JPS5942327B2 - Control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device, and more particularly to a control device capable of automatically controlling an excessive flow rate of a controlled fluid.

The present invention provides a control device that is particularly useful for use in a regulating device installed to purify vehicle exhaust gas.
The present invention will be explained in detail below based on the drawings.

In FIG. 1, the casing 1 is equipped with an atmospheric side passage 25 and a high pressure side passage 27, and has a cavity 3 and a fluid passage 3 inside.
5 is formed.

The void 3 is the first, second and third diaphragm 10, 15
. A third chamber 9 is formed by the third diaphragm 20 . The third chamber 9 is configured to communicate with the atmosphere side passage 25 and the high pressure side passage 27 via the communication passage 29, and also between the connection passage 29 and the atmosphere side passage 25 and between the communication passage 29 and the high pressure side passage 27. Communication with passage 27
The shutoff is provided by a control valve 30 which is fixed at one end to the first diaphragm 10. That is, the valve seat surface 2 provided on the high pressure side passage 27 side of the valve 30
8 (upper part of the figure), the high pressure side passage 27 and the communication passage 29 are blocked, and the atmosphere side passage 25
On the other hand, when the valve 30 is pressed against the valve seat surface 26 (up and down in the figure) provided on the atmospheric side passage 25 side, the high pressure side passage 27 and It communicates with the communication passage 29, and blocks the atmosphere side passage 25 and the communication passage 29.

A decompression passage 6 opens in the first chamber 5, and the second chamber 7 communicates with the atmosphere, and a first spring means 37 and a second spring means 39 are arranged. The first spring means 37 acts to push the first diaphragm 10 and the second diaphragm 15 apart in opposite directions in the axial direction.
The spring means 39 of the casing 1 and the second diaphragm 1
5, and presses the second diaphragm 15 toward the third diaphragm 20. Further, one end of the valve 32 and one end of a feedback pin 43 are each fixed to the third diaphragm 20, and the other end of the feedback pin 43 extends to the vicinity of the second diaphragm 15, and the other end of the valve 32 is fixed to the third diaphragm 20. The end extends into fluid passageway 35 . The other end of the valve 32 has a conical shape.

Further, the fluid passage 35 is provided with a truncated conical valve seat surface 36 corresponding to the other end, and cooperates with the other end of the valve 32 to control the flow rate of the fluid passage 35. Furthermore, a flange 2 extends from the casing 1 into the second chamber 7, which regulates the amount of axial movement of the second diaphragm 15 and provides a spring receiving seat for the third spring means 41. There is. The third spring means 41 connects the flange 2 and the third diaphragm 2.
0, and presses the third diaphragm 20 toward the third chamber 9. Also, usually the first diaphragm 1
The effective diameter of 0 is smaller than the effective diameter of the second diaphragm 15, and the spring force of the first spring means 37 is designed to be smaller than the spring force of the second spring means 39.

The control device of the present invention configured as described above operates as follows. If the pressure inside the first chamber 5 is not reduced,
First diaphragm 10 and second diaphragm 15
On the other hand, since no negative pressure is applied, each member occupies the position shown in FIG. When the pressure of As shown, the first diaphragm 10 is drawn toward the second diaphragm 15 against the first spring means 37, but the second diaphragm 15 is pushed toward the flange 2 by the second spring means 39. It is kept in the same condition.

That is, the gauge pressure in the first chamber 5 is −p, and the pressing force of the first spring means 37 in the state shown in FIG. 1 is F.
.

The pressing force of the second spring means 39 in the state shown in FIG.
.

If the effective pressure receiving area of the first diaphragm 10 is a and the effective pressure receiving area of the second diaphragm 15 is A, then the first diaphragm 10 pushes the second diaphragm 15 with a force of p-a.
The pressure (-p) in the first chamber 5 becomes p-a>
Once the FO conditions are met, the first diaphragm 10
is displaced toward the second diaphragm 15 side.

The second diaphragm 15 is attracted in the direction away from the flange 2 with a force of p·(A-a), but
)<The second diaphragm 15 is not separated from the flange 2 while the FO relationship is maintained. As a result, the control valve 30 is released from sealed contact with the valve seat surface 28 and
form a sealed contact with. For this reason, the high pressure side passage 27
The high-pressure fluid flows into the third chamber 9 through the communication passage 29 and pushes the third diaphragm 20 up against the third spring means 41 toward the second chamber 7 . With this displacement of the third diaphragm 20, the sealed contact between the other end of the valve 32 and the valve seat surface 36 is released, allowing fluid to flow within the fluid passage 35.

At this time, if the displacement of the third diaphragm 20 is large and the amount of fluid flowing in the fluid passage 35 becomes excessive,
As shown in FIG. 3, the other end of the feedback pin 43 pushes up the second diaphragm 15 toward the first chamber 5, and then, as the second diaphragm 15 moves,
The first diaphragm 10 is also pushed up. As a result,
Control valve 30 is brought out of sealing contact with valve seat surface 26 and into sealing contact with valve seat surface 28 .

Therefore, the flow of high-pressure fluid from the high-pressure side passage 27 into the third chamber 9 is blocked, and the fluid in the third chamber 9 flows out via the atmospheric side passage 25. The pressure in chamber 9 decreases. As the pressure in the third chamber 9 decreases, the third diaphragm 20 is displaced toward the third chamber 9,
The valve 32 is displaced in a direction in which the amount of fluid flowing through the fluid passage 35 is reduced.

On the other hand, when the pressure (-p) in the first chamber 5 is further reduced through the pressure-reducing passage 6 and the condition p.(A-a)>FO is satisfied, the second diaphragm 15 2 against the spring means 39 of the first flange 2,
The valve 32 is displaced toward the valve seat surface 28 through the spring means 37 of the third diaphragm 10 and the first diaphragm 10.
The inside of the chamber 9 communicates with the atmosphere side passage 25 via the communication passage 29, and the third diaphragm 20 is pressed by the third spring means 41 to cause the valve 32 to close the fluid passage 35.

In this way, the control device according to the present invention is capable of adjusting the flow rate in the fluid passage 35 by the valve 32 in accordance with the degree of pressure reduction introduced into the first chamber 5 through the pressure reduction passage 6. , Furthermore, when the degree of decompression exceeds a specific value, the second
Due to the displacement of the diaphragm 15, the valve 32 can be closed and the flow inside the fluid passage 35 can be cut off, and the flow rate inside the fluid passage 35 can become excessive compared to the degree of reduced pressure inside the first chamber 5. Sometimes, the control valve 30 is displaced and the valve 32 is throttled by pushing up the feedback pin 43 attached to the third diaphragm 20, so that the flow in the fluid passage 35 can be maintained normally. be.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, and FIGS. 2 and 3 are operational diagrams of the device shown in FIG. 1. 1...Casing, 2...Flange,
3...Empty space, 5...First room, 6...
...Decompression passage, 7...Second chamber, 9...
...Third chamber, 10...First diaphragm, 15...Second diaphragm, 20...
...Third diaphragm, 25...Atmospheric side passage, 26...Valve seat surface, 27...High pressure side passage, 28...Valve seat surface , 29... Communication passage, 30... Control valve, 32... Valve, 35... Fluid passage, 36... Valve seat surface. , 37...first spring means, 39...
...Second spring means, 41...Third spring means, 43...Feedback pin.

Claims (1)

[Claims] 1. A casing 1, a cavity 3 provided in the casing 1, a fluid passage 35, an atmosphere side passage 25, a high pressure side passage 27, and a first, second, and second passage that sequentially partition the cavity 3 in the axial direction. 3 diaphragms 10, 15, 20, the first
a first chamber 5 which is partitioned by the diaphragm 10 and the second diaphragm 15 and has a decompression passage 6 open therein;
a second chamber 7 which is partitioned by 0 and communicates with the atmosphere, a third chamber 9 which is partitioned by the third diaphragm 20, and the third chamber 9 is connected to the fore air atmosphere side passage 25 and the high pressure A communication passage 29 for communicating with the side passage 27, one end of which is fixed to the first diaphragm 10 and the other end between the communication passage 29 and the atmosphere side passage 25 and between the communication passage 29 and the high pressure side. A control valve 30 that controls communication with the passage 27, a valve 32 that has one end fixed to the third diaphragm 20 and the other end that controls the flow rate of the fluid passage 35, and one end that is connected to the third diaphragm 20. 20, the other end of which extends toward the second diaphragm 15; a first spring means 37 disposed between the first diaphragm 10 and the second diaphragm 15; a second spring means 39 arranged in said first chamber 5 between said second diaphragm 15 and said casing 1; and in said second chamber 7 said third spring means 39;
and a third spring means 41 disposed between the diaphragm 20 and the casing 1, the pressure inside the first chamber 5 is reduced through the pressure reduction passage 6, and the first diaphragm 10 is By being displaced toward the diaphragm 15 of No. 2, the control valve 30 blocks off the high pressure side passage 27 and the communication passage 29, and connects the atmosphere side passage 25 and the communication passage 29. The high pressure side passage 27 and the communication passage 29 are communicated with each other, and the atmosphere side passage 25 and the communication passage 29 are disconnected from each other. By increasing the pressure, the third diaphragm 20 is displaced toward the second diaphragm 15, and when the pressure led to the pressure reduction passage 6 is further reduced, the second diaphragm 15 is The third spring means 39 is compressed to displace the first diaphragm 10, thereby displacing the control valve 30 toward the valve seat surface 28, and directing the atmosphere side passage 25 into the third chamber 9. By communicating with each other, the third diaphragm 20 is displaced toward the third chamber 9, and the amount of displacement of the third diaphragm 20 toward the second diaphragm 15 or the third chamber 9 is The valve 32 is displaced in accordance with the flow rate of the fluid passage 35 so that the flow rate of the fluid passage 35 can be controlled, and when the flow rate of the fluid passage 35 becomes excessive, the feedback pin 43 The control valve 30 is displaced via the first diaphragm 10 and the second diaphragm 15, and the high pressure fluid is prevented from entering the third chamber 9 from the high pressure side passage 27. The third chamber 9 is communicated with the atmosphere side passage 25, and the pressure inside the third chamber 9 is lowered, so that the valve 32 is displaced in the direction of reducing the flow rate of the fluid passage 35. A control device characterized by: