JPS622082A - Three way fluid control valve - Google Patents

Abstract

PURPOSE:To prevent misoperation of an actuator by operating a second spherical valve member which is conjoined with a first spherical valve member for controlling ports, when the supply pressure exceeds a set pressure. CONSTITUTION:When an actuating member 18 is in its operative condition, it moves a first spherical valve member to a first position, permitting communication between a load part (b) and a pressure supply port (a) and interrupting communication between the load port (b) and a return port (c). At this time, the first spherical valve member 11 is in abutment against the second spherical valve member 10 and permits flow of pressure oil from the pressure supply port (a) to the load port (b), when the pressure of the pressure supply port (a) is lower than a set pressure. When such an abnormal pressure as to exceed the set pressure is generated in the pressure supply port (a), the load port (b) is closed with respect to the pressure supply port (a) to prevent misoperation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in the valve structure of a three-port two-position switching valve, that is, a three-way fluid control valve, which controls a working fluid by electromagnetic force or the like.

(Prior art) Such a three-way fluid control valve is disclosed in Japanese Patent Publication No. 49-1037, for example.
No. 1 and JP-A No. 60-44671 No. 1 and Japanese Patent Application Laid-open No. 60-44671 are known. The ones in these publications have a structure that balances the pressure before and after the valve body so that fluid pressure across the valve body does not act. Because of this, the number of parts is large and the parts have a special shape, making them expensive.

It's worth it. Furthermore, the latter has a sliding part and there is a risk that the fitting sliding part may become stuck due to dirt. A well-known valve with a simple structure is shown in Fig. 6, but in this case, when the supply pressure fluctuates abnormally, for example when there is surge pressure, this pressure resists the spring and the steel R
@)k It had the disadvantage that it would open and the intended function would be lost.

(Problems to be Solved by the Present Invention) The purpose of the present invention is to provide stable operation without malfunction even in the face of unexpected increases in supply pressure, to provide highly reliable power and low cost. To provide a complete three-way fluid control valve which has no sliding part and is free from sticking due to dust.

(Means for Solving All Problems) Therefore, the present invention selectively allows the load bows (K) provided in the valve body to communicate with the pressure supply port and fully communicates with the return port. 1st block
a first spherical valve body disposed within the valve body so as to be movable between a first position and a second position permitting communication between a load port and a return port; 1. A spherical valve body is contacted directly or indirectly through an intermediate member, and in the first position, when the pressure of the pressure supply port is below the set pressure, the pressure supply port is allowed to communicate with the load port, and when the pressure is above the set pressure. 3, further comprising a second spherical valve body movably disposed within the valve body so as to cut off the communication and, in the second position, cut off communication between the load port and the pressure supply port. It is a companion to directional fluid control valves.

(Function) For example, when the actuating member is in an actuated state by an electromagnetic device, the first spherical valve body is moved to the first position by the actuating member, allowing the load port to communicate with the pressure supply port. And completely cut off communication with the return port. At this time, the first spherical valve body comes into contact with the second spherical valve body, and when the pressure of the pressure supply port is lower than the set pressure, the flow of pressure oil from the pressure supply port to the load port is completely allowed, and there is an abnormality in the pressure supply port. When pressure is generated and becomes higher than the set pressure, the load port is closed to the pressure supply port to prevent malfunction. When the actuating member is in the inoperative state, the second spherical valve body blocks communication between the load port and the pressure supply port through the pressure valve of the pressure supply port, and the first spherical valve body moves to the second position. The load port and the return port are allowed to communicate with each other, and the operation is performed so that there is a stable flow of pressurized oil from the load port to the return port without leakage from the pressure supply port. Since the first and second spherical valve bodies roll without sliding, they are not stuck by dust and have high durability.

(Embodiments) Below, embodiments of the present invention will be described with reference to the drawings.
In the figure, there are two spacers (3) that have port holes for the working fluid to enter and exit the valve body (1) in the housing hole (2).
, (4) A sheet (7) which is arranged opposite to each other, has a port hole in the middle of these 62 spacers, and has two steel ball contact parts (5) and (6) (seat parts). By inserting spherical valve bodies, that is, steel balls C1O and σ11Th, into the two cylindrical spaces (8) and (9) constituted by these parts, the fluid switching of the embodiment is achieved. The department is composed of: In addition, spacer (3) and (
There is a triangular groove between the 0 ring (1) and the seat (7).
4 eliminates leaks inside the housing (2).

Each of the above-mentioned parts is inserted and fixed into the valve body (1) by a tightening nut αη through the fixed iron core αe and the rendoid guide αQ. Stroke displacement of steel ball 0
This is a part for transmitting information to η. The parts that make up the solenoid, such as the coil case υ, coil reel flywheel, yoke flywheel, manual bottle (c), and coil mounting nut (c), are the same as those of the oil-immersed solenoid on the market, so we will not provide a complete explanation. Omitted.

The total length of the push rod α→ is determined so that the distance S1 between the plunger (2) (movable iron core) and the fixed iron core is slightly larger than S. By doing this, even if it becomes energized, the moving iron core and the fixed iron core (g) will not completely attract each other, so the return port (tank port)
can be completely closed.

Next, the operating state will be explained. The state shown in FIG. 1 is a case where the lenoid is not excited. At this time, fluid flows in from the pressure supply port (a), and the steel ball αO is pressed against the edge (5) of the seat (7) due to the supply pressure.
supply bow) (a) is closed. The other steel ball σM
is pressed against the stopper α$ side. As a result, the load port (1)] and the return port (c) (tank port) are in a state where oil is flowing.

Next, we will discuss the case when the ni-solenoid is excited. When the solenoid is energized, plunger α! 1 (movable iron core)
is attracted to the fixed iron core α, resulting in stroke displacement. The stroke displacement is transmitted to the steel ball through the bush rod (till) and the steel ball (111 is the seat) (7
) is pressed against the edge (6). As a result, the return port (C) (tank port) becomes closed.

As a result, the pressure supply port (a) and the load bow) (b) are brought into communication by the other steel ball αG, and fluid flows to the pressure supply port (a) V- and the load bow) (b). .

When it becomes de-energized again, the steel ball cage is pressed against the edge (5) by the supply pressure, resulting in the above-mentioned state. Further, since the return from the energized state to the de-energized state is operated by the pressure of the supplied fluid, a return spring is not required. However, when the spring (4) is inserted, more reliable operation can be obtained as shown in FIG. 3 of the embodiment.

First, compared to the structure shown in Figure 6, the valve does not open even if the supply pressure suddenly increases, so it is safer. To explain in detail, the inner diameter (d) of the edge (6) of the seat (7) is determined by the supply pressure P and the suction force Fs of the solenoid. The steel ball (10) is pressed against the edge (6) of the seat (7) by the supply pressure P of the pressure supply port, and the pressing force F is F=P・-d2, so the suction force Fs of the solenoid is The setting pressure set by the suction force F of this solenoid is higher than the supply pressure, communication between the pressure supply port (a) and the load port (b) is allowed. Pressure supply bow) When abnormal surge pressure occurs in (a), the supply pressure P will be higher than this set pressure, so
The steel ball is pressed against the edge (6) and cuts off the communication.

FIG. 4 shows a different embodiment from FIGS. 1 and 3, in which both steel balls αOqη are in contact via a small steel ball 0, that is, an intermediate member. The small steel ball (13) is loosely fitted into the hole (13') of the seat (7), which makes it possible to reduce the diameter of the steel ball αGQtl, make the valve high pressure, and obtain stable operation. Fifth The figure shows yet another example, in which the small steel ball α of FIG.
] Instead, a bottle (a) is used, and the bottle holder is guided by a hole (z7Q) in the seat holder, making a reliable operating sound.

(Effects of the Invention) As described above, in the present invention, when there is an unexpected increase in the supply pressure and the pressure becomes higher than the set pressure, the second spherical valve body is connected to the pressure supply port by closing the load hole. We are committed to providing a complete range of highly reliable 3-way fluid switching valves that can prevent actuator malfunctions and ensure stable operation at all times. In addition, the first and second spherical valve bodies can use all commercially available steel balls, making them inexpensive, and since there are no sliding parts, they are extremely resistant to dust, making the valve highly durable and reliable.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a three-way fluid switching valve according to an embodiment of the present invention, FIG. 2 is a partial sectional view taken along line A and -A in FIG. 1, and FIGS. 3 to 5 are FIG. 6 is a partial cross-sectional view similar to FIG. 1 showing embodiments different from FIG. 1, and FIG. 6 is a vertical cross-sectional view of a conventional three-way R switching valve. 1... Valve body 10... Steel ball (second spherical valve element) 11... Steel ball (first spherical valve element) 13... Small steel ball (intermediate member) 18... Bush rod (operating Part) 27...Bin (intermediate member) a...Pressure supply port b...Load port C...Return port Agent Patent attorney Jun Kawachi 2it Figure U 12 Figure N3 Figure 4 Figure 5 figure

Claims (1)

[Claims] A first position that allows communication with the pressure supply port and cuts off communication with the return port, or allows communication between the load port and the return port, selectively by the actuating member. a first spherical valve body disposed within the valve body so as to be movable between a second position in which the valve body receives pressure from the pressure supply port and directly or via an intermediate member; In indirect contact,
In the first position, when the pressure of the pressure supply port is below the set pressure, the pressure supply port is allowed to communicate with the load port, when the pressure is above the set pressure, the communication is cut off, and when the pressure of the pressure supply port is below the set pressure, the communication is cut off;
a second spherical valve body movably disposed within the valve body so as to interrupt communication between the load port and the pressure supply port in the three-way fluid control valve.