JPH0425567Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a control valve used, for example, in a secondary air supply device in an automobile exhaust gas purification system.

(Prior art) As a means of purifying automobile exhaust gas, negative pressure in the intake pipe of the engine is detected, and secondary air for exhaust gas purification is supplied into the exhaust pipe in response to the negative pressure. The device is widely used.

The one shown in Fig. 3 and Fig. 4 is an example of a control valve used in the secondary air supply device of the above-mentioned exhaust gas purification system. An inner cylinder 3 formed concentrically with the outer wall and having a valve seat 4 attached to the end thereof is provided at the end of the case 1, and is in contact with and separated from the valve seat 4 to communicate or block communication between the inside and outside of the inner cylinder 3. A working fluid chamber 7 is equipped with a diaphragm 5 equipped with a valve part 6 and has a working pressure inlet 8 attached to the back of the diaphragm 5.
A spring 9 is arranged on the back of the diaphragm 5 to press the diaphragm 5 toward the valve seat 4, and a reed valve 10 that functions as a check valve is attached to the other end of the case 1. There is.

The control valve described above has inlet 2 connected to 2
Next, the operating pressure inlet 8 is connected to the air supply source, and the reed valve 10 is connected to the pressure detection part of the engine intake pipe.
The outlet ports 11 attached to the exhaust pipes are respectively connected to the secondary air supply target part of the exhaust pipe, so that the suction force against the diaphragm 5 due to the negative pressure introduced into the working fluid chamber 7 becomes stronger than the pressing force of the spring 9. When
The blockage caused by the valve part 6 is released, and the secondary air guided to the inlet 2 flows through the reed valve 10 and the outlet 11.
It is configured to be sent to the supply target section via.

(Problems to be solved by the invention) In the conventional control valve described above, as is clear from FIG.
It is located lower in the figure than the valve seat 4 attached to the valve seat 4, and as shown in FIG.
Since it intersects the center axis of the inner cylinder 3 at a substantially right angle, the air flow guided from the inlet 2 to the valve seat 4 side is
They are divided by the inner cylinder 3, collide with each other on the opposite side of the inlet 2, and flow toward the valve seat 4, and the air flow is significantly different from that of the air flow on the inlet 2 side and the air flow in the middle, resulting in overall turbulence. diaphragm 5.
The acting force on the valve becomes uneven depending on the position on the circumference, and the valve opening operation becomes extremely unstable.

The purpose of the present invention is to solve the above-mentioned problems and to present a structure of a control valve that can maintain the influence of the flow acting on the diaphragm uniformly at each position on the circumference when the valve is opened. .

(Means for Solving the Problems) In consideration of the problems with the control valves according to the prior art described above, the present invention provides a method for installing a valve inside a case having a cavity provided with an inlet, which is the same as the outer wall of the case. A diaphragm is provided with an inner cylinder formed on a core and having a valve seat attached to an end thereof, and a diaphragm provided at an end of the case with a valve part that connects and separates from the valve seat to communicate or shut off communication between the inside and outside of the inner cylinder. In the control valve, a working fluid chamber with a working pressure inlet is formed at the back of the diaphragm. A flow path formed between the outer wall of the case and the inner cylinder and extending from the inlet to the valve seat is spirally formed from the inlet to the valve seat.

The spiral flow path is formed by rotating the bottom portion that connects the outer wall of the case and the inner cylinder in a generally threaded shape from the inlet side toward the valve seat side.

(Function) In the control valve having the above configuration, the inlet is arranged substantially tangentially with respect to the inner cylinder, and the flow path from the inlet to the valve seat is formed in a spiral shape. The flow leading to the valve seat is guided in a spiral around the outside of the inner cylinder, and the force acting on the diaphragm is kept approximately equal at each position on the circumference.

(Embodiment) The embodiment shown in FIGS. 1 and 2 includes a diaphragm 5 attached with a valve portion 6 and mounted above the case 1 in the figure, a working fluid chamber 7 formed at the back of the diaphragm 5, The spring 9 disposed in the working fluid chamber 7, the reed valve 10 connected to the opposite end of the case 1, etc. are the same as those in the conventional example described above, but as shown in FIG. As shown in FIG.
In that the bottom part 12 connecting the inner surface of the outer wall of the case 1 and the outer periphery of the inner cylinder 3 goes around in a substantially screw shape from the inlet port 2 side toward the valve seat 4 side, forming a spiral flow path. , which is different from the conventional example described above.

(Effects of the invention) As described above, the control valve of the present invention has an inner part formed concentrically with the outer wall of the case and having a valve seat at the end, inside a case having a cavity with an inlet. A cylinder is provided, a diaphragm is attached to the end of the case with a valve part that connects and separates from the valve seat to communicate or shut off the inside and outside of the inner cylinder, and an operating pressure inlet is attached to the back of the diaphragm. A fluid chamber is formed, an inlet is formed approximately tangentially to the inner cylinder, and a flow path formed between the outer wall of the case and the inner cylinder from the inlet to the valve seat side is connected to the inlet. Since the structure is spirally formed from the inlet to the valve seat side, the flow from the inlet to the valve seat side is guided by the spiral flow path and passes around the valve seat while going around the outer periphery of the inner cylinder. Since it flows to the side, the force acting on the diaphragm is kept uniform over the entire circumference, and the operation of the diaphragm is stabilized.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention at the position indicated by the arrow in FIG. Cross-sectional view at the position indicated with -, 3rd
The figure is a longitudinal cross-sectional view of an example of a control valve according to the prior art, and FIG. 4 is a cross-sectional view of the same example at the position indicated by the arrow - on FIG. 3. 1...Case, 2...Inflow port, 3...Inner cylinder, 4
...Valve seat, 5...Diaphragm, 6...Valve part, 7
...Working fluid chamber, 8...Working pressure inlet, 9...
Spring, 10... Reed valve, 11... Outlet, 12... Bottom.

Claims (1)

[Scope of utility model registration request] A case 1 includes an inner cylinder 3 that is provided with an internal cavity connected to an inlet 2, is formed concentrically with an outer wall, and has a valve seat 4 formed at its end; It includes a valve part 6 that communicates or shuts off the inside and outside of the
A diaphragm 5 attached to the end of the case 1
and a working fluid chamber 7 formed at the back of the diaphragm 5. and a bottom portion 12 that connects the outer circumferential surface of the inner cylinder 3.
is formed around the outer side of the inner cylinder 3 in a substantially screw shape, and the fluid flow path between the outer wall of the case 1 and the inner cylinder 3 is formed from the inlet 2 side to the valve seat 4 side. The control valve is spirally shaped.