JP2827211B2 - Idling speed control valve diagnostic device - Google Patents

Description

Description: Object of the Invention [Industrial application field] The present invention relates to an idle rotation speed control valve diagnostic device for diagnosing an operation state of an idle rotation speed control valve at the time of vehicle maintenance or factory shipment. .

[Prior Art] An idle that controls the rotation speed of an internal combustion engine at idle by controlling the amount of air flowing through the throttle valve by electrically controlling the opening of an ISCV provided in a bypass passage of the throttle valve. In general, the rotation speed control device controls the idle speed so that the idle speed matches a target rotation speed set in advance according to a warm-up state of the engine or an operating condition.
The internal combustion engine is operated in an optimal state by controlling the opening of the CV.

However, if the ISCV does not operate normally due to the disconnection or short circuit of the coil of the linear solenoid valve, the sticking of the sliding spindle in the linear solenoid, or the occurrence of a stick-slip phenomenon, the idle speed control may be performed. In some cases, the internal combustion engine may run at an abnormally high speed, causing problems such as deterioration of fuel efficiency and deterioration of exhaust gas purification performance.

Therefore, while operating the internal combustion engine, it is possible to diagnose the above-described abnormality of the ISCV and perform control at the time of the abnormality.
For example, JP-A-59-25056 or JP-A-59-685
There is an idle rotation speed control device disclosed in Japanese Patent Application Publication No. 41-41.

The device disclosed in JP-A-59-25056 diagnoses the operating state of the ISCV by detecting a surge voltage generated at the time of ISCV operation. During operation, the ISCV opening degree instruction is shifted every predetermined time, and the ISCV
It is for diagnosing the operation state of the.

[Problems to be Solved by the Invention] When a vehicle or the like provided with the conventional idle speed control device as described above is inspected, maintained, and maintained at a production factory or a maintenance factory, the operating state of the ISCV is determined by the internal combustion engine. Diagnosis is based on changes in the internal combustion engine rotation speed when the air conditioner is turned on or off after the engine is started.

However, there is a problem that a vehicle without an air conditioner cannot be diagnosed by the above-described method. Also, in vehicles equipped with an air conditioner, in order to operate the air conditioner, the operator must go to the driver's seat, move between the measuring device outside the vehicle,
Alternatively, it is necessary to work with two or more workers,
There was also a problem that workability was poor.

Configuration of the Invention The present invention employs the following configuration for the purpose of solving such a problem.

[Means for Solving the Problems] That is, the gist of the present invention is to diagnose the operation state of the idle rotation speed control valve M1 at the time of vehicle maintenance or factory shipment, as exemplified in FIG. An idling rotational speed control valve diagnostic device, comprising: a diagnostic instruction input means # 2 operable by an operator in an engine room; and the idle rotational speed control valve when a diagnostic instruction is input from the diagnostic instruction input means # 2. A control device # 3 for increasing or decreasing the opening of # 1 by a predetermined amount, and a control device # 3 for controlling the idling speed control valve.

[Operation] When diagnosing the operation state of the idle rotation speed control valve # 1, the operator inputs a diagnosis instruction by operating the diagnosis instruction input means # 2 in the engine room after starting the internal combustion engine of the vehicle. . Then, the control means # 3 controls the opening of the idle rotation speed control valve # 1 to increase or decrease by a predetermined amount. A change in the rotational speed of the internal combustion engine caused by the above control is measured by an operator or a machine to determine whether the idle rotational speed control valve # 1 is operating normally. The control means # 3 is a diagnostic instruction input means # 2.
The above-described control may be started at the same time as the input of the diagnostic instruction, or the control may be started after a predetermined time has elapsed after the input of the diagnostic instruction.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a system configuration diagram of an embodiment of the present invention.
In the intake passage 11 of the engine body 10, a throttle valve
12 is provided, and the amount of air taken into the engine body 10 is controlled by controlling the opening of the throttle valve 12. A bypass passage 13 is formed so as to bypass the intake passage 11 in which the throttle valve 12 is inserted. In the bypass passage 13, an ISCV 20 is inserted. The opening of the ISCV20 is adjusted by duty control of the linear solenoid 21 forming the actuator, and the throttle valve
The amount of air taken into the engine body 10 is controlled independently of the amount of the air. Thus, the linear solenoid
A device for controlling the idle rotation speed by adjusting the opening of the ISCV 20 by using 21 has conventionally been known as a linear solenoid type idle rotation speed control device, and a detailed description thereof will be omitted.

When the amount of intake air to the engine body 10 is controlled by the throttle valve 12 or the ISCV 20, the amount of intake air is measured by an intake air amount sensor (not shown), and the amount of intake air is determined in advance according to the measured amount of intake air. Fuel is injected by the fuel injection valve 57, and the engine speed is controlled. The operation of the linear solenoid 21 and the fuel injection valve 57
The detection is controlled by a control circuit 40 as the control means # 3. Therefore, although not shown, the control circuit 40 receives various detection signals from the above-described intake air amount sensor and the like.
Therefore, when the engine is idling, when the throttle valve 12 is closed, the control circuit 40 detects the state of the throttle valve 12 by a switch provided on the throttle valve 12, controls the opening of the ISCV 20, and sets the engine speed to a predetermined target value. Can be maintained.

The compressor 31 of the air conditioner is connected to the output shaft 30 of the engine body 10 by a belt 33 via an electromagnetic clutch 32. The operation of this air conditioner is controlled by a dedicated air conditioner control device. Air conditioner controller 34
Is connected to an air conditioner switch 35 at the driver's seat, and the input / output signal line is also connected to the control circuit 40 described above.

Further, a check connector is provided in the engine room, and a T terminal 60 provided on the check connector is used as a diagnostic instruction input means # 2 when diagnosing the operation state of the ISCV in a maintenance shop or the like.

FIG. 3 is a block diagram of an electric circuit portion centering on the control circuit 40. The control circuit 40 is mainly composed of a microcomputer. As is well known, the microcomputer includes a central processing unit (CPU) 41, a random access memory (RAM) 42, a read-on memory (ROM) 43, and an I / O
The circuits 44a to 44c are connected via a bus 45, and data transfer and the like are performed via the bus 45.

An A / D converter 47 having an analog multiplexer function is connected to one I / O circuit 44a of the microcomputer, and a water temperature sensor 51 is connected to the A / D converter 47 via buffers 48a and 48b. , A detection signal from a sensor that outputs an analog signal, such as a vehicle speed sensor 52 and an intake air amount sensor (not shown). Then, the A / D converter 47 converts a detection signal from the water temperature sensor 51 and the like into a digital signal according to a command from the CPU 41, and outputs a completion signal via the I / O circuit 44a when the A / D conversion is completed. The digital signal is sent to the CPU 41 and received again by the CPU 41, and the digital signal is stored in the RAM.

The I / O circuit 44b also receives signals from sensors that output digital signals such as a throttle sensor 53, a crank angle sensor 54, and a neutral switch 55 via buffers 48c to 48g, and turns on a compressor from the air conditioner control device 34. A signal indicating an ON / OFF state, a diagnosis instruction signal due to a short circuit of the T terminal 60, and the like are input. These signals input to the I / O circuit 44b are also processed according to a command from the CPU 41.

The above-described sensors detect the following values and states, respectively.
The water temperature sensor 51 is a cooling water temperature of the engine body 10, a vehicle speed sensor.
Reference numeral 52 denotes a vehicle speed, a throttle sensor 53 detects an opening of the throttle valve 12, and a crank angle sensor 54 detects a rotation angle of a crank of the engine body 10, and generates a signal corresponding to each value. The neutral switch 55 is provided on the transmission and is turned on when the gear position is in a neutral position (including a parking position in the case of an automatic transmission). Note that the signal from the crank angle sensor 54 is sent to the CPU 41 and then used for calculating the engine speed.

Further, the I / O circuit 44c has a free-run counter, a register, and the like, and the fuel injection valve 5 is provided via drive circuits 49a and 49b.
7. The linear solenoid 21 is connected. And CPU
The register 41 receives data on the valve opening time of the combustion injection valve 57 or the energization time of the linear solenoid 21 from the register 41, and compares the value of the register with the value of the free-run counter to form a valve opening signal or an energization signal. The valve opening signal and the energization signal are supplied to the fuel injection valve 57 and the linear solenoid 21 via the drive circuits 49a and 49b. In addition, I /
The O circuit 44c is also connected to the air conditioner control device 34. In addition, an igniter (not shown) for generating an ignition signal is also connected to the I / O circuit 44c.

On the other hand, in the ROM 43, various programs of the microcomputer are stored, and in addition, various data, tables, and the like necessary for arithmetic processing are stored.

As described above, the program stored in the ROM 43 is interrupted and executed at every predetermined crank angle or at every predetermined time, and the program for calculating the engine speed and the signal of the fuel injection valve 57 based on the signal from each sensor are executed. A program for calculating the valve opening time and the igniter energizing time, and a program for calculating the energizing time of the linear solenoid 21 so as to maintain the engine rotational speed at the target rotational speed when the engine is idling. There is,
Since these are all publicly known, the description is omitted here. In addition to ROM43, ISCV20 during engine acceleration
(Linear solenoid 21) and air conditioner (electromagnetic clutch 3
A control program for changing the operation state of the ISCV20 (linear solenoid 21), which is executed when the diagnosis instruction signal is input when the T terminal 60 is short-circuited, in which a program relating to the control of 2) is stored. Is stored.

Next, a description will be given of a first embodiment of the present invention with reference to the drawings, with respect to a diagnostic control process of the operating state of the ISCV 20 executed by the idle speed control device having the above-described configuration.

The operation diagnosis processing of the ISCV 20 of this embodiment is executed according to the procedure shown in the flowchart of FIG. This routine is executed every predetermined time after the engine is started.

When the internal combustion engine is started and the control process is started,
Whether the T terminal 60 is short-circuited in step 100,
It is determined whether a diagnosis instruction has been input. T terminal 60
Until is short-circuited, the determination in step 100 is negative and the process is temporarily terminated, and then the process of this step is repeated at predetermined time intervals. If the T terminal 60 is short-circuited by the operator, the determination in step 100 is affirmative, and the process proceeds to step 110. In step 110, it is determined whether the neutral switch 55 is on. The process of this step is
This process is necessary for AT vehicles and is intended to prevent the vehicle from starting during diagnosis. Therefore, this processing need not be performed for MT vehicles. Neutral switch
If 55 is not turned on, the process is temporarily terminated, and the process returns to step 100 again. On the other hand, if the neutral switch 55 is on, that is, the vehicle does not start moving when the gear position is neutral or parking,
In this step, the determination is affirmative, and the process proceeds to step 120. In step 120, a corresponding pulse duty ratio control signal is output via the drive circuit 49b so as to increase the opening of the ISCV 20 by a predetermined amount, and the opening of the linear solenoid 21 is instructed. Here, the processing of this step is executed only once when the affirmative judgment is made in steps 100 and 110 for the first time. Thereafter, the process proceeds to step 130, and the processes of steps 100, 110, and 130 described above are repeated until a predetermined time t1 has elapsed after the T terminal 60 is short-circuited. After the lapse of the predetermined time t1, step 13
If the determination is 0, the determination is affirmative, and the routine proceeds to step 140, where an opening instruction is output to the linear solenoid 21 via the drive circuit 49b so as to decrease the opening of the ISCV 20 by the amount increased in step 120, and the process ends.

This process is executed only once after the T terminal 60 is short-circuited, and the change in the engine rotation speed accompanying the above-described process is measured by, for example, an oscillograph or the like. By measuring changes in sound
Diagnosis of the operating status of ISCV20 can be performed.

Next, a change in the opening degree of the ISCV 20 and a change in the engine speed due to the above-described processing will be described with reference to the timing chart of FIG. Incidentally, the dotted line in the figure shows the case where the T terminal 60 is short-circuited in the conventional device.

First, when the internal combustion engine is started, the engine speed is reduced to E0.
, The ISCV 20 is set to the opening α0 by the ISC feedback control. Subsequently, when the T terminal 60 is short-circuited at the time T0, the ISCV
The opening of 20 is increased by a predetermined amount Δα1 irrespective of the ISC feedback control. As a result, the engine speed increases to E1. Thereafter, the opening of the ISCV 20 is decreased by a predetermined amount Δα2 by the ISC feedback control so as to maintain the target rotation speed E0. In this embodiment, the ISC feedback control is executed once during the predetermined time t1, and the ISCV20
The opening is reduced by Δα2. Thereafter, a predetermined time t1 elapses (step 130), and when the time reaches time T1, the opening is decreased by the amount of opening Δα1 increased at time T0 regardless of the ISC feedback control of the ISCV 20 (step 140).
Here, the ISCV opening is already reduced by Δα2 at the time T1 by the ISC feedback control during the predetermined time t1 as shown in the figure, and the initial ignition timing is adjusted by short-circuiting the T terminal 60. Therefore, the engine rotation speed temporarily drops to E4 as shown in the figure. Thereafter, the opening degree of the ISCV 20 is increased by a predetermined amount Δα2 by the ISC feedback control in order to return the engine rotation speed to the original target rotation speed E0, and the opening degree α1 is reached, and the engine rotation speed returns to E0. The reason why the opening of the ISCV 20 for maintaining the target rotational speed E0 before and after the short-circuit of the T terminal 60 is different is that the initial ignition timing of the internal combustion engine is adjusted by the short-circuit of the T terminal 60, and the ISCV 20 corresponding to the target rotational speed E0 is opened. This is because the degree is changed. As shown in the drawing, the engine rotation speed after time T1 sequentially changes to E4, E3, and E0 with the stepwise change of the ISCV 20 by the ISC feedback control.

Next, a second embodiment will be described with reference to FIGS.

The control processing procedure of the present embodiment is mostly the same as that of the first embodiment, and the steps for executing the same processing are indicated by (step number +100 of the first embodiment). The feature of this embodiment is that the processing of step 215 is added, and the step 215 prevents the processing of step 220 from being executed until a predetermined time t2 has elapsed after the T terminal 60 is short-circuited. is there. By adding this process, as shown in FIG. 7, the process of step 220 is performed at time T2 after the initial ignition timing is adjusted by the short circuit of the T terminal 60 and the engine speed is stabilized by the ISC feedback control. Executed. As a result, in the process of step 220, the engine rotational speed can be increased to E1 as in the first embodiment with Δα3 smaller than Δα1 of the first embodiment as the opening increment of the ISCV20, and the opening of the ISCV20 is reduced at time T3. (Step 24
0), the change in the amount of air flowing into the engine body 10 becomes small, and the ISC feedback control accompanying the adjustment of the initial ignition timing has already been performed during the predetermined time t2, as shown in FIG. A large undershoot E4 can be prevented.

Step 140 in the first embodiment and step 140 in the second embodiment
In the process of 240, the undershoot can be reduced by gradually reducing the opening of the ISCV20.

According to the above embodiment, the operation diagnosis of the ISCV can be easily executed even in a vehicle not equipped with an air conditioner. Further, since the operator does not need to operate the air conditioner switch in the vehicle, the operation can be easily performed by one person, and workability is greatly improved. Further, in the second embodiment, since the operation check is performed after the idling rotational speed is stabilized by the ISC feedback control, the reliability of the measured value is increased, and the load on the engine due to the diagnostic work is reduced. Furthermore, by reducing the opening degree of the ISCV 20 increased in Steps 120 and 220 after a lapse of a predetermined time (Steps 140 and 240), the control of the internal combustion engine thereafter can be executed smoothly.

Although the two embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various embodiments can be adopted without departing from the gist of the present invention.

For example, by performing a change in the opening degree of the ISCV20 in a stepwise manner and measuring a change in the engine rotational speed accompanying the stepwise change, it is diagnosed whether all the opening states of the ISCV20 are correctly executed. It may be a thing. The diagnostic instruction input means may use a check terminal or the like which is conventionally mounted, or may be newly provided with a dedicated one. Further, control may be performed such that the opening degree of the ISCV 20 is reduced as the processing of steps 120 and 220. Further, the ISCV operation processing routine may be started by a hard interruption due to a short circuit of the T terminal 60. Note that T
If terminal 60 is shorted (steps 100, 200), ISCV
Until the operation diagnosis processing is completed, the ISC feedback control may be prohibited. In this case, for example, since the ISC feedback control between times T2 and T3 as shown in FIG. It is possible to prevent an undershoot of the engine speed when the opening of the ISCV20 decreases after the passage of T3. Further, the ISCV 20 may be driven by a step motor. Further, for example, in FIG. 5, at time T0, the opening of the ISCV 20 is increased by Δα1, and
By rewriting the stored value of the ISCV opening in the C feedback control to the actual opening (α1 + Δα1), the ISCV opening is repeated so as to reach the target rotation speed E0 without performing the processing of step 130 and thereafter. Is reduced. Similarly, at time T1 in FIG. 5, the stored value of the ISCV opening in the ISC feedback control is changed to the actual opening (α1 + Δ
α1−Δα2).

According to the present invention, it is possible to easily and easily diagnose the operating state of the ISCV even in a vehicle not equipped with an air conditioner. Further, it is not necessary to operate the air conditioner switch in the vehicle for the diagnosis work, and even a single worker can easily execute the diagnosis work, thereby improving workability.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the configuration of the present invention, FIG. 2 is a block diagram of a main part of the embodiment, FIG. 3 is a block diagram of a control circuit thereof, and FIG. FIG. 5 is a timing chart illustrating changes in the ISCV opening and the engine rotation speed when the control processing is executed. FIG. 6 is a flowchart illustrating a control processing procedure in the second embodiment. Is the ISCV when the control process was executed
4 is a timing chart illustrating changes in the opening degree and the engine rotation speed. Μ1 ... Idle rotation speed control valve Μ2 ... Diagnostic instruction input means, Μ3 ... Control means 10 ... Engine body, 20 ... ISCV 21 ... Linear solenoid 34 ... Air conditioner control device 35 ... Air conditioner switch, 40 ... ... Control circuit 60 ... T terminal

Claims (1)

(57) [Claims] 1. An idle speed control valve diagnostic device for diagnosing an operation state of an idle speed control valve at the time of vehicle maintenance or shipment from a factory, wherein a diagnostic instruction input operable by an operator in an engine room. Means for controlling the opening of the idle speed control valve to increase or decrease the opening of the idle speed control valve by a predetermined amount when a diagnostic instruction is input from the diagnostic instruction input means. Valve diagnostic device.