JPS63297875A - Three-way fluid control valve - Google Patents

Abstract

PURPOSE:To make it possible to equilibrate the pressure of fluid so as to use a high supply pressure by forming a valve element for opening and closing the communication between ports, in a spherical shape so as to prevent a valve element from being stuck due to dust, and by driving the valve element by means of a piston. CONSTITUTION:A sleeve 33 having a pressure supply port (a), a load port (b) and a return port (c) is disposed in a housing hole 2 in a valve body 1. Steel balls 10, 11 as valve elements 13 are loosely fitted in middle diameter chambers 8, 9 in the sleeve 33, and a small diameter ball 13 is loosely fitted in a small diameter chamber 12 in the sleeve. The steel ball 10 is normally urged upward by the supply pressure, and the steel ball 11 is pressed upward through the intermediary of the small ball 13. When a solenoid section 30 is energized, movable iron core 19 is moved downward so as to move the steel balls 10, 11 by means of a piston 31 in order to change over the communication between the ports. The supply pressure is exerted to the rear of the piston 31 through a passage 35 so as to equilibrate the pressure.

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 Japanese Unexamined Patent Publication No. 60-44671 are known. The one published by these authors has a structure that balances the pressure before and after the valve body so that the fluid pressure that crosses the valve body does not act, so it has a large number of parts and a special shape. It was expensive.

In order to solve this problem, the applicant of the present application disclosed a three-way fluid control valve as shown in FIG. The use of steel balls is inexpensive, durable, and reliable, and is an improvement over the above-mentioned ones, but since the fluid pressure is not balanced, the supply pressure is, for example, 20 to 301 J.
+! There are some types, such as IJ, which can only be used at relatively low pressures and whose switching response speed is relatively slow due to the influence of the supply pressure.

The purpose of the present invention is to always be able to obtain stable operation,
It is a highly reliable and inexpensive valve, and it is a three-way fluid control valve that does not have a sliding part that does not get stuck due to dirt. It can also be used at high supply pressures, and the valve does not change due to differences in supply pressure. An object of the present invention is to provide a three-way fluid control valve that eliminates the difference in response speed. By doing so, the above-mentioned problems were solved.

(Embodiments) Below, embodiments of the present invention will be described with reference to the drawings.
In the figure, the sleeve 0→, which is an integral piece with holes (a, b, c) through which working fluid enters and exits the housing hole (2) of the valve body (1), is easily attached and detached via a screw (to). The main body (1) and the sleeve 03 together with internal members that cooperate with the body form a cartridge valve, and are easily attached to and removed from the cartridge valve support part 02 via screws. (14, 14", 20)
This ensures a seal between the maintenance members and between each port (a, b, c). Medium diameter chamber of sleeve 03 (8
) (Inside the 91, a steel ball, which is a spherical valve body, is loosely fitted, and the edges (5) and (6) of the steel ball αGα are formed in the small diameter part (6) of the sleeve. A small steel ball α] is loosely fitted in the sleeve 03.In addition, unlike the embodiment, the main body (1) and the cartridge valve support portion Oa are formed as one body, and the sleeve 03 is formed in two or three pieces. The steel ball α force is applied to the load port (b) in the second position shown in the medium diameter chamber (9).
and return bow) (c).

When the actuating member pushes the piston downward by a stroke (8) f' as seen in the figure through the piston 0η,
The steel ball αυ is pressed against the edge (6) and the load port (b
) and the return port (C), and move it to a first position that allows communication between the load port (b) and the pressure supply port (a). Steel ball scream is small steel ball C13″f
, disposed in the medium diameter chamber (8) so as to be able to come into contact with the steel ball through the n
1. In the second position shown in the figure, the edge (5) is closed by receiving the pressure oil from the pressure supply bow (a), completely cutting off communication between the pressure supply port (a) and the load port (b), and the piston 0υ is In the first position, where the stroke is lowered by 81, communication between the load port (b) and the pressure supply port (a) is allowed.

eQ is a snap ring that regulates the axial position of the steel ball.

The actuating member αS is fixed to the movable iron core (to) and the piston 0
η is in contact with the pressure receiving surface (31a), and the movable iron core (191
is fixed iron core (to), solenoid part c! Q (Body (1)
When the solenoid coil (fixed at 0) is excited and attracted at t'16, it pushes down the piston 0]). The piston 01 is slidably supported in the center hole of the fixed iron core α, and a large diameter spring holder (31a) is fixed therein, and the spring (b) is attached to the spring holder (31):l.
) and the sleeve shoulder (b).

When the piston G1) is pushed down by a stroke (s) from the position shown, it is at gn so as to bias the piston 01) upwardly. Pressure oil of the pressure supply port is introduced from the passage (g) (aSa) to the pressure receiving surface (ata) on the operating member side of the piston G1) from the pressure supply port hole OQ via the port chamber (a6a). and piston 0η
The outer diameter (d'') and the inner diameter (d) of the edges (5) and (6) are almost the same. The inner diameter areas of the faces (5) and (6) are approximately the same.The distance S between the movable iron core α9 and the fixed iron core 0 is set to be slightly larger than the stroke S of the piston 0η. Determine the total length of the operating member α mark O By doing this, the movable iron core α Yu and the fixed iron core CI!19 will not be completely attracted to each other even in the energized state, so RA) Ho) (C) (Tank port) can be completely closed.

Next, the operating state will be explained. The state shown in FIG. 1 is when the solenoid is de-energized.

At this time, fluid flows in from the pressure supply port (a), but the supply pressure forces the steel ball αO against the edge (5) of the sleeve small diameter portion (6), so that the supply port (a) is not closed. The other steel ball αη is pressed against the zero side of the piston. As a result, the load (b) and the return (return))
(c) (Tank port) is in communication state O At this time, the supply pressure is between the steel ball side and the rear pressure receiving surface (ala) of piston 0η according to the communication state of supply port 1-(a) described above.
is pressurized. Steel ball (Edge, which is the main part of IQ)
) and the outer diameter d1 when the piston is fully retracted, the above-mentioned supply pressure is equal to the force that presses the steel ball ■ against the edge (5) and the back pressure receiving surface (aXa) of the piston 01).
The force applied to the spring (b) is equal, but the force applied to the spring (b)
Since the pressing of piston G1) is relative to the force, as a result, the steel ball (10) is pressed against the edge (5), which is the steel ball abutting part, by the spring force of the spring (B).
That will happen. Therefore, supply bow) (a) will be closed. On the other hand, the steel ball (b) has an edge (5) on the steel ball αO.
The edge (6) of the small diameter part (a) that is pressed against the
In other words, the distance from the abutment part of the steel ball receiver is a stroke S, and the load port (b) and return port (C) are kept in communication with each other.

Next, when the solenoid coil is energized, the movable core α flaw is attracted to the fixed core 5, so that the stroke is displaced by the stroke S. This stroke displacement is transmitted to the steel ball η via the operating member α frame and the piston (31), and the steel ball αυ1 continues the stroke S until it is pressed against the edge I; stroke displacement. At the same time, the stroke f is a small steel ball A3
It is also transmitted to the steel ball (ICI) via the steel ball (IG). Therefore, even if the steel ball C1G is seated on the edge (6), the steel ball C1G is prevented from coming into contact with the snap ring hct, and the supply fluid is supplied through the port hole (G) and the port chamber (36a). , passes through the port (a) and the cylindrical medium diameter chamber (8), enters the small diameter part α, and communicates with the load port (b).On the other hand, the return port (
On the C) side, the steel ball ση is seated on the edge (6), so it is closed. Considering the balance of forces acting on the steel ball αM at this time, the steel ball (IIJ) opposes the suction force of the solenoid with a force equal to the supply pressure multiplied by the pressure receiving area due to the inner diameter d of the edge (6). direction, that is, the steel ball (l
A force is applied in the direction of separating the IUt edge (6), but according to the above-mentioned communication state of the supply port, supply pressure is also applied to the rear pressure receiving surface (31a) of the piston Gυ at the outer diameter a+, which is the same as the edge inner diameter d. The same force as the force applied to the steel ball lJi is applied to the piston 0η in the opposite direction. Therefore, the only force that opposes the suction force of the solenoid is the spring force caused by the spring (b). As a result, the responsiveness at the time of valve switching is always constant regardless of the supply pressure, and the problem that occurred in Japanese Patent Application Laid-Open No. 62-2084 has been solved.

Here, when the solenoid coil (A) becomes de-energized again, the spring force of the spring (B) causes the piston (three swords, steel ball αO
Qη and small steel ball α3 return. The small steel ball α3 is used to widen the port hole Φ & forming the load port CI:l) and the small diameter part α2 to facilitate the machining of these parts. The small steel ball υ may be omitted.

Fig. 2 shows a three-way fluid control valve according to an embodiment of the present invention, which is different from Fig. 1, and the sleeve (a31) has a snap ring GO.
is not inserted, but instead an edge ring (26') forming an edge □□□ is driven and fixed into the hole (33') provided at the end of the sleeve (33°). Etsuji□□□
When the pressure in the load port (a) rises above the pressure in the pressure supply port (a), it acts on the steel ball αQ and seats on the edge 4, closing the pressure supply port (a) and increasing the pressure in the load port (a).
b) to prevent pressure oil from the load port (b) from flowing back into the pressure supply port (a). That is, in operation, when the solenoid coil (a) is energized and the pressure supply port (a) and the load port (b) are in communication, the pressure supply port (a) is connected to the load port (b).
), the steel ball C1O moves away from the steel ball (Jl) via the small steel ball α3 due to the pressure.
Seats on edge □□□ of edge ring (26') and closes pressure supply port (a) from load port) (b) to pressure supply port (0 or load port) (b) to pressure supply port)
No working fluid flows through (a), and it functions as a check valve. Looking at the blocked state of the load port 佽) at this time, the pressure supply bow) The cone contact f?:, ri.And even when the steel ball is struck by a small steel ball, the pressure is balanced and pressure is received from both sides, so as a result, there is no sliding part other than the cone contact on the port side in example n. etc. does not exist, making the checking function complete.

(Effects of the Invention) As described above, according to the present invention, the steel ball QO
and αυ have no sliding parts, so they are extremely dust resistant, durable, and reliable. Also, since steel balls are used, no special processing is required, making it inexpensive. In addition, since the fluid pressure is balanced by the piston (3), it can be used at high supply pressures such as 7 Q'yld to 200'y/cJ, and there is a drawback that the response varies depending on the difference in supply pressure. The problem is always constant and responsiveness can be ensured. Therefore, the present invention can always obtain stable operation, is highly durable and reliable, and is stable even against fluctuations in supply pressure, ensuring nine operations *m
The present invention provides a simple three-way fluid control valve that can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a three-way fluid control valve according to an embodiment of the present invention, FIG. 2 is a sectional view of a main part of a three-way fluid control valve showing an embodiment different from that in FIG. The figure is a sectional view of a conventional three-way flow rate switching valve. 1... Valve body 5.6... Edge (pressure supply port pressure receiving area)
lO... Steel ball (second spherical valve body) 1)...
・Steel ball (first spherical valve body) 13... Small steel ball (intermediate member) 31... Vistos 31a... Operating member side pressure receiving surface 33.33'...・Sleeve a...Pressure supply port b...Load port C...Return port

Claims (3)

[Claims] (1) A first position in which the actuating member selectively allows the load ports provided in the valve body to communicate with the pressure supply port and cuts off communication with the return port; or a second position allowing communication;
a first spherical valve body disposed within the valve body so as to be movable between the valve body; a second spherical shape movably disposed within the valve body so as to allow communication between the load port and the pressure supply port in the first position and to block communication between the load port and the pressure supply port in the second position; A three-way fluid control valve including a valve body, wherein the first and second spherical valve bodies are movable by the actuating member via a piston, and the area of the actuating member side pressure receiving surface of the piston and each of the spherical valve bodies are A three-way fluid control valve characterized in that the pressure is balanced with the pressure receiving area of the pressure supply port of the valve body. (2) The three-way fluid according to claim 1, wherein the second spherical valve body is capable of closing off the pressure supply port from the load port when the pressure of the load port is higher than the pressure of the pressure supply port. control valve. (3) The sleeve that surrounds the piston, the first and second spherical valve bodies, and in which the ports are formed is integrally formed and is attached to the main body so as to be easily attachable and detachable. 3. The three-way fluid control valve according to item 2.