JPH06123257A - Exhaust gas recirculation controller for internal combustion engine with speed governor - Google Patents

Abstract

PURPOSE:To provide an exhaust gas recirculation controller in which driving stability in a speed governing behavior area can be maintained by performing optimal control of a recirculation amount, by which driving stability can be maintained within the engine performance areas including speed governing, behavior for an internal combustion engine provided with an air speed governor. CONSTITUTION:In an internal combustion engine with a speed governor provided with an air speed governor 20 between a carburetor 10 and an intake manifold 30, a speed governor throttle valve negative pressure inlet 25, which is opened toward the upstream side of the air speed governor 20, and a negative pressure operation chamber 52 of an exhaust gas recirculation control valve 50 are communicated with each other by negative pressure passages 93, 94, and a switching three way electromagnetic valve 40, which shuts off the negative pressure passage interlocking with a closure of a throttle valve 11 of the carburetor 10, is provided in the negative pressure passage. A valve element 54 of the exhaust gas recirculation valve 50 is arranged between an exhaust gas recirculation passages 90, 91, which are connected to the intake manifold 30, and a negative pressure control valve 60 regulating the negative pressure inside the negative pressure passage 94 by proportioning to a venturi negative pressure of the carburetor 10 is provided, so that exhaust gas recirculation is eliminated during idling, while the exhaust gas recirculation amount is controlled proportionate to the partial load or the load in a full open behavior area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas recirculation control device capable of controlling exhaust gas recirculation so as to maintain operational stability of an internal combustion engine with a speed governor.

[0002]

2. _Description of the Related Art It is known that a part of exhaust gas is recirculated into intake air as a technique for reducing NO _x emitted from an internal combustion engine. Generally, when the exhaust gas recirculation rate is increased, the NO _x reducing effect is increased. However, because of this, the drivability and the fuel economy also deteriorate, so the optimal control is performed so that the amount of recirculation corresponds to the engine operation. The speed regulation performance range of an internal combustion engine equipped with an air governor is less stable in operation when the operating load is lighter than in other performance ranges, and even more stable when exhaust gas is uniformly recirculated. In this speed control performance range, it has been desired to develop an exhaust gas recirculation control device capable of optimally controlling the exhaust gas recirculation amount according to the load.

[0003]

SUMMARY OF THE INVENTION The present invention is directed to an internal combustion engine with an air speed governor, in which a portion of the exhaust gas is recirculated into the intake air to reduce NOx, and the operation in the speed control performance range is further reduced. The present invention aims to provide an exhaust gas recirculation control device capable of controlling the amount of exhaust gas recirculation so that stability can always be maintained.

[0004]

The present invention is an internal combustion engine with a speed governor in which an air speed governor is arranged between a carburetor and an intake manifold, and is provided with a device for returning exhaust gas to an intake system. In an internal combustion engine with a speed governor equipped with an air speed governor between the carburetor and the intake manifold, the speed control device of the internal combustion engine with a speed governor has an opening at the upstream side of the air speed governor. A speed regulator throttle valve negative pressure inlet and a negative pressure operating chamber of the exhaust gas recirculation control valve are connected by a negative pressure passage, and the negative pressure passage is shut off in conjunction with the closing of the throttle valve of the carburetor. An exhaust gas recirculation control device for an internal combustion engine with a speed governor, wherein an electromagnetic valve is provided, and the exhaust gas recirculation control valve is arranged in an exhaust gas recirculation passage connected to the intake manifold.

[0005]

[Operation] In the idling state of the engine, the negative pressure passage connected to the negative pressure inlet of the governor throttle valve is cut off in conjunction with the closing of the carburetor throttle valve, and negative pressure is applied to the negative pressure working chamber of the exhaust gas recirculation control valve. It does not work, and the valve body does not perform exhaust gas recirculation with the exhaust gas recirculation passage being closed. In the partial load performance range and the full-open performance range, the negative pressure from the governor throttle valve negative pressure inlet is activated by the opening of the carburetor throttle valve and the exhaust gas recirculation control valve is activated via the negative pressure passage to respond to changes in negative pressure. The exhaust gas recirculation is performed. The negative pressure in the negative pressure passage decreases as the load increases, but the negative pressure control valve operates to increase the negative pressure in the negative pressure passage by the Venturi negative pressure that changes depending on the opening degree of the carburetor throttle valve. Then, the exhaust gas recirculation control valve is operated in proportion to the load. That is, the exhaust gas recirculation amount is controlled in proportion to the load.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram of an exhaust gas recirculation system according to the present invention.
An air governor 20 is provided on the downstream side of the carburetor 10, and the downstream side of the air governor 20 is connected to an intake manifold 30. A switch lever 13 is rotatably supported on the valve shaft of the throttle valve 11 of the carburetor 10, and the switch lever 13 operates a throttle valve switch 15 that operates an open / close three-way solenoid valve 40. The opened venturi negative pressure inlet 14 is connected to a venturi negative pressure operating chamber 62 between the diaphragms 65 and 66 of the negative pressure control valve 60 via a negative pressure passage 95. The air governor 20 includes a speed governor throttle valve 21 and a stabilizer rod 22, and the stabilizer rod 22 is a stabilizer portion 23.
The stabilizer rod 22 is pushed by the atmospheric pressure through the atmosphere passage 24 communicating with the upper portion of the venturi portion 12 to supplement the closing force of the speed governor throttle valve 21. Further, a speed governor throttle valve negative pressure introducing port 25 is opened on the inlet side of the air speed governor 20, that is, on the upstream side of the position where the speed governor throttle valve 21 is fully closed, and opened / closed via a negative pressure passage 93. It communicates with the connecting portion 43 of the three-way solenoid valve 40. Open / close three-way solenoid valve 40
Is a decompression passage 92 connected to an upper portion of the venturi portion 12,
The negative pressure passage 94 and the negative pressure passage 93 are communicated with each other through the connecting portion 41, the connecting portion 42, and the connecting portion 43, respectively, and are operated by the throttle valve switch 15 when the throttle valve 11 is closed. 43 is closed to form a pressure reducing passage 92 and a negative pressure passage 94.
And the negative pressure passages 93 and 94 are electrically connected to each other by closing the connecting portion 41 when not operating. A part of the negative pressure passage 94 is branched to be connected to a vacuum delay valve 80 for reducing the fluctuation of the negative pressure, and a thermo switch valve 44 is arranged between the vacuum delay valve 80 and the open / close three-way solenoid valve 40 to cool the engine body. It is attached to the water jacket 45 and is opened and closed by the heat of the engine body cooling water jacket 45. The vacuum delay valve 80 is connected to the negative pressure operating chamber 52 of the exhaust gas recirculation control valve 50, and the valve body 54 of the exhaust gas recirculation control valve 50 is connected to the exhaust gas passage (not shown) and the air speed governor 20. The valve body 54 is provided between the exhaust gas recirculation passage 91 connected to the intake air passage 26 of the diaphragm 5 which divides the negative pressure working chamber 52 and the atmospheric chamber 53.
1, the diaphragm 51 is biased by the spring 55, and biases the valve body 54 in the valve closing direction.

Reference numeral 60 denotes a negative pressure control valve for adjusting the negative pressure applied to the exhaust gas recirculation control valve 50, and the diaphragms 65, 6
6 and 67 are built in, and these diaphragms are rod 6
It is fixed integrally with 8. An atmosphere chamber 61 is provided above the diaphragm 65. The atmosphere chamber 61 is a negative pressure working chamber of the exhaust gas recirculation control valve 50 via a vacuum delay valve 80 via a negative pressure passage 94 via an opening / closing valve 69 connected to a rod 68. The on-off valve 69 is connected to the spring 70.
Is urged in the direction to open the negative pressure passage 94. A venturi negative pressure operating chamber 62 connected to the venturi negative pressure inlet 14 of the carburetor 10 by a negative pressure passage 95 is provided between the diaphragms 65 and 66, an atmosphere chamber 63 is provided between the diaphragms 66 and 67, and a discharge chamber is provided below the diaphragm 67. 64,
A spring 71 for urging the rod 68 upward is provided, and is connected to an exhaust gas recirculation passage 90 via an exhaust pressure passage 96.

The mixed gas supplied by the vaporizer 10 is supplied to the intake manifold 30 through the intake passage 26 of the air governor 20. In the idling state of the engine, the throttle valve 11 of the carburetor 10 moves in the closing direction, so the throttle valve switch 15 is actuated by the switch lever 13, the open / close three-way solenoid valve 40 is activated, the connecting portion 43 is closed, and the pressure reducing passage 92 and the negative pressure passage 92 are closed. The pressure passage 94 is brought into conduction, and the negative pressure passage 93 connected to the governor throttle valve negative pressure introduction port 25 of the air governor 20 is not brought into conduction with either the negative pressure passage 94 or the pressure reducing passage 92.
As described above, when the open / close three-way solenoid valve 40 is operating, the negative pressure passage 94 communicates with the atmosphere above the venturi portion 12, and the idling control valve 60 has a venturi negative pressure operating chamber for idling. In 62, the venturi negative pressure is small, the on-off valve 69 is wide open, and the negative pressure passage 94 is in a state in which it communicates with the atmosphere.
5, the exhaust gas recirculation passages 90 and 91 are closed. That is, exhaust gas recirculation is not performed in the idling state.

In the partial load performance range, the throttle valve 1 of the carburetor 10
1 opens at an opening according to the load, and the speed governor throttle valve 21 is balanced by the stabilizer rod 22 and the speed governor spring (not shown) so that the opening similarly corresponds to the load.
In this state, the throttle valve switch 15 does not work, the open / close three-way solenoid valve 40 becomes inactive, the connecting portion 41 closes, and the negative pressure passage 93
And 94 are conducting. Then, intake negative pressure generated at the time of passage of the speed governor throttle valve 21 is generated in the speed governor throttle valve negative pressure introduction port 25, and this negative pressure is a performance range in which the negative pressure operates due to the opening degree of the speed governor throttle valve 21. Is set, and the negative pressure passage 93
To the negative pressure passage 94, and acts on the negative pressure working chamber 52 of the exhaust gas recirculation control valve 50 via the thermo-off valve 44 and the vacuum delay valve 80, and the opening degree of the valve element 54 is controlled according to the negative pressure. Exhaust gas has a recirculation amount depending on the opening degree of the valve body 54, passes through exhaust gas recirculation passages 90 and 91, and the intake passage 2 of the air governor 20.
Reflux to 6. That is, in the partial load performance range, the exhaust gas recirculation amount is controlled by the exhaust gas recirculation control valve 50 according to the change in the intake negative pressure due to the opening of the governor throttle valve 21 corresponding to the load. Next, in the full-open performance range, the throttle valve 11 of the carburetor 10 is in a fully open state, and when a predetermined load is applied, the governor throttle valve 21 causes the tension of a governor spring (not shown) and the stabilizer rod 2 to be increased.
The atmospheric pressure of 2 receives a force for closing the governor throttle valve 21. Further, the governor throttle valve 21 is installed with its valve shaft eccentric,
A force that closes the governor throttle valve 21 acts by the intake air. In the full-open performance range, these are balanced and the governor throttle valve 21 opens and closes so as to achieve a predetermined rotation. Therefore, even in the full open performance range, the exhaust gas recirculation amount is controlled by the exhaust gas recirculation control valve 50 in accordance with the change in the intake negative pressure due to the opening degree of the governor throttle valve 21, similarly to the exhaust gas recirculation in the partial load performance range. It

The thermo-open / close valve 44 is opened / closed by the heat of the engine body cooling water jacket 45. When the temperature reaches a predetermined temperature, the passage of the thermo-open / close valve 44 becomes conductive, and the thermo-open / close valve 44 is closed at a predetermined temperature or lower. That is, exhaust gas recirculation is not performed when the engine is cold. Further, the vacuum delay valve 80 softens the fluctuation of the negative pressure acting on the negative pressure working chamber 52 of the exhaust gas recirculation control valve 50 and reduces the change of the exhaust gas recirculation amount to maintain the operability of the engine. Further, the negative pressure control valve 60 operates the opening / closing valve 69 by the vertical movement of the diaphragms 65, 66, 67 which are integrally fixed by the rod 68, and the negative pressure of the negative pressure operating chamber 52 of the exhaust gas recirculation control valve 50. Is being adjusted. That is, the negative pressure of the Venturi negative pressure inlet 14 acts on the Venturi negative pressure working chamber 62 partitioned by the diaphragms 65 and 66, and the diaphragm 6
6 has a larger area than 65, and the diaphragm 66 moves upward due to negative pressure. Further, the exhaust pressure chamber 64 receives the exhaust pressure from the exhaust gas recirculation passage 90 via the exhaust passage 96 and moves the diaphragm 67 up and down. This allows the rod 6
Reference numeral 8 is a balance between springs 70 and 71 that moves up and down to control the opening / closing amount of the opening / closing valve 69 with respect to the negative pressure passage 94 to adjust the negative pressure of the negative pressure operating chamber 52 of the exhaust gas recirculation control valve 50.

Further, the negative pressure of the governor throttle valve negative pressure introducing port 25 and the operation of the governor throttle valve 21 will be described. The opening position of the governor throttle valve negative pressure introducing port 25 is upstream from the position where the governor throttle valve 21 is fully closed, and when the governor throttle valve 21 reaches a predetermined opening, the intake negative pressure is Set it so that it does not work. Now, with the throttle valve 11 of the carburetor 10 fully open, the governor throttle valve 21
In the speed governor performance range in which the speed is controlled only by itself, as the load decreases, the speed governor throttle valve 21 moves toward the closing direction, and the intake negative pressure is as shown in FIG.
As shown by the curve 100, it increases as the load decreases. At this time, the curve 101, which is a negative pressure slightly smaller than the curve 100, acts on the governor throttle valve negative pressure introducing port 25, and the negative pressure passage 9
The negative pressure acts on the negative pressure control valve 60 via 3, 94.
Since the air flow rate at this time is large, the Venturi negative pressure largely acts on the Venturi negative pressure working chamber 62 of the negative pressure control valve 60 from the Venturi negative pressure introducing port 14 through the negative pressure passage 95,
The on-off valve 69 moves in a direction to close the negative pressure passage 94, reduces the amount of negative pressure leak from the negative pressure passage 94, increases the opening degree of the valve body 54 of the exhaust gas recirculation control valve 50, and increases the amount of exhaust gas recirculation. . Further, as the load decreases, the negative pressure leak amount from the negative pressure passage 94 is increased, and the exhaust gas recirculation control valve 50 reduces the exhaust gas recirculation amount. In this way, the negative pressure control valve 60 reduces the negative pressure acting on the exhaust gas recirculation control valve 50 as the load becomes smaller, as shown by the curve 103 in FIG. 2, and the exhaust gas recirculation amount can be reduced. It is possible to easily set the exhaust gas recirculation region that can maintain the stability of the engine. That is, the exhaust gas recirculation amount is controlled in proportion to the load in the partial load and full-open performance ranges. When the valve opening position of the governor throttle valve 21 comes to the position 102 as shown by the chain line in FIG.
The intake negative pressure does not act on the governor throttle valve negative pressure introducing port 25, and the exhaust gas recirculation control valve 50 controls the governor throttle valve 21 and the carburetor 10.
Although the negative pressure between the throttle valves 11 is received, the negative pressure is small and the exhaust gas recirculation control valve 50 cannot be operated. That is, when the speed governor throttle valve 21 reaches a predetermined opening, a negative pressure for operating the exhaust gas recirculation control valve 50 is not generated in the speed governor throttle valve negative pressure introducing port 25, and exhaust gas recirculation is not performed. Therefore, the operating range of the exhaust gas recirculation control valve 50 can be set by setting the opening position 104 (see FIG. 4) of the governor throttle valve negative pressure introducing port 25 to a desired position. The same operation is performed in the partial load performance range in which the throttle valve 11 of the carburetor 10 is partially opened. A curve 105 in FIG. 4 shows the valve opening position of the governor throttle valve 21 in the partial load performance range, where the lower region is not exhaust gas recirculation and the upper region is the exhaust gas recirculation amount proportional to the magnitude of the load.

[0012]

As described above, according to the present invention, in the internal combustion engine with a speed governor, the exhaust gas recirculation control valve is controlled to be opened / closed by opening / closing the speed governor throttle valve, and the exhaust gas recirculation is eliminated during idling. Performance in which the negative pressure does not work at the governor throttle valve negative pressure inlet, by controlling the exhaust gas recirculation amount in proportion to the load in the partial load performance range and the full open performance range where negative pressure acts on the speed regulator throttle negative pressure inlet. Exhaust gas recirculation does not occur in the engine range, the operation of exhaust gas recirculation can be set in the desired engine performance range by selecting its position, and the exhaust gas recirculation amount can be set in the speed control performance range considering the stability peculiar to the engine. It has a beneficial effect.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between engine operating load and intake negative pressure.

FIG. 3 is an explanatory diagram in the vicinity of a governor throttle valve and a governor throttle valve negative pressure introducing port.

FIG. 4 is a diagram showing the relationship between engine output and rotational speed.

[Explanation of symbols]

 10 Vaporizer 11 Throttle valve 12 Venturi section 13 Switch lever 14 Venturi negative pressure inlet port 15 Throttle valve switch 20 Air governor 21 Governor throttle valve 22 Stabilizer rod 23 Stabilizer section 24 Atmosphere passage 25 Governor throttle valve Negative pressure Inlet 26 Intake passage 30 Intake manifold 40 Open / close three-way solenoid valve 41 Connecting part 42 Connecting part 43 Connecting part 44 Thermo open / close valve 45 Engine body cooling water jacket 50 Exhaust gas recirculation control valve 51 Diaphragm 52 Negative pressure operating chamber 53 Atmospheric chamber 54 valve Body 55 Spring 60 Negative pressure control valve 61 Atmosphere chamber 62 Venturi negative pressure operation chamber 63 Atmosphere chamber 64 Exhaust pressure chamber 65 Diaphragm 66 Diaphragm 67 Diaphragm 68 Rod 69 Open / close valve 70 Spring 71 Spring 80 Vacuum delay valve 90 Exhaust gas recirculation passage 91 Exhaust Gas Recirculation Passage 92 Decompression Passage 93 Negative Pressure Passage 94 Negative Pressure Passage 95 Negative Pressure Passage 96 Discharge Pressure Passage 100 Curve 101 Curve 102 Valve Opening Position 103 Curve 104 Opening Position 105 Curve

Claims (4)

[Claims] 1. An internal combustion engine with a speed governor in which an air speed governor is provided between a carburetor and an intake manifold, wherein the internal combustion engine with a speed governor is provided with a device for returning exhaust gas to an intake system. Exhaust gas recirculation control device. 2. An internal combustion engine with a speed governor, wherein an air speed governor is provided between a carburetor and an intake manifold, and a speed governor throttle valve negative pressure introducing port and exhaust gas recirculation control opened on the upstream side of the air speed governor. A negative pressure passage is connected to the negative pressure operating chamber of the valve, and a solenoid valve is provided in the negative pressure passage to shut off the negative pressure passage in conjunction with the closing of the throttle valve of the carburetor. An exhaust gas recirculation control device for an internal combustion engine with a governor, which is arranged in an exhaust gas recirculation passage connected to an intake manifold. 3. A negative pressure control valve for adjusting the negative pressure in the negative pressure passage in proportion to the venturi negative pressure of the carburetor, between the venturi portion of the carburetor and the negative pressure passage. An exhaust gas recirculation control device for an internal combustion engine with a speed governor as described above. 4. A thermo-on / off valve which is attached to a cooling water jacket of an engine body and shuts off the negative pressure passage at a predetermined temperature or less is provided in the negative pressure passage between the solenoid valve and the negative pressure working chamber of the exhaust gas recirculation control valve. Item 4. An exhaust gas recirculation control device for an internal combustion engine with a speed governor according to Item 2 or 3.