JPH0521466Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a constant speed driving control device that allows a vehicle to travel at a constant speed, and in particular, as a fail-safe function, it detects the energization state of a control valve and controls the control valve for a predetermined period of time or longer. The present invention relates to a constant speed cruise control device including an abnormality detection means that outputs an abnormality detection signal to cancel constant speed cruise control when electricity is continuously applied.

[Conventional technology]

FIG. 1 is a configuration diagram of a constant speed cruise control device equipped with a fail-safe function. 1 is a power switch for constant speed cruise control, 2 is a vehicle speed sensor that sends a vehicle speed signal to the microcomputer 5, and 3 is a constant speed cruise control device. 4 is a cancel switch, which is comprised of a brake switch, a parking switch, a clutch switch, etc., and by operating any of these switches, constant speed driving control is canceled.

CV is a control valve that opens and closes the negative pressure port and atmospheric port of the actuator (not shown) that controls the throttle valve.By energizing the solenoid installed in the actuator, the atmospheric port is closed and negative pressure is introduced into the actuator. Then, with no current applied, close the negative pressure port and introduce atmospheric air into the actuator. Then, the amount of negative pressure introduced is changed according to the time ratio of energization and de-energization (hereinafter referred to as duty ratio), and the position of the diaphragm in the actuator is controlled to control the opening degree of the throttle valve. The RV is a release valve that opens and closes the air port of the actuator. When driving at constant speed, the air port is energized and closed, and when constant speed driving control is canceled, it is de-energized and air is introduced. Reference numeral 5 denotes a microcomputer which takes in the switch signals, sensor signals, etc., performs vehicle speed calculation, duty calculation, determines switch information, and performs processing control, etc. 6 is a control valve drive circuit, and a transistor TR6 is driven by a control signal from the microcomputer 5.
Turn on and off to control the control valve CV. 7 is a release valve driving circuit, which operates a transistor TR by a control signal from the microcomputer 5.
5 and controls the release valve RV. 8 is a 100% duty detection circuit which is an abnormality detection means, and when 100% duty is detected, this detection output is sent to the microcomputer 5 and the output transistor of the release valve drive circuit 7.
Turn off TR4 and de-energize release valve RV.

Next, the operation will be explained.

When entering constant speed driving control while driving a vehicle, first turn on the constant speed driving control power switch 1, and the microcomputer 5 sends an "L" signal to the release valve drive circuit 7, turning on the transistor TR5 to release the control. The valve RV is turned on, and the vehicle speed signal from the vehicle speed sensor 2 is stored in the microcomputer 5 as a set vehicle speed. Thereafter, the duty ratio is calculated in the range of minimum value 0% and maximum value 90% based on the difference between the set vehicle speed and the actual vehicle speed, and this calculated signal is sent to the control valve drive circuit 6.
In addition to the transistor TR6, the emitter and collector are made conductive or non-conductive, and the control valve CV is repeatedly turned on and off according to the duty ratio to maintain the set vehicle speed.

In addition, the range of the duty ratio is from the minimum value 0% to
If the maximum value is set to 100%, even in normal conditions, when the duty ratio reaches 100%, the detection signal of the 100% duty detection circuit de-energizes the release valve and cancels constant speed driving, so the duty ratio is set to a range of ratios.

In this way, during normal operation, the duty ratio of the control signal applied to the control valve CV is
Although it is prohibited to reach 100%, the transistor TR6 of the control valve control circuit 6
Due to a short circuit between the emitter and collector or a failure of the microcomputer 5, etc., the duty ratio
If a 100% signal is applied to the control valve CV, the control valve CV will remain in the ON state and a sudden acceleration will occur, which is not desirable from a safety standpoint. Therefore, in such cases, it is a fail-safe function.
The 100% duty detection circuit 8 operates to cancel constant speed running control.

This 100% duty detection circuit 8 will be explained below.

When the control valve CV is in the energized state, the diode D is cut off, so the capacitor C1 is charged along the path indicated by the arrow shown by the solid line in the figure.When the control valve CV is not energized, the diode D is conductive, so the capacitor C1 is charged. C1 is discharged along the path indicated by the broken line in the figure. Therefore, during normal operation, the control valve CV is duty-controlled (with a cycle of, for example, 50 ms) and is repeatedly turned on and off, so the capacitor C1 is repeatedly charged and discharged, and the potential at the point does not exceed a certain potential, and the transistor TR1 is turned on. state remains and therefore TR
2 also remains on. However, if the duty ratio becomes 100% due to the above-mentioned failure, that is, if the ON state of the control valve CV continues for longer than the period of the duty signal, for example, 70 ms or more, the control valve CV continues to be energized and there is no discharge path for the capacitor C1. The potential at the point rises and turns off the transistor TR1. When transistor TR1 is turned off, transistors TR2 and
TR3 turns off and goes to microcomputer 5 100
The "H" signal, which is the % duty detection signal, is sent to cancel constant speed driving control, and at the same time, a signal is sent to the base of transistor TR4 to turn off transistor TR4 and turn off the release valve RV in a hardware manner. to cancel constant speed driving control. In this way, when the control valve CV is continuously energized for a predetermined time (70 ms) or more, the 100% duty detection circuit 8 is activated and the constant speed running control is stopped.

[Problem that the invention attempts to solve]

However, in the conventional constant speed cruise control device described above,
The 100% duty detection circuit does not operate when the constant speed cruise control device is operating normally.
Even if there is a malfunction, the driver will not know. Therefore, if this 100% duty detection circuit is malfunctioning and you are using the constant speed cruise control device without knowing it, the duty ratio will become 100% due to a malfunction of the transistor TR6 or the microcomputer 5, etc. However, because the duty detection circuit did not work 100%, there was a problem with safe driving, such as sudden acceleration and surprising the driver.
The present invention was developed in view of these conventional problems, and aims to improve safety by starting constant speed driving control after checking the 100% duty detection circuit.

[Means for solving problems]

Therefore, the present invention includes a control valve that introduces engine negative pressure into the chamber of the actuator that controls the opening degree of the throttle valve when it is energized and introduces atmospheric pressure when it is de-energized, and a control valve that introduces atmospheric pressure into the chamber of the actuator when it is de-energized. a release valve that introduces atmospheric pressure and shuts off the atmospheric pressure when energized; a control means that controls the control valve and the release valve to control constant-speed travel; and a control means that detects the energized state of the control valve for a predetermined time In the constant speed cruise control device comprising an abnormality detection means for canceling the constant speed cruise control by the control means by outputting an abnormality detection signal when the power is continuously energized, the constant speed cruise control device includes a check switch; is operated, the release valve is de-energized, the control valve is energized for a predetermined period of time or more, it is detected whether or not an abnormality detection signal is generated from the abnormality detection means, and when the abnormality detection signal is generated, a determination is made. This is a constant speed running control device characterized by being provided with a check means that enables speed running control.

[Function] According to the above configuration, when the check switch is turned on, the microcomputer outputs a signal to turn off the release valve and a signal to turn on the control valve, and checks whether a detection signal is returned from the 100% duty detection circuit. If it returns, constant speed driving control is enabled. At that time, since the addition/extraction valve is off, the actuator for constant speed driving control does not operate. By inspecting the vehicle in advance in this manner, it is possible to prevent sudden speed increases during operation, thereby improving safety.

[Example of idea]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a flowchart of the processing executed by the microcomputer 5 in FIG.

Since the configuration of the constant speed cruise control device shown in FIG. 1 is the same as described above, a detailed explanation will be omitted here, but the processing executed by the microcomputer 5 of the present invention will be explained using FIGS. explain.

In this embodiment, the power switch 1 also serves as a check switch, and when the power switch 1 is turned on, the microcomputer 5 is initialized (step S1), and the microcomputer 5 sends an "H" signal to the release valve drive circuit 7. is output to turn off the release valve RV, and at the same time, the control valve drive circuit 6 is outputted for a predetermined period of time or more, for example, 70ms.
An "L" signal is output (step S2), the transistor TR6 is made conductive, an on signal is applied to the control valve CV, and the process moves to step S3. in this case,
Release valve even if control valve CV is turned on.
Since the RV is turned off, the actuator does not operate because atmospheric air is introduced inside, and there is no problem with driving. In this step S3, it is determined whether a detection signal is detected from the 100% duty detection circuit 8 or not. That is, when the 100% duty detection circuit 8 is normal, the ON signal output to the control valve CV eliminates the discharge path of the capacitor C1 in the 100% duty detection circuit 8, and the point potential rises, turning off the transistor TR1. This turns off the transistor TR2, and sends an "H" signal to the microcomputer 5 to confirm that the 100% duty detection signal has returned. However, transistor TR2,
If the 100% duty detection circuit 8 is out of order due to a path failure in TR1, etc., the transistor TR2
Since the output remains "L", no detection signal is output. When a detection signal is detected in step S4, constant speed driving control is permitted. This permission is displayed, for example, by setting a predetermined flag. However, if the 100% duty detection signal is not detected in step S3, the process moves to step S5, where constant speed driving control is prohibited, and a diagnostic display (step S6) is performed.
This notifies the driver that the 100% duty detection circuit 8 is out of order. This prohibition is displayed by resetting the flag. From then on,
When the set switch is turned on, the state of this flag is detected and constant speed driving control is carried out only when it is set.

However, in the above circuit configuration, if a short-circuit failure occurs in the transistor TR5 in the release valve drive circuit 7 during the check of the 100% duty detection circuit 8, the release valve RV and control valve CV are both energized, resulting in sudden acceleration. There is a problem.

In order to solve this problem, another embodiment will be described using FIGS. 3 and 4.

In FIG. 3, the same symbols are attached to the functional parts equivalent to those in FIG. 1, and the explanation thereof will be omitted. 11 is a microcomputer, 12 is 100%
This is a duty detection circuit.

13 is the control valve CV and release valve
This is an actuator ground cut circuit that limits the current flowing through RV.When transistor TR4 is on, resistor R1 (high resistance) is shot, so sufficient current flows through release valve CV to drive each of them. . This enables constant speed running control. However, when the transistor TR4 is off, the high resistance R1 is connected in series with the release valve RV and the control valve CV, so the current value flowing through each becomes extremely small and cannot be driven. In this state, constant speed running control becomes impossible.
14 is a release valve drive circuit controlled by a release signal from the microcomputer 11 and a detection signal from the 100% duty detection circuit 12, and also controls the actuator earth cut circuit 13.

In this embodiment, the check switch is also used as the set switch 3.

Next, the operation during constant speed running will be explained.

First, when the power switch is turned on, the microcomputer 11 is initialized. When the set switch 3 is turned on in this state, a 100% duty detection circuit 12 (described later) is checked, and if normal, constant speed running control is started. That is, an "L" signal is applied from the microcomputer 11 to the base of the transistor TR5 of the release valve drive circuit 14 to turn off the transistor TR5. On the other hand, since transistor TR1 is in the on state, transistor TR
2, TR3 and TR4 are turned on and the release valve is turned on.
While turning on the RV, the vehicle speed signal from the vehicle speed sensor 2 is memorized as the set vehicle speed, and thereafter the duty ratio is calculated in the range of 0% to 90% according to the difference between the actual vehicle speed and the set vehicle speed, and this signal is The control valve CV is controlled to maintain the set vehicle speed by turning on and off the transistor TR6 and turning the control valve CV on and off repeatedly according to the duty ratio. In this case, 100% duty is prohibited as above. However, the failure (for example, transistor TR6 or microcomputer 11, etc.)
Therefore, if the control valve CV remains on for more than 70ms, the discharge path for the capacitor C1 disappears, and the point potential rises, causing the transistor to
TR1 is turned off and an "L" signal, which is an abnormality detection signal, is sent to the microcomputer 11. When the microcomputer 11 receives this abnormality detection signal, it activates a transistor to reset the constant speed running control.
Turn on TR5. This turning on turns off transistors TR2, TR3, and TR4. When the transistor TR3 is turned off, the current flow to the release valve RV is cut off, but even if the transistor TR3 is short-circuited, the high resistance R1 is turned off when the transistor TR4 is turned off.
Since it is inserted in series with CV, the release valve RV and control valve CV do not operate and constant speed driving control is reliably interrupted.

Next, a flowchart at the time of checking executed by the microcomputer 11 will be explained using FIGS. 3 and 4.

When the power switch 1 for constant speed running control is turned on, the microcomputer 11 is initialized (step S1), and the process moves to step S2. Here, it is determined whether or not the set switch 3 has been turned on. The process goes through step 2 until the set switch 3 is turned on, and when the set switch 3 is turned on, the actual vehicle speed at that time is stored as the set vehicle speed, and the release valve drive circuit 14 is then used to execute the check function.
outputs an "H" signal to turn on transistor TR5. Therefore, transistors TR2, TR3,
TR4 is turned off, and the release valve RV is turned off. Furthermore, output a signal to turn on the control valve CV for a short period of time (e.g. 70ms) (step
S3). In addition, in step S3, the control valve CV
Even if energized, control valve CV will not operate because high resistance R1 is connected. Next, in step S4, it is determined whether the 100% duty detection circuit 12 has generated an abnormality detection signal or not, and its output is "L".
Judgment will be made based on whether or not. When an abnormality detection signal occurs
Since the 100% duty detection circuit 12 is normal, the process moves to step S5 to enter constant speed running control. However, if the 100% duty signal is not detected from the 100% duty detection circuit 11 in step S4, the 100% duty detection circuit 12 is abnormal, so the process moves to step S6, prohibits constant speed driving control, and displays the diagnostic display (step S4). S7) by 100
The driver is informed that the % duty detection circuit 12 is abnormal.

In this way, in the embodiment shown in Fig. 3, the release valve RV and the control valve are closed except during constant speed driving control.
A transistor that controls the release valve RV at the time of check because a high resistance R1 is connected in series with CV.
Release valve RV even if TR3 has short circuit fault.
does not operate, and even though 100% duty is applied to the control valve CV during check, the control valve CV does not operate. Therefore, it is possible to safely check the 100% duty detection circuit.

[Effect of idea]

According to the present invention, before entering constant speed driving control, 100
The % duty detection circuit is inspected and if it is normal, constant speed driving control is enabled, which prevents sudden speed increases during driving and improves safety.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a constant speed cruise control device, FIG. 2 is a flowchart executed by the microcomputer 5, and FIG. 3 is a configuration diagram showing another embodiment of the present invention.
FIG. 4 is a flowchart of the processing executed by the microcomputer 11. In the figure, 1 is a power switch, 2 is a vehicle speed sensor, 3 is a set switch, 4 is a cancel switch, 5 is a microcomputer, 6 is a control valve drive circuit, 7 is a release valve drive circuit, 8
is a 100% duty detection circuit, CV is a control valve, RV is a release valve, 11 is a microcomputer, 12 is a 100% duty detection circuit,
13 is an actuator earth cut circuit, and 14 is a release valve drive circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A control valve that introduces negative engine pressure into the chamber of an actuator that controls the opening degree of the throttle valve when it is energized and introduces atmospheric pressure when it is not energized; a release valve that introduces atmospheric pressure in a de-energized state and cuts off the atmospheric pressure in an energized state; a control means that controls the control valve and the release valve to control constant speed running; and a control means that controls the energized state of the control valve. A constant speed cruise control device comprising: an abnormality detection means for detecting and canceling constant speed cruise control by the control means by outputting an abnormality detection signal when the power is continuously energized for a predetermined time or more; When the check switch is operated, the release valve is de-energized and the control valve is energized for a predetermined period or more;
A constant speed cruise control device comprising a check means for detecting whether or not an abnormality detection signal is generated from the abnormality detection means and enabling constant speed cruise control when the abnormality detection signal is generated. (2) The check switch is a power switch for the control means, and when the power switch is turned on, the check means is operated, and when an abnormality detection signal is generated from the abnormality detection means, constant speed running control is enabled. A constant speed cruise control device according to claim 1 of the utility model registration claim. (3) The check switch is a set switch that starts constant speed running control, and when the set switch is turned on, it operates the checking means, and when an abnormality detection signal is generated from the abnormality detection means, the constant speed running control is started. The constant speed traveling control device according to claim 1, characterized in that the constant speed traveling control device starts the operation.