JPS5917265B2 - exhaust gas recirculation valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust gas recirculation valve (hereinafter simply referred to as an EGR valve) that reduces harmful components such as NOx by re-burning exhaust gas including unburned gas discharged from vehicles etc. .

This type of EGR valve, which is already known, can reduce NOx by performing EGR operation, but at the same time, it causes a decrease in output, a decrease in fuel efficiency, a deterioration in drivability due to unstable combustion, and a deterioration in HC ■ mission. This brings about problems such as:

Therefore, in order to minimize such problems, it has been considered to stop EGR when the vehicle is cold or when driving at high speed.

However, in the past, the temperature sensing valve for stopping EGR operation when cold and the valve means for stopping EGR operation when driving at high speed were configured completely independently of the EGR valve, and these were connected by appropriate piping. As a result, the structure was complicated and expensive, and it was difficult to install it within the limited space of the vehicle.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the conventional drawbacks by integrally incorporating a valve means into an EGR valve body to stop EGR operation in accordance with temperature changes or vehicle driving conditions.

The configuration of the present invention includes a main body of an EGR valve that is connected to a diaphragm that is displaced according to negative pressure introduced into the servo chamber, and that opens and closes the EGR passage according to the displacement of the diaphragm.
A passage connecting the negative pressure introduction port and the servo chamber is formed, and a sensing 1 [depending on the configuration or bench 1 It has a valve means that shuts off depending on the novaculum.

An embodiment of the apparatus of the present invention will be described below with reference to the drawings.

Reference numeral 10 denotes an EGR valve, which introduces the manifold valve generated in the intake manifold (not shown) into a chamber 12 from a port 11 provided on the main body, and passes through the chamber 12 and a pipe 15. Communication with the chamber 16 is provided by two bimetallic valves 13 built into the main body.
By operating a temperature sensing valve including 14, the valve is shut off when the temperature is low and the valve is open, and communication is established within a predetermined temperature range.

Also, depending on the driving condition of the vehicle, the carburetor venturi part (
A working fluid pressure (not shown) generated by a venturi vacuum is introduced into the chamber 18 from the port 11.

Further, air is introduced into a chamber 20 from a port 19, and the chamber 18 and the chamber 20 are separated by a tire flam 21.

A pipe 23 communicating with the chamber 16 is inserted into the opening at the right end of the pressure grate 22 attached to the diaphragm 21, and a pipe 23 communicating with the chamber 16 is inserted into the inner chamber 56 with one end fixed to the pressure grate 22. A movable valve 25 biased to the right by a spring 24 is disposed so as to be able to come into contact with the tip of the pipe 23, and
On the other hand, the town motion valve 25 is connected to the pressure grate 2.
The valve seat 22a is arranged so as to be able to come into contact with the second valve seat 22a.

A chamber 27, which is attached to the pressure grate 22 and partitioned from the chamber 20 by a diaphragm 26 having a smaller effective area than the diaphragm 21, communicates with a servo chamber 29 via a passage 28.

The air introduced into the chamber 20 is introduced into the chamber 56 through a passage 30 provided in the pressure plate 22, and the chamber 56 and the pipe 23 are connected to each other through a passage 31 provided in the pressure grate 22. Said chamber 27
It is possible to communicate with

The venturi vacuum introduced into the chamber 18 operates the diaphragm 33 through the sintered orifice 32.
It was introduced in 4.

A shaft 36 fixed to the diaphragm 33 together with the plate 35 can be displaced to the right against the biasing force of a spring 37 in response to the venturi vacuum in the chamber 34, and due to the displacement, the shaft 36 By contacting a plate 38 attached to the diaphragm 21 and further pressing the plate 38, the diaphragm 21 and the pressure plate 22 are displaced to the right, and the valve seat portion 22a is moved toward the movable valve 25.
The chamber 56 and the chamber 27 are communicated through the passage 31 without being separated from the chamber 56 and the chamber 27.

Air is introduced into a chamber 39 of the diaphragm 33 on the back side of the chamber 34 through a passage 40, and is maintained at atmospheric pressure at all times.

The servo chamber 29 and the atmospheric chamber 41 are separated by a diaphragm 4.
A plate 43 and a control valve 44 are fixed to the plate 42, and a biasing force of a spring 45 acts on the plate 42, so that when the servo chamber 29 becomes an atmospheric chamber, the diaphragm 4
2 is in the illustrated position due to its urging force, and at this time, the control valve guides the exhaust gas to the engine intake port (not shown) (contacts the valve seat 46a of the passage 46, blocks the passage 46, and stops the EGR operation. Eggplant.

Furthermore, when negative pressure is generated in the servo chamber 29, the diaphragm 42 is displaced to the right against the biasing force of the spring 45, and the control valve 44 is separated from the valve seat portion 46a, releasing the passage 46 at the appropriate position and opening the exhaust gas. Gas is routed to the outside of the engine inlet to activate EGR.

A check valve 48 is provided between the chamber 18 and the chamber 34 to open and close the passage 47, so that the vacuum in the chamber 34 is connected to the chamber 18.
A check valve 48 is installed to open the scavenge passage 47, which is lower than the vacuum level, and close the passage 41 in the case of correspondence.
works.

Now, the engine ambient temperature or the two bimetal valves 13
．． When the manifold vacuum is within a predetermined temperature range where both pipes 15 and 14 are open, ports 11. Room 12. Pipe 15 and reaches chamber 16.

When the venturi vacuum is introduced into the chamber 18 from the port 17, the diaphragm 21 is displaced to the left, the pressure plate 22 is not displaced to the left while maintaining contact with the movable valve 25, and the pipe of the movable valve 25 is moved. 23
The pipe 23 and the passage 31 are communicated with each other without coming out of contact with the pipe 23, and the vacuum in the chamber 16 is guided to the chamber 21.
When the vacuum of
3 and the passage 31, the pressure plate 22 is further displaced to the right, and the movable valve 25
The vacuum value in the chamber 21 is reduced by separating the chamber 56 from the passageway 31 and reducing the vacuum value in the chamber 21.
Since the effective area of the chamber 18 is smaller than the effective area of the chamber 18, the vacuum generated in the chamber 27 is amplified by a reciprocal of its area ratio, and the vacuum generated in the chamber 27 is guided to the servo chamber 29 and the diaphragm 43 is In response, the control valve 44 is deactivated to open the passage 46 and perform EGR operation.

The vacuum introduced into the chamber 18 causes the sintering process to begin. Weiss 32
It also reaches the chamber 34 after a predetermined time has elapsed.

When vacuum is introduced into the chamber 18, the venturi vacuum increases when the vehicle accelerates or cruises at high speed. 32
Since it takes 0 hours, which is longer than the acceleration time, for the 1,000 neem to be transmitted to the chamber 34 through R operation is possible.

Then, as time passes and it becomes high speed cruising, chamber 18
The vacuum reaches the chamber 34 through the sintered orifice 32, and the diaphragm 33 is not displaced to the right against the biasing force of the spring 37, and the right movement of the shaft 36 causes the diaphragm 21 and pressure plate 22 to remain unchanged. When the valve seat portion 22a is removed from the movable pulp 25, the chamber 56 and the chamber 21 are no longer communicated via the passage 31, and the chamber 2
Air is introduced into the servo chamber 29 through the passage 28.
Air is introduced into the vehicle, the diaphragm 42 is moved to the position shown, and the control valve 44 blocks the passage 46, thereby stopping the EGR operation during high-speed cruising.

After that, when high-speed cruising is stopped, the vacuum in the chamber 18 decreases, the check valve 48 is activated, and the vacuum in the chamber 34 decreases through the passage 4T in the same way as in the chamber 18, and due to the vacuum change in the chamber 34, the shaft 36 moves to the left and separates from the plate 38 of the diaphragm 21, brings the valve seat portion 22a of the pressure grate 22 into contact with the movable valve 25, cuts off communication between the chamber 56 and the chamber 27, and returns to E.
It is possible to enable GR operation to start.

As explained above, the device of the present invention opens and closes the EGR passage.
Since a valve means for stopping EGR operation in response to temperature changes or vehicle operating conditions is integrated into the main body of the GR valve, these valve means are integrated into the body of the GR valve. This has the effect of eliminating the need for piping required to connect the two, making it easy to install within a limited space, and since these main bodies can be shared, the configuration is simple and inexpensive. This has a practical effect.

[Brief explanation of drawings]

The drawing is a sectional view showing an embodiment of the device of the present invention. 10... EGR valve body, 11...
Boat for introducing negative pressure, 13, 14...Temperature sensing valve, 1T...Port for working fluid pressure, 25.
...Movable valve, 29...Servo chamber, 4
1... Atmospheric chamber, 42... Diaphragm, 44... EGR control valve.

Claims (1)

[Claims] 1 A diaphragm disposed inside the main body to partition an atmospheric chamber and a servo chamber, and displaced in response to negative pressure introduced outside the servo chamber; connected to the diaphragm to open and close an exhaust gas recirculation passage in accordance with displacement of the diaphragm; a control valve provided on the main body for introducing the negative pressure; a passage formed in the main body connecting the port and the servo chamber; An exhaust gas recirculation valve having valve means for shutting off negative pressure to the servo chamber in response to a sensed temperature change or in response to venturi vacuum.