JP2012254788A - Equivalent circuit to start electric vacuum pump at failure of controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an equivalent circuit that generates the negative pressure indispensable to actuate a negative pressure brake booster by other method in an internal combustion engine without a throttle valve such as a diesel engine or a present gasoline engine that performs gasoline direct injection.SOLUTION: An electric vacuum pump 200 and a signal output part 130 are mutually connected so that the signal to start the electric vacuum pump is output from the signal output part. The second signal input part 120 is connected with the signal output part so that the output of the signal that starts the electric vacuum pump is suppressed in the signal output part 130, when a reference signal 121 that shows that the first control device 140 can operate is applied to the second signal input part.

Description

  The present invention relates to an equivalent circuit used for a brake amplifying apparatus in an automobile, and more particularly to an equivalent circuit for starting an electric vacuum pump when a controller fails.

  In current cars, the driver is assisted by a brake booster during braking. The brake booster reduces the operating force essential for braking the vehicle. For this purpose, the auxiliary force provided by the brake booster is generated by a differential pressure between the negative pressure formed in the brake booster and the atmospheric pressure in a negative pressure brake booster generally used in an automobile.

  Even when a brake booster is installed, the brake pedal acts directly on the brake master cylinder as in the case of a brake system without a conventional amplifier, and the master brake cylinder supplies the brake fluid used to transmit the brake force. Pumps into a pipeline system that communicates with the brake. The brake booster supports the pumping pressure via a diaphragm in the cylinder, and a negative pressure is applied to the stop position of the brake booster, that is, to both sides of the diaphragm when the brake is not operated. When the brake pedal is operated, atmospheric pressure is applied to the diaphragm via the valve on the side facing the pedal, thereby assisting the brake force applied to the pedal in the same direction of action based on the adjusted differential pressure. Force to do.

  In this case, the negative pressure indispensable in the brake booster can be generated in various forms. In an internal combustion engine having a throttle valve in the suction line, a reduced pressure relative to the ambient pressure is generated behind the throttle valve and this pressure can be guided into the brake booster. Of course, this negative pressure is arranged only in the partial load region of the engine. At full load when the throttle valve is fully open, there is no negative pressure that can be guided to the brake booster.

  For example, in an internal combustion engine without a throttle valve, as in the case of a diesel engine or a current gasoline engine with direct gasoline injection, the negative pressure necessary to operate the negative pressure brake booster must be generated in other ways. . The generation of the negative pressure can be performed by, for example, a mechanical vacuum pump (MVP) or an electric vacuum pump (EVP). In general, EVP is used to generate the negative pressure that is essential in current vehicles by providing a simpler configuration and better adjustability. Furthermore, EVP has the advantage that a vacuum can be generated regardless of the operating state of the internal combustion engine. This is particularly important in a vehicle having a start-stop function, a hybrid vehicle, or an electric vehicle.

  The pump is controlled and adjusted by a controller. Such an EVP control unit is incorporated in various forms in a controller that accommodates an electronic stability program (ESP) that is currently generally incorporated in a vehicle. ESP affects the distribution of driving and braking forces to the individual wheels of the vehicle through anti-lock braking systems and slip control mechanisms.

  If the vacuum pump can no longer be driven due to a controller error, the driver must brake the vehicle without assistance from the brake booster because no negative pressure is provided to operate the brake booster. Even in such a case, it is necessary to ensure that the brake device satisfies the laws and regulations concerning the deceleration action. However, even if the regulations regarding deceleration are met, the operating force of the braking device resulting from the lack of vacuum is felt at least uncomfortable and even frustrating for the driver.

  According to the present invention, an equivalent circuit for starting an electric vacuum pump with a brake booster device is proposed, the equivalent circuit comprising a first signal input for supplying a signal representing a brake operation, for example an ESP control. A second signal input unit for supplying a reference signal for a primary control device of an electric vacuum pump such as a vacuum vessel, and a signal output unit for controlling the electric vacuum pump, the first signal input unit and the signal output unit Is interconnected so that a signal for starting an electric vacuum pump is output at the signal output unit when a signal representing a brake operation is input to the first signal input unit, and the second signal input unit is When the reference signal indicating that the ESP controller can be operated is applied to the second signal input unit, the signal output unit suppresses the output of the signal for starting the electric vacuum pump. Connect to output It has been.

  The equivalent circuit according to the present invention ensures a sufficient vacuum supply to maintain the brake amplification even when the ESP controller as the EVP primary controller fails or stops.

  The equivalent circuit according to the invention evaluates whether the brake has been operated. For this purpose, for example, information on the brake light switch can be taken into account. Alternatively and / or additionally, information on brake lights, brake pressure sensors, force sensors, force switches, pedal distance sensors and / or pedal angle sensors can be taken into account for detecting brake operation. When a brake operation is detected, a control signal for controlling the EVP is generated. Along with the evaluation of the brake operation, the equivalent circuit receives information on the operating state or availability of the primary controller of the EVP in the form of a reference signal. When the primary control device is operable and control without an EVP error is ensured by the primary control device according to the reference signal, the output of the control signal generated by the equivalent circuit to the EVP is suppressed. If there is no reference signal, and therefore it is assumed that the primary controller cannot be operated, the control signal generated by the equivalent circuit is output to the EVP, ensuring a sufficient vacuum supply to the brake booster.

  In one configuration of the invention, the equivalent circuit includes a current supply separate from the primary controller (140). This further increases the operational reliability. In this case, the separate current supply is advantageously designed in such a way that the availability of this separate current supply is ensured without a large time lag when the vehicle system is started.

  According to another configuration of the invention, the separate current supply is designed to also supply the vacuum pump with the voltage essential for operation when a signal is output to the vacuum pump via the signal output. . This provides additional system redundancy.

  According to another configuration of the present invention, the equivalent circuit includes a monitoring circuit, and the monitoring circuit can monitor the operability of the equivalent circuit and can output an error signal when an error occurs. As a result, malfunction can be ascertained early and operational reliability can be ensured.

  In one configuration of the equivalent circuit according to the present invention, the equivalent circuit includes a delay module, and a signal for starting the electric vacuum pump by the delay module is sent to the signal output unit with a delay t1 that can be defined after the signal representing the brake operation is input. Can be output. This advantageously prevents adverse effects due to signal quality. In another configuration, the signal output unit can output a signal for starting the electric vacuum pump by the delay module exceeding the application time of the signal representing the brake operation by the time t2. As a result, it is possible to compensate for the vacuum loss that occurs in the brake booster when the brake is released.

Furthermore, the present invention is a method for compensating for malfunctions when controlling an electric vacuum pump by a primary controller of a brake booster system, comprising the following method steps:
Supplying a signal representing a brake operation to an equivalent circuit;
Providing a reference signal representative of the operability of the primary controller to the equivalent circuit;
Generating a signal for starting an electric vacuum pump;
When a signal indicating the operability of the primary control device is applied to the signal input section of the equivalent circuit, the signal output section of the equivalent circuit suppresses the output of a signal for starting the electric vacuum pump. It relates to the method.

  In one configuration of the method according to the invention, the generation of the signal for starting the electric vacuum pump and / or the output at the signal output of the equivalent circuit is delayed when a signal representing the brake operation is applied for a time t1. . This avoids adverse effects due to signal quality.

  In another configuration of the method according to the invention, the generation of the signal for starting the electric vacuum pump and / or the output at the signal output part of the equivalent circuit is the application time of the signal representing the brake operation for a time t2 representing the brake operation Is applied at a signal output unit. Thereby, it is possible to compensate for the vacuum loss that may occur in the brake booster due to the release of the brake.

  In another configuration of the method according to the invention, a signal for starting the electric vacuum pump is applied to the brake output at the signal output of the equivalent circuit when a reference signal indicating preparation of the primary control device is not applied to the equivalent circuit. Is output in the form of pulses regardless of the presence or absence of a signal representing. This ensures a continuous vacuum supply to the brake booster in the event of a failure of the primary controller and ensures that the brake operation can be monitored, which means that further redundancy of the system and thus failure Contributes to safety against

  Next, the present invention will be further described with reference to the drawings.

FIG. 3 is a functional schematic diagram of an equivalent circuit according to the present invention when the primary control device is operable. It is a functional schematic diagram of an equivalent circuit according to the present invention when the primary control device fails. It is a figure which shows the output delay of the control signal to a vacuum pump.

  FIG. 1 shows a schematic diagram of the operation of the equivalent circuit 100 according to the invention when the primary controller 140 is operable. An equivalent circuit 100 for starting the electric vacuum pump 200 by the brake booster device 300 includes a first signal input unit 110 for supplying a signal 111 representing a brake operation, and a primary controller 140 of the electric vacuum pump 200. And a second signal input unit 120 for supplying a reference signal 121. In this case, for example, the ESP controller can serve as the primary controller 140. Further, the equivalent circuit includes a signal output unit 130 for controlling the electric vacuum pump 200. The first signal input unit 110 and the signal output unit 130 are connected to each other, and when the signal 111 indicating the brake operation is input to the first signal input unit 110, a signal 131 for starting the electric vacuum pump 200. Is output from the signal output unit 130. The second signal input unit 120 is connected to the signal output unit 130. When the reference signal 121 indicating that the primary control device 140 is operable is applied to the second signal input unit 120, the signal output is performed. The output of the signal 131 for starting the electric vacuum pump 200 in the unit 130 is suppressed. The starting of the electric vacuum pump 200 is obtained by an operable primary controller 140. Further, in the equivalent circuit 100, a delay module that can delay the output of the signal 131 with respect to the input of the signal 111 is disposed.

  FIG. 2 shows a schematic diagram of the operation of the equivalent circuit according to the invention when the primary controller 140 fails. If the primary controller 140 fails and thus the primary controller 140 cannot be operated, the electric vacuum pump 200 cannot be started by the primary controller 140. Since the operation of the primary control device 140 is not possible, the reference signal 121 is not applied to the signal input unit 120. Since the signal 111 indicating the brake operation is applied to the signal input unit 110 in order to start the electric vacuum pump 200, the output of the control signal 131 generated by the equivalent circuit is not suppressed and is transmitted through the signal output unit 130. And output to the electric vacuum pump 200. As a result, even when the primary control device 140 cannot be operated, the electric vacuum pump 200 is started when the brake is operated, and sufficient vacuum supply to the brake booster device 300 is ensured.

  FIG. 3 shows the output delay of the control signal to the vacuum pump. The delay module 150 delays the output of the signal 131 for starting the electric vacuum pump by t1 with respect to the input of the signal 111 in the signal input unit 110. This can prevent adverse effects that may occur due to the quality of the signal 111. Further, the delay module 150 can delay the output of the signal 131 by t2 from the application of the signal 111. As a result, a vacuum is generated even if the brake operation time is exceeded by the electric vacuum pump, and the brake is released. The resulting vacuum loss in the brake booster can be compensated. Further, the delay module 150 can output a signal 131 for starting the electric vacuum pump in a pulse shape. For this reason, the signal 131 is output over time t3, and the output is suppressed over time t4. Thus, the signal 131 for starting the electric vacuum pump is output in a pulse shape, so that the vacuum pump is continuously operated during the brake operation, and accordingly, the vacuum pump is excessively loaded with heat. It is prevented.

100 equivalent circuit 110 first signal input unit 111 signal 120 second signal input unit 121 reference signal 130 signal output unit 131 signal 140 primary control signal 150 delay module 200 electric vacuum pump 300 brake booster device

Claims (10)

  In an equivalent circuit (100) for starting the electric vacuum pump (200) by the brake booster device (300), the equivalent circuit supplies a signal (111) representing a brake operation. 110), a second signal input unit (120) for supplying a reference signal (121) of a primary controller (140) of an electric vacuum pump such as an ESP controller, and the electric vacuum pump (200). A signal output unit (130) for controlling, and the first signal input unit (110) and the signal output unit (130) receive a signal representing a brake operation in the first signal input unit (110). When the signal is input, the electric vacuum pump (200) is interconnected so that a signal for starting the electric vacuum pump (200) is output from the signal output unit (130), and the second signal input unit (120) When the reference signal (121) indicating that the P controller (140) can be operated is applied to the second signal input unit, the output of the signal for starting the electric vacuum pump is the signal output unit ( 130), an equivalent circuit, characterized in that it is connected to the signal output unit so as to be suppressed in step 130).   The equivalent circuit according to claim 1, wherein the signal representing the brake operation is a signal of a brake light, a brake light switch, a brake pressure sensor, a force sensor, a force switch, a pedal distance sensor and / or a pedal angle sensor.   The equivalent circuit according to claim 1, wherein the equivalent circuit includes a current supply unit that is separate from the primary control device.   The said separate electric current supply part is designed so that the voltage indispensable for operation may be supplied also to the said vacuum pump (200) at the time of the output of the signal via the said signal output part (130). Equivalent circuit.   The equivalent circuit includes a monitoring circuit, the operability of the equivalent circuit (100) can be monitored by the monitoring circuit, and an error signal can be output when an error occurs. An equivalent circuit according to claim 1.   The equivalent circuit includes a delay module (150), and a signal (131) for starting the electric vacuum pump (200) by the delay module (150) is defined after input of the signal (111) indicating the brake operation. 6. The equivalent circuit according to claim 1, wherein the signal output unit (130) can output the signal with a possible delay t1.   The signal (131) for starting the electric vacuum pump (200) exceeds the application time of the signal (111) indicating the brake operation by the delay module (150) for a time t2, and is output from the signal output unit (130). The equivalent circuit according to claim 6, wherein output is possible. A method for compensating malfunctions when controlling an electric vacuum pump (200) by an ESP device (140) of a brake booster system (300), the following method steps:
Supplying a signal (111) representing a brake operation to the equivalent circuit (100);
Supplying a reference signal (121) representative of the operability of the ESP controller (140) to the equivalent circuit (100);
Generating a signal (131) for starting the electric vacuum pump (200).
When a signal indicating the operability of the ESP control device (140) is applied to the signal input unit (120) of the equivalent circuit (100), the signal output unit (130) of the equivalent circuit (100). And suppressing the output of the signal (131) for starting the electric vacuum pump (200).   The generation of the signal (131) for starting the electric vacuum pump (200) and / or the output at the signal output unit (130) of the equivalent circuit (100), the signal (111) representing the brake operation is time t1 9. The method of claim 8, wherein the method is delayed if only applied.   The generation of the signal (131) for starting the electric vacuum pump (200) and / or the output at the signal output unit (130) of the equivalent circuit (100) indicates that the signal (111) indicating the brake operation is only at time t2. The method according to claim 8 or 9, wherein the signal output unit (130) outputs the signal when a signal representing a brake operation is applied beyond an application time.

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