JPH0562376U - Warning lamp control circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] When the anti-lock brake system is abnormal, the main relay is used to forcibly shut off the power supply to the solenoid that controls the hydraulic actuator, switching to the normal brake system and turning on the warning lamp. An object of the warning lamp control circuit is to make the warning lamp blink normally without taking risks such as turning on the power supply again and without overlapping installation of lamps and drive circuits. [Structure] An opening / closing means is provided to electrically open a gap between the warning lamp and the main relay when the antilock brake system is in an abnormal state so that the failure code blinking control means of the warning lamp can operate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a warning lamp control circuit, and more particularly to a warning lamp control circuit of an antilock brake system (hereinafter sometimes abbreviated as ABS).

[0002]

[Prior Art]

 Conventionally, the anti-lock brake system has been equipped with a warning lamp control circuit that blinks the warning lamp according to a predetermined failure code to display an abnormal state when a system abnormality is detected. In order to put the system in a fail-safe state in this state, the following legal regulations ~ have been established.

The warning lamp is turned on when the electronic control unit that diagnoses and controls the system is physically disconnected. The warning lamp is turned on when the actuator power is cut off due to a system error. Diagnose the system after turning on the power of the system, turn on the warning lamp until it determines that the system is normal, turn it off after confirming the normal condition.

FIG. 8 shows a typical warning lamp control circuit of the prior art designed to satisfy the above restrictions (1), and includes an electronic control unit (ECU) 1 for performing control and diagnosis, a warning lamp (in the drawing). 2), a solenoid 3 that controls a hydraulic actuator (not shown), a diode 4, a main relay 5 that shuts off the power supply to the solenoid 3 when an abnormality occurs, and the entire warning lamp control circuit. The electronic control unit 1 further controls the CPU 10, the power supply circuit 11, the transistor 12 for controlling the warning lamp 2, and the solenoid 3. It is composed of a transistor 13 and a main relay drive circuit 14 for controlling the main relay 5.

Hereinafter, an operation example (No. 1 to No. 3) of the CPU 10 in the warning lamp control circuit will be described with reference to flowcharts of FIGS. 9 to 11.

Operation example (part 1: see FIG. 9) When the power switch 6 is turned on (step S1), the power circuit 11 is turned on, so that the CPU 10 is in an operating state and the main relay 5 via the main relay drive circuit 14 is activated. Is turned on (step S2). As a result, the main relay 5 is switched from the OFF position to the ON position shown in the drawing, but at this time, no current flows through the warning lamp 2.

Next, the CPU 10 turns on the transistor 12 to turn on the warning lamp 2 for about 5 seconds to perform the lamp check (step S3), diagnoses the system (step S4), and determines whether or not there is an abnormality. It is determined (step S5). The procedure of steps S1 to S5 described above is called an initial check.

When there is no abnormality in this initial check, the routine shifts to normal control (step S6), and during that time, normal control is continued while determining whether or not abnormality occurs (step S7). In the normal control, the CPU 10 turns on the transistor 13 to set the antilock brake system in the operation mode.

When an abnormality occurs in the initial check or normal control, the ABS control is stopped (step S8). That is, since the main relay 5 is turned off by the main relay drive circuit 14 (step S9), the solenoid 3 is turned off and the ABS control is stopped.

In such a conventional technique, when a system abnormality occurs, the main relay 5 is set to the OFF position and the power source of the solenoid 3 is cut off as described above, so that the warning lamp 2 is continuously turned on. The operator cannot be notified by blinking the failure code that indicates the diagnosis result.

Therefore, after the occurrence of the system abnormality, if there is a request to display the content of the system abnormality by the warning lamp 2 by blinking the failure code, the main relay 5 is turned on (step S11) and the transistor 12 is controlled to cause the failure. The code blinking is enabled (step S12).

Example of Operation ( No. 2: See FIG. 10) In the case of this example of operation, it is determined whether or not there is an instruction for blinking the fault code after step S 2 in the initial check shown in FIG. 9 ( In step S20), when there is an instruction, a procedure is added in which the transistor 12 causes the warning lamp 2 to blink and display the fault code (step S21).

Since there is no blinking display of the fault code from the beginning, these steps S20 and S21 are not executed, the initial check (steps S2 to S5) and the normal control (steps S6 and S7) are performed, and in step S5 or S7. When an abnormality is detected and the main relay 5 is turned off (steps S8 and S9), the operator recognizes that the warning lamp 2 is continuously turned on when the main relay 5 is turned off, and the operator restarts the switch 6 as determined in advance. Since it is turned on, the warning lamp 2 is displayed in a blinking manner through step S2 (steps S20 and S21).

Example of Operation ( No. 3: See FIG. 11) In the case of this example of operation, the same procedure is performed from step S1 to step S10 shown in FIG. 9, and further when there is a failure code blinking instruction in step S10. Displays a fault code by a separately installed lamp or circuit (not shown) (step S13).

[0015]

As described above, in the conventional warning lamp control circuit, after detecting an abnormality, the main relay 5 is turned off, and after switching to the normal braking system, the warning code is output to the warning lamp 2. There were three methods of blinking display, but all had the following problems.

That is, in the operation example (No. 1: FIG. 9), since the main relay 5 that was once turned off when the system is abnormal is turned on again, the power is reapplied to the solenoid 3 and the ABS control safety is improved. Not only is there a problem above, but there is a danger that the failure will be exacerbated.

In addition, in the operation example (part 2: FIG. 10), since the power is again turned on by the switch 6 when the system is abnormal, there is not only the same risk, but also the reproducibility of the content of the defect that has occurred. It may decrease and it may become impossible to investigate the failure.

Further, in the operation example (part 3: FIG. 11), another lamp and a drive circuit must be provided, which causes an increase in the cost of the circuit.

Therefore, the present invention forcibly shuts off the power supply to the solenoid that controls the hydraulic actuator using the main relay when the antilock brake system is abnormal, switches to the normal brake system, and lights the warning lamp. The purpose of the warning lamp control circuit is to display the warning lamp normally without taking the risk of turning the power on again and without duplicating the lamp and drive circuit.

[0020]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the warning lamp control circuit according to the present invention electrically opens the warning lamp and the main relay between the warning lamp and the main relay when the system is abnormal to enable the failure code blinking control means of the warning lamp It is characterized by the provision of opening and closing means.

Further, in the present invention, a means may be provided for giving a failure code to the failure code blinking control means only when the open state of the opening / closing means is detected.

[0022]

[Action]

 In the warning lamp control circuit according to the present invention, when the ABS control system is abnormal, the main relay is turned off to cut off the power supply to the solenoid and switch to the normal brake system. When performing, the warning lamp and the main relay are electrically disconnected by opening the opening / closing means, and the blinking display of the warning lamp by the fault code blinking control means becomes possible.

Furthermore, if the open state of the open / closed states of the opening / closing means is detected, the fault code can be given to the fault code blinking control means and blinked.

[0024]

【Example】

 FIG. 1 is a diagram showing an embodiment of a warning lamp control circuit according to the present invention. The difference between this embodiment and the conventional example of FIG. 8 is that the warning lamp 2 and the main relay 5 are opened and closed electrically. The electronic control unit 1 is provided with a connector 20 as means and a level converter 15 for detecting the open / closed state of the connector 20 and inputting it to the CPU 10. The CPU 10 and the transistor 12 constitute a failure code blinking control means.

The operation of this embodiment of the warning lamp control circuit will be described below with reference to the flowchart of FIG.

In FIG. 2, steps S1 to S10 correspond to steps S1 to S10 of the conventional example shown in FIG. 9, but in this embodiment, the CPU 10 returns the main relay 5 to ON after step S10. Instead, in step S12, the transistor 12 controls the warning lamp 2 to blink the failure code.

At this time, since the main relay 5 is in the OFF position, the warning lamp 2 is in a continuous lighting state even if the transistor 12 is controlled by the CPU 10.

However, since the operator who knows such a continuous lighting state of the warning lamp 2 opens the connector 20 to electrically disconnect the warning lamp 2 from the main relay 5, the CPU 10 turns the transistor 12 on. The warning lamp 2 will flash through the failure code.

Further, in FIG. 1, the open / closed state of the connector 20 is detected by the level converter 15 at an analog voltage level, converted into a digital signal and given to the CPU 10, so that the CPU 10 recognizes that the connector 20 is in the open state. It is also possible at this point for the first time to flash the warning lamp 2 via transistor 12 with the fault code. This control corresponds to step S30 shown by the dotted line in FIG.

As described above, the open / closed state of the connector 20 can be electrically detected by the CPU 10 via the level converter 15. However, in FIGS. 3 (1), 3 (2), and 3 (3), the connector 20 is opened and closed. An example of detection of the open / closed state is specifically shown, and the relationship between these three detection examples and the detected electrical state is shown in FIG.

That is, in the example of FIG. 3 (1), when the main relay 5 is OFF, the voltage detected at the terminal D of the electronic control unit 1 is 0.6 V when the connector 20 is closed, and the voltage is open when the connector 20 is closed. For example, in the example of Fig. 2 (2), it is 12 V in the closed state, in the open state it is in the floating state, and in the example of Fig. 3 (3) it is 0 V in the closed state. 6V, 12V in the open state. As a result, the open / closed state of the connector 0 can be identified in any of the examples. In the floating state, the CPU 10 can recognize the open state of the connector 20 by converting the divided voltage into a digital value by the voltage dividing resistors _RA, RB _{, RC} in the level converter 15. it can.

Although some other examples of the opening / closing means are possible, in the example shown in FIG. 5, the connector 20 is represented by a mechanical switch 20a, and terminals A to C correspond to each other. ing.

Further, as shown in FIG. 6, it is possible to use the electric switch 20a as the opening / closing means and automatically open / close the electric switch 20b when receiving an electric command signal from another external unit. is there.

Further, as shown in FIG. 7, in addition to the electronic control unit 1, another electronic control unit 22 is provided to receive the open / closed state information from another system or switch 21 which controls the connector 20, and the main relay 5 It is also possible to blink the failure code other than the ABS control by the warning lamp 2 which is shared between the units 1-2 even when is turned off.

[0035]

[Effect of the device]

 As described above, according to the warning lamp control circuit of the present invention, when the ABS system is abnormal, the warning lamp and the main relay are electrically opened to enable the warning lamp failure code blinking control means. Since the opening / closing means is provided, even if the system malfunctions, the power supply to the actuator will be cut off, there will be no risk of turning the power on again, and there will be no need to install a separate lamp or circuit to display the failure code flashing. Therefore, it greatly contributes to the improvement of safety and maintenance performance.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a warning lamp control circuit according to the present invention.

FIG. 2 is a flowchart showing an operation sequence of an embodiment of a warning lamp control circuit according to the present invention.

FIG. 3 is a diagram specifically showing an example of detection of the open / closed state of the opening / closing means used in the present invention.

FIG. 4 is a diagram showing, using a table, the detected electrical state of the open / closed state of the opening / closing means used in the present invention.

FIG. 5 is a diagram in which the opening / closing means used in the present invention is represented by a mechanical switch.

FIG. 6 is a diagram showing a configuration example in which an electric switch is used as the opening / closing means used in the present invention, and an electric command signal from another external unit is received to open / close the electric switch.

FIG. 7 is a diagram showing a configuration example in which another electronic control unit is provided and a fault code other than the ABS control is blinked and displayed by a shared warning lamp in the embodiment of the present invention.

FIG. 8 is a diagram showing a circuit configuration of a conventional technique.

FIG. 9 is a flowchart showing an operation example (1) of the conventional technique.

FIG. 10 is a flowchart showing an operation example (No. 2) of the conventional technique.

FIG. 11 is a flowchart showing an operation example (No. 3) of the conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic control unit 2 Warning lamp 3 Solenoid 5 Main relay 6 Switch 10 CPU 12, 13 Transistor 15 Level converter 20 Opening / closing means (connector) In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Scope of utility model registration request] 1. A warning lamp control circuit for forcibly shutting off power supply to a solenoid for controlling a hydraulic actuator when an antilock brake system is abnormal by using a main relay to switch to a normal braking system and for turning on a warning lamp. 2. A warning lamp control circuit according to claim 1, further comprising an opening / closing means for electrically opening the warning lamp and the main relay at the time of the abnormality to enable the failure code blinking control means of the warning lamp. 2. The warning lamp control circuit according to claim 1, further comprising means for giving a failure code to the failure code blinking control means only when the open state of the opening / closing means is detected.