JPS6332927Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake-exhaust gas recirculation control device for an internal combustion engine used in a vehicle such as an automobile, and in particular to an intake control and exhaust gas recirculation control device for an internal combustion engine having a variable intake swirl type intake port structure. The present invention relates to a control device that performs related control with gas recirculation control.

One of the intake port structures of a variable intake swirl used in an internal combustion engine has a helical passage swirling around an open end of a combustion chamber and a straight passage leading straight to the open end, and a straight passage is provided in the middle of the straight passage. An intake port structure in which an intake control valve for opening and closing the straight passage is provided has already been proposed in Japanese Patent Application No. 56-51149 and Japanese Patent Application No. 120634-1987, filed by the same applicant as the present applicant. .

In an internal combustion engine equipped with the above-mentioned intake port structure, when the straight passage is closed by the intake control valve, all of the intake air (air mixture) flows through the helical passage and flows into the combustion chamber. A strong intake swirl occurs, which increases the apparent combustion rate and enables operation with a lean mixture. However, when such rapid combustion is performed, the amount of NOx generated increases, and the amount of NOx released into the atmosphere together with exhaust gas increases.

Exhaust gas recirculation, which recirculates exhaust gas into the combustion chamber, is well known as a means of reducing NOx generation. Exhaust gas recirculation has the effect of reducing NOx generation and is effective when implemented in internal combustion engines equipped with the above-mentioned intake port structure, but it worsens the combustion condition of the engine and, as a result, the intake control valve If exhaust gas recirculation is performed even when the engine is open, a strong intake swirl is not generated, and the engine's combustibility is reduced, the engine's drivability will be significantly deteriorated.

The present invention is designed to control the opening/closing of the intake control valve and exhaust gas recirculation in an internal combustion engine having a variable intake swirl type intake port structure as described above. Exhaust gas recirculation is performed when the amount of NOx generated is large, and when the intake control valve is open and the amount of NOx generated is low, and when the combustion condition of the engine is low, exhaust gas recirculation is not performed. Large amounts of
It is an object of the present invention to provide an intake-exhaust gas recirculation control device for an internal combustion engine that prevents NOx from being discharged into the atmosphere and does not significantly impede the drivability of the internal combustion engine.

This purpose, according to the present invention, includes a helical passage that turns around an opening end to the combustion chamber and a straight passage that linearly communicates with the opening end, and the straight passage is opened and closed in the middle of the straight passage. An intake-exhaust gas recirculation control device for an internal combustion engine having an intake port structure provided with an intake control valve, comprising: a diaphragm device that opens and closes the intake control valve in accordance with fluid pressure introduced into a diaphragm chamber; An intake control fluid pressure supply means for supplying fluid pressure to the diaphragm chamber of the diaphragm device according to the operating state of the engine; a diaphragm-type exhaust gas recirculation control valve that opens when a fluid pressure other than atmospheric pressure is acting on the diaphragm chamber; a fluid pressure supply means for controlling exhaust gas recirculation, which is responsive to fluid pressure in the diaphragm chamber of the diaphragm device, and the fluid pressure acts on the diaphragm chamber to open the intake control valve; and an atmospheric release valve for introducing atmospheric pressure into the diaphragm chamber of the exhaust gas recirculation control valve when at fluid pressure.
This is accomplished by an exhaust gas recirculation control device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 of the accompanying drawings is a schematic diagram showing one embodiment of an internal combustion engine incorporating an intake-exhaust gas recirculation control device according to the present invention.

In the figure, 1 indicates an internal combustion engine, and the internal combustion engine has a combustion chamber 2. The internal combustion engine 1 takes in a mixture of fuel and air through an intake port 3 and discharges exhaust gas through an exhaust port 4. Intake port 3
An intake manifold 6 and a carburetor 7 are connected in this order to the exhaust port 4, and an exhaust manifold 8 is connected to the exhaust port 4.

The intake port 3 has a guide vane 9,
The guide vane divides the intake port 3 into a helical passage 10 that turns around the opening end into the combustion chamber 2 and a straight passage 11 that linearly communicates with the opening end. An intake control valve 12 is provided in the middle of the straight passage 11, and the intake control valve is configured as a butterfly valve supported on a valve shaft 13 to open and close the straight passage 11.

A drive lever 15 is attached to the valve shaft 13 of the intake control valve 12.
is mounted, the drive lever being drivingly connected to the rod 17 of the diaphragm device 16.
The diaphragm device 16 defines a diaphragm chamber 19 on the upper side of the diaphragm 18, and when a negative pressure of a predetermined value or more is introduced into the diaphragm chamber, the diaphragm 18 absorbs the spring force of the compression coil spring 20. , thereby driving the intake control valve 12 to the closed position as shown, whereas the diaphragm chamber 1
When a negative pressure of a predetermined value or more is not introduced into the valve 9, the diaphragm 18 moves downward in the figure due to the spring force of the compression coil spring 20, thereby driving the intake control valve 12 to the open position. .

Diaphragm chamber 19 is connected to port 24 of negative pressure control valve 23 via conduits 21 and 22. The negative pressure control valve 23 is a switching valve type, and has a negative pressure port 25 and an atmospheric port 26 in addition to the port 24, and when a negative pressure of a predetermined value or more is introduced into the diaphragm chamber 27, the diaphragm 28 is closed. The valve element 30 closes the valve port 31 by moving upward in the figure against the spring force of the helical compression spring 29;
The port 24 is connected to the negative pressure port 25, and when the negative pressure above a predetermined value is not introduced into the diaphragm chamber 27, the diaphragm 28 is lowered by the spring force of the compression coil spring 29, and the valve element 30
opens the valve port 31 and closes the negative pressure port 25 to connect the port 24 to the atmospheric port 26. The negative pressure port 25 is connected to the intake pipe negative pressure outlet port 36 provided in the intake manifold 6 through a conduit 32, a check valve 33, and conduits 34 and 35.The diaphragm chamber 27 is connected to the intake manifold through conduits 37 and 35. It is connected to an intake pipe negative pressure outlet port 36 provided at 6.

An exhaust gas recirculation control device 40 is attached to the internal combustion engine 1 . Exhaust gas recirculation control device 40
includes an exhaust gas recirculation control valve 41 having an inlet port 43 and an outlet port 42, the inlet port 43 being connected via a conduit 46 to an exhaust gas intake port 47 provided in the exhaust manifold 8. The outlet port 42 is connected via a conduit 44 to an exhaust gas supply port 45 provided in the intake manifold 6. Exhaust gas recirculation control valve 4
1 has a valve element 48 that opens and closes the inlet port 43 and controls its effective opening area, and when the negative pressure of a predetermined value or more is not introduced into the diaphragm chamber 49, the diaphragm 50 closes the compression coil. The inlet port 43 is closed by descending due to the spring force of the spring 51, and when a negative pressure of a predetermined value or more is introduced into the diaphragm chamber 49, it rises against the spring force of the compression coil spring 49 according to the negative pressure. The inlet port 43 is opened. The diaphragm chamber 49 is connected to an intake pipe negative pressure outlet port 56 provided in the carburetor 7 via conduits 52, 53, a negative pressure regulating valve 54, and a conduit 55. The intake pipe negative pressure outlet port 56 is located upstream of the throttle valve 14 which is in the fully closed position as shown, and is located downstream of the throttle valve 14 when the throttle valve is opened beyond a relatively small predetermined opening. It is set up to do so.

The negative pressure regulating valve 54 includes a valve element 58 that opens and closes the valve port 57 and a diaphragm 59 that supports the valve element.
In the drawing, the diaphragm 59 defines an atmosphere opening chamber 61 which is open to the atmosphere through an air filter 60 in the upper part, and a diaphragm chamber 62 in the lower part. The diaphragm 59 is in a position to open the valve element 58 by separating it from the valve port 57 by the spring force of the compression coil spring 63 when a pressure (positive pressure) exceeding a predetermined value is not introduced into the diaphragm chamber 62. On the other hand, when a pressure higher than a predetermined value is introduced into the diaphragm chamber 62, the diaphragm moves upward in the figure against the spring force of the compression coil spring 63, and the valve port 57 is closed by the valve element 58. ing. The diaphragm chamber 62 is connected via a conduit 64 to an exhaust gas passage between the inlet port 43 and an orifice 65 provided upstream of the inlet port 43, so that the exhaust gas pressure in the passage is introduced. .

Negative pressure regulating valve 54 and orifice 65 as described above
This structure adjusts the negative pressure supplied to the diaphragm chamber 49 of the exhaust gas recirculation control valve 41 so as to keep the exhaust gas pressure in the exhaust gas passage substantially constant, thereby controlling the amount of exhaust gas recirculation. The function is to keep the ratio of EGR to the amount of intake air, that is, the EGR rate, almost constant.

Conduits 52 and 53 connect to conduit 66 at their connection.
is connected to the port 68 of the atmosphere release valve 67. The atmosphere release valve 67 is an on-off valve type, and when a negative pressure of a predetermined value or more is introduced into the diaphragm chamber 69, the diaphragm 70 is activated by a compression coil spring 71.
valve element 72 by rising against the spring force of
closes valve port 73 and isolates port 68 from atmospheric port 74, whereas diaphragm chamber 69
When a negative pressure of a predetermined value or higher is not introduced into
3 is opened and port 68 is connected to atmospheric port 74. The diaphragm chamber 69 is connected by a conduit 75 to the junction of the conduits 21 and 22 and is supplied with the same fluid pressure as that introduced into the diaphragm chamber 19. The switching set pressure of the atmosphere release valve 67 and the operating set pressure of the diaphragm device 16 are equal to each other, so when the diaphragm device 16 is driving the intake control valve 12 to the closed position as shown, the atmosphere release valve 67 is When the valve is closed and the diaphragm device 16 is driving the intake control valve 12 to the open position, the atmosphere release valve 67 is open.

Next, the operation of the intake-exhaust gas recirculation control device constructed as described above will be explained.

The illustrated state is when the internal combustion engine 1 is running at idle, and at this time the negative pressure control valve 2
By introducing negative pressure of a predetermined value or more into the diaphragm chamber 27 of the valve element 3, the valve port 31 is connected to the valve element 3.
0 and port 24 is closed by negative pressure port 2.
5, a negative pressure of a predetermined value or more is introduced into the diaphragm chamber 19 of the diaphragm device 16, and the intake control valve 12 is closed. Further, at this time, a negative pressure of a predetermined value or more is introduced into the diaphragm chamber 69 of the atmosphere release valve 67, and the atmosphere release valve is closed.
However, at this time, the intake pipe negative pressure outlet port 56 is located upstream of the throttle valve 14 and is exposed to atmospheric pressure, so the exhaust gas recirculation control valve 41
Negative pressure above a predetermined value is not introduced into the diaphragm chamber 49 of the exhaust gas recirculation control valve 41, and the exhaust gas recirculation control valve 41 is closed.
There is no exhaust gas recirculation.

When the throttle valve 14 is opened in the above-mentioned state and the intake pipe negative pressure outlet port 56 is located downstream of the throttle valve 14 and intake pipe negative pressure is applied to it, the negative pressure regulating valve 54 is opened. By introducing the negative pressure adjusted by the above into the diaphragm chamber 49 of the exhaust gas recirculation control valve 41, the exhaust gas recirculation control valve opens and exhaust gas recirculation is performed.

Exhaust gas recirculation is performed in this way when negative pressure is applied to the intake pipe negative pressure outlet port 56, and moreover, as described above, negative pressure of a predetermined value or higher is introduced into the diaphragm chamber 19, and the atmosphere release valve 67 is closed. The intake control valve 12 closes, and the diaphragm chamber 6 closes.
This is when a negative pressure of a predetermined value or more is introduced into the diaphragm chamber 69, and when the negative pressure of a predetermined value or more is no longer introduced into the diaphragm chamber 19, the intake control valve 12 opens. When the negative pressure exceeding the value is no longer introduced and the atmospheric release valve 67 is opened, atmospheric pressure is introduced from the atmospheric port 74 into the diaphragm chamber 49 of the exhaust gas recirculation control valve 41 . is closed and exhaust gas recirculation is stopped.

As a result, exhaust gas recirculation is performed only when the intake control valve 12 is closed, a relatively strong intake swirl is generated in the combustion chamber 2, and rapid combustion is being performed.
When the intake control valve 12 opens and rapid combustion is no longer performed, it is stopped accordingly, and deterioration in the operability of the internal combustion engine 1 is avoided.

The intake control valve 12 responds to the intake pipe negative pressure and closes only when the intake pipe negative pressure is greater than a predetermined value, that is, when the engine load is below a predetermined value, and accordingly, exhaust gas recirculation is also performed. It can be performed only when the engine is below the predetermined value.

FIG. 2 shows another embodiment of the intake-exhaust gas recirculation control device according to the present invention. In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals as in FIG. In this embodiment, the negative pressure control valve 23 is of an on-off valve type, and the valve element 30 is adapted to open and close the valve port 31. Further, the negative pressure control valve 23 connects the diaphragm chamber 27 to a negative pressure outlet port 78 provided in the bench lily 77 of the carburetor 7 through a conduit 76.
When the negative pressure of the bench lily is below a predetermined value, the valve is closed and the port 24 is connected only to the negative pressure port 25, and when the negative pressure of the vent lily is above a predetermined value, the valve is opened and the port 24 is connected to the atmospheric port 26. It's starting to connect.

The atmosphere release valve 67 is a switching valve type, and the port 68
, an atmospheric port 74 , and a negative pressure port 79 , and the port 68 is connected to the diaphragm chamber 49 by the conduit 52 .
The negative pressure port 79 is connected to the intake pipe negative pressure outlet port 56 through the conduit 55, and the valve element 72 closes the valve port 72 when a negative pressure of a predetermined value or more is introduced into the diaphragm chamber 69. This connects the port 68 to the negative pressure port 79, and when the negative pressure of a predetermined value or more is not introduced into the diaphragm chamber 69, the valve element 72 opens the valve port 72 and closes the negative pressure port 79, thereby closing the port 68. It is adapted to be connected to an atmospheric port 74.

In this embodiment, the intake control valve 12 closes when the negative pressure at the vent is below a predetermined value, that is, when the amount of intake air is below a predetermined value, and when the negative pressure at the vent is above the predetermined value, that is, when the amount of intake air is below the predetermined value. When the value is greater than or equal to the value, the intake control valve 12 opens.

In this embodiment as well, the same fluid pressure as the fluid pressure introduced into the diaphragm chamber 19 of the diaphragm device 16 is supplied to the diaphragm chamber 69 of the atmosphere release valve 67, thereby controlling the opening/closing of the intake control valve 12 and the exhaust gas. The recirculation is controlled in conjunction with the intake control valve 12.
Exhaust gas recirculation can only take place when the valve is closed. Therefore, it will be understood that the same effects as the above-mentioned embodiment can be obtained in this embodiment as well.

Although the present invention has been described in detail with respect to specific embodiments above, it will be appreciated by those skilled in the art that the present invention is not limited to these embodiments, and that various embodiments are possible within the scope of the present invention. It should be obvious.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing an embodiment of an intake-exhaust gas recirculation control device for an internal combustion engine according to the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Internal combustion engine, 2... Combustion chamber, 3... Intake port, 4... Exhaust port, 6... Intake manifold, 7... Carburetor, 8... Exhaust manifold, 9
...Guide vane, 10...Helical passage, 11
... Straight passage, 12 ... Intake control valve, 13
... Valve shaft, 14 ... Throttle valve, 15 ...
Lever, 16...Diaphragm device, 17...Rod, 18...Diaphragm, 19...Diaphragm chamber, 20...Compression coil spring, 21, 22...
... Conduit, 23 ... Negative pressure control valve, 24 ... Port,
25...Negative pressure port, 26...Atmospheric port, 27
...Diaphragm chamber, 28...Diaphragm, 2
9... Compression coil spring, 30... Valve element, 31...
... Valve port, 32 ... Conduit, 33 ... Check valve, 3
4, 35... Conduit, 36... Intake pipe negative pressure extraction port, 37... Conduit, 40... Exhaust gas recirculation device, 41... Exhaust gas recirculation control valve, 42... Outlet port, 43... Inlet port, 44...conduit,
45... Exhaust gas supply port, 46... Conduit, 4
7...Exhaust gas intake port, 48...Valve element, 4
9...Diaphragm chamber, 50...Diaphragm,
51... Compression coil spring, 52, 53... Conduit,
54... Negative pressure regulating valve, 55... Conduit, 56... Intake pipe negative pressure take-out port, 57... Valve port, 58...
... Valve element, 59 ... Diaphragm, 60 ... Air filter, 61 ... Atmospheric release chamber, 62 ... Diaphragm chamber, 63 ... Compression coil spring, 64 ... Conduit, 65 ... Orifice, 66 ... Conduit, 67 …
...Atmospheric release valve, 68...Port, 69...Diaphragm chamber, 70...Diaphragm, 71...Compression coil spring, 72...Valve element, 73...Valve port, 74...Atmospheric port, 75, 76... …conduit,
77... Bench lily, 78... Bench lily negative pressure extraction port, 79... Negative pressure port.

Claims (1)

[Scope of utility model registration request] An intake port that has a helical passage that turns around an opening end to a combustion chamber and a straight passage that linearly communicates with the opening end, and an intake control valve that opens and closes the straight passage is provided in the middle of the straight passage. The intake-exhaust gas recirculation control device for an internal combustion engine has a diaphragm device that opens and closes the intake control valve in accordance with fluid pressure introduced into a diaphragm chamber, and the diaphragm device in accordance with the operating state of the internal combustion engine. intake control fluid pressure supply means for supplying fluid pressure to the diaphragm chamber;
A diaphragm-type exhaust gas recirculation control that is provided in the middle of the exhaust gas recirculation passage and closes when atmospheric pressure is acting on the diaphragm chamber and opens when fluid pressure other than atmospheric pressure is acting on the diaphragm chamber. a valve, and an exhaust gas recirculation control fluid pressure supply means for supplying fluid pressure to the diaphragm chamber of the exhaust gas recirculation control valve in accordance with the operating state of the internal combustion engine;
In response to a fluid pressure in the diaphragm chamber of the diaphragm device, when the fluid pressure is such that the fluid pressure acts on the diaphragm chamber to open the intake control valve, a large amount is applied to the diaphragm chamber of the exhaust gas recirculation control valve. An air intake-exhaust gas recirculation control device for an internal combustion engine, comprising an atmosphere release valve for introducing atmospheric pressure.