Liquid directional control valve

In a liquid directional control valve, a hollow rotary valve element is accommodated in a valve chamber for angular movement about a rotary axis of the rotary valve element. The rotary valve element has first, second and third openings. A liquid passageway formed by the rotary valve element is simple in construction. First seal elements are arranged about first, second and third outlet ports formed in the valve chamber and in close contact with an outer circumferential surface of the rotary valve element. A pair of circumferential grooves are provided respectively in outer circumferential surface sections of respective both ends of the rotary valve element. Each of the pair of grooves has a sloped bottom. A pair of second annular seal element are arranged respectively in the pair of circumferential grooves in concentric relation thereto.

BACKGROUND OF THE INVENTION 
The present invention relates to a liquid directional control valve for use 
with, for example, a liquid purifier, each of various liquid instruments 
and so on. 
As a liquid directional control valve of the kind referred to above, there 
have been proposed various liquid directional control valves each of which 
uses a ball valve element or a rotary valve element. However, such liquid 
directional control valves have such problems that sealing around the 
valve element is not necessarily sufficient, a water hammer tends to 
occur, a liquid passageway is complicated in construction or structure so 
that pressure loss is large, and the like. 
SUMMARY OF THE INVENTION 
It is therefore an object of the invention to provide a liquid directional 
control valve in which a liquid passageway is simple in structure and 
which is superior in sealing function. 
It is another object of the invention to provide a liquid directional 
control valve in which a water hammer is difficult to occur. 
According to the invention, there is provided a liquid directional control 
valve comprising: 
a valve chamber having an axis thereof and having a first position, a 
second position on the opposite side of the valve chamber from the first 
position, an intermediate position between the first and second positions 
and a third position located at the second position but spaced a 
predetermined distance therefrom along the axis of the valve chamber, the 
valve chamber having an inlet port at the first position, a first outlet 
port at the intermediate position, a second outlet port at the second 
position and a third outlet port at the third position, the inlet port, 
the first outlet port and the second outlet port being arranged in a 
common first plane perpendicular to the axis of the valve chamber, the 
third outlet port being arranged in a second plane spaced the 
predetermined distance from the common first plane along the axis of the 
valve chamber in parallel relation to the common first plane; 
a hollow rotary valve element having a rotary axis extending 
perpendicularly to the common first plane, the rotary valve element being 
accommodated in the valve chamber such that the rotary axis of the rotary 
valve element is in conformity with the axis of the valve chamber, for 
angular movement about the rotary axis of the rotary valve element, the 
rotary valve element having first, second and third openings formed in the 
rotary valve element; 
a selecting lever arranged on the outside of the valve chamber and 
connected to one end of the rotary valve element for selecting 
communication between the inlet port and first, second and third outlet 
ports and the first, second and third openings; 
a faucet mounting section arranged at a location adjacent the first 
position and connected to the inlet port; 
a discharge section arranged at a location adjacent the second position and 
having a central discharge port and a shower discharge port formed in the 
discharge section, the central discharge port communicating with the 
second outlet port, while the shower discharge port communicates with the 
third outlet port; 
first seal means arranged about the first, second and third outlet ports 
and in close contact with an outer circumferential surface of the rotary 
valve element; 
wherein the first opening is provided in the rotary valve element in the 
common first plane circumferentially of the rotary valve element in an 
angular extent of approximately 90.degree. through 180.degree., the first 
opening always communicating with the inlet port and being capable of 
communicating simultaneously with the first outlet port; 
wherein the second opening is provided in the rotary valve element in the 
common first plane and is capable of communicating only with the second 
outlet port; 
wherein the third opening is provided in the rotary valve element in the 
second plane at a location spaced circumferentially of the rotary valve 
element by a predetermined angle from the second opening, the third 
opening being capable of communicating only with the third outlet port; 
a pair of circumferential groove means provided respectively in outer 
circumferential surface sections of the respective one and the other ends 
of the rotary valve element, each of the pair of groove means having a 
bottom which is sloped such that one of opposite sides of the groove means 
adjacent a corresponding one of the one and the other ends of the rotary 
valve element, is shallower in depth than the other side; and 
a pair of second annular seal means arranged respectively in the pair of 
circumferential groove means in concentric relation thereto. 
With the arrangement of the invention, since a liquid passageway formed by 
the rotary valve element is simple in construction or structure, pressure 
loss at running or passage of the liquid is extremely low. Further, the 
first seal means is arranged about the first, second and third outlet 
ports of the valve chamber, and the pair of sloped circumferential groove 
means for the respective second annular seal means are provided 
respectively in the outer circumferential surface sections of the one and 
the other ends of the rotary valve element. Thus, the liquid directional 
control valve is high in reliability of sealing. 
Preferably, at least one of the first, second and third outlet ports of the 
valve chamber and at least one of the first, second and third openings 
formed in the rotary valve element cooperate with each other, in an 
intermediate stage at control of running of the liquid, to define a liquid 
passageway whose cross-sectional minimum area is approximately 10% through 
50% of an area of a fluid passageway formed by the at least one outlet 
port and the at least one opening at full running of the liquid. 
With the above arrangement of the invention, the liquid passageway whose 
cross-sectional area has a predetermined ratio is always secured at 
control of running of the liquid. Thus, the liquid directional control 
valve is difficult to receive a water hammer so that it is possible to use 
the liquid directional control valve for a long period of time.

DESCRIPTION OF THE EMBODIMENTS 
Referring to FIGS. 1 and 2, there is shown a liquid directional control 
valve according to an embodiment of the invention. The liquid directional 
control valve comprises a body 31 having a center at which a valve chamber 
1 is defined. The valve chamber 1 has an axis thereof and has a first or 
upper position, a second or lower position on the opposite side of the 
valve chamber 1 from the first position, an intermediate position between 
the first and second positions and a third position located at the second 
position but spaced a predetermined distance therefrom along the axis of 
the valve chamber 1. 
The valve chamber 1 has an inlet port 10 at the first position, a first 
outlet port 11 (refer to FIG. 2) at the intermediate position, a second 
outlet port 12 at the second position and a third outlet port 13 at the 
third position. The first outlet port 11 is connected to a liquid or water 
purifier or the like through a connecting section 17. The inlet port 10, 
first outlet port 11 and second outlet port 12 are arranged in a vertical 
or common first plane perpendicular to the axis of the valve chamber 1. In 
this connection, refer also to FIG. 3. The third outlet port 13 is 
arranged in a second plane spaced the predetermined distance from the 
common first plane along the axis of the valve chamber 1 in parallel 
relation to the common first plane. Each of the first, second and third 
outlet ports 11, 12 and 13 has a circular or elliptic configuration in 
plan. Normally, the first, second and third outlet ports 11, 12 and 13 
have their opening areas which are substantially the same as each other. 
Referring back to FIGS. 1 and 2, a rotary valve element 2 has a rotary axis 
extending perpendicularly to the common first plane. The rotary valve 
element 2 is accommodated in the valve chamber 1 such that the rotary axis 
of the rotary valve element 2 is in conformity with the axis of the valve 
chamber 1, for angular movement about the rotary axis of the rotary valve 
element 2. That is, the rotary valve element 2 is accommodated in the 
valve chamber 1 under an inscribed condition. The rotary valve element 2 
has first, second and third openings, 21, 22 and 23 which are formed in an 
outer circumferential portion of the rotary valve element 2 subsequently 
to be described. As illustrated in FIGS. 1 and 2, the rotary valve element 
2 is hollow. A selecting lever 3 is arranged on the outside of the valve 
chamber 1 and is connected to one end of the rotary valve element 2 
through a joint 9 for selecting communication between the inlet port 10 
and first, second and third ports 11, 12 and 13 and the first, second and 
third openings 21, 22 and 23 subsequently to be described. 
The body 31 has a faucet mounting section 4 which is arranged at a location 
adjacent the first position. A passage 16, into which a faucet is 
inserted, is formed in the faucet mounting section 4 and is connected to 
the inlet port 10. 
The body 31 also has a discharge section 5 which arranged at a location 
adjacent the second position and which has a central discharge port 14 and 
a shower discharge port 15 formed in the discharge section 5. The central 
discharge port 14 communicates with the second outlet port 12, while the 
shower discharge port 15 communicates with the third outlet port 13. 
Three first seal elements 6 (only two shown in FIG. 2) are arranged 
respectively about the first, second and third outlet ports 11, 12 and 13 
and are in close contact with the outer circumferential surface of the 
rotary valve element 2. By these first seal elements 6, sealing is 
conducted between the outer circumferential surface of the rotary valve 
element 2 and the circumferential surface of the valve chamber 1. In this 
connection, since the first, second and third outlet ports 11, 12 and 13 
are sealed respectively by the first seal elements 6, the liquid 
directional control valve is superior in accuracy of sealing, as compared 
with a construction in which only the inlet port 10 is sealed by a seal 
element. 
The above-described first opening 21 is provided in the rotary valve 
element 2 in the common first plane circumferentially of the rotary valve 
element in an angular extent of approximately 90.degree. through 
180.degree., preferably, approximately 100.degree. through 160.degree.. 
The first opening 21 always communicates with the inlet port 10. Further, 
the first opening 21 is capable of communicating simultaneously with the 
first outlet port 11 by angular movement of the rotary valve element 2 
about the rotary axis thereof, and can takes a communicating condition 
illustrated in FIG. 5(e). 
The second opening 22 is provided in the rotary valve element 2 in the 
common first plane and is capable of communicating only with the second 
outlet port 12 by the angular movement of the rotary valve element 2 about 
the rotary axis thereof. 
The third opening 23 is provided in the rotary valve element 2 in the 
second plane at a location spaced circumferentially of the rotary valve 
element 2 by a predetermined angle from the second opening 22. The third 
opening 23 is capable of communicating only with the third outlet port 13 
by the angular movement of the rotary valve element 2 about the rotary 
axis thereof. 
FIGS. 5(a), 5(c) and 5(e) are schematic side elevational views showing a 
relationship between the valve chamber 1 and the rotary valve element 2 
under each of three liquid passage conditions which are formed due to 
selection or control of liquid running or passage. FIGS. 5(b), 5(d) and 
5(f) are schematic front elevational views showing arrangement conditions 
of the rotary valve element 2, which correspond respectively to FIGS. 
5(a), 5(c) and 5(e). FIG. 5(a) and 5(b) show a condition under which the 
inlet port 10 communicates with the second outlet port 12. FIG. 5(c) and 
5(d) show a condition under which the inlet port 10 communicates with the 
third outlet port 13. FIG. 5(e) and 5(f) show a condition under which the 
inlet port 10 communicates with the first outlet port 11. Liquid or water 
flows along directions indicated respectively by the arrows in FIGS. 5(a), 
5(c) and 5(e). In this connection, parts of seal elements and O-ring seal 
elements are omitted in illustration from FIGS. 5(a) through 5(f). 
Further, in FIGS. 5(a) through 5(f), angular movement of the selecting 
lever 3 about the rotary axis of the rotary valve element 2 twice 
45.degree. by 45.degree. , that is, by 90.degree. in total causes the 
liquid running conditions to be altered in order of FIGS. 5(a), 5(c) and 
5(e). In this connection, it is possible to suitably set the total 
selecting angles to a value within a range substantially equal to or less 
than 160.degree.. 
Furthermore, in the liquid directional control valve according to the 
embodiment of the invention, the arrangement angles of the respective 
first, second and third openings 21, 22 and 23 formed in the rotary valve 
element 2 are set such that, at selection or control of liquid running 
among the liquid running conditions shown respectively in FIGS. 5(a), 5(c) 
and 5(e), the second outlet port 12 and the third outlet port 13 
communicate simultaneously with the inlet port 10, and the third outlet 
port 13 and the first outlet port 11 communicate simultaneously with the 
inlet port 10. By doing so, it is possible to suppress or restrain a water 
hammer phenomenon at control of the liquid running. In order to exhibit 
such effect, it is preferable that at least one of the first, second and 
third outlet ports 11, 12 and 13 of the valve chamber 1 and at least one 
of the first, second and third openings 21, 22 and 23 formed in the rotary 
valve element 2 cooperate with each other, in an intermediate stage at 
control of the liquid running, to define a liquid passageway whose 
cross-sectional minimum area is above approximately 10% of an area of a 
fluid passageway formed by the at least one outlet port and the at least 
one opening at full running of the liquid. It is sufficient that the 
liquid passageway defined in the intermediate stage at control of the 
liquid running has the cross-sectional minimum area which is of the order 
of approximately 50% of the area of the fluid passageway formed by the at 
least one outlet port and the at least one opening at the full passage of 
the liquid. 
As shown in FIGS. 4(a) and 4(b), a pair of circumferential grooves 7 (only 
one shown) is provided respectively in outer circumferential surface 
sections of respective both ends of the rotary valve element 2. Each of 
the pair of grooves 7 has a bottom which is sloped such that one of 
opposite sides of the groove 7 adjacent a corresponding one of the both 
ends of the rotary valve element 2, is shallower in depth than the other 
side. A pair of second annular seal elements or 0-ring seal elements 8 
(only one shown) are arranged respectively in the pair of circumferential 
grooves 8 in concentric relation thereto. With such groove construction, 
when the liquid pressure is applied to the 0-ring seal element 8, the 
latter moves toward the shallow side of the groove 7 so that the interface 
between the outer circumferential surface of the rotary valve element 2 
and the circumferential surface of the valve chamber 1 can be sealed under 
a compressed condition of the O-ring seal element 8. Thus, it is possible 
to well maintain the sealing condition.