JPS61286533A - Operating state detecting device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable accurate detection of the operating state of an engine for a long time, by a method wherein a pressure detector is connected to the actuating system of a butterfly valve for control of a suction air amount, and a rotating actuating amount of the valve is fetched as a voltage signal by a pressure detector. CONSTITUTION:An accelerator pedal 19, pivotally supported around a fulcrum 20, having the one end which is on the side opposite to a pedalling surface 19a and to which a return spring 21 is stretched, and the other end to which one end 4a of an accelerator wire 4 is bonded. The other end of the accelerator wire 4 is bonded to a pulley 5 on the valve stem of a butterfly valve situated in a feed air pipe 1. With this constitution, a tension sensor 22 is located to the middle of the accelerator wire 4. The tension sensor 22 is formed such that a piezo-electric element 24 is located between insulating terminal members 25 and 26 contained in a housing 23, and this enables detection of a tensile force exerted on the accelerator sensor 4, e.g., a power value exerted on the valve stem.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an operating state detection device for an internal combustion engine, particularly an internal combustion engine installed in an automobile.

[Conventional technology]

The driving states of a car are idle, acceleration, and constant speed.

It can be divided into various states of deceleration. Conventionally, in order to detect each of these operating conditions, a variable resistor is generally connected to the valve shaft of a butterfly valve installed in the intake pipe of an on-vehicle internal combustion engine.

An idle switch is installed and placed on the stopper of the same valve shaft, and the main conditions are the resistance value obtained according to the valve opening of the variable resistor and the opening/closing of the idle switch, and the auxiliary conditions are the engine speed etc. I am trying to detect it as .

In other words, the idle state can be detected from the fact that the idle switch is closed and the vehicle speed signal is zero, and the strength of the acceleration state can be detected by the time change in the resistance value of a variable resistor. The condition can be detected by the load condition of constant speed running based on the resistance value of the variable resistor and the engine speed, and the deceleration condition can be detected by the idle switch being closed and the vehicle speed signal being at a value. Therefore, it can be detected.

FIGS. 7 to 9 show an outline of the configuration of such a conventional device. In each of these figures, reference numeral 1 indicates an intake pipe that constitutes the fuel supply system for an on-vehicle internal combustion engine, and 2 indicates a valve shaft of a butterfly valve 3 disposed within this intake pipe 1, with the end of the shaft taken out outside. As is well known, in order to increase the output of the engine, the accelerator wire 4 is connected via the accelerator wheel 5, and a return spring B is provided between the shaft lever 2a protruding from the coaxial portion and the pipe wall. is interposed, and the coaxial lever 2a is brought into contact with the stopper pin 7 protruding from the pipe wall by the elastic force of the spring, so that the butterfly valve 3 can be selectively set to the minimum opening degree.

Reference numeral 8 denotes a variable resistor connected to one end of the valve shaft 2 taken out from the outside, and an operating lever 9 at the coaxial end. It is composed of a resistance piece 11 that presses the contactor 10 at the tip of this lever, and a cover 12 that covers these, and when the valve shaft 2 rotates with accelerator operation, the rotation angle of the valve shaft 2 changes, and thus the butterfly valve 3 can be detected as a change in the resistance value of the resistor piece 11.

Further, reference numeral 13 denotes an idle switch connected to the other shaft end taken out from the outside of the valve shaft 2, and a movable contact 14 attached to the tip of the shaft lever 2a via an insulating material 15. The fixed contact 1B is attached to the stopper bottle 7 and moves the movable contact 14 into and out of contact with the fixed contact 1B, and when both of these contacts 14 and 18 are closed, that is, in this state, the butterfly/<lub 3 is at its minimum opening degree. It is now possible to detect when the vehicle is idling or decelerating.

In addition, in FIG. 7, 17 is a fuel injection valve disposed upstream of the butterfly valve 3 in this case.

Therefore, in the case of the device configuration in the conventional example, when the engine is in an idle state, the accelerator wire 4 is not pulled, and both contacts 14 of the idle switch 13. ift is closed, the butterfly valve 3 is held at the minimum opening degree, the vehicle speed signal is also zero, and the output of the variable resistor 8 also shows the minimum resistance value.

Then, when the driver steps on the accelerator, the accelerator wire 4
is towed, the butterfly valve 3 is gradually opened, and the resistance value of the variable resistor 8 increases, so that the opening degree of the butterfly valve 3 is detected, and at the same time, the idle switch 13 is also opened and the engine is turned off. is in the operating state, and since the resistance value output of the variable resistor 8, that is, the opening angle of the butterfly valve 3, represents the intake air amount of the engine, this output value is input into the computer, The amount of fuel corresponding to the opening angle is injected from the fuel injection valve 17.

Furthermore, when the vehicle is traveling at a constant speed, the operating lever 9 of the variable resistor 8 is in contact with the resistance piece 11 at a fixed position, but when accelerating from this state, the valve shaft 2 is A corresponding angular velocity is generated, which can be extracted from the output of the variable resistor 8 as a change in resistance value over time. Namely.

The value of the change in resistance value over time represents the magnitude of acceleration, and this value is input into the computer to determine the acceleration increase in the amount of fuel injected from the fuel injection valve 17.

Furthermore, in the deceleration state, the traction of the accelerator wire 4 is released, and therefore both contacts 14, 18 of the idle switch 13
is closed, the butterfly valve 3 is returned to the minimum opening,
At the same time, the vehicle speed gradually decreases, and the computer detects this and determines it as deceleration, and cuts off the fuel supply to the fuel injection valve 17 to stop injection.

In the manner described above, each operating state of the vehicle, such as idling, acceleration, constant speed, and deceleration, is detected.

[Problem that the invention seeks to solve]

However, in the case of such conventional devices, an idle switch is required because the installation of a variable resistor to the butterfly valve causes variations in the resistance output value at idle due to angular errors, etc. In addition, since the device itself consists of mechanical sliding parts for the variable resistor and mechanical opening/closing contacts for the idle switch, each of these parts may develop poor sliding or resistance over long periods of use. It is easy to cause value changes and poor contact, which can lead to large errors in the fuel injection amount, which can cause problems such as worsening engine exhaust gas and causing the engine to stop when idling, so-called engine stalling. In any case, the atmosphere and environmental conditions (strong continuous vibrations) are extremely harsh, such as the engine room of a car.

When used under conditions such as high temperature and humidity, oil mist scattering, etc., there were problems such as a significant decrease in durability.

Therefore, in view of the above-mentioned conventional problems, it is an object of the present invention to eliminate the need for mechanical sliding parts and opening/closing contacts. An object of the present invention is to provide this type of internal combustion engine operating state detection device with a novel configuration.

[Means for solving problems]

In order to achieve the above object, the internal combustion engine operating state detection device according to the present invention uses a pressure detection device such as a piezoelectric element in the butterfly valve operating system instead of the variable resistor, idle switch, etc. in the conventional device. It is made by connecting and intervening vessels.

[For production]

That is, in this invention, the amount of force applied to the valve shaft during rotational movement starting from the minimum opening of the butterfly valve is measured by a pressure sensor such as a piezoelectric element connected and interposed in the butterfly valve operating system. This value can be detected and each operating state of the engine can be confirmed using this strength value as a reference.

〔Example〕

Embodiments of the operating state detection device for an internal combustion engine according to the present invention will be described in detail below with reference to FIGS. 1 to 6.

Fig. 1 is a configuration explanatory diagram showing an overview of an operating state detection device according to an embodiment, Fig. 2 is a cross-sectional view of a tension sensor using a piezoelectric element as a pressure detector, and Fig. 3 shows the output voltage and voltage of the piezoelectric element. FIG. 4 is a graph showing the relationship with the rotation angle of the butterfly valve shaft; FIG. 4 is an explanatory diagram showing the outline of another embodiment of the device; and FIGS. FIG. 3 is an explanatory diagram showing the operating mode. In each figure of these embodiments, the same reference numerals as in each figure of the conventional example indicate the same or corresponding parts.

First, in one embodiment shown in FIGS. 1 and 2, the accelerator 18 has an accelerator pedal 18 rotatably supported at a fulcrum 20, as is well known. A tread surface 19a is formed at one end, a return spring 21 is stretched at the other end, and the end 4a of the accelerator wire 4 is connected to the accelerator wire 4 as a pressure sensor. A tensile sensor 22 is interposed therebetween. The tension sensor 22 also has a housing 23 fixed to the chassis.
Piezoelectric element 2 sandwiched between insulating terminal members 25 and 26 within 3
A tensile force is applied to the accelerator wire 4 by interposing the accelerator wire 4.

Furthermore, the force value applied to the valve shaft 2 is detected, and the output voltage corresponding to this force value can be detected.

Therefore, in the configuration of this embodiment, when the accelerator pedal 19 is idle and the accelerator pedal 19 is not depressed, no tensile force is applied to the accelerator wire 4 by the return spring 21, and the output voltage of the piezoelectric element 24 is zero.

Subsequently, when the accelerator pedal 19 is depressed, a tensile force is applied to the accelerator wire 4, and the butterfly valve 3 is rotated starting from its minimum opening degree, and the valve shaft 2
The force value applied to the pedal is output as a voltage corresponding to the stepping force by the piezoelectric element 24, and each operating state of the engine can be confirmed as described above using the force value detected in this way as a reference. It is.

That is, this state is shown in FIG. 3. In the figure, the vertical axis represents the output voltage V of the piezoelectric element 24 (the horizontal axis represents the rotation angle θ4 of the valve shaft 2, and the accelerator pedal is turned at the angle θ1). 19 is depressed, and this operation causes the piezoelectric element 2 to
4 represents the state in which the output voltage has risen to V1.

In other embodiments shown in FIGS. 4 to 6, between the shaft lever 2a of the valve shaft 2 and the actuating pin 27a protruding from the accelerator wheel 27 connecting the accelerator wire 4,
Similarly to the above, the piezoelectric element 28 is interposed, and the depression operation of the accelerator pedal 19 is transmitted from the accelerator wire 4 to the actuation bin 27a of the accelerator wheel 27 via the piezoelectric element 28.
The signal is transmitted to the valve shaft 2 via the shaft lever 2a, and the same action and effect as the previous example can be obtained.

〔Effect of the invention〕

As detailed above, according to the present invention, a pressure sensor such as a piezoelectric element is connected and interposed in the operating system of the butterfly valve in place of the variable resistor, idle switch, etc. in the conventional device. Since the amount of rotational movement can be extracted as a voltage signal using this pressure sensor, it is possible to detect the force value applied to the valve shaft during rotational movement starting from the minimum opening of the butterfly valve. Using this strength value as a reference, it is possible to check various operating states of the engine together with the vehicle speed signal, etc. Also, since the idle state is detected by the output voltage from the pressure detector, it is especially difficult to use in conventional methods. Since there is no need for a separate idle switch, and there is no use of mechanical sliding parts or opening/closing contacts as in conventional systems, there is no loss in durability even in harsh atmospheres and environmental conditions, and the product can be used for a long period of time. It has the advantage of being able to obtain a stable output from the pressure detector over a long period of time, having no risk of deterioration of engine operating performance or deterioration of exhaust gas, and being extremely simple in structure and can be implemented easily and inexpensively. It has the following.

[Brief explanation of drawings]

FIG. 1 is a configuration explanatory diagram showing an overview of one embodiment of the operating state detection device according to the present invention, FIG. 2 is a sectional view of a tension sensor using a piezoelectric element as a pressure detector, and FIG. 3 is a piezoelectric element as described above. A graph showing the relationship between the output voltage of the butterfly valve and the rotation angle of the valve shaft of the butterfly valve, Fig. 4 is an explanatory diagram showing the outline of another embodiment of the device, and Figs. 5 and 6 show the same as the above pressure detector. FIG. 7 is an explanatory view showing the outline of the conventional device, and FIGS. 8 and 9 are detailed views of the main parts of the device. 1... Intake pipe that constitutes the fuel supply device, 2...
... Valve shaft, 2a ... Axis lever, 3 ... Butterfly valve, 4 ... Accelerator wire, 5, 27.
...Accelerator wheel, 6...Return spring, 7...Stow/pabin, 18...Accelerator pedal, 20...-
...Fulcrum, 21...Return spring, 22...
...Tensile sensor, 24.28...Piezoelectric element 24.2
7a... Operating pin. Agent Masuo Oiwa Figure 1 Figure 2 18 Near 7 Binon Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Procedural amendment (voluntary)

Claims (1)

[Claims] In an apparatus configuration that has a butterfly valve installed in the intake pipe of the engine to control the amount of intake air, and is adjusted so that the butterfly valve is maintained at a minimum opening degree in an idling state by the elastic force of a return spring, A pressure sensor such as a piezoelectric element is connected to and interposed in the operating system of the butterfly valve, and the pressure sensor measures the force value applied to the valve shaft during rotational movement starting from the minimum opening of the butterfly valve. 1. An operating state detection device for an internal combustion engine, characterized in that the operating state of the engine can be confirmed using the power value as a reference.