JPH0337352A - Idle revolution speed controller - Google Patents

Abstract

PURPOSE:To prevent the sharp increase of the engine revolution speed in the case when an ISCV control part fails, by arranging an air regulator and the ISCV (idle speed control valve) in series state into a bypass passage which makes a detour around a throttle valve. CONSTITUTION:In an engine, a fuel injection valve 10 is arranged in a manifold intake passage 16 on the directly upstream side of an intake port 18 on the downstream side of a throttle valve 12, and a bypass passage 26 is formed so as to make a detour around a throttle body 6. An air regulator 28 which is opening/closing-controlled by the intake pipe pressure and an ISCV 30 successively arranged in series state midway in the bypass passage 26. The ISCV 30 is controlled by a control part 32 into which the detection value of the engine drive state is inputted as feedback value. When the control part 32 fails, and the ISCV 30 is put into the perfect opened state, the reckless driving of the engine is prevented by restricting the air quantity by the air regulator 28.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an idle speed control device, and in particular, uses a detected value of the driving state of an engine as a feedback control value, and uses this feedback control value to control the idle speed.
The present invention relates to an idle rotation speed control device that controls the idle rotation speed by controlling the opening and closing of a control valve.

[Conventional technology] In recent years, the energy situation has increased the demand for lower fuel consumption in automobiles, and in conjunction with the tightening of exhaust gas regulations, various measures have been proposed to improve fuel efficiency and purify exhaust gas. ing. One such strategy is to precisely control the idle speed according to various engine conditions, such as intake air temperature and engine coolant temperature.

This strategy's idle speed control device usually
This is called speed control (SC) and is intended to control the idle rotation speed to a target value, that is, the target rotation speed, by adjusting the amount of air flowing through the passage that bypasses the throttle valve during idling.

The idle speed control device is disclosed in Japanese Patent Application Laid-Open No. 60-2
There is one disclosed in Japanese Patent No. 81951. The idle speed control device disclosed in this publication is provided with a protection device to ensure the maximum idle flow rate and minimum idle flow rate determined depending on temperature independently of the action of the valve body drive device. The protection device is formed by a guard device that restricts the movement of the valve body within a range having upper and lower limits in a fixed relationship, and a second bypass passage formed by bypassing the valve body and the throttle valve, and a second bypass passage formed by bypassing the valve body and the throttle valve. Minimum with temperature as the boundary
Different control forms are used to ensure maximum idle flow rate, eliminating fluctuations in air flow during idle and stabilizing idle speed.

Further, there is one disclosed in Japanese Patent Application Laid-Open No. 81-98157. The idle speed control method disclosed in this publication determines whether the transmission is automatic or manual at the first start of the internal combustion engine, stores this determination result in a non-volatile storage means,
The data in the non-volatile storage means is checked during idling upon subsequent restart to maintain an appropriate idling speed and prevent engine stall or unstable rotation.

[Problems to be Solved by the Invention] By the way, as shown in FIG.
2, the air cleaner 104 is arranged in series,
An idle speed control (ISC) valve 1301, an air regulator valve 128, and other air valves 140 are arranged in parallel with the throttle valve 112, and the idle speed control valve 130 and other air valves 140 are arranged in parallel. is connected to a control unit (ECU) 132.

In addition, Fig. 5 shows the relationship between air volume and engine water temperature. In Fig. 5, symbol A indicates the control air range of the idle speed control (ISO) valve, and symbol B indicates the control air range of the idle speed control (ISO) valve. The temperature/air amount characteristics of other air valves are disclosed, and symbol C discloses the required air amount characteristics of the engine.

Then, the control unit 132 adjusts the temperature/air amount characteristics B of other air valves and the control air range A of the idle speed control (ISO) valve with respect to the required air amount characteristic C of the engine according to the engine water temperature and operating state. The air flow is controlled appropriately and the desired amount of air is supplied to the engine body.

However, the temperature and air amount characteristics B of the other air valves
Since there is a large variation in the air amount of the air valve, and it is necessary to have a large air amount control range of the idle speed control valve, the size of the control air range A of the idle speed control Cl5G) valve becomes large.

Therefore, if the control unit 132 fails and the idle speed control valve 130 becomes fully open, there is a problem that the engine runs out of control, that is, the engine speed rapidly increases, and safety deteriorates.

In addition, if the air volume of the air valve with temperature/air volume characteristic B of other air valves is large, that is, when the engine water temperature is low, there will be variations in the engine starting air volume, causing a condition in which the engine cannot be started properly. This has the disadvantage of reducing startability.

Furthermore, in the case of extremely low temperatures (lower than a in Figure 5), it is difficult to increase the air volume of the air valve in temperature/air volume characteristic B of other air valves, and when the engine water temperature is lower than b in Figure 5, However, there are disadvantages in that it cannot meet the desired required characteristics and is not easy to use.

Furthermore, in controlling the idle speed, the provision of other air valves complicates the configuration, making manufacturing difficult and increasing costs, which is disadvantageous economically.

[Object of the Invention] Therefore, in order to eliminate the above-mentioned disadvantages, an object of the present invention is to arrange an air cleaner, a throttle valve, and an engine body in series, and to provide a bypass passage that bypasses the throttle valve and supplies air to the engine. In addition to providing an air regulator that opens and closes depending on the intake pipe pressure, an idle speed control valve that controls the idle speed to a target speed is provided, and a control section that controls the opening and closing of this idle speed control valve is provided. By sequentially arranging the air regulator and idle speed control valve in series in the middle of the bypass passage, it is possible to effectively prevent a sudden increase in engine speed in the event of a control unit failure, improving safety. It is an object of the present invention to realize an economically advantageous idle speed control device which can improve startability, have a simple configuration, and reduce costs.

[Means for Solving the Problems] To achieve this object, the present invention provides an idle speed control device that controls the idle speed using a detected value of the driving state of the engine as a feedback control value. and the engine body in series, a bypass passage is provided to bypass the throttle valve and supply air to the engine, an air regulator is provided that opens and closes depending on intake pipe pressure, and the idle speed is adjusted to the target speed. An idle speed control valve is provided to control the idle speed control valve, a control section is provided to control opening and closing of the idle speed control valve, and the air regulator and the idle speed control valve are sequentially arranged in series in the middle of the bypass passage. It is characterized by having been established.

[Operations] With the above-described configuration, in the event of a failure in the control section, the idlers, which are sequentially arranged in series in the middle of the bypass passage,
Although the speed control valve is fully open, the air regulator, which opens and closes depending on the intake pipe pressure, effectively prevents a sudden increase in engine speed, improving safety and starting performance. Moreover, the structure is simple and the cost is low.

[Examples] Examples of the present invention will be described in detail below based on the drawings.

1 to 3 show embodiments of this invention. Second
In the figure, 2 is the engine body, 4 is the air cleaner, and 6 is the engine body.
1 is a throttle body, 8 is a body intake passage, 10 is a fuel injection valve, 12 is a throttle valve, 14 is an intake manifold, 16 is a manifold intake passage, 18 is an intake boat, 2
0 is a combustion chamber, 22 is an exhaust manifold, and 24 is a manifold exhaust passage.

The fuel injection type fuel injection valve 10 is disposed in the manifold intake passage 16 immediately upstream of the intake port 18 on the downstream side of the throttle valve 12, and the fuel injection valve 10 is supplied with fuel in a fuel tank (not shown). has been done.

A bypass passage 28 to bypass the throttle body 6
For example, an air regulator 28 is provided in the bypass passage 26, and the air regulator 28 is opened and closed by the intake pipe pressure from the upstream side.
and an idle speed control (ISO) valve 30 are sequentially arranged in series.

Further, as shown in FIG. 1, a control section 32 is connected to the idle speed control valve 30, and this control section 32 uses a detected value (not shown) of the engine driving state as a feedback control value. It has a configuration that performs feedback control of the idle rotation speed.

Next, the effect will be explained.

When the engine main body 2 is driven, the opening degree of the idle speed control valve 30 is controlled by the control section 32, and an appropriate amount of air is supplied to the engine main body 2 in all engine water temperature ranges shown in FIG.

Furthermore, if the control section 32 fails, the idle/
Although the speed control valve 30 is fully open, the amount of air supplied to the engine body 2 by the air regulator 28, which opens and closes depending on the intake pipe pressure, is
Adjustments are made to maximize the temperature/air amount characteristic B of the other air valves shown in the figure.

As a result, it is possible to reliably prevent the engine from running out of control, that is, from a sudden increase in the engine speed in the event that the control section 32 fails and the idle speed control valve 30 becomes fully open, thereby improving safety. be able to.

In addition, by making it possible to reduce the variation in the engine starting air amount when the air amount of the air valve with the temperature/air amount characteristic B of other air valves is large, that is, when the engine water temperature is low, it is possible to achieve a good start, This can improve startability.

Furthermore, in the case of extremely low temperatures, it is possible to easily increase the air volume of the air valve in accordance with the temperature/air volume characteristic B of other air valves, and it is also possible to match the desired required characteristics, thereby improving usability. I can do it.

Furthermore, since there is no need to provide any other air valve in controlling the idle speed, the configuration is simplified, manufacturing is easy, and costs can be reduced, which is also economically advantageous.

Furthermore, by stabilizing the warm-up rotational state, it becomes possible to set the rotational speed during warm-up to a low value, which is advantageous in practice, as noise can be reduced and fuel efficiency improved.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made.

For example, in the embodiment of the present invention, the air regulator and the idle speed control valve are sequentially arranged in series from the upstream side in the middle of the bypass passage.
It is also possible to use the air regulator and idle speed control valve by changing their arrangement order.

[Effects of the Invention] As explained in detail above, according to the present invention, the air cleaner, the throttle valve, and the engine body are arranged in series, and a bypass passage is provided to bypass the throttle valve and supply air to the engine. In addition to installing an air regulator that opens and closes depending on the intake pipe pressure,
An idle speed control valve that controls the idle speed to a target speed is provided, a control section that controls opening and closing of the idle speed control valve is provided, and the air regulator and the idle speed control valve are placed in the middle of the bypass passage. Since they are arranged in series, it is possible to reliably prevent the engine speed from increasing rapidly even if the control section fails and the idle speed control valve becomes fully open, improving safety. obtain. In addition, by making it possible to reduce variations in the amount of air at engine startup when the air amount of other air valves, temperature, and air volume is large, that is, when the engine water temperature is low, it is possible to achieve a good start.
This can improve startability.

Furthermore, it is possible to easily increase the air volume of the air valve compared to the temperature and air volume characteristics of other air valves at extremely low temperatures, and it is possible to match the desired required characteristics,
Usability can be improved. Furthermore, since there is no need to provide any other air valve in controlling the idle speed, the configuration is simplified, manufacturing is easy, and the cost can be reduced, which is advantageous economically. Furthermore, by stabilizing the warm-up rotational state, it becomes possible to set the rotational speed during warm-up to a low value, which is advantageous in practice, as noise can be reduced and fuel efficiency improved.

[Brief explanation of drawings]

1 to 3 show embodiments of the present invention, FIG. 1 is a block diagram of an idle speed control device, FIG. 2 is a schematic diagram of the idle speed control device, and FIG. 3 is a diagram showing the relationship between air volume and engine water temperature. FIG. 4.5 shows the prior art of the present invention, FIG. 4 is a block diagram of an idle speed control device, and FIG. 5 is a diagram showing the relationship between air amount and engine water temperature. In the figure, 2 is the engine body, 4 is the air cleaner, and 6 is the engine body.
1 is a throttle body, 8 is a body intake passage, 10 is a fuel injection valve, 12 is a throttle valve, 14 is an intake manifold, 16 is a manifold intake passage, 18 is an intake port, 2
0 is the combustion chamber, 22 is the exhaust manifold, 24 is the manifold exhaust passage, 26 is the exhaust passage, 28 is the air regulator, 30 is the idle speed control (ISO
) valve, 32 is a control section. patent

Claims (1)

[Claims] 1. In an idle rotation speed control device that controls the idle rotation speed using a detected value of the driving state of the engine as a feedback control value, an air cleaner, a throttle valve, and an engine body are arranged in series, and the throttle valve is bypassed. A bypass passage for supplying air to the engine is provided, an air regulator is provided that opens and closes depending on intake pipe pressure, and an idle speed control valve is provided to control the idle speed to a target speed. An idle speed control device comprising: a control section for controlling opening and closing of the air regulator; and the air regulator and the idle speed control valve are sequentially arranged in series in the middle of the bypass passage.