JPH0979399A - Three-way valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a pressure at a low cost with high precision through a single valve drive part by a method wherein a valve drive member is formed in size lower than a minimum distance between first and second valves and drive by a valve drive means being different from the first and second valves. SOLUTION: The thickness D of a switching plate is decreased to a value lower than a minimum distance between two valve bodies when first and second valve bodies 8 and 9 are both brought into a closed state. Since in an initial state wherein energization to a linear solenoid 12 is stopped, the energization force of a return spring 13 is increased to a value higher than that of a spring 11, a second valve body 9 is brought into an opening state wherein it is separated away from the valve sealant 7L of a valve seat part 2a. The first valve body 8 is energized in the direction of the valve seat part 2a through the force of a spring 10 to maintain a closed state. Thus, only a portion between a negative pressure port 5 and an output port 6 is brought into a communication state, and an atmospheric pressure outputted through the output port 6 is bled through the negative pressure port 5 and a pressure is reduced to generate and feed a negative pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-way valve that controls pressure by opening and closing three-way flow passages.

[0002]

2. Description of the Related Art Heretofore, there has been known an EACV (electric air control valve) which electrically controls an opening / closing operation of a valve to control air pressure. This EACV
Is a valve for controlling the flow rate of air of about 600 l / min by opening and closing the air passage by a valve provided at the tip of the plunger shaft of the linear solenoid or a bellows connected to the tip of the plunger shaft. Is.

Further, as a valve mechanism other than the valve structure or the bellows structure, there is known a valve structure of a spool structure for controlling the flow rate of air.

[0004]

[Problems to be Solved by the Invention] However, the above EACV
Then, because it is a structure that controls the flow rate of air,
It was possible to introduce atmospheric pressure, but it was impossible to create a negative pressure (0 to -760 mmHg) by removing atmospheric pressure. Further, when controlling the air pressure by using the EACV, it is necessary to use two EACVs, and moreover, one of them must be kept in an open state by continuously supplying a current in order to be in a normally open state. There was also a problem in terms of running cost.

Further, in the valve mechanism having the spool structure, it is possible to introduce the atmospheric pressure and create the negative pressure, but there is a problem that the leak flow rate becomes large and the fine air pressure control becomes difficult. That is, in order to reduce the leakage flow rate, it is necessary to close the sliding gap of the spool, but for this purpose,
Since it is necessary to use a large linear solenoid having a large driving force, the cost is high.

The present invention has been made under such a background, and an object thereof is to provide a three-way valve which can control the pressure at a low cost and with high precision by one valve drive section.

[0007]

In order to achieve the above object, the present invention according to claim 1 provides a first port and an output port in a housing in which a first port, a second port and an output port are formed. A first valve for switching communication / cutoff between the first port and the second port, and a second valve for switching communication / shutdown between the second port and the output port for opening and closing the first valve and the second valve. A three-way valve provided with a valve drive member interposed between a first valve and a second valve, wherein the first valve and the second valve are the first port and the second port. The valve drive member is arranged to face each other with a valve seat portion formed therebetween, and the valve drive member is configured to be smaller than the minimum distance between the first valve and the second valve. It is configured to be driven by a valve drive means that is separate from the valve.

[0008] According to the second aspect of the present invention, in the first aspect,
The inside of the described housing is formed in a symmetrical structure with the valve seat portion as an axis of symmetry.

[0009]

In the invention according to claim 1, the valve drive member is
It is configured to be smaller than the minimum distance between the first valve and the second valve, and is driven by one valve drive means separate from these two valves, thereby increasing pressure, reducing pressure, and maintaining pressure. Can create a state. Further, since a large flow rate of fluid can be controlled, the above three states can be created with good responsiveness. Further, since the sealability is good, the fluid does not leak even if a small valve drive means is used, and the pressure can be controlled with high precision by an inexpensive structure.

According to the second aspect of the present invention, since the inside of the housing is formed in a symmetrical structure with the valve seat portion as the axis of symmetry, the first valve and the second valve are parts having exactly the same specifications. Can be used, the number of types of parts can be reduced, and the cost can be further reduced.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
~ It will be described in detail with reference to FIG.

FIG. 1 is a sectional view showing the structure of a three-way valve according to an embodiment of the present invention. In the figure, 1 is a valve housing, and this valve housing 1 is a metal cylindrical valve housing. It has a main body 2 and left and right metal lid portions 3R and 3L.

The valve housing body 2 has a cylindrical shape, and an atmospheric pressure port 4 for introducing atmospheric pressure (PA) and a negative pressure (P) are formed on the side surface of the valve housing body 2.
And a negative pressure port 5 for supplying B) is bored, and
An output port 6 for outputting atmospheric pressure or negative pressure is formed in the right lid 3R.

A donut-shaped valve seat portion 2a is formed at a depth position of 1/2 in the cylindrical valve housing main body 2, and an annular valve is formed on both surfaces of the valve seat portion 2a. Sealing materials (valve seats) 7R and 7L are embedded. The atmospheric pressure port 4 and the negative pressure port 5 are formed on both sides of the valve seat portion 2a at corresponding positions with the valve seat portion 2a as the axis of symmetry. In other words, the valve housing body 2 has the valve seat portion 2
The shape is such that the left and right sides are completely symmetrical with a as the axis of symmetry.

A cylindrical first valve body 8 and a second valve body 9 each having a bellows structure are attached to face each other in the space portions on both sides of the valve seat portion 2a. ,
One end of the second valve body 9 is sandwiched between the right lid portion 3R and the valve housing main body 2 and between the left lid portion 3L and the valve housing main body 2, respectively, and the other ends are respectively attached to the spring 1
It is urged toward the valve seat portion 2a by 0 and 11. It should be noted that the first valve body 8 and the second valve body 9 are simply opposite in direction because they are opposed to each other, and are composed of completely identical parts (made of resin).

A linear solenoid 12 is attached to the left lid 3L of the valve housing 1. A disc-shaped switching plate 14 as a valve driving member is attached to the tip of the armature 12a of the linear solenoid 12 so as to be biased to the left in FIG. 1 by a return spring 13.

The switching plate 14 is biased by springs 10 and 11 in the direction of the valve seat portion 2a to close the first valve body 8 and the second valve body 9, respectively.
Is opened by separating it from the valve seat portion 2a, and the thickness of the switching plate 14 (see FIG.
D) is the distance between both valve bodies when both the first valve body 8 and the second valve body 9 are closed, that is, the minimum distance between both valve bodies (see FIG. 2 (b)). ) Is thinner than. In other words, by making the thickness of the switching plate 14 thinner than the minimum distance between the first valve body 8 and the second valve body 9, the first valve body 8 and the second valve body 9 are closed at the same time. It is possible to.

Under such a configuration, by controlling the current flowing through the linear solenoid 12, the first valve body 8 or the second valve body 9 is driven and controlled in the left-right direction via the switching plate 14, Air pressure increase control, pressure reduction control,
Hold control is performed.

That is, in the initial state where the energization of the linear solenoid 12 is stopped, the urging force of the return spring 13 is stronger than the urging force of the spring 11, so that as shown in FIG. Are located to the left of the valve seat portion 2a. That is, the second valve body 9 is separated from the valve seal member 7L of the valve seat portion 2a to be in the valve open state, and the first valve body 8 is biased by the spring 10 toward the valve seat portion 2a to be in the valve closed state. I am maintaining. Therefore, only the negative pressure port 5 and the output port 6 are in communication with each other, the atmospheric pressure output from the output port 6 is extracted through the negative pressure port 5 to reduce the pressure, and the negative pressure is generated and supplied. To be done.

Then, as shown in FIG. 2B, when the current of the linear solenoid 12 is controlled to position the switching plate 14 at a position facing the valve seat portion 2a,
Both the first valve body 8 and the second valve body 9 are closed by the biasing force of the springs 10 and 11, and the previous pressure (atmospheric pressure or negative pressure) is maintained. When the switching plate 14 moves in this case, the biasing force of the spring 11 acts in the moving direction of the switching plate 14, so that the load on the linear solenoid 12 is small and the power consumption is small.

Further, as shown in FIG. 2C, when the switching plate 14 is positioned to the right of the valve seat portion 2a by controlling the current of the linear solenoid 12, the first
The valve body 8 is separated from the valve seal member 7R of the valve seat portion 2a and is in a valve open state, and the second valve body 9 is biased by the spring 11 toward the valve seat portion 2a to maintain the valve closed state. Therefore,
Only the atmospheric pressure port 4 and the output port 6 are in communication with each other, and the atmospheric pressure is introduced from the atmospheric pressure port 4 and input through the output port 6.

As described above, in the present three-way valve, 1
Three valve drive parts (linear solenoid, switching plate) can create three states of pressure increase, pressure decrease, and pressure retention. Further, since a large flow rate of air can be flown, the air pressure can be controlled in the range of atmospheric pressure to negative pressure with good responsiveness. Further, since the sealing property is good, air leakage does not occur even if a small linear solenoid is used, and the pneumatic pressure can be controlled with high precision with an inexpensive configuration.

Further, since the symmetry type valve mechanism of the bellows structure is used, the bellows is not affected by the pressure difference of air, the power consumption of the linear solenoid can be reduced, and the kinds of parts can be reduced. It is possible to reduce the cost.

The present invention is not limited to the above embodiment, and for example, as a fluid for producing pressure,
It is also possible to use a gas other than air, a liquid, a viscous body, or the like. A motor other than the linear solenoid may be used as the driving means for the switching plate.

[0025]

As described above, in the three-way valve according to the present invention, the communication between the first port and the output port is established in the housing in which the first port, the second port and the output port are bored. A first valve for switching cutoff and a second valve for switching communication / cutoff between the second port and the output port
Valve and the first valve and the second valve to open and close the first valve and the second valve.
A three-way valve including a valve drive member interposed between the first valve and the second valve, wherein the first valve and the second valve are valves formed between the first port and the second port. The valve drive member is disposed to face each other with the seat portion interposed therebetween, and the valve drive member includes the first valve and the second valve.
Smaller than the minimum distance between the valve and the first valve,
Since it is configured to be driven by the valve driving means that is separate from the second valve, it is possible to control the pressure at a low cost and with high accuracy by using one valve driving section.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a three-way valve according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a valve opening / closing operation of a three-way valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Valve housing 2 ... Valve housing main body 2a ... Valve seat part 4 ... Atmospheric pressure port 5 ... Negative pressure port 6 ... Output port 7R, 7L ... Valve sealing material 8 ... 1st valve body 9 ... 2nd valve body 10, 11 … Spring 12… Linear solenoid 13… Return spring 14… Switching plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuto Chisaka 1-4-1 Chuo, Wako-shi, Saitama Incorporated Honda Research Laboratory

Claims (2)

[Claims] 1. A first valve for switching connection / disconnection between the first port and the output port in a housing in which the first port, the second port and the output port are formed, and a second valve.
A second valve for switching communication / shutoff between the port and the output port, and a valve drive interposed between the first valve and the second valve to open and close the first valve and the second valve. A three-way valve including a member, wherein the first valve and the second valve are the first
The valve driving member is arranged to face each other with a valve seat portion formed between the port and the second port interposed therebetween, and the valve driving member is configured to be smaller than the minimum distance between the first valve and the second valve. A three-way valve characterized by being driven by a valve driving means separate from the first valve and the second valve. 2. The three-way valve according to claim 1, wherein the inside of the housing is formed in a symmetrical structure with the valve seat portion as an axis of symmetry.