JPH09323637A - Brake defect detecting circuit for anti-lock brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the rusting in a contact and allow fail safe by connecting a pull-up resistance to a second wire harness through a third connector provided on an ABS controller, and setting the branching point of the first and second wire harnesses near a second connector. SOLUTION: A pull-up resistance 52a provided within an ABS controller 1 is connected between the other end part of a second wire harness H2 and a circuit power source iGN. The pull-up resistance 52a is connected to the other end part of the second wire harness H2 through a third connector CN12 provided on the ABS controller 1. The branching point A of the first and second wire harnesses H1 , H2 is provided near a second connector CN41. Consequently, a current is regularly supplied to a main circuit 51a, when an ignition switch is ON, to prevent the rusting in a contact. When a differential switch 53 is ON by a leakage or the like, production of a brake defect is recognized in the main circuit 51a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake failure detection circuit for an antilock brake system, and more particularly to an antilock brake system for detecting an oil leak in a brake pipe by opening / closing a switch and inputting it to an ABS controller. The present invention relates to a brake failure detection circuit. Here, “ABS” is an abbreviation for an anti-lock brake system (hereinafter the same).

[0002]

2. Description of the Related Art A conventional example is shown in FIGS. First, in FIG. 3, reference numeral 51 indicates an ABS controller.
A main circuit 51a for controlling the ABS is mounted on the ABS controller, and one end of a resistor 51b for setting an input voltage and a connector CN51 are provided in an input stage of the main circuit 51a.
1 is connected. The other end of the resistor 51b is grounded. The RC module 52 is connected to the connector CN 511 of the ABS controller 51. The RC module 52 is configured such that the resistor 52a and the capacitor 52b are connected in series, the end of the resistor 52a is connected to the circuit power supply iGN, and the end of the capacitor 52b side is grounded. A connector CN521 is interposed between the circuit power supply iGN and the resistor 52a. On the other hand, a connector CN524 is interposed between the ground point and the capacitor 52b. Two connectors CN522 and CN523 are connected to the connection point between the resistor 52a and the capacitor 52b. Of these, the connector CN522 is connected to the connector CN511 of the ABS controller 51 by a wire harness. Here, the pull-up resistor 52a is
It is set to a relatively large resistance value of about 2 kΩ.

Connector CN523 of RC module 52
Includes a diode 54 and a differential switch 5
3 is connected. The diode 54 has a connector CN 541 at the cathode terminal and a connector CN 542 at the anode terminal. Then, the cathode side connector CN541 is connected to the connector CN523 of the RC module via the wire harness. Further, the differential switch 53 includes connectors CN531 and CN532 on both sides of the contacts, respectively, and the connector CN531 connects the RC module 5 via a wire harness.
The connector CN532 is connected to the second connector CN523 and the connector CN541 of the diode 54, and the connector CN532 is grounded. This differential switch 53
Has a function of detecting the failure when an oil leak occurs in the brake pipe, and is specifically configured as shown in FIG.

In FIG. 4, a differential switch 53 includes a front wheel brake fluid pressure detecting portion 78F which communicates with a front wheel brake pipe (not shown) and a rear wheel which communicates with a rear wheel brake pipe (not shown). The brake fluid pressure detector 78R includes a piston 80 that moves by being biased by the difference between the front wheel brake fluid pressure and the rear wheel brake fluid pressure, and a push rod 82 that moves as the piston 80 moves. A recess 80c is formed at the center of the piston 80, and a protrusion 82v that fits into the recess 80c is formed at the base end of the push rod 82. That is, when the piston 80 moves in the direction of the right arrow 84F or the left arrow 84R in FIG. 4, the fitting between the concave portion 80c and the convex portion 82v is released, so that the push rod 82 moves upward.
Move in the direction of 6. Push rod 82 is up arrow 86
Moving in the direction, the electric contact indicated by reference numeral 53 in FIG.
Output to If the front wheel brake becomes defective for some reason, a difference occurs between the front wheel brake fluid pressure and the rear wheel brake fluid pressure. For example, when an oil leak occurs in a part of the brake pipe for the front wheels, the front wheel brake fluid pressure becomes lower than the rear wheel brake fluid pressure, so that the piston 80 moves to the right arrow 8
The defect is detected by moving in the 4F direction.

Returning to FIG. 3, the description of the circuit diagram will be continued. A warning lamp 57 is connected between the anode side connector CN542 of the diode 54 and the circuit power supply iGN.
The resistance value of the warning lamp 57 is set to several Ω, which is smaller than the pull-up resistance 52a of the RC module 52 described above. Reference numeral 55 denotes a parking brake switch, which is connected between the anode side connector CN542 of the diode 54 and one terminal of the warning lamp 57 and the ground point via the connectors CN551 and CN552. Further, reference numeral 56 indicates a brake oil level switch, and similarly to the parking brake switch 55, between the anode side connector CN542 of the diode 54 and one terminal of the warning lamp 57 and the ground point via the connectors CN561 and CN562. It is connected.

Next, the operation of this conventional example will be described.

When the vehicle ignition switch is turned on, the circuit power supply iGN is input. Now, the differential switch 53, the parking brake switch 55,
If both the brake oil level switch 56 and the brake oil level switch 56 are off (open), the circuit lamp iGN outputs a warning lamp 57.
And a predetermined current flows from the resistor 51b to the ground through the diode 54. Here, the current flowing through the warning lamp is set to be several mA. For this reason, although a current flows through the warning lamp 57, it cannot be confirmed that it is lit. At this time, the voltage applied to the resistor 51b is input to the main circuit 51a as a high-level signal, and the main circuit determines that no brake failure has occurred and executes normal ABS control.

When the parking brake switch 55 or the brake oil level switch 56 is turned on (short-circuited), the warning lamp 57 is clearly turned on, and the circuit power iGN pulls up the pull-up resistor 5 of the RC module 52.
A current flows from the resistor 51b to the ground via the 2a, and a high level signal is input to the main circuit 51a. In this case also, the main circuit 51 determines that the brake failure has not occurred, and executes the normal ABS control.

On the other hand, when an oil leak occurs in the brake pipe, the differential switch 53 is turned on, the warning lamp 57 is clearly turned on, and the voltage input to the main circuit 51a of the ABS controller 51 is at the ground level (low level). Level). Therefore, the occurrence of the brake failure is reported to the main circuit 51a of the ABS controller 51, and the special control at the time of the brake failure is executed.

[0010]

However, in the above-mentioned conventional example, since there are many connection points by the Ikansen connector, the assemblability is poor and there is room for improvement in the reliability of the circuit. Further, there is a disadvantage that the cost of the wire harness for connection is high. Further, there is also a disadvantage that the cost of parts of the RC module is high.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a brake failure detection circuit for an antilock brake system which has a high reliability and which has a relatively low cost and which has the disadvantages of the prior art. To aim.

[0012]

In order to achieve the above object, in the invention according to claim 1, one end of a first wire harness is connected to a main circuit of an ABS controller via a first connector, The diode module is connected to the other end of the first wire harness via the second connector. This diode module is configured by connecting two diodes whose cathode terminals are connected to each other in series, and the anode terminal of one of the diodes is connected to the other end of the first wire harness. Further, a warning lamp is connected between the anode terminal of the other diode of the diode module and the circuit power supply, and one or more predetermined switches for sharing the warning lamp are connected between the anode terminal and the ground point. are doing. Further, a differential switch that operates with the occurrence of a brake failure is connected between the cathode terminals of two diodes constituting the diode module and the ground point. Then, from the first wire harness to the second
The wire harness is branched, and a pull-up resistor is connected between the other end of the second wire harness and the circuit power supply. Further, a predetermined resistor for dividing the voltage of the circuit power source is provided between the input stage of the main circuit and the ground point together with the pull-up resistor. Of these, the pull-up resistor is provided inside the ABS controller, and the pull-up resistor and the other end of the second wire harness are connected via a third connector provided in the ABS controller.
Furthermore, a branch point of the second wire harness from the first wire harness is set near the second connector,
The configuration is adopted.

According to the present invention, when all the predetermined switches that share the differential switch and the warning lamp are off, the circuit power supply pulls up the resistor → the third connector → the harness branch point → the first connector → the predetermined amount. A current flows through the piezoresistive route, and a high level signal is input to the main circuit of the ABS controller. In addition, if the wire breakage of the harness or the contact failure of the connector occurs between the circuit power supply on the pull-up resistor side and the main circuit, the current does not flow according to the above route, and the ABS controller is the same as when the differential switch was turned on. A low level signal is input to.

According to the second aspect of the invention, the branch point of the second wire harness from the first wire harness is connected inside the second connector.

According to the present invention, when the wire breakage occurs in the first or second wire harness or the contact failure occurs in any of the first, second and third connectors, the main circuit 51a of the ABS controller 1 has a low voltage. A level signal is input.

With these, the above-mentioned object is to be achieved.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
It will be described based on.

In FIG. 1A, one end of a _first wire harness H ₁ is connected to the main circuit 51a of the ABS controller 1 via a first connector CN511, and this first wire harness H ₁ is connected. A diode module 4 is connected to the other end of the diode module 4 via a second connector CN41.

This diode module 4 comprises a series connection of two diodes 4a and 4b whose cathode terminals are connected to each other, and the anode terminal of one of the diodes 4a is the first wire harness H. It is connected to the other end of ₁ .

A warning lamp 57 is connected between the anode terminal of the other diode 4b of the diode module 4 and the circuit power supply iGN, and the warning lamp 57 is shared between the anode terminal and the ground point. The parking brake switch 55 and the brake oil level switch 56 are connected to each other. Furthermore, the two diodes 4a and 4b that form the diode module 4 are provided.
A differential switch 53, which operates together with the occurrence of a brake failure, is connected between the cathode terminals of and the ground point. The configuration of this differential switch 53 is the same as the conventional example.

A second wire harness H ₂ is branched from the first wire harness H ₁ and a pull-up resistor 52a is provided between the other end of the second wire harness H ₂ and the circuit power supply iGN. Are connected. Further, a predetermined resistor 51b for dividing the voltage of the circuit power supply iGN is provided between the input stage of the main circuit 51a and the ground point together with the pull-up resistor 52a.

Of these, the pull-up resistor 52a is AB
It is provided inside the S controller 1. Then, a third connector CN1 provided in the ABS controller 1
The pull-up resistor 52a is connected via _{2 to} the other end of the _second wire harness H ₂ . In particular, the branch point A of the second wire harness H ₂ from the first wire harness H ₁ is set near the second connector CN41.

More specifically, in this embodiment, the branch point of the second wire harness H ₂ from the first wire harness H ₁ is the second connector as shown in FIG. It is connected inside the CN 41.

Here, each circuit element is harness-connected through a predetermined connector. In particular,
The ABS controller 1 has connectors CN511 and CN1.
It is connected via 2. Diode module 4
Are connected via connectors CN41, CN541, CN542. The differential switch 53 is
They are connected via connectors CN531 and CN532. The parking brake switch 55 has a connector CN.
It is connected via 551 and CN552. The brake oil level switch 56 has connectors CN561 and C
It is connected through N562. When a failure occurs in each circuit element, the defective part can be individually removed from the connector and easily replaced. Moreover, it is necessary to use a relatively long harness for connection. The reason is that, unlike the ABS controller 1, the warning lamp 57 is provided in the vehicle compartment. In particular, the first and second harnesses H ₁ , H ₂
A long harness is used for. For this reason, it is necessary to consider that a disconnection failure may occur in the middle of the harness.

In addition, the parking brake switch 55
Is short-circuited when the parking brake is set to the effective state. Further, the brake oil level switch 56 is adapted to be short-circuited when the brake oil falls below a certain amount. Further, in the present embodiment, the resistor 51b is provided inside the ABS controller 1 between the input stage of the main circuit 51a and the ground point.

Next, the overall operation of this embodiment will be described.

When the ignition switch of the vehicle is turned on, the circuit power supply iGN is input. Now, the differential switch 53, the parking brake switch 55,
If both the brake oil level switch 56 and the brake oil level switch 56 are off (open), the circuit power supply iGN pulls up the resistor 52a → the third connector CN12 → the branch point A (that is, the second connector CN41) → the first connector CN511. →
A predetermined current is supplied through the route of the resistor 51b. As a result, a high level signal is input to the main circuit 51a. The main circuit 51a of the ABS controller 1 which receives the input of the high level signal determines that the failure due to the abnormality of the brake pipe has not occurred, and executes the normal ABS control.

Here, no current flows through the warning lamp 57 due to the action of the diode 4a. Therefore, the differential switch 53, the parking brake switch 5
5. When the brake oil level switch 56 is normally off, current is always supplied from the connector CN12 side to the main circuit 51a, so that the connectors CN12, CN41, CN are provided.
It is possible to effectively prevent the generation of rust at the contact point of 511 and ensure the reliability of the connector connection.

Next, when a failure such as an oil leak occurs in the brake pipe and the differential switch 53 is turned on, a warning lamp 57 → diode 4 is supplied from the circuit power supply iGN.
Current flows through a route of b-> differential switch 53-> grounding point, the warning lamp 57 is turned on, and the driver is warned that the brake failure has occurred. At the same time, the pull-up resistor 52a → diode 4a → from the circuit power supply iGN →
A current flows through the route of the differential switch 53. At this time, since the potential of the first wire harness H ₁ is set to the ground level, the ABS controller 1
A low-level signal is input to the main circuit 51a, the occurrence of a brake failure is recognized in the main circuit 51a, and special control at the time of brake failure is executed.

Next, when the parking brake switch 55 or the brake oil level switch 56 is turned on,
From the circuit power supply iGN to the warning lamp 57 → the parking brake switch 55 or the brake oil level switch 56
→ A current flows through the route of the grounding point, the warning lamp 57 is turned on, and the driver is warned that the parking brake is in an effective state or that the brake oil is insufficient. At this time, by the action of the diode 4b, the current flowing through the pull-up resistor 52a through the second wire harness H ₂ from the circuit power source iGN does not flow to the side of the parking brake switch 55 and the brake oil level switch 56, ABS controller 1 main circuit 5
A high level signal is continuously input to 1a. Therefore, in the main circuit 51a, normal ABS control is executed without detecting a brake failure.

Next, the first wire harness H ₁ or the second wire harness H ₁
When a wire breakage occurs at an arbitrary position of the wire harness H ₂ of No. 1, or the first, second or third connector CN511,
The operation when a contact failure occurs in either CN41 or CN12 will be described.

When such disconnection or poor contact occurs,
From circuit power supply iGN to pull-up resistor 52a → third connector CN12 → branch point A (second connector CN41) →
The current supplied through the route from the first connector CN511 to the resistor 51b is cut off, and a low level signal is input to the main circuit 51a. Therefore, in the main circuit 51a, the same special control as in the case where the brake failure occurs is performed.

On the other hand, as a circuit for solving the problems of the conventional example, a configuration as shown in FIG. 2 can be considered.
The brake failure detection circuit shown in FIG. 2 has the pull-up resistor 52a connected inside the ABS controller 51 in the configuration of the conventional example shown in FIG. Even in this case, the number of connectors for connection can be reduced and the reliability of connection can be improved. However, in the present comparative example, even if the harness is disconnected or the contact is defective at the location indicated by the reference numeral NG, the high-level signal is continuously input to the main circuit 51a, and the defect due to the disconnection is generated as in the present embodiment. There is an inconvenience that you cannot fail-safe.

On the other hand, in this embodiment, the pull-up resistor 5
2a is not only provided inside the ABS controller 1 but also connected to the _second wire harness H ₂ which is branched from the first wire harness H _{1 at} the second connector CN41, so that the pull-up resistor 52a is connected to the branch point. Between A or from the branch point A to the main circuit 51 of the ABS controller 1.
Even if the wire breakage of the harness or the contact failure of the connector occurs up to a, the low level signal is input to the main circuit 51a, and the main circuit 51a of the ABS controller 1 recognizes the abnormality and fails. Special control for safety can be executed.

Further, in this embodiment, the pull-up resistor 5 is used.
Since the 2a is provided inside the ABS controller 1, the cost can be far reduced as compared with the case where the resistor 52a is provided on the wire harness, and the number of connectors can be reduced as compared with the conventional example, thereby further reducing the cost. It can be reduced. Furthermore, since the first wire harness H ₁ and the second wire harness H ₂ are branched at the second connector CN41 of the diode module 4,
And the disconnection of the second wire harnesses H ₁ and H ₂ can be detected particularly efficiently, and any contact failure in the first, second and third connectors CN511, CN41, CN12 can be detected. it can.

[0036]

Since the present invention is constructed and functions as described above, according to the present invention, when the predetermined switch which shares the differential switch and the warning lamp is normally turned off, the main switch is always operated from the third connector side. Since the current is supplied to the circuit, it is possible to effectively prevent the generation of rust at the contact points of the first and third connectors, and to secure the reliability of the connector connection. In addition, pull-up resistor
Since it is provided inside the S controller and is connected to the second wire harness branched from the first wire harness in the vicinity of the second connector, it is connected from the pull-up resistor to the branch point or from the branch point to the ABS controller. Even if the wire breakage of the harness or the contact failure of the connector occurs up to the main circuit, the main circuit of the ABS controller can recognize the abnormality and execute the special control for fail-safe. Further, since the pull-up resistor is provided inside the ABS controller, the cost can be far reduced compared to the case where the pull-up resistor is provided on the wire harness, and the number of connectors can be reduced as compared with the conventional example. Therefore, further cost reduction can be achieved.

According to the second aspect of the invention, since the first wire harness and the second wire harness are branched by the second connector of the diode module, the disconnection of the first and second wire harnesses can be prevented. In addition to being able to detect particularly efficiently, any contact failure in the first, second, and third connectors can be detected, and a more reliable fail-safe can be realized. It is also possible to provide a brake failure detection circuit for an anti-lock brake system.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention, and FIG.
1A is a circuit diagram showing the configuration of the present embodiment, and FIG.
(B) is a block diagram which shows the connection state of the 1st wire harness and the 2nd wire harness in the 2nd connector in Fig.1 (a).

FIG. 2 is a circuit diagram showing a comparative example with the embodiment shown in FIG.

FIG. 3 is a circuit diagram showing a conventional example.

FIG. 4 is a partially omitted sectional view showing the configuration of the differential switch in FIGS. 1 and 3.

[Explanation of symbols]

1 ABS controller 4 Diode module 4a, 4b Diode 51a Main circuit 51b Predetermined resistance 52a Pull-up resistor 53 Differential switch 55 Parking brake switch (predetermined switch) 56 Brake oil level switch (predetermined switch) 57 Warning lamp CN12 Third Connector CN41 Second connector CN511 First connector H ₁ First wire harness H ₂ Second wire harness

Claims (2)

[Claims] 1. A diode module, wherein one end of a first wire harness is connected to a main circuit of an ABS controller via a first connector, and the other end of the first wire harness is connected to a second connector. And the diode module is composed of a series connection of two diodes whose cathode terminals are connected to each other, and the anode terminal of one of the diodes is connected to the other end of the first wire harness. One or two or more connected warning lamps are connected between the anode terminal of the other diode of the diode module and the circuit power supply, and the warning lamp is shared between the anode terminal and the ground point. Between the cathode terminals of the two diodes that make up the diode module by connecting a predetermined switch and between the ground point A differential switch that operates with the occurrence of a brake failure is connected to the second wire harness to branch the second wire harness from the first wire harness, and a pull-up is made between the other end of the second wire harness and the circuit power supply. A resistor is connected to the pull-up resistor, and a predetermined resistor for dividing the voltage of the circuit power supply together with the pull-up resistor is provided between the input stage of the main circuit and a ground point. The pull-up resistor and the other end of the second wire harness are connected to each other via a third connector provided in the ABS controller, and the pull-up resistor is connected to the first wire harness of the second wire harness. Of the brake failure of the antilock brake system, characterized in that the branch point of is set near the second connector. circuit. 2. The branch point of the second wire harness from the first wire harness is connected inside the second connector.
A brake failure detection circuit of the described anti-lock brake system.