of an upper valve cylinder 19 and a lower valve cylinder 24, and the boundary between the two has a groove formed from the outer periphery, and an annular protrusion with a through hole 26 of a minute diameter bored near the base. 25' is provided, and the 01J ring 25 is fitted into the groove and attached to the inner wall of the valve body 1, and when the end face of the upper valve cylinder 19 abuts the first valve 1 seat 13, the 01J ring 25 is inserted into the groove. A first valve 21 formed so that the flow path is blocked is connected to a second valve seat 22 provided in the second valve seat cylinder 10 on the end face of the lower valve cylinder 24.
A second valve 23 is provided so that the flow path to the second outlet 16 is cut off when the second valve 23 comes into contact with the second outlet 16 . Valve body 1
O-rings 18 and 27 are fitted into grooves bored on the inner periphery of annular protrusions 18 and 27 provided on the inner wall of the O-rings 18 and 27, respectively, and are fitted onto the outer peripheries of the upper valve cylinder 19 and the lower valve cylinder 24, respectively. Therefore, the first pressure chamber 6 and the second pressure chamber 7 formed with the annular protrusion 25 as a boundary are kept airtight with respect to the first outlet 14 and the second outlet 16.

Furthermore, a pilot valve 28 and an exhaust pipe 29 whose terminal end is open to the atmosphere are attached to the exhaust port 3. In the above configuration, the inner diameter of the valve body 1 is d, and the outer diameter of the lower valve cylinder is d1s.
The outer diameter of the upper valve plate is d2゜ The weight of the valve cylinder 20 and the O-ring 18
, 15.27 and the frictional drag generated during sliding is Wl
If the difference between them is w', the closing pressure of the valve is S, and the liquid pressure in the first pressure chamber is ph, which will be described later, the liquid pressure in the second pressure chamber when the pilot valve is open is p2, then the above '+dl+d2+
"+-'+' r pI and p2 are set to appropriate values so as to satisfy the following equation.

pI-dl (d-dl)”>pg・↑(d-dx)”+
w-1-s・・・・・・(1) PI −÷(d-d 鳳)
"<pl・spear (d-dB)"+w'-s・・・・・・(
2) To explain the present invention in detail based on the above embodiments, FIG. 1 shows the fluid pressure p adjusted so that the pilot valve 28 is closed and a constant pressure is maintained at all times.

is applied to the first pressure chamber 6 from the pressure introduction port 2 through the through hole 4, and the second valve seat 22 and the second valve 23 are closed while maintaining a force relationship that satisfies the equation (2) described below. Since the space between the first valve seat 13 and the first valve 21 is open, the fluid led from the inlet 8 flows to the first outlet 14.

Here, when the pilot valve 28 is opened, the second pressure chamber 7
The fluid in the through hole 5. Outlet 3. The fluid in the first pressure chamber 6 begins to be discharged into the atmosphere through the pilot valve 28 and the discharge pipe 29, and accordingly, the fluid in the first pressure chamber 6 passes through the through hole 26 and enters the second pressure chamber 7.
The fluid in the second pressure chamber 7 begins to leak into the atmosphere while maintaining a pressure value slightly higher than atmospheric pressure (this pressure value is defined as p2). Continue to discharge to. In this case, within the first pressure chamber 6, the fluid is
Even if fluid leaks into the pressure chamber 7, the fluid is replenished from the through hole 4, which has a diameter sufficiently larger than that of the through hole 26, so that the pressure value pl remains constant.
is held. That is, as shown in equation (1) above, the value of the product of the fluid pressure p1 in the first pressure chamber and the pressure receiving area in the axial direction of the valve cylinder 20 + (, 1 - a +)'' is the value of the product in the second pressure chamber. Resistance W (valve cylinder 2
Since the value is larger than the sum of the dead weight of 0 and the frictional force generated by the sliding of the O-ring) and the closing pressure of the valve, it is shown in Figure 2 (the same parts as in Figure 1 are given the same reference numerals). As shown in Figure 1), the valve barrel 20 moves upward until the first valve 21 comes into contact with the first valve seat 13, and the flow path leading from the inlet 8 to the first outlet 14 is cut off, and at the same time , the second valve 23 is the second
It is separated from the valve seat 22 and the flow path is opened, allowing fluid from the inlet 8 to flow to the outlet 16.

Next, when the pilot valve 28 is closed from the above condition,
The fluid in the second pressure chamber 7 passes through the through hole 26 to the first pressure chamber 7.
Since the pressure becomes equal to the fluid pressure pt in the pressure chamber 6, the above (2)
As shown in the formula, the value of the product of the fluid pressure p1 in the first pressure chamber 6 and the pressure receiving area in the axial direction of the valve cylinder 20)·(d - dt)'' is the fluid pressure in the second pressure chamber 7. p! and pressure receiving area i (
Add the resistance w' (difference between the self-weight of the valve cylinder 20 and the frictional force caused by the sliding of the O-ring) generated when the valve cylinder 20 moves downward to the product of ``d-dz)'' to obtain the valve pressure S. Since the value is smaller than the subtracted value, the valve cylinder 20 moves downward until the second valve 23 comes into contact with the second valve seat 22, as shown in FIG.
At the same time that the flow path leading from the inlet 8 to the second outlet 16 is cut off, the first valve 21 that was in contact with the first valve seat 13
/fi moves downward, and the fluid from the inlet 8 begins to flow to the first outlet 14.

As described above, according to the present invention, the fluid outlet can be switched only by opening and closing the small-diameter pilot valve, and since there are few components, the failure rate is low, the weight is reduced, and the three-way valve is inexpensive. It becomes possible to provide

7-

[Brief explanation of drawings]

The figures are cross-sectional views showing one embodiment of the present invention, in which FIG. 1 shows the case when the valve is lowered, and FIG. 2 shows the case when the valve is raised. DESCRIPTION OF SYMBOLS 1... Valve body, 2... Pressure introduction port, 6... First pressure chamber, 7... Second pressure chamber, 8... Inflow port, 10...
Second valve seat tube, 13... First valve seat, 14... First outlet, 16... Second outlet, 19... Upper valve tube, 20
...Valve cylinder, 21...First valve, 22...Second valve seat,
23...Second valve, 24...Lower valve cylinder, 26...Through hole, 28...Pilot valve, 29...Drainage pipe agent Patent attorney Mamoru Takeuchi 8- Figure 1, 2 figure

Claims (1)

[Claims] an inlet at one end and a first valve seat at the terminal end of the inlet;
The outer periphery is equipped with two outflow ports, a constant pressure inlet and a discharge port for valve operation, and the other end is fixed to a member with a second valve seat inside a valve body formed to be closed. , the first at one end
A valve, a second valve at the other end, and a valve barrel that can slide along the wall of the valve body while maintaining airtightness, and two pressure chambers partitioned between the valve body and the valve barrel, communicating with each other. A three-way valve having a configuration including a pore, wherein the outlet is switched by applying a constant pressure to the pressure inlet and opening/closing a pilot valve provided at the outlet.