JP2010162914A - Vacuum pump control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum pump control device reducing operation frequency of a vacuum pump and ensuring boosting function by a brake booster. <P>SOLUTION: The vacuum pump control device 10 for controlling the vacuum pump 7 for producing a negative pressure used in a negative pressure type brake booster 4 includes a constitution provided with a speed reduction operation detection means 3 for detecting speed reduction operation by a driver, in which the vacuum pump is operated for a predetermined period according to at least one of starting and completion of the speed reduction operation detected by the speed reduction operation control means and is stopped after that. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vacuum pump control device that generates negative pressure used in a brake booster of a vehicle such as an automobile.

  BACKGROUND ART A brake device for an automobile includes a brake booster that amplifies a braking force using an intake pipe negative pressure of an engine. In addition, it is known that an engine-electric hybrid vehicle in which the intake pipe negative pressure of the engine cannot be obtained or an electric vehicle not equipped with an engine generates negative pressure using an electric vacuum pump. Yes.

The vacuum pump as described above is normally operated and stopped according to the internal pressure of the negative pressure chamber of the brake booster, and is intermittently operated while the vehicle is running. If this is performed, the lifetime is remarkably shortened.
On the other hand, for example, in Patent Document 1, when the number of times of driving the vacuum pump motor when the load is not used is equal to or greater than a predetermined set value, it is determined that a negative pressure leak has occurred and that is the reason. And a vacuum pump control device that prompts the user to protect the vacuum pump and its motor.
Patent Document 2 describes a negative pressure system for a vehicle that determines whether a negative pressure leak and a negative pressure sensor are stuck, and protects a motor and the like by disabling an electric negative pressure pump when an abnormality occurs. Has been.

Japanese Patent Laid-Open No. 1-178070 JP 2008-68747 A

As described in Patent Document 2, if a vacuum pump malfunctions when a malfunction occurs in the negative pressure sensor, the negative pressure used in the brake booster is not generated and the boosting function is impaired, and the braking effect is reduced. Will fall.
On the other hand, for example, it is conceivable that the vacuum pump is continuously operated when the negative pressure sensor breaks down, or the on / off is repeated intermittently at a constant cycle. Since the vacuum pump operates even when the engine is not used, the operating frequency of the vacuum pump is increased and the service life is shortened. In the worst case, the boost function of the brake booster is impaired due to failure of the vacuum pump. In addition, power consumption increases as the operating frequency of the vacuum pump increases.
The subject of this invention is providing the vacuum pump control apparatus which reduced the operating frequency of the vacuum pump and ensured the boosting function by a brake booster.

The present invention solves the above-described problems by the following means.
The invention of claim 1 is a vacuum pump control device for controlling a vacuum pump for generating a negative pressure used in a negative pressure type brake booster, comprising a deceleration operation detecting means for detecting a deceleration operation by a driver, wherein the deceleration operation control In accordance with at least one of the start and end of the deceleration operation detected by the means, the vacuum pump is operated for a predetermined period and then stopped.

  The invention of claim 2 is a vacuum pump control device that controls a vacuum pump that generates a negative pressure used in a negative pressure type brake booster, the negative pressure sensor detecting a negative pressure in a negative pressure chamber of the brake booster, An abnormality detection means for detecting an abnormality of the negative pressure sensor and a deceleration operation detection means for detecting a deceleration operation by a driver, and the negative pressure sensor when the abnormality detection means does not detect an abnormality of the negative pressure sensor In response to the output of the vacuum pump, the first control for operating and stopping the vacuum pump is performed, and the deceleration operation detected by the deceleration operation control means when the abnormality detection means detects an abnormality of the negative pressure sensor. Performing a second control for operating the vacuum pump for a predetermined period and then stopping the vacuum pump according to at least one of the start and end of A vacuum pump control apparatus according to symptoms.

  The invention according to claim 3 is the vacuum pump control device according to claim 1 or 2, wherein the deceleration operation detecting means detects an operation of the brake device by the driver.

  According to the present invention, the vacuum pump is operated for a predetermined period in accordance with at least one of the start and end of the deceleration operation by the driver and then stopped, so that at the start or end of braking where negative pressure is consumed. A negative pressure is generated, and a boosting function can be secured by a negative pressure type brake booster. In addition, since the vacuum pump does not operate when traveling at a constant speed where no negative pressure is consumed, the motor can be prevented from burning and the life of the vacuum pump can be extended. In addition, by reducing the operating frequency of the vacuum pump and reducing the power consumption, in the case of an electric vehicle etc., it is possible to preserve the electric power for traveling and extend the cruising distance, and in the case of a vehicle with an engine It is possible to reduce the power generation load and improve the fuel consumption rate.

It is a figure which shows the structure of the brake device which has the Example of the vacuum pump control apparatus to which this invention is applied. It is a flowchart which shows the fail safe control of the vacuum pump in the vacuum pump control apparatus of FIG. It is a timing chart which shows the vacuum pump action | operation at the time of performing the fail safe control of FIG.

  The present invention provides a vacuum pump control device that reduces the frequency of operation of a vacuum pump and secures a boosting function by a brake booster. After the state of a brake lamp switch transitions between on and off, a predetermined The problem was solved by turning on the vacuum pump over time and then shutting it down.

Embodiments of a vacuum pump control apparatus to which the present invention is applied will be described below.
FIG. 1 is a diagram illustrating a configuration of an automobile brake device including a vacuum pump control device according to an embodiment. In FIG. 1, the flow of mechanical force is indicated by solid arrows, the flow of vacuum pump driving power is indicated by dotted arrows, and the flow of various signals is indicated by dashed-dotted arrows.
The brake device 1 is provided in a passenger vehicle such as an electric vehicle that does not have an engine as a negative pressure generation source and an engine-electric hybrid vehicle that has an electric vehicle traveling mode in which the engine is stopped.

  The brake device 1 includes a brake pedal 2, a brake lamp switch (BLS) 3, a brake booster 4, a negative pressure sensor 5, a master cylinder 6, a vacuum pump 7, a battery 8, a relay 9, a controller 10, and the like. .

The brake pedal 2 is an operation input unit that performs a braking operation when the driver steps on the foot.
BLS3 is a switch that is incorporated in the brake pedal 2 and is turned on when the driver depresses the brake pedal 2, and is turned off when the driver releases the brake pedal 2. The output of BLS3 is input to a brake lamp relay (not shown) and the controller 10. The BLS 3 functions as a deceleration operation detecting means according to the present invention that detects a braking operation by a driver.

The brake booster 4 is a vacuum booster that applies assist force to the input from the brake pedal 2 using the negative pressure generated by the vacuum pump 7 and transmits the resultant force to the master cylinder 6.
The negative pressure sensor 5 transmits an output signal corresponding to the pressure in the negative pressure chamber of the brake booster 4 to the controller 10.
The master cylinder 6 pressurizes the brake fluid of the hydraulic service brake in response to the input from the brake booster 4 and causes the wheel cylinders provided in the brake calipers of the wheels to press the friction material such as brake pads. Generate braking force.

The vacuum pump 7 is an electric pump that generates negative pressure used in the brake booster 4.
The battery 8 is a secondary battery such as a lithium ion battery or a nickel hydride battery, for example, and is charged by a charging facility provided outside the vehicle or a generator mounted on the vehicle. The power for driving the pump 7 is supplied.
The relay 9 is provided in a wiring for supplying electric power from the battery 8 to the vacuum pump 7, and switches between energization and interruption according to a control current from the controller 10.

The controller 10 controls the operation and stop of the vacuum pump 7 via the relay 9 based on inputs from the BLS 3 and the negative pressure sensor 5 and the like. The controller 10 includes, for example, a storage unit such as a RAM and a ROM, an information processing unit such as a CPU, an input / output interface, and the like.
The controller 10 also functions as an abnormality detection means for detecting an abnormality such as a failure or disconnection of the negative pressure sensor 5. The abnormality of the negative pressure sensor 5 is diagnosed based on the abnormality of the output value. For example, when the output voltage value is fixed to a constant voltage value, it is determined that it is abnormal.

  When the abnormality of the negative pressure sensor 5 is not detected, the controller 10 performs normal control (first control) of the vacuum pump 7 based on the negative pressure detected by the negative pressure sensor 5. Specifically, when the detected value of the negative pressure sensor 5 is higher than a predetermined vacuum pump operating threshold (approaching atmospheric pressure), the vacuum pump 7 is operated, and then the detected value of the negative pressure sensor 5 is When the pressure becomes lower than a predetermined vacuum pump stop threshold, the vacuum pump 7 is stopped.

Further, when an abnormality of the negative pressure sensor 5 is detected, the controller 10 performs fail-safe control (second control) described below.
FIG. 2 is a flowchart showing fail-safe control.
Hereinafter, the steps will be described step by step.

<Step S01: BLS determination>
The controller 10 determines whether or not BLS3 is on. If the BLS3 is on, the controller 10 proceeds to step S02. If the BLS3 is off, the process proceeds to step S07.

<Step S02: Counter 2 = 8 sec>
The controller 10 sets the counter value of the counter 2, which is a timer for managing the operation time of the vacuum pump 7 after the BLS 3 transitions from on to off, to 8 sec.
Thereafter, the process proceeds to step S03.

<Step S03: Counter 1 judgment>
The controller 10 determines whether or not the counter value of the counter 1 that is a timer for managing the operation time of the vacuum pump 7 after the BLS 3 transitions from OFF to ON exceeds zero. If the counter value of counter 1 is greater than zero, the process proceeds to step S04, and if it is zero, the process proceeds to step S06.

<Step S04: Counter 1 decrement>
The controller 10 decreases the counter value of the counter 1 by a predetermined value.
Thereafter, the process proceeds to step S05.

<Step S05: Vacuum pump on>
The controller 10 controls the relay 9 to energize the vacuum pump 7 and operates the vacuum pump 7.
Thereafter, the process returns, the process returns to step S01, and the subsequent processing is repeated.

<Step S06: Vacuum pump off>
The controller 10 controls the relay 9 to cut off the power supply to the vacuum pump 7 and stops the vacuum pump 7.
Thereafter, the process returns, the process returns to step S01, and the subsequent processing is repeated.

<Step S07: Counter 1 = 8 sec>
The controller 10 sets the counter value of the counter 1 described above to 8 seconds.
Thereafter, the process proceeds to step S08.

<Step S08: Determination of Counter 2>
The controller 10 determines whether or not the counter value of the counter 2 described above exceeds zero. When the counter value of the counter 2 is greater than zero, the process proceeds to step S09, and when it is zero, the process proceeds to step S11.

<Step S09: Counter 2 decrement>
The controller 10 decreases the counter value of the counter 2 by a predetermined value.
Then, it progresses to step S10.

<Step S10: Vacuum pump on>
The controller 10 controls the relay 9 to energize the vacuum pump 7 and operates the vacuum pump 7.
Thereafter, the process returns, the process returns to step S01, and the subsequent processing is repeated.

<Step S11: Vacuum pump off>
The controller 10 controls the relay 9 to cut off the power supply to the vacuum pump 7 and stops the vacuum pump 7.
Thereafter, the process returns, the process returns to step S01, and the subsequent processing is repeated.

FIG. 3 is a timing chart showing the operation of the vacuum pump when the above-described fail-safe control is performed.
As shown in FIG. 3, the vacuum pump 7 operates and stops for 8 seconds immediately after the BLS 3 transitions from ON to OFF, and operates and stops for 8 seconds immediately after the BLS 3 transitions from OFF to ON.
The operating time of the vacuum pump 7 (8 seconds in the embodiment) is, for example, from a state where the negative pressure chamber of the brake booster 4 is almost atmospheric pressure to a pressure (negative pressure) at which a necessary braking assist force can be obtained. 7 is set in consideration of the time required for vacuum suction.

According to the embodiment described above, after the brake pedal 2 is operated and the state of the BLS 3 transitions between on and off, the negative pressure is reduced by, for example, operating the vacuum pump 7 for 8 seconds and then stopping. A negative pressure is generated at the start or end of consumed braking, and a boosting function by the brake booster 4 can be secured. Further, since the vacuum pump 7 is not driven when traveling at a constant speed where no negative pressure is consumed, the life of the vacuum pump 7 can be extended.
Further, by reducing the operation frequency of the vacuum pump 7, it is possible to reduce power consumption and extend the cruising distance of the vehicle.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
(1) In the embodiment, the vacuum pump is operated both at the start and at the end of the braking operation by the driver. However, the present invention is not limited to this, either at the start or at the end of the braking operation. Only the vacuum pump may be activated. Further, the time for operating the vacuum pump is not particularly limited.
(2) In the embodiment, the driver's braking operation is detected based on on / off of the brake lamp switch, but the method of detecting the braking operation is not limited to this. For example, the brake operation may be detected based on the pressure of the brake fluid or the stroke of the brake pedal. Further, the driver's deceleration operation may be detected based on a full closing operation of the accelerator pedal, a change in the vehicle speed detected by the vehicle speed sensor, a longitudinal acceleration acting on the vehicle body, or the like.
(3) In the embodiment, the abnormality of the negative pressure sensor is detected based on the fixed output value, but the method for detecting the abnormality of the negative pressure sensor is not particularly limited. For example, a plurality of negative pressure sensors may be provided, and an abnormality may be detected based on the difference between the output values.
(4) In the embodiment, the vehicle is, for example, an electric vehicle or an engine-electric hybrid vehicle. However, the vehicle to be mounted is not limited to this. The vehicle may be equipped with an engine in which intake pipe negative pressure is difficult to obtain, such as a diesel engine that adjusts the output by the injection amount.

DESCRIPTION OF SYMBOLS 1 Brake device 2 Brake pedal 3 Brake lamp switch 4 Brake booster 5 Negative pressure sensor 6 Master cylinder 7 Vacuum pump 8 Battery 9 Relay 10 Controller

Claims (3)

A vacuum pump control device that controls a vacuum pump that generates negative pressure used in a negative pressure brake booster,
A deceleration operation detecting means for detecting a deceleration operation by the driver is provided.
The vacuum pump control device, wherein the vacuum pump is operated for a predetermined period and then stopped according to at least one of the start and end of the deceleration operation detected by the deceleration operation control means. A vacuum pump control device that controls a vacuum pump that generates negative pressure used in a negative pressure brake booster,
A negative pressure sensor for detecting negative pressure in the negative pressure chamber of the brake booster;
An abnormality detecting means for detecting an abnormality of the negative pressure sensor;
A deceleration operation detecting means for detecting a deceleration operation by a driver,
When the abnormality detection means does not detect an abnormality of the negative pressure sensor, a first control is performed to operate and stop the vacuum pump according to the output of the negative pressure sensor, and the abnormality detection means When a sensor abnormality is detected, a second control for operating the vacuum pump for a predetermined period and then stopping it according to at least one of the start and end of the deceleration operation detected by the deceleration operation control means. A vacuum pump control device characterized in that: The vacuum pump control device according to claim 1, wherein the deceleration operation detection unit detects an operation of the brake device by the driver.

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