JPS5840014B2 - High gas control touch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention particularly provides two types of control negative pressures supplied to a plurality of differential pressure response devices that control the individual operations of a control device for an internal combustion engine for an automobile or a plurality of exhaust gas purification devices. This invention relates to a pneumatic control device that centrally controls the size of the leak valve using one leak valve.

Exhaust gas recirculation devices, ignition timing retard devices, and secondary air supply devices, which are generally used with the main purpose of reducing harmful gases (HC, CO, NOx, etc.) in exhaust gas, are used during low-speed, light-load, or high-frequency operation. It is activated when the engine is accelerating, especially when the amount of harmful gases emitted is large, but it is desirable to stop or moderate the activation under operating conditions such as at high speeds or high loads, or for a certain period of time after startup.

Furthermore, it is desirable for the dashpot to operate at high speeds and stop operating at low speeds.

However, when these exhaust gas purification devices are controlled by differential pressure response devices such as diaphragm devices or piston devices, conventionally, the control negative pressure supplied to each differential pressure response device is controlled by each exhaust gas purification device. Since this was done separately for each device, the negative pressure circuit was complicated, the number of control parts increased, the device became expensive, and there were drawbacks such as poor mountability on a vehicle, repairability, and reliability.

The exhaust gas control device of the present invention has been proposed in view of the above, and is applicable to a control device for an internal combustion engine that operates according to the magnitude of negative pressure, and a negative pressure chamber of a differential pressure responsive device that controls the device. A negative pressure passage that conducts the negative pressure of the intake system, an atmosphere release passage provided in the middle of the passage, and a leak valve provided in the atmosphere release passage for controlling opening and closing of the passage according to the operating state of the engine; an orifice that is interposed in the atmosphere opening passage between the leak valve and the negative pressure passage to regulate the amount of air flowing in; an exhaust gas purification device that is controlled according to the magnitude of the negative pressure; A first invention characterized in that it has an air passage communicating between a negative pressure chamber of a differential pressure response device for controlling the leak valve and the atmosphere opening passage between the leak valve and the orifice; , and a second invention characterized in that an orifice is interposed in the air passage.

Next, one embodiment of the present invention will be described in detail with reference to FIG.

In FIG. 1, 1 is an intake passage connected to an intake port of an automobile internal combustion engine (not shown), and 2 is a carburetor that is interposed in the middle of the passage 1 and opens and closes in conjunction with an accelerator pedal (not shown). A throttle valve, 10 is a vacuum advance angle control device for the distributor 11, 30 is an exhaust gas recirculation amount control device installed in the middle of the exhaust gas recirculation passage 200 that recirculates a part of the exhaust gas to the intake system of the engine, and 40 is the exhaust gas recirculation amount control device. A switching valve 53 switches between control negative pressure and atmospheric pressure supplied to the flow rate control device 30, and reference numeral 53 indicates the switching valve 40.
60 is a dashpot that prevents the throttle valve 2 from suddenly returning to the idle opening when decelerating using the engine brake; A switching valve 80 controls the operation of the dashbot 60, and a leak valve 80 controls the control air pressure supplied to the vacuum advance angle control device 10 and the two switching valves 40 and 70 according to various operating conditions of the engine. Valve, 90 is the same leak valve 8
This is a control device for the controlled negative pressure supplied to 0.

The vacuum advance angle control device 10 in this embodiment is of a dual diaphragm type, and an advance side diaphragm 13 and a retard side diaphragm 14 are arranged side by side in a diaphragm housing 12, and are divided by the two diaphragms 13 and 14. 3
Among the chambers, the advance side diaphragm chamber 15 is connected to the negative pressure passage 10.
1, the throttle valve 2 is connected to a port 5 formed in a tube wall 4 near the upstream free end 3 of the throttle valve 2 at a position slightly upstream of the fully closed position, and a retard side diaphragm chamber 16 is not shown. The chamber 17 between the advance side diaphragm 13 and the retard side diaphragm 14 is opened to the atmosphere, and the ignition timing control rod 18 is fixed to the center of the advance side diaphragm 13. The advance side diaphragm chamber 15 has a built-in spring 19 that presses the diaphragm 13 toward the retard side, and the retard side diaphragm chamber 16 has a built-in spring 20 that presses the retard side diaphragm 14 toward the advance side. A stopper 22 that comes into contact with a stopper 21 fixed to the advance diaphragm 13 is fixed to the retard diaphragm 14, and a stopper 22 is formed on the outer peripheral surface of a cylindrical member 23 protruding from the center of the retard diaphragm chamber 16. An annular member 25 supplied to the annular groove 24
is fixed.

In the advance vacuum control device having the above configuration, the negative pressure generated in the intake manifold in the retard side diaphragm chamber 16, that is, the negative pressure generated in the intake passage downstream of the throttle valve 2 (hereinafter referred to as intake manifold negative pressure) is When conductive, the retard side diaphragm 14 is attracted to the retard side against the biasing force of the spring 20, and the position of the stopper 22 moves to the retard side, and this movement range is regulated by the annular groove 24. There is.

On the other hand, when the negative pressure (hereinafter referred to as disboost) generated at the port 5 is conducted to the advance side diaphragm chamber 15, the advance side diaphragm 13 resists the biasing force of the spring 19.
is attracted to the advance side and stops at a balanced position.

Therefore, when atmospheric pressure or low negative pressure is conducted to the advance side diaphragm chamber 15, the diaphragm 13 is stopped with the stopper 21 in contact with the stopper 22, the ignition timing is delayed, and the diaphragm chamber In a state where a high negative pressure is conducted to 15, the advance angle is performed in accordance with the magnitude of this negative pressure.

Next, the exhaust gas recirculation amount control device 30 will be explained.
The device 30 includes a valve body 33 that controls the amount of restriction of a valve hole 32 provided in the middle of an exhaust gas recirculation passage 200;
The housing 35 of the device 34 is provided with a diaphragm 38 that divides the interior into two chambers 36 and 37, and the valve body 33 is protruded from the center of the diaphragm 38. The chamber 36 is communicated via the air passage 102 with a port 6 formed in the pipe wall 4 on the slightly upstream side of the port 5 protruding from the pipe wall 4 of the intake passage 1. The chamber 36 has a diaphragm 38 and a valve body 33 connected to the valve hole 3.
A spring 39 is provided that biases 2 in the closing direction.

Next, the switching valve 40 will be explained. The switching valve 40 controls the air pressure that is supplied to the chamber 36 of the exhaust gas recirculation amount control device 30 via the air passage 102 to generate negative pressure (hereinafter referred to as EGR boost) or Consisting of a valve device 41 that switches to atmospheric pressure and a diaphragm device 42 that controls the valve device 41, a valve body 45 that selectively closes the communication hole 43 and the atmosphere release hole 44 of the air passage 102 is connected to the diaphragm via a rod 46. It is connected to the center of a diaphragm 50 that divides the device 42 into two chambers 48° 49, one chamber 48 being communicated with the air passage 103 and the other chamber 49 being open to the atmosphere through a hole 51. A spring 52 is provided therein for biasing the diaphragm 50 in a direction in which the valve body 45 closes the atmosphere opening hole 44 .

Next, the leak valve 80 will be described. A fixed orifice 105 and a valve hole 88 opened and closed by a valve body 81 are interposed in series in an atmosphere release passage 104 branched from the middle of the negative pressure passage 101. is connected to the center of a diaphragm 84 of a diaphragm device 83 via a rod 82, and has two chambers 8 divided by the diaphragm 84.
5.86, the chamber 85 is communicated with the air passage 106,
The chamber 86 is opened to the atmosphere through a hole 87, and a spring 89 is provided in the chamber 85 to bias the diaphragm 84 in a direction in which the valve body 81 closes the valve hole 88.

Note that an atmosphere opening passage 104 between the valve hole 88 and the orifice 105 communicates with the air passage 103.

Next, the control device 90 will be explained. This control device 90 detects the vehicle speed, load, and temperature of the engine, as well as the magnitude of various negative pressures in the intake system, and controls the air passage 10.
The device 90 controls the negative pressure of the intake system supplied to the air intake system 6, and details of the control by the device 90 will be described later.

Next, the delay device 53 will be explained. The device 53 has a fixed orifice 54 and a check valve 55 that are interposed in parallel in the middle of the air passage 103. The structure is configured so that the atmosphere can flow only in this direction.

Next, the dashpot 60 will be explained. One end of the rod 61 contacts the free end of the lever 8 fixed to one end of the shaft 7 for rotating the throttle shaft 2, and the other end of the rod 61 is connected to the center of the diaphragm 62. Of the two chambers 63 and 6.4 divided by the same diaphragm 62, one chamber 63 is communicated with the atmosphere through an air passage 107, and the other chamber 64 is connected to the chamber 63 through an orifice 65 and a check valve 66. A spring 67 , which is communicated with the chamber 64 and provided within the chamber 64 , biases the diaphragm 62 in the direction in which the rod 61 comes into contact with the lever 8 .

Note that the check valve 66 is configured to allow air to flow only from the chamber 63 to the chamber 64 direction, and the movement of the diaphragm 62 by the spring 67 is caused by the protrusion 68 provided on the diaphragm 62 touching the inner surface of the housing 69 of the dashpot 60. It will stop at the point of contact.

Next, the switching valve 70 will be explained.
0 is composed of a valve body 71 that opens and closes the air passage 107 and a diaphragm device 72 that controls the valve body 71.
1 is connected to the center of a diaphragm 74 via a rod 73, and has two chambers 75.1 divided by the diaphragm 74.
One of the chambers 75 is communicated with the atmosphere opening passage 104 between the valve hole 88 and the orifice 105 through the air passage 103, and the other chamber 76 is opened to the atmosphere through the hole 77.
A spring 78 is built into the chamber 75 and biases the diaphragm 74 in the direction in which the valve body 71 closes.

When the engine is driven, negative intake pressure is generated in the intake passage 1 of the above embodiment device.

The magnitude of this intake negative pressure changes depending on the operating state of the engine, and also becomes completely different if the negative pressure is taken out at a different position within the intake passage 1, especially in relation to the throttle valve 2.

Therefore, the port 5 of the intake passage 1 in the above embodiment device
FIGS. 2 and 3 show general negative pressure characteristics of the disboost generated in the engine, the negative pressure generated in port 6, and the intake manifold negative pressure.

In addition, in Figures 2 and 3, the vertical axis represents the engine output (P
S) is an engine output diagram with the engine speed (rpm) plotted on the horizontal axis; in each of the above diagrams, the solid line A is the output line when the throttle valve 2 is fully open, and the solid line B is the output line when the throttle valve 2 is fully opened. It is.

Further, in this embodiment, if the rotation angle from the fully closed position of the throttle valve 2 is defined as the throttle opening, the throttle opening at idle is set to 10 degrees, and the port 5 is set to 10 degrees when the throttle opening is 13 degrees. Throttle valve 2 in
The port 6 is bored in the tube wall facing the free end 3 when the throttle opening is 20 degrees.

The one-dot chain line shown in Figure 2 is the constant negative pressure line of the disboost generated at port 5, the broken line shown in the same figure is the equal throttle opening line, and the one-dot chain line shown in Figure 3 is the equal negative pressure line of the disboost generated at port 6. The negative pressure line and the broken line shown in the figure are equal negative pressure lines of the intake manifold negative pressure.

Now, when a negative pressure greater than the set negative pressure is applied to the chamber 85 through the air passage 106 under the control of the control device 90, the diaphragm 84 is sucked upward against the biasing force of the spring 89, and the valve hole 88 is opened. Open air passageway 104
More atmospheric pressure is supplied to the air passage 103 and the negative pressure passage 101.

In this case, the air passage 103 is at atmospheric pressure, but since the atmosphere flows into the negative pressure passage 101 via the orifice 105, the vacuum advance angle control device 10 conduction to the advance side diaphragm chamber 15, and the ignition timing is delayed by the amount by which the disboost is weakened.

Therefore, by adjusting the amount of restriction of the orifice 105, it is possible to advance the ignition angle in proportion to the magnitude of the disboost generated at the port 5 while giving an appropriate amount of ignition timing retardation.

By the way, the chambers 48 and 75 communicating with the air passage 103
becomes atmospheric pressure, the diaphragm 50 is urged downward by the urging force of the spring 52, the valve body 45 opens the communication hole 43 and closes the atmosphere release hole 44, and the diaphragm 74 is also urged downward by the urging force of the spring 78. Then, the valve body 71 closes the air passage 107.

Therefore, the EGR boost generated at the port 6 is conducted to the chamber 36 of the exhaust gas recirculation amount control device 30 via the air passage 102, and the valve body 33 is connected to the diaphragm 38.
It stops at a position where the upward suction force and the downward biasing force of the spring 39 are balanced, and the amount of restriction of the valve hole 32 is controlled according to this stop position.

On the other hand, the dashpot 60 is activated due to the air passage 107 being closed.

That is, when the accelerator pedal (not shown) is suddenly released in order to apply engine braking while the vehicle is running, the throttle valve 2 suddenly rotates in the direction of arrow X in FIG. 1 due to the return force of a return spring (not shown). ,
The lever 8 comes into contact with the rod 61 at the set opening before the idle opening, and from this point on, the dashpot 60 operates and the rotational speed of the throttle valve 2 decreases.

Next, when a low negative pressure or atmospheric pressure below a set value is conducted to the chamber 85 under the control of the control device 90, the diaphragm 84 moves downward due to the biasing force of the spring 89, and the valve body 81 moves through the valve hole 88. Obstruction.

As a result, the disturbance generated at the port 5 is directly conducted to the advance side diaphragm chamber 15 of the vacuum advance angle control device 10, and each chamber 48. of the switching valve 40.70.
Disboost is also conducted to 75 through the negative pressure passage 101, the atmosphere opening passage 104, and the air passage 103, but especially the disboost conducted to the chamber of the switching valve 40 is caused by the large throttle amount of the delay device 53. Since this is done through the orifice 54, a time delay occurs.

This delay time is controlled by adjusting the amount of restriction of the orifice 54.

When the disboost is conducted to the chamber 48, the diaphragm 50 rises against the biasing force of the spring 52, and the valve body 4
5 closes the communication hole 43 and opens the atmosphere opening hole 44.

Therefore, atmospheric pressure is conducted to the chamber 36 of the exhaust gas recirculation amount control device 30 through the air passage 102, and the diaphragm 38
is lowered by the biasing force of the spring 39, the valve body 33 closes the valve hole 32, and exhaust gas recirculation is stopped.

On the other hand, when the disboost is conducted to the chamber 75 of the switching valve 70, the diaphragm 74 rises against the biasing force of the spring 78, and the valve body 71 opens the air passage 107.

Therefore, even if the chamber 63 is opened to the atmosphere and the diaphragm 62 is pushed toward the chamber 64 against the urging force of the spring 67, the atmosphere is sucked into the chamber 63 through the air passage 107.
The differential pressure generated between the chambers 63 and 64 is small, the diaphragm 62 moves smoothly only against the biasing force of the spring 67, and the rotational delay of the throttle valve 2 is small.

In the above embodiment, for example, the control device 90 opens the valve hole 88 during low-speed, light-load, medium-load, or engine acceleration, which is frequently operated, and after starting the engine during high-speed, high-load, and warm-up operation of the engine. If the valve hole 88 is controlled to be closed under operating conditions such as for a certain period of time, the following effects can be expected.

In other words, during low-speed, light-load, medium-load, and engine acceleration, which occur frequently, the ignition timing is delayed and exhaust gas is recirculated, resulting in harmful gases (HC, CO, etc.).

NOx, etc.) emissions are reduced, the ignition timing is advanced at high speeds and under high load, and exhaust gas recirculation is stopped, preventing heat loss and fire caused by overheating of the exhaust system, increasing output and reducing fuel consumption. As a result, the ignition timing is advanced for a certain period of time after starting, and exhaust gas recirculation is stopped, improving startability and preventing engine malfunctions immediately after starting.
Improves drivability.

The dashpot 60 operates at low speeds and light loads, during medium loads, and during deceleration after engine acceleration to limit the return of the throttle valve 2, thereby suppressing increases in emissions of HC, CO, etc. during deceleration. During deceleration, the operation is stopped to allow the throttle valve 2 to return quickly and prevent the effectiveness of the engine brake from deteriorating.

By the way, if the ignition timing is advanced and the exhaust gas recirculation is stopped at the same time when the valve hole 88 is blocked, there will be a problem that the output will suddenly increase and the drivability will deteriorate. After the ignition timing is advanced by the operation of the delay device 53, exhaust gas recirculation is stopped with an appropriate delay, so drivability is improved.

In the above embodiment, the vacuum advance angle control device 10 is adopted as an exhaust gas purification device that is proportionally controlled according to the magnitude of the negative pressure, and the vacuum advance angle control device 10 is switched in two stages according to the magnitude of the negative pressure. Switching valve 4 as a controlled exhaust gas purification device
However, in place of the dashpot 60, a throttle positioner that opens the throttle valve 2 until a certain rotational speed is reached during deceleration is used. Alternatively, an exhaust gas recirculation amount control device 3 may be adopted as a device that is proportionally controlled according to the magnitude of negative pressure.
0 may be adopted, and the vacuum advance angle control device 10 having a switching valve 40 may be adopted as a device that performs switching control in two stages depending on the magnitude of negative pressure.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is an engine output diagram showing characteristics of disboost and throttle opening, and Fig. 3 is an engine showing characteristics of EGR boost and intake manifold negative pressure. It is an output diagram. 1... Intake passage, 2... Throttle valve, 4... Pipe wall, 5, 6... Port, γ... Shaft, 8...Lever, 10...
...Vacuum advance angle control device, 11...Distributor, 13,14...Diaphragm, 1
5... Advance side diaphragm chamber, 30...
・Exhaust gas recirculation amount control device, 32... Valve hole, 33
... Valve body, 34 ... Diaphragm device, 40 ... Switching valve, 41 ... Valve device, 42 ... Diaphragm device, 53・・・・・・
...Delay device, 54... Orifice, 55...
... Check valve, 60 ... Dashpot, 70 ... Switching valve, 71 ...
Valve body, 72...Diaphragm device, 80...
...Leak valve, 81... Valve body, 83...
...Diaphragm device, 88...Valve hole, 9
0...Control device, 101...
Negative pressure passage, 102, 103, 106° 107...
・Air passage, 104...Atmospheric opening passage, 105
... Orifice, 200 ... Exhaust gas recirculation passage.

Claims (1)

[Scope of Claims] 1. A control device for an internal combustion engine that operates according to the magnitude of negative pressure, and a negative pressure passage that conducts negative pressure of an intake system to a negative pressure chamber of a differential pressure response device that controls the device. , an atmosphere opening passage provided in the middle of the negative pressure passage, a leak valve provided in the atmosphere opening passage and controlling the opening and closing of the atmosphere opening passage according to the operating state of the engine, and the leak valve and the negative pressure passage. an orifice that is interposed in the atmosphere opening passageway between the two and regulates the amount of air flowing in; an exhaust gas purification device that is controlled according to the magnitude of the negative pressure; and a difference that controls the exhaust gas purification device. An exhaust gas control position characterized by having an air passage communicating a negative pressure chamber of a pressure response device with the atmosphere opening passage between the leak valve and the orifice. 2. A control device for the internal combustion engine that operates according to the magnitude of negative pressure, a negative pressure passage that conducts the negative pressure of the intake system to the negative pressure chamber of the differential pressure response device that controls the device, and a An atmosphere opening passage provided in the middle, a leak valve provided in the atmosphere opening passage and controlling the opening/closing of the atmosphere opening passage according to the operating state of the engine, and an atmosphere between the leak valve and the negative pressure passage. An orifice installed in the open passage to regulate the amount of air flowing in, an exhaust gas purification device that is controlled according to the magnitude of the negative pressure, and the negative pressure of the differential pressure responsive device that controls the exhaust gas purification device. An exhaust gas control device comprising: an air passage communicating a chamber with the leak valve and the atmosphere opening passage between the orifice; and an orifice interposed in the air passage.