JPS6189951A - Control system for idle rotational speed of engine - Google Patents

Abstract

PURPOSE:To prevent breathing spell of an engine and an engine stall by providing a feedback control means which controls positions of movement of an actuator for an opening adjustment mechanism and further providing a wrong operation preventive means which stops or returns said mechanism at a specific time. CONSTITUTION:A feedback control means 9 controls positions of movement of an actuator 14 for an opening adjustment mechanism 7 so as to bring an engine rotational speed close to a target idle rotational speed. In case of confirming that the engine rotational speed is not changed to the direction of control regardless of the lapse of a definite time after the feedback control means 9 puts the opening adjustment mechanism 7 in operation, the wrong operation preventive means 10 either stops said mechanism 7 at its position or returns the mechanism to a position of operation before the lapse of the definite time. Thus, breathing spell of the engine and engine stall can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of Industry The present invention relates to an idle rotation speed control system mainly applied to automobile engines.

[Conventional technology] Recent eyes! HV engines incorporate various systems to improve fuel economy, and many employ an idle rotation control system as one of them.

As a prior art related to this type of control system, for example, there is one disclosed in Japanese Patent Application No. 135522/1982. That is, this engine rotational speed control system includes a rotational speed detection means for detecting the engine rotational speed, and an actuator that locks the rotating part of the throttle valve that returns to the closing direction by itself. an opening adjustment mechanism that adjusts the closing position of the slow 2 torque valve by moving a child forward and backward; An idle switch that has a movable contact that recedes bonyly and switches the retracted movable contact into a conductive state by bringing it into elastic contact with a stationary contact.

In the operating range in which the idle switch is maintained in a conductive state, the operating element ii is under the control of the opening adjustment mechanism so that the engine rotation speed detected by the rotation detection means converges to the target rotation speed. and feedback control means for controlling the road position. The target rotational speed is updated in accordance with the engine cooling water temperature, so that the idle rotational speed can be stably maintained at the lowest possible value within a range that does not cause engine stall.

However, with just this, a problem may arise in which the alignment of the side pieces is impaired due to the so-called play of the idle switch.

Figure 4 is a theory to specifically explain this problem! E! 1 in the figure is a carburetor of an automobile gasoline engine,
2 is the throttle valve of this carburetor L, 3 is the rotating part of this slow and dollar valve 2, and 4 is the throttle valve 2.
A spring 5 biases the throttle valve in the closing direction, and 5 is an accelerator pedal that biases the throttle valve in the opening direction via a wire 6. 7 is the opening degree tJR Tachibana that engages the rotating part 3 of the throttle valve 2 to adjust the closing + L position of the throttle valve 2, and 8 is related to this opening degree so-called tJ machine @7. This is an idle switch installed.

The opening adjustment mechanism 7 includes a feed screw portion 13 provided on the output shaft 12 of the DC motor 11, and a bagner,
The *goc motor 11 is actuated by a signal from the feed control means, and the rotation is stopped by a guide member (not shown). The actuator 14 is screwed back and forth in the axial direction. Then, the idle switch 8 is opened at #opening degree 2! l! ! Actuator 1 of rj mechanism 7
4 has a 6F moving contact 15 that elastically retreats in response to the contact pushing force of 7 when the rotating portion 3 contacts 6, and the retreated movable contact 15 also makes 811 contact with the stationary contact 16. It is designed to switch to a conductive state. Physically, the DC
The output @12 of the motor 11 is supported so that it can freely move in the axial direction within a certain range, and is elastically biased in the forward direction with a weak force, and then connected to the output shaft 3 via the insulating member 17. The movable contact 15 is held, and the stationary contact 16 is supported by a medium housing 18 with a constant current of 1 gA. Therefore, when the rotating part 3 of the throttle valve 2 of the carburetor 1 is separated from the actuator 14, the switch 8 moves the output shaft 12 to the forward position I! (a), and the movable contact 15 is separated from the stationary contact 16, so it is maintained in a non-conducting state (see Figure 1a).
When the rotary part 3 comes into contact with the actuator 14 and the output shaft 12 is pushed back at the retracted position (b) 11 by the contact pushing force, the movable contact 15 contacts the stationary contact 16 and Ji ! It is designed to change yJ to 1 state (No. S''
Figure C pot! J! ), By the way, in such a structure, in order to ensure the contact pressure between the movable contact 15 and the stationary contact 16 and maintain a reliable conductive state, the output +Ii! The movable contact work 5 and the stationary contact 16 are set to start contacting each other while the movable contact 5 and the stationary contact 16 are moving back from the forward position (A) to the retracted position (B) (°C), and after contact, Furthermore, an appropriate contact pressure can be ensured in a state in which the output shaft 12 is retracted while deforming the #i contact 16ta.

However, with such a system, a problem arises when, for example, the accelerator pedal 5 is depressed within the range from the idling state (see C' in FIG. 5) to the idle state.

In other words, if you lightly put your foot on the accelerator pedal 5 from an idling state, the slow/ ) Le Parve 2
will open up a little, and the engine speed will increase a little. At this time, if the throttle (!34) of the t-shib 2 is small and the operating amount of the middle moving part 3 is less than the above-mentioned free play (in the case of w!IJ1 state with C in Figure 1), In this case, the idle switch 8 is maintained in a conductive state, and the opening A node means 7 is still under the control of the first stage feedback control AA#. However, when it rises.

The feedback control hand E1 erroneously determines that the idle speed has naturally increased, and sends a signal τ to the opening adjustment means 7 indicating that the idle speed should be lowered.
A signal indicating that the actuator 14 should be moved backward is output. therefore.

If you release your foot from the accelerator pedal 5 from the state shown in step 7, the actuator 14 will have moved back to an unexpected position, and the throttle valve 2 will momentarily close too much, causing the engine to rotate. This causes the inconvenience that the system may become temporarily malfunctioning or simply stop working.

[Problems to be solved by the invention] The present invention was made with a focus on such hidden circumstances.
The purpose of this invention is to reliably eliminate N7 during which the consistency of control is impaired due to the so-called play of the idle switch.

[Means for Solving the Problems] In order to achieve such an object, the present invention provides a rotary intake detection hand yt (26) for detecting the engine rotation speed, and a closing direction Rotating part (3) of the throttle valve (2) that self-returns to t-locking actuator (1)
4) to advance the actuator (14)! ! Opening degree ml to adjust the closing position of the help (2)
l! mechanism (7) and the actuator (
14) has a movable contact (15) that moves elastically in response to the contact pushing force when the rotating part (3) comes into contact with the rotating part (3). ), and the opening adjustment mechanism (7) is controlled and controlled in the operating amount range in which the idle switch (8) is maintained in the conductive state. The operating element (
14) feedback control means (
9) and the engine speed detected by the rotation speed detection means (26) even after a certain period of time has elapsed after the feed control means (9) activated the WJ mechanism (7). A malfunction prevention means (lO) that stops the opening adjustment bridge (7) at that position or returns it to the operating position before the elapse of a certain period of time when it is confirmed that the rotation speed does not change in the control direction. It is characterized by being made up of 11.

According to this means, when the rotational speed of the engine slightly increases from the fitting state due to placing your foot on the accelerator pedal, etc., the feedback η control means (9) first changes the opening degree adjusting means (7). ), a signal indicating that the idle speed should be lowered is output, and the actuator (14) is moved backward. However, if the engine speed is hH due to placing one foot on the ground, etc., the engine speed may change even if the actuator (14) is moved to change the closing position of the throttle valve (2). The amount by which the engine rotation speed detected by the rotation speed detection means (7) does not change in the control direction even after a certain period of time has elapsed since the output of the signal is defined as the malfunction. If the prevention means (10) confirms I, the feedback control is temporarily stopped and the opening adjustment mechanism (7) is stopped on the spot or returned to the operating position before the elapse of the certain period of time. . Therefore, when the footrest, etc. is released and the throttle valve returns to its original position, the throttle valve (2)
The actuator (14) of the engine speed adjustment means (7) locks the engine at a proper position, and problems such as engine start-up and engine stall do not occur.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

Note that the same reference numerals are given to the same or corresponding parts as those shown in FIG. 4, and the explanation thereof will be omitted.

This system is similar to that shown in Figure 8g4.

[It is applied to a 39-ton engine. In the figure, 1 is a carburetor, 2 is a throttle valve, and 3 is a rotating part of the throttle valve 2. 0 The rotating part 3 is a lever-like object that is connected to the throttle valve body. It rotates together with the support shaft 2b that supports the support shaft 2a. Also, 7 is the opening level! ! ! ! The DC motor 11 of the opening adjustment mechanism 7 is driven by applying a DC voltage in a pulsed manner. Then, the output shaft 12 is moved a certain distance a', ! in the axial direction with respect to the nationally specified frame 18 (a distance corresponding to the distance from the road position to the backward position). It is held in such a way that it can move forward, and is attached to the front (towards the center) by a spring (not shown) that is much weaker than the spring 4. Additionally, an actuator 14 screwed onto this output shaft 12
is comprised of a cylindrical main body @1% 14m screwed into the 12 threaded parts 13 of the output shaft, and a pressure receiving part 14b press-fitted into the tip of this main body part 14a, and this pressure receiving part 14
The rotation m3 is locked at the tip of b.

and a protrusion 14C protruding from the main body portion 14a for external use.
is fitted into a slide hole (not shown) provided in an axial groove (not shown) provided in a cover attached to the Ifi'7 surface of the fixed frame 18, and rotated by 4f. 't. Reference numeral 21 denotes a microcomputer system for controlling the opening gR joint mechanism 7, and serves as a feedback control means and malfunction prevention means. This bicycle computer stem 21 has a central H calculation processing unit (C
PU) 22, memory 23, and interface 24.2
5 and X@. Then, the interface 2
4, a signal from the idle switch 8, a signal b from the rotation speed output means 26, a signal C from the transmission state detection hand 27, a signal d from the water temperature sensor 28, and a signal e from the vehicle speed sensor 29, respectively. As well as being manually operated, the opening from the interface 25! A driving signal f is outputted to the f adjustment means 7. The idle switch 8 includes an insulating member 17 fixed to the output shaft 12.
5 and a stationary contact 16 supported by a fixed frame 18, and has exactly the same structure as that shown in FIGS. 4 and 5. . Further, the rotation speed detection means 26 is for detecting the rotation speed of the engine, and uses, for example, an ignition pulse. 3! Ta. The power transmission condition detection device 27 is for detecting whether or not the power transmission state between the engine and the drive wheels is disconnected.
・This corresponds to Ralsuinnah, etc., which is switched when John is shifted to the neutral position. The water temperature sensor 28 is used to detect the engine cooling water temperature. For example, the water temperature sensor 28 includes a thermistor that converts the water temperature into an analog electrical signal, and an A/Df converter that converts the output of this thermistor into a digital electrical signal. It will be punished.

The microcomputer system is programmed to operate according to the procedure schematically shown in FIG. First, in step 51, each signal color b, c, d, e from the idle switch 81 rotation speed detection means 26, transmission type detection means 27, water temperature sensor 28, and vehicle speed sensor 29 at a specific time is detected. input.

Also, in step 52, it is determined whether the engine is started. This means that the engine rotation speed detected by the rotation speed detection means 26 is, for example, 500.
The determination is made based on whether or not the speed exceeds the rpm. Further, in step 53, it is determined whether or not the idle switch 8 is in the conductive state 1 (ON), and in step 54,
Is the heavy speed detected by the vehicle speed sensor 29, for example, 2.
Step 5
In step 5, it is determined whether the transmission system is in non-transmission:)X=.

Then, when all the conditions in each of these steps 52 to 55 are satisfied, the process goes to step 56 for 4 lines, and @
If any of the conditions listed above is not satisfied, the process returns to step 51 and repeats the same procedure at a different time. If the process moves to step 56, the engine cooling water temperature detected by the water temperature sensor 28 is determined. Target idle rotation F of the value according to! Nt is stored in the memory 23 and is recovered from a table. Then, in step 57, the target engine rotation shell N1 and the actual engine rotation speed N detected by the rotation speed detection means 26 are determined.
Compare with 1. As a result, the actual engine rotation a N
1 and the reference idle speed N, is the allowable 1
1111 (for example, ±20 rpm).

Sue P- because there is no need to operate the control mechanism 7.
2 Return to step 51, change the point in time and repeat the same procedure,
On the other hand, the actual engine speed N! If the difference between the target idle rotation speed Nl and the target idle rotation speed Nl exceeds the permissible value, the process proceeds to step 58. Degree adjustment means 7
A command is issued to apply a voltage equivalent to 1 pulse to the DC motor 11 of
If it is higher than the target idle rotation speed N1, the motor 11 is operated by one pulse in the direction in which #i marked moving element 14 retreats, and the actual engine rotation aN1 is higher than the target idle rotation speed N. In the low case, the actuator 1
4 operates the motor 11 in the forward direction. After operating the DC motor 11 at opening airi stage 7 in this way for one pulse, step 5
Step 9 waits until a certain period of time (for example, one second) has elapsed, and then, in step 60, new information from the rotation detecting means 26 is input. Then, in Step 1, it is determined whether the engine rotation speed N1 detected by the rotation speed detection means 26 has changed in the control direction.

As a result, if it is confirmed that the engine speed Nt has changed in the control direction, it is determined that normal feedback control is being performed, and the process returns to step 51 to repeat the same procedure. If it is confirmed that the rotation speed N1 is not changing in the control direction, that is,
Even though the DC motor 11 is operated in the direction in which the actuator 14 moves backward, the engine rotation speed N1 detected after the motor is activated is only an appropriate value compared to the engine rotation speed Nt detected before the motor is activated. If it is confirmed that the melon has not been lowered, it is determined that normal feedback control is not being performed, and the process proceeds to step 62. Step 6
In Step 2, a command is output to operate the DC motor 11 of the opening adjustment means 7 by one pulse in the direction opposite to the direction in which it was operated in Step 58, and then the process returns to Step 51.

With such a configuration, normally steps 51 to 57→51 or steps 51 to 61→51
This procedure is repeated, and normal feedback control is performed to maintain the idle speed within an appropriate range depending on the water temperature. On the other hand, in the range in which the idle switch 8 does not switch to a non-conducting state (instead of play), such as when the driver lightly places his foot on the accelerator pedal 5,
When the throttle valve 2 is slightly opened, the engine speed increases without releasing the feedback control described above, so the process moves from step 57 to step 58, and the DC motor 58 of the opening adjustment means 7 is activated. child 14
is driven by one pulse in the direction of retracting. However, in this case, the throttle valve 2 is opened by pressing the accelerator pedal 5, so even if the motor 11 is operated and the actuator 14 is moved backward, the throttle valve 2 will not follow the control. When the engine is closed, the engine speed will not change in the downward direction.
Therefore, in this case, the process moves from step 1 to step 62, and the motor 11
4 is reversely driven by one pulse in the direction of advancing. Then, while the accelerator pedal continues to be depressed slightly, the control is repeated in the order of steps 5.1 to 62→51. Therefore, no matter at what point the accelerator pedal 5 is released, the actuator 14 is waiting at the appropriate position, which may cause temporary engine malfunction or engine stall. No inconvenience will occur.

In the above embodiment, when it is confirmed that the engine rotation speed detected by the rotation speed detection means does not change in the control direction even after a certain period of time has elapsed after operating the opening adjustment Wi mechanism, Said opening degree 3Rf! Although a case has been described in which the Ta mechanism is returned to the operating position before the elapse of a certain period of time, the present invention is not necessarily limited to such a case; for example, the opening adjustment mechanism is may be stopped at the operating position.

[Effects of the Invention] Since the present invention has the above configuration, the following effects can be obtained.

First, when feedback control is being performed on the idle speed, if the engine speed cannot follow the control and change, the feedback movement of the actuator at the opening of 21!412 may temporarily change. This prevents the control integrity from being compromised due to so-called play in the idle switch, i.e. the engine does not breathe when the foot is released from the accelerator pedal. This can reliably eliminate inconveniences such as starting or stopping.

In addition, since the carrot rotation speed, which is the final target of control, is directly detected and the feedback control and malfunction prevention control are performed based on the detection, it is possible to perform control by detecting indirect factors. Control with high precision compared to
It is rrti. Therefore.

Economical driving is possible by setting the idle speed to the lowest possible value without causing discomfort to the driver or causing engine stall.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram for clearly explaining the present invention. FIG. 2 is a schematic configuration explanatory diagram showing one embodiment of the present invention;
The figure is an explanatory diagram for explaining the control procedure in the same embodiment, Fig. 4 is a schematic configuration explanatory diagram showing a conventional example, and Figs. 5 a and b.
, c are operation explanatory diagrams of the conventional example. 1... Carburetor 2... Φ throttle valve 3, life, rotation part 7, fist, opening adjustment means 8, idle switch 9... feedback control means 10, fist malfunction prevention means 11-...・DC motor 12...-Output shaft 15...Movable contact lε Medium ・Static 11+Contact 21...Microcomputer 26・Fist・Rotation speed detection means

Claims (1)

[Claims] It has a rotational speed detection means for detecting the rotational speed of the engine, and an actuator that locks a rotating part of the throttle valve that returns to the closing direction by itself, and moves the actuator forward and backward to determine the closed position of the throttle valve. an opening adjustment mechanism to be adjusted; and a movable contact that moves elastically in response to the contact pushing force when the rotary part contacts an actuator of the opening adjustment mechanism, and the moved movable contact an idle switch that is brought into elastic contact with a stationary contact to switch to a conductive state; and in an operating range where the idle switch is maintained in a conductive state, the opening adjustment mechanism is controlled and detected by the rotation detection means. feedback control means for controlling the forward and backward positions of the actuator so that the engine speed approaches a target rotation speed; malfunction prevention means for stopping the opening adjustment mechanism at that position or returning it to the operating position before a predetermined period of time when it is confirmed that the engine speed detected by the detection means does not change in the control direction; An engine idle speed control system comprising: