Backup braking circuit applied to parking braking

Abstract

The utility model discloses a backup braking circuit applied to parking braking, which relates to the technical field of braking control, and comprises an IPB (Intelligent Power Block) which is used for supplying power to a parking motor of a whole vehicle in a normal state and feeding back a backup parking starting signal to a gear shifting domain control unit when the IPB reports a failure of parking braking; after the gear shifting domain control unit receives the backup parking starting signal, power supply of a parking motor of the IPB is cut off through an H-bridge relay, and gear shifting domain control is switched to supply power to the parking motor; and the parking motor directly performs braking control on the left rear brake disc after being powered by the gear shifting domain control unit. According to the utility model, the state information of PB parking failure is obtained in time, so that the power supply of the parking motor is switched from the IPB to the power supply of the parking motor by the gear shifting domain control unit through the switching of the power supply of the parking motor, and the harm caused by the braking failure of the IPB is effectively avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of braking control, and particularly relates to a backup braking circuit applied to parking braking. Background Art

[0002] The failure of the parking brake means that the parking brake system of the vehicle loses or partially loses its due braking efficiency, which may cause the vehicle to be unable to maintain stability when stationary, especially on a slope. The parking brake system usually includes a handbrake (manual parking brake) or a foot-operated parking brake, as well as the electronic parking brake (EPB) that is becoming more and more common in modern vehicles.

[0003] The ECU (Electronic Control Unit) plays a crucial role in modern vehicles, especially for those vehicles with an electronic parking brake system (EPB, Electrical Park Brake). The electronic parking brake system relies on the ECU to control the electric motor or electromagnetic device of the brake caliper to achieve the parking braking function. If the ECU fails, this will have a direct and serious impact on the parking braking function of the vehicle. Therefore, how to urgently apply parking brake to the vehicle in case of ECU failure and avoid the generation of secondary hazards is the technical problem to be solved by this solution. Summary of the Utility Model

[0004] To avoid the hazards brought by the failure of the parking brake, the utility model proposes a backup braking circuit applied to parking braking, including:

[0005] The IPB is used to supply power to the parking motor of the whole vehicle in the normal state, and feedbacks a backup parking start signal to the shift domain control unit when the IPB reports a parking brake failure;

[0006] The shift domain control unit is used to disconnect the power supply of the parking motor of the IPB and switch to the shift domain control to supply power to the parking motor after receiving the backup parking start signal;

[0007] The current detection module is used to detect the parking braking current fed back by the brake motor when the vehicle parking key is triggered, and the parking braking current is used to reflect the braking ratio;

[0008] The parking motor directly controls the braking of the left rear brake disc after being powered by the shift domain control unit.

[0009] Further, the H-bridge relay includes a power supply switching unit and a power supply unit. The power supply unit is used to provide parking power supply for the parking motor, and the power supply switching unit is used to switch the flow direction of the supply current.

[0010] Further, the power supply switching unit includes an electromagnetic relay, which has the first pin to the tenth pin, where:

[0011] The first pin is connected to the positive electrode of the ninth diode and the collector of the fifth triode at the same time; the negative electrode of the ninth diode and the second pin are connected to the relay voltage together; the emitter of the fifth triode is grounded; the base of the fifth triode is connected to the backup parking start signal through the ninety-fourth resistor, and is connected to one end of the parallel-connected one-hundredth resistor and the seventy-ninth capacitor, and the other end of the parallel connection is grounded;

[0012] The sixth pin is connected to the positive electrode of the twelfth diode and the collector of the seventh triode at the same time; the negative electrode of the twelfth diode and the seventh pin are connected to the relay voltage together; the emitter of the seventh triode is grounded; the base of the seventh triode is connected to the backup parking start signal through the one-hundred-and-fourth resistor, and is connected to one end of the parallel-connected one-hundred-and-fifth resistor and the eightieth capacitor, and the other end of the parallel connection is grounded;

[0013] The third pin and the eighth pin are power supply access ports, connected to the power supply unit; the fifth pin and the tenth pin are power supply ports for the parking motor under the power supply of the shift domain control unit; the fourth pin and the ninth pin are power supply ports for the parking motor under the power supply of IPB.

[0014] Further, before the H-bridge relay receives the backup parking start signal, the third pin and the fourth pin, and the eighth pin and the ninth pin are in a normally-conductive state; when the H-bridge relay receives the backup parking start signal, the conduction state switches to between the third pin and the fifth pin, and between the eighth pin and the tenth pin.

[0015] Further, the power supply unit includes a first power supply circuit and a second power supply circuit, where:

[0016] One end of the first power supply circuit is connected to the fourth pin of the electromagnetic relay, and is connected to the second system voltage through the one-hundred-and-forty-sixth resistor, grounded through the one-hundred-and-forty-eighth resistor, and is connected to the positive electrode of the twenty-second diode, one end of the one-hundred-and-twentieth capacitor and one end of the one-hundred-and-fifty-third resistor through the third resistor, the negative electrode of the twenty-second diode is connected to the first system voltage, and the other end of the one-hundred-and-twentieth capacitor is grounded; the other end of the first power supply circuit is connected to the negative power supply of the shift domain control unit, connected to the other end of the one-hundred-and-fifty-third resistor and grounded through the one-hundred-and-nineteenth capacitor;

[0017] One end of the second power supply circuit is connected to the eighth pin of the electromagnetic relay, and is connected to the second system voltage through the one-hundred-and-forty-ninth resistor, grounded through the one-hundred-and-fifty-second resistor, and is connected to the positive electrode of the twenty-first diode, one end of the one-hundred-and-twenty-first capacitor and one end of the one-hundred-and-fifty-fourth resistor through the one-hundred-and-fifty-first resistor, the negative electrode of the twenty-first diode is connected to the first system voltage, and the other end of the one-hundred-and-twenty-first capacitor is grounded; the other end of the second power supply circuit is connected to the positive power supply of the shift domain control unit, connected to the other end of the one-hundred-and-fifty-fourth resistor and grounded through the one-hundred-and-eighteenth capacitor.

[0018] Further, when the IPB supplies power to the parking motor of the whole vehicle, the pre-driver is used to drive and control the braking motor.

[0019] Further, the positive pole of the parking motor is connected to the fifth pin of the electromagnetic relay and grounded through the eighty-second capacitor and the eighty-third capacitor respectively; the negative pole of the parking motor is connected to the tenth pin of the electromagnetic relay and grounded through the eighty-eighth capacitor and the eighty-ninth capacitor respectively; the positive and negative poles of the parking motor are connected through the eleventh zener diode and the eighty-fourth capacitor respectively.

[0020] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0021] A backup braking circuit and a parking method applied to parking braking according to the present utility model can effectively avoid the harm caused by the failure of the IPB braking by timely obtaining the state information of the PB parking failure, thereby switching the power supply to the parking motor, that is, switching the power supply of the parking motor from the IPB to the shift domain control unit. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the system composition of a backup braking circuit applied to parking braking;

[0023] Figure 2 It is a schematic diagram of the circuit of the power supply switching unit;

[0024] Figure 3 It is a schematic diagram of the circuit of the power supply unit;

[0025] Figure 4 It is a schematic diagram of the circuit of the parking motor;

[0026] Figure 5 It is a schematic diagram of the steps of a backup braking method applied to parking braking. Detailed Embodiments

[0027] The following are specific embodiments of the present utility model in combination with the drawings to further describe the technical solutions of the present utility model, but the present utility model is not limited to these embodiments.

[0028] EPB, namely Electrical Park Brake, is an advanced technology used to replace the traditional mechanical handbrake in modern vehicles. It utilizes an electronic control unit (ECU) to manage the electric actuators of the brake calipers or brake drums to achieve the function of parking braking. It controls a small electric motor through the on-vehicle computer. This motor can drive the brake calipers to clamp the brake discs, or there is a dedicated EPB brake drum on the rear wheels to achieve parking braking by tightening the brake band. When the vehicle needs to park, the driver only needs to press the EPB button, and the ECU will send a signal to make the motor work, thereby activating the brake. However, there are potential problems such as disconnection, short circuit, and corrosion in electronic devices, and once these problems occur, it will lead to the failure of the parking brake. To solve this problem, as Figure 1 shown, the present utility model proposes a backup braking circuit applied to parking braking, including:

[0029] IPB, which is used to supply power to the parking motor of the whole vehicle in the normal state, and feedbacks a backup parking start signal to the shift domain control unit when IPB reports a fault and the parking brake fails;

[0030] The shift domain control unit is used to disconnect the power supply of the parking motor of IPB through the H-bridge relay and switch to the shift domain control to supply power to the parking motor after receiving the backup parking start signal;

[0031] The current detection module is used to detect the parking braking current fed back by the brake motor when the vehicle parking key is triggered, and the parking braking current is used to reflect the braking ratio;

[0032] The parking motor directly controls the braking of the left rear brake disc after being powered by the shift domain control unit.

[0033] Among them, IPB is the abbreviation of Intelligent Integrated Brake system, which is an electronically controlled braking system. Compared with the traditional vacuum booster braking system, it makes the response of the braking system faster and the control more precise. Moreover, with this intelligent electronically controlled braking system, more functions can be extended. It will convert the braking demand applied by the driver into amplified braking pressure, and IPB also integrates the vehicle dynamic stability control system, including ABS, traction control, and vehicle stability control functions. Under normal circumstances, IPB controls two calipers, and the left hard wire of IPB passes through the shift domain control, and the domain control performs a long-pass process.

[0034] Since it is an electronic parking system, when parking occurs, it will inevitably bring about a change in current. Therefore, here the IPB can detect the internal control current and determine whether it reaches the current magnitude required for normal parking, so as to determine whether the parking is effective. When the current is less than this limit value, it means that there is a problem with the parking function. Or when certain faults occur in the IPB itself, the IPB can report a fault and feedback a backup parking start signal to the shift domain control unit.

[0035] In the normal operation state of the IPB, the front and rear wheel parking motors of the vehicle are both powered by the IPB, and the parking motors are driven and controlled via a pre-driver (Pre-driver). In order to avoid the harm caused by parking failure when the IPB fails, the present utility model proposes to realize the intelligent switching between the power supply of the IPB parking motor and the power supply of the shift domain control unit parking motor in different states through the setting of the H relay. Specifically, the H-bridge relay includes a power supply switching unit and a power supply unit. The power supply unit is used to provide parking power supply for the parking motor, and the power supply switching unit is used to switch the flow direction of the power supply current.

[0036] As Figure 2 shown, the power supply switching unit includes an electromagnetic relay K1 (model number HFKA / 012-2ZSPT), which has pins from the first to the tenth, where:

[0037] The first pin is simultaneously connected to the positive electrode of the ninth diode D9 and the collector of the fifth triode Q5; the negative electrode of the ninth diode D9 and the second pin are jointly connected to the relay voltage Relay_12V; the emitter of the fifth triode Q5 is grounded; the base of the fifth triode Q5 is connected to the backup parking start signal (MMCU_IPB+) through the ninety-fourth resistor R94, and is connected to one end of the parallel-connected one-hundredth resistor R100 and the seventy-ninth capacitor C79, and the other end of the parallel connection is grounded;

[0038] The sixth pin is simultaneously connected to the positive electrode of the twelfth diode D10 and the collector of the seventh triode Q7; the negative electrode of the twelfth diode D10 and the seventh pin are jointly connected to the relay voltage Relay_12V; the emitter of the seventh triode Q7 is grounded; the base of the seventh triode Q7 is connected to the backup parking start signal (MMCU_IPB-) through the one-hundred-and-fourth resistor R104, and is connected to one end of the parallel-connected one-hundred-and-fifth resistor R105 and the eightieth capacitor C80, and the other end of the parallel connection is grounded;

[0039] The third pin and the eighth pin are power supply access ports, connected to the power supply unit; the fifth pin and the tenth pin are the parking motor power supply ports under the power supply of the shift domain control unit; the fourth pin and the ninth pin are the parking motor power supply ports under the power supply of the IPB.

[0040] As Figure 3As shown, the power supply unit includes a first power supply circuit and a second power supply circuit, where:

[0041] One end of the first power supply circuit is connected to the fourth pin of the electromagnetic relay K1, and accesses the second system voltage SYS_12V through the first four-six resistor R146, is grounded through the first four-eight resistor R148, and is simultaneously connected to the positive electrode of the twenty-second diode D20, one end of the first twenty capacitor C120, and one end of the first fifty-three resistor R153 through the third resistor R3. The negative electrode of the twenty-second diode D20 accesses the first system voltage SYS_5V, and the other end of the first twenty capacitor C120 is grounded; the other end of the first power supply circuit accesses the negative power supply (MMCU_EPB-_AD) of the shift domain control unit, is connected to the other end of the first fifty-three resistor R153 and is grounded through the first nineteen capacitor C119;

[0042] One end of the second power supply circuit is connected to the eighth pin of the electromagnetic relay K1, and accesses the second system voltage SYS_12V through the first four-nine resistor R149, is grounded through the first fifty-two resistor R152, and is simultaneously connected to the positive electrode of the twenty-first diode D21, one end of the first twenty-one capacitor C121, and one end of the first fifty-four resistor R154 through the first fifty-one resistor R151. The negative electrode of the twenty-first diode D21 accesses the first system voltage SYS_5V, and the other end of the first twenty-one capacitor C121 is grounded; the other end of the second power supply circuit accesses the positive power supply (MMCU_EPB+_AD) of the shift domain control unit, is connected to the other end of the first fifty-four resistor R154 and is grounded through the first eighteen capacitor C118.

[0043] As Figure 4 shown, it is a circuit schematic diagram of the parking motor. The positive electrode of the parking motor is connected to the fifth pin of the electromagnetic relay K1 and is grounded through the eighty-second capacitor C82 and the eighty-third capacitor C83 respectively; the negative electrode of the parking motor is connected to the tenth pin of the electromagnetic relay K1 and is grounded through the eighty-eighth capacitor C88 and the eighty-ninth capacitor C89 respectively; between the positive electrode and the negative electrode of the parking motor, they are connected through the eleventh voltage stabilizing diode D11 and the eighty-fourth capacitor C84 respectively.

[0044] In this circuit design, before the H-bridge relay receives the backup parking start signal, the third pin and the fourth pin, as well as the eighth pin and the ninth pin, are normally conducting; while when the H-bridge relay receives the backup parking start signal, it will attract the electromagnetic switch under the electromagnetic action, thus switching to the conducting state between the third pin and the fifth pin, and between the eighth pin and the tenth pin. In this way, the power supply to the IPB parking motor is switched to the power supply to the parking motor by the shift domain control unit, so that in the case where the IPB cannot perform normal braking control, the shift domain control unit performs the backup braking action on the left rear caliper. Further, during the whole process, the working current of the motor is monitored by the current detection module to perform the feedback of the braking control ratio.

[0045] To better understand the technical content of the present invention, the present invention is also described herein in the form of method steps, as Figure 5 shown, a backup braking method applied to parking braking includes the steps:

[0046] S1: Determine whether the backup parking start signal fed back by the IPB is received. If so, proceed to the next step; if not, supply power to the parking motor of the whole vehicle by the IPB and return to step S1;

[0047] S2: Disconnect the power supply to the parking motor of the IPB through the H-bridge relay and switch to supply power to the parking motor by the shift domain control unit;

[0048] S3: Perform braking control on the left rear brake disc after the parking motor is powered by the shift domain control unit.

[0049] In summary, for a backup braking circuit and its parking method applied to parking braking according to the present invention, by timely obtaining the state information of the IPB parking failure, the power supply to the parking motor is switched from the IPB to supply power to the parking motor to the shift domain control unit to supply power to the parking motor, effectively avoiding the occurrence of hazards caused by the IPB braking failure.

[0050] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0051] In addition, in the present utility model, descriptions such as "first", "second", "one", etc. are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0052] In the present utility model, unless otherwise clearly stipulated and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0053] In addition, the technical solutions between various embodiments of the present utility model can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

Claims

1. A backup braking circuit applied to parking braking, characterized in that, Comprising: IPB, which is used to supply power to the parking motor of the whole vehicle under normal conditions, and feedbacks a backup parking start signal to the shift domain control unit when the IPB reports a fault and the parking brake fails; The shift domain control unit is used to disconnect the power supply of the parking motor of the IPB through the H-bridge relay and switch to the shift domain control to supply power to the parking motor after receiving the backup parking start signal; The current detection module is used to detect the parking brake current fed back by the brake motor when the vehicle parking key is triggered, and the parking brake current is used to reflect the braking ratio; The parking motor directly controls the braking of the left rear brake disc after being powered by the shift domain control unit.

2. The backup braking circuit for parking braking according to claim 1, wherein The H-bridge relay includes a power supply switching unit and a power supply unit. The power supply unit is used to provide parking power supply for the parking motor, and the power supply switching unit is used to switch the flow direction of the supply current.

3. The backup braking circuit applied to parking braking according to claim 2, wherein The power supply switching unit includes an electromagnetic relay, which has pins from the first to the tenth, where: The first pin is simultaneously connected to the positive electrode of the ninth diode and the collector of the fifth triode; the negative electrode of the ninth diode and the second pin are connected to the relay voltage together; the emitter of the fifth triode is grounded; the base of the fifth triode is connected to the backup parking start signal through the ninety-fourth resistor and is connected to one end of the parallel-connected one-hundredth resistor and the seventy-ninth capacitor, and the other end of the parallel connection is grounded; The sixth pin is simultaneously connected to the positive electrode of the twelfth diode and the collector of the seventh triode; the negative electrode of the twelfth diode and the seventh pin are connected to the relay voltage together; the emitter of the seventh triode is grounded; the base of the seventh triode is connected to the backup parking start signal through the one-hundred-and-fourth resistor and is connected to one end of the parallel-connected one-hundred-and-fifth resistor and the eightieth capacitor, and the other end of the parallel connection is grounded; The third pin and the eighth pin are power supply access ports, connected to the power supply unit; the fifth pin and the tenth pin are the parking motor power supply ports under the power supply of the shift domain control unit; the fourth pin and the ninth pin are the parking motor power supply ports under the power supply of the IPB.

4. The backup braking circuit for parking braking according to claim 3, characterized in that Before the H-bridge relay receives the backup parking start signal, the third pin and the fourth pin, and the eighth pin and the ninth pin remain normally conducting; during the period when the H-bridge relay receives the backup parking start signal, it switches to the conducting state between the third pin and the fifth pin, and the eighth pin and the tenth pin.

5. The backup braking circuit applied to parking braking according to claim 3, characterized in that, The power supply unit includes a first power supply circuit and a second power supply circuit, where: One end of the first power supply circuit is connected to the fourth pin of the electromagnetic relay, accesses the second system voltage through the one-hundred-and-forty-sixth resistor, is grounded through the one-hundred-and-forty-eighth resistor, is simultaneously connected to the positive electrode of the twenty-second diode, one end of the one-hundred-and-twentieth capacitor and one end of the one-hundred-and-fifty-third resistor through the third resistor, the negative electrode of the twenty-second diode accesses the first system voltage, and the other end of the one-hundred-and-twentieth capacitor is grounded; the other end of the first power supply circuit accesses the negative power supply of the shift domain control unit, is connected to the other end of the one-hundred-and-fifty-third resistor and is grounded through the one-hundred-and-nineteenth capacitor; One end of the second power supply circuit is connected to the eighth pin of the electromagnetic relay, accesses the second system voltage through the first 149 resistor, is grounded through the first 152 resistor, and is simultaneously connected to the positive electrode of the twenty-first diode, one end of the first 21 capacitor, and one end of the first 154 resistor through the first 151 resistor. The negative electrode of the twenty-first diode accesses the first system voltage, and the other end of the first 21 capacitor is grounded; the other end of the second power supply circuit accesses the positive power supply of the shift domain control unit, is connected to the other end of the first 154 resistor, and is grounded through the first 118 capacitor.

6. The backup braking circuit for parking brake according to claim 1, wherein When the IPB supplies power to the parking motor of the whole vehicle, the pre-driver is used to drive and control the braking motor.

7. The backup braking circuit for parking braking according to claim 3, wherein The positive electrode of the parking motor is connected to the fifth pin of the electromagnetic relay and is grounded through the eighty-second capacitor and the eighty-third capacitor respectively; the negative electrode of the parking motor is connected to the tenth pin of the electromagnetic relay and is grounded through the eighty-eighth capacitor and the eighty-ninth capacitor respectively; the positive and negative electrodes of the parking motor are connected through the eleventh voltage stabilizing diode and the eighty-fourth capacitor respectively.

Images