JPS6217656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is applicable to various control devices that control the operating state of an engine, such as an engine ignition advance control device or an engine exhaust gas recirculation device.
This invention relates to a negative pressure operating device for an engine that controls a gas recirculator (hereinafter referred to as EGR) according to the engine's intake negative pressure.

[Prior Art] Normally, a vehicle engine is provided with a negative pressure operating device in order to control the engine to an appropriate operating state, and the negative pressure in the intake system of the engine is transferred to the negative pressure chamber of the negative pressure operating device. Various control devices that govern engine operating conditions are controlled according to the intake negative pressure.For example, the engine's ignition advance angle is controlled according to the intake negative pressure, and the EGR The valve was opened in response to intake negative pressure to allow exhaust gas to flow back into the intake system, reducing the amount of nitrogen oxides emitted.

By the way, when a vehicle travels at high altitudes, the atmospheric pressure is generally low at high altitudes and the amount of air intake decreases, so it is necessary to increase the opening of the throttle valve in order to obtain the same output as at low altitudes. It is something.

[Problem that the invention seeks to solve]

However, in the conventional negative pressure operating device, due to its structure, in the low load region where the intake negative pressure of the negative pressure port increases as the throttle valve opening increases, it is difficult to increase the throttle valve opening at high altitudes compared to low altitudes as mentioned above. If you increase it, the negative pressure will increase and the ignition angle will advance greatly,
Various engine control devices were not controlled properly, such as by opening the EGR valve too wide or too early, and as a result, there was a problem in which the engine was not controlled to an appropriate operating state at high altitudes.

In view of these problems, the present invention aims to provide a negative pressure operating device for an engine that can appropriately control various control devices such as an ignition advance control device and EGR even at high altitudes.

[Means for solving problems]

Therefore, the present invention provides a negative pressure operating device for an engine that controls various control devices according to the intake negative pressure introduced into a negative pressure chamber, in which the throttle valve is upstream when the throttle valve is fully closed, and the downstream valve is closed when the throttle valve is opened at a predetermined opening degree or more. a first negative pressure port that opens at a position upstream of the first negative pressure port and downstream of the throttle valve at an opening greater than the predetermined opening; The apparatus is provided with an atmospheric pressure detection device that detects the atmospheric pressure, and a control device that controls the state of communication between the first and second negative pressure ports and the negative pressure chamber in accordance with the output of the atmospheric pressure detection device.

[Effect]

In this invention, the atmospheric pressure is detected by the atmospheric pressure detection device, and when driving in lowland, that is, when the atmospheric pressure is higher than a set value, the control device receives the output of the atmospheric pressure detection device and connects the first negative pressure port. The negative pressure chamber is communicated with the negative pressure chamber, and intake negative pressure is introduced into the negative pressure chamber through this first negative pressure port, and various control devices of the engine are controlled according to the intake negative pressure in the negative pressure chamber.

On the other hand, when traveling at high altitudes, that is, when the atmospheric pressure is below the set value, the control device receives the output from the atmospheric pressure detection device and connects the second negative pressure port or both the first and second negative pressure ports and the negative pressure chamber. The intake negative pressure is introduced into the negative pressure chamber through this second negative pressure port or both the first and second negative pressure ports, and various control devices of the engine are connected to the intake negative pressure in this negative pressure chamber. Although controlled accordingly,
In this case, the rise of negative pressure in the second negative pressure port is slower than that in the first negative pressure port, and even if the throttle valve opening is increased to increase the filling amount at high altitudes, the intake negative pressure in the negative pressure chamber will increase unnecessarily. It will never rise.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The drawing shows a negative pressure operating device for an engine according to an embodiment of the present invention. In the figure, 1 is an intake pipe of an engine, a throttle valve 2 is provided in the intake pipe 1, and a first negative pressure port 3 is opened and provided upstream of the fully closed throttle valve 2 of the intake pipe 1. A second negative pressure port 4 is open and provided upstream of the first negative pressure port 3. Both the first and second negative pressure ports 3 and 4 are located at a position where the intake negative pressure increases as the opening of the throttle valve 2 increases in the low load region of the engine, that is, in the region where the opening of the throttle valve 2 is small. In addition, the rise of the negative pressure in the second negative pressure port 4 is slower than that in the first negative pressure port 3. In addition, both negative pressure ports 3,
4 are connected to first and second negative pressure passages 5 and 6, respectively, and the other ends of both negative pressure passages 5 and 6 are switched and connected to a common negative pressure passage 8 by a control valve 7. Further, the control valve 7 is controlled to be energized by a contact 9a of a bellows 9 so as to be switched.

Further, the other end of the negative pressure passage 8 is branched into two from the middle, and the other ends are connected to the negative pressure chambers 11 and 19 of the first and second diaphragm devices 10 and 18, respectively. In this first diaphragm device 10, atmospheric pressure is introduced into its pressure chamber 12, and the diaphragm 13 is connected to a movable base plate 15 of the interrupter by a connecting rod 14. is provided with a cam 16 and a contact 17 of the interrupter, and a movable base plate 15 of the interrupter, a cam 1
6 and the contact 17 constitute an ignition advance control device 30 that controls the ignition advance angle of the engine.

Further, in the second diaphragm device 19, atmospheric pressure is introduced into the pressure chamber 20 in the same manner as above, and the diaphragm 21 is connected to the connecting rod 22.
Connected to valve 23 of EGR 31, said valve 2
3 is provided in a recirculation passage 25 that recirculates exhaust gas from the engine 24 to the intake pipe 1 .

In the above configuration, the bellows 9 serves as an atmospheric pressure detection device for detecting atmospheric pressure, and the ignition advance control device 30 and EGR 3
Reference numeral 1 serves as various control devices that control the operating state of the engine, and the first and second diaphragm devices 10 and 18 introduce the intake negative pressure of the engine into their negative pressure chambers 11 and 19, and reduce the negative pressure. It is a negative pressure operating device that controls various control devices according to the intake negative pressure in the chambers 11 and 19, and the control valve 7 and negative pressure passages 5, 6, and 8 receive the output of the atmospheric pressure detection device. , when the atmospheric pressure is above a predetermined value, the first negative pressure port 3 and the negative pressure chambers 11, 19 are communicated, and when the atmospheric pressure is below a predetermined value, the second negative pressure port 4 is communicated with the negative pressure chambers 11, 19. It is a control device.

Next, the operation will be explained.

When the automobile is traveling in a lowland, the bellows 9 is in the state shown in the figure, and the control valve 7 connects the first negative pressure passage 5 of the first negative pressure port 3 and the common negative pressure passage 8. Inlet negative pressure is introduced into the negative pressure chambers 11 and 19 of the first and second diaphragm devices 10 and 18 through the first negative pressure port 3 and through the first negative pressure passage 5 and the common negative pressure passage 8. be done. Then, in the first diaphragm device 10, the diaphragm 13 moves upward in the figure due to the pressure difference between the negative pressure chamber 11 into which the negative pressure is introduced and the atmospheric pressure chamber 12, and the diaphragm 1
3 rotates the movable base plate 15 of the circuit breaker in the direction of arrow A in the figure through the connecting rod 14 to advance the ignition timing, and in this way the first diaphragm device 10, which is a negative pressure operating device, The ignition timing is controlled according to the intake negative pressure of the engine.

In the second diaphragm device 18, the diaphragm 21 moves upward in the figure due to the pressure difference between the negative pressure chamber 19 into which the negative pressure is introduced and the atmospheric pressure chamber 20,
The diaphragm 21 opens the valve 23 via the connecting rod 22 to allow the exhaust gas to flow back into the intake pipe 1. In this way, the second diaphragm device 18, which is a negative pressure operating device, adjusts the EGR 31 according to the intake negative pressure. Controls the amount of exhaust gas recirculation.

By the way, when a car starts traveling at high altitudes, the atmospheric pressure decreases and the amount of air intake into the engine decreases. To compensate for this, the throttle valve 2 is set to open slightly, but even in this case, as mentioned above, When intake negative pressure is introduced through the first negative pressure port 3, the intake negative pressure of the first negative pressure port 3 increases, and even though the intake air filling amount is the same, the first and second Since the intake negative pressure introduced into the second diaphragm device 10, 11 increases, the ignition timing is advanced more than the required advance angle, and the exhaust gas is recirculated in a larger amount than the set amount.

However, in this device, at high altitudes, the bellows 9 extends and the contact 9a closes, thereby switching the control valve 7 to connect the second negative pressure port 6 and the common negative pressure passage 8. The intake negative pressure from the negative pressure port 4 is introduced into the negative pressure chambers 11, 19 of the first and second diaphragm devices 10, 18 via the second negative pressure passage 5 and the common negative pressure passage 8, and in this case, the intake air When the charging amount is the same, this second negative pressure port 4 at high altitudes exhibits almost the same intake negative pressure as the first negative pressure port 3 at low altitudes, so the ignition advance angle matches the required advance angle, and The recirculation amount of exhaust gas also becomes equal to the set amount. Therefore, in the low load region and at high altitudes, the ignition advance and EGR31
The valve opening degree of the engine does not become too large compared to the required angle advance and the set opening degree, and in this way, the negative pressure actuator allows the engine's ignition advance angle control device 30 and
The EGR 31 is appropriately controlled both at low altitudes and at high altitudes, and as a result, the operating state of the engine is appropriately controlled.

In the above embodiment, the first negative pressure port is switched to the second negative pressure port at high altitudes, and the second negative pressure port is connected to the negative pressure chamber of the negative pressure operating device.
In this case, both the first and second negative pressure ports may be connected to the negative pressure chamber of the negative pressure actuator, and in this case, the negative pressure from the second negative pressure port is increased by the control valve as the altitude increases. Better control can be obtained by increasing the rate of vacuum applied to the actuator.

Furthermore, in the above embodiment, the case where the control target is the ignition advance angle control device and EGR is explained.
It goes without saying that the negative pressure operating device of the present invention may be applied to control various other control devices that control the operating state of the engine.

〔Effect of the invention〕

As described above, according to the negative pressure operating device for an engine according to the present invention, atmospheric pressure is detected, and when the atmospheric pressure is above a predetermined value, it is upstream of a fully closed throttle valve, and when the throttle valve is opened at a predetermined opening degree or more, it is downstream. A first negative pressure port that opens at a position communicates with a negative pressure chamber of a negative pressure actuator, and when the atmospheric pressure is below a predetermined value, the first negative pressure port is opened at an opening greater than the predetermined opening, upstream of the first negative pressure port. Since the second negative pressure port or both the first and second negative pressure ports, which open downstream of the throttle valve, are communicated with the negative pressure chamber of the negative pressure actuator, it is possible to reduce the filling amount at high altitudes. Even when the throttle valve opening is increased to increase the throttle valve opening, the increase in intake negative pressure in the negative pressure chamber caused by this can be suppressed, and various control devices such as the ignition advance control device and EGR can be appropriately controlled, and as a result, the engine This has the effect of appropriately controlling the operating conditions of the aircraft regardless of changes in altitude.

[Brief explanation of the drawing]

The drawing is a sectional view of a negative pressure operating device for an engine according to an embodiment of the present invention. 2... Throttle valve, 3... First negative pressure port, 4... Second negative pressure port, 5, 6, 8... Negative pressure passage (control device), 7... Control valve (control device), 10 ,18...
First and second diaphragm devices (negative pressure actuation devices), 30...ignition advance control device (various control devices), 31...EGR (various control devices).

Claims (1)

[Scope of Claims] 1. A negative pressure operating device for an engine, into which the negative pressure of the intake air of the engine is introduced, and which controls various control devices governing the operating state of the engine in accordance with the negative pressure of the intake air of the negative pressure chamber. , a first negative pressure port that opens at a position upstream of the fully closed throttle valve and downstream at a predetermined opening degree or more of the throttle valve; and an opening degree upstream of the first negative pressure port that is larger than the predetermined opening degree. A second negative pressure port opens at a position downstream of the throttle valve; an atmospheric pressure detection device for detecting atmospheric pressure; a control device that communicates between the first negative pressure port and the negative pressure chamber and the second negative pressure port or both the first and second negative pressure ports and the negative pressure chamber when atmospheric pressure is below a predetermined value; A negative pressure operating device for an engine, characterized in that: