JP2006347192A - Hydraulic brake system and self-excited vibration sensing method for linear valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic brake system using linear valves capable of enhancing its practical applicability. <P>SOLUTION: The brake system using linear valves to a pressure boosting valve 70 and a decompression valve 72 for increasing or decreasing the liquid pressure in each wheel cylinder is formed able to execute at least one of the sensing process for the self-excited vibration of the linear valve and the eliminating process for the self-excited vibration. Sensing the self-excited vibration is conducted using a method of frequency analysis on the basis of the periodic variation of the liquid pressure in the wheel cylinder. The eliminating process is conducted so that a shutoff valve 92 is installed between a reserver 26 and the decompression valve 72, and by operating the shutoff valve, inside the boosting valve and the decompression valve is put under a pressurized condition so as to nullify bubbles in the valves. The sensing process and the eliminating process may be executed during a vehicle being stopped, but even during running, these processes can be executed by installing a shutoff valve 90 between each wheel cylinder 24 and decompression valve and putting the shutoff valves in operation. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a hydraulic brake system including a linear valve, and more particularly, to a hydraulic brake system having a function to cope with self-excited vibration of the linear valve, and to a method for detecting self-excited vibration of the linear valve.

In a hydraulic brake system that employs a linear valve as a hydraulic control valve for a wheel cylinder, as described in the following patent document, the linear valve is susceptible to self-excited vibration.
JP 2003-252189 A

  Since the self-excited vibration of the linear valve impairs the comfort in driving the vehicle due to the vibration noise etc. accompanying it, effectively dealing with the self-excited vibration improves the practicality of the hydraulic brake system It leads to letting. This invention is made | formed in view of such a situation, and makes it a subject to improve the practicality of the hydraulic brake system which employ | adopted the linear valve.

  In order to solve the above-described problems, a hydraulic brake system according to the present invention is a brake system that employs a linear valve as at least one of a pressure increasing valve and a pressure reducing valve for increasing and decreasing a wheel cylinder hydraulic pressure. The target linear valve that is at least one of the target linear valve is configured to be capable of executing at least one of a process for detecting self-excited vibration of the target linear valve and a process for eliminating the self-excited vibration of the target linear valve. It is characterized by that. Moreover, the self-excited vibration detection method for a linear valve according to the present invention is characterized in that self-excited vibration is detected based on periodic fluctuations in hydraulic pressure during operation of the linear valve.

  Since the hydraulic brake system of the present invention is configured to be able to execute the above processing, it is possible to effectively cope with self-excited vibration and improve the practicality of the hydraulic brake system employing a linear valve. It becomes possible to make it. Further, according to the self-excited vibration detection method of the present invention, it is possible to easily detect the self-excited vibration of the linear valve, for example, effective detection for improving the practicality of a brake system employing the linear valve. Become a method.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following items, (1) corresponds to claim 1, (2) and (3) are combined in claim 2, (6) in claim 3, ( The combination of (13) and (14) is in claim 4, (17) is in claim 5, (22) is in claim 6, (23) is in claim 7, ( The combination of the items (27) and (28) corresponds to claim 8 respectively. The (41) term corresponds to the ninth claim.

(1) A brake having a wheel cylinder for braking the wheel, a hydraulic pressure source, a reservoir, a pressure increasing valve provided between the wheel cylinder and the hydraulic pressure source, the wheel cylinder and the reservoir, A hydraulic brake system including a pressure reducing valve provided between the pressure increasing valve and a valve control device that controls the pressure increasing valve and the pressure reducing valve,
At least one of the pressure increasing valve and the pressure reducing valve is a linear valve,
For a target linear valve that is at least one of the linear valves, self-excited vibration detection processing that is a process for detecting self-excited vibration of the target linear valve, and elimination of self-excited vibration of the target linear valve A hydraulic brake system configured to be capable of executing a self-excited vibration process that is at least one of a self-excited vibration canceling process that is a process for the purpose.

  The mode described in this section is a function for dealing with self-excited vibration of the linear valve in a hydraulic brake system employing a linear valve, that is, a function for detecting self-excited vibration and self-excited vibration. This is a mode having at least one of the functions. As explained earlier, the vibration noise generated by self-excited vibration becomes a factor that impedes the comfort of driving the vehicle. Therefore, if self-excited vibration can be detected and eliminated, self-excited vibration It becomes possible to cope effectively, and it becomes possible to improve the practicality of the hydraulic brake system employing a linear valve. In this embodiment, one of the pressure increasing valve and the pressure reducing valve may be a linear valve, and the self-excited vibration process for the linear valve can be executed. Both the pressure valve and the pressure reducing valve may be linear valves, and the self-excited vibration process for either one or both of the two linear valves may be executed.

  Various causes of the self-excited vibration of the linear valve are conceivable, and the aspect of this section can broadly target the self-excited vibration due to the various causes. According to the present inventor, from the research on the self-excited vibration, it is considered that the cause of the self-excited vibration is the bubble existing in the linear valve, and the aspect of this section is suitable for the self-excited vibration caused by the bubble. It becomes the aspect which can cope with.

  (2) The hydraulic brake system according to (1), wherein the hydraulic brake system is configured to execute at least the self-excited vibration detection process as the anti-excited vibration process.

  A series of terms after this term is a term describing various modes capable of executing the self-excited vibration detection process.

  (3) The hydraulic brake system includes a self-excited vibration detecting device that detects self-excited vibration of the target linear valve based on a periodic fluctuation of the hydraulic pressure when the target linear valve is operated (2) The hydraulic brake system according to item.

  The mode described in this section is a mode provided with a self-excited vibration detection device. When self-excited vibration occurs, the hydraulic pressure fluctuates periodically. Therefore, the self-excited vibration can be easily detected by detecting the periodic fluctuation of the hydraulic pressure. The "hydraulic pressure" here is preferably the hydraulic pressure downstream of the closing portion of the linear valve when the target linear valve is a pressure increasing valve, and when the target linear valve is a pressure reducing valve, It is desirable that the hydraulic pressure is upstream of the closing portion. More specifically, for example, when the system includes a sensor that detects the wheel cylinder hydraulic pressure, it is possible to detect self-excited vibration based on a change in a detection value by the sensor.

  (4) The liquid according to (3), wherein the self-excited vibration detecting device detects self-excited vibration of the target linear valve by frequency analysis of a change in hydraulic pressure during operation of the target linear valve. Pressure brake system.

  If frequency analysis is used as in the aspect described in this section, detection based on periodic fluctuations in hydraulic pressure can be easily performed. In the aspect of this section, for example, processing according to the fast Fourier transform method can be adopted, and rapid detection is possible according to the processing according to the method. When executing a process according to the fast Fourier transform technique, for example, the self-excited vibration detection device can be configured mainly by a computer, and the computer can execute the process.

  (5) The self-excited vibration detection device detects self-excited vibration of the target linear valve based on the peak frequency and intensity of the power spectrum obtained by the frequency analysis. Hydraulic brake system.

  According to the frequency analysis, a power spectrum for hydraulic pressure fluctuation can be acquired, and the mode of this section is a mode of detecting self-excited vibration based on the power spectrum. Specifically, for example, when the intensity of a peak existing in a frequency range where self-excited vibration may occur exceeds the set threshold intensity, it is determined that self-excited vibration has occurred, and the recognition It is possible to detect self-excited vibration.

  (6) Any one of the items (2) to (5), wherein the hydraulic brake system is configured to execute the self-excited vibration detection process when the brake fluid temperature is a set fluid temperature. The hydraulic brake system according to the above.

  The present inventor has understood from self-excited vibration research that the self-excited vibration of the linear valve depends on the temperature of the brake fluid, and that the higher the fluid temperature, the easier the self-excited vibration occurs. Therefore, it is possible to effectively cope with the self-excited vibration by detecting the self-excited vibration in association with the fluid temperature of the brake fluid. The embodiment of this section is a useful embodiment from such a viewpoint. The “brake fluid temperature” in the description of this section may be the fluid temperature at any location in the hydraulic brake system, but is desirably the fluid temperature at a location where the temperature is relatively high. The fluid temperature of the brake fluid in the aspect of this section may be measured directly, or in the case where a component of the system including the linear valve is present in the engine room, etc. It is possible to simulate the temperature of the brake fluid with the temperature in the engine room. Specifically, some temperature sensor may be provided, and the self-excited vibration detection process may be executed based on the detection value by the sensor. Note that the mode of this section is not limited to the set liquid temperature of 1, but a plurality of different set liquid temperatures are set, and self-excited vibration detection processing is performed at various liquid temperatures. It can also be configured to be executable. The set liquid temperature may be set as a range having a certain width.

  (7) The hydraulic brake system according to any one of (2) to (6), wherein the hydraulic brake system includes a storage device that stores a detection result of self-excited vibration of the target linear valve.

  If the detection results of self-excited vibration are stored, diagnosis of the degree of occurrence of self-excited vibration, identification of the cause of self-excited vibration, and the urgency of measures to eliminate self-excited vibration are based on the detection result It is possible to effectively cope with self-excited vibrations such as determination and determination of a specific method of treatment. The embodiment described in this section is an excellent embodiment from that viewpoint. If the vehicle is provided with a diagnosis device (diagnosis) for diagnosing its own status, the storage unit of the diagnosis device can also function as the storage device.

  (8) The storage device relates to at least one of a brake fluid temperature, a hydraulic pressure difference before and after the operation of the target linear valve, and a hydraulic pressure change gradient in the operation of the target linear valve. The hydraulic brake system according to item (7), which stores a detection result of self-excited vibration.

  The fluid temperature, fluid pressure difference, and fluid pressure change gradient listed in this section are factors related to the occurrence of self-excited vibration, more specifically, factors indicating the possibility of self-excited vibration. If the detection result of the self-excited vibration is stored in association with this factor, the self-excited vibration can be dealt with more effectively.

  (9) The hydraulic brake system includes a detection result transmission device that transmits the detection result of the self-excited vibration of the target linear valve to the outside of the vehicle via the in-vehicle communication device. The hydraulic brake system according to any one of the above.

  If it is possible to transmit the detection result of self-excited vibration to the outside of the vehicle by a communication device mounted on the vehicle, more specifically, for example, to a dealer capable of maintaining the vehicle, an external engine such as a vehicle support center, etc. The remote diagnosis of vibration, determination of treatment direction, and the like can be performed by those external organizations, and convenience is improved. Further, if the diagnosis result, the treatment determination result, and the like are fed back to the vehicle via the communication device, further convenience improvement can be expected.

(10) The valve control device
When performing the self-excited vibration detection process, the pressure-increasing valve and the pressure-reducing valve are set so that the pressure-increasing valve and the pressure-reducing valve perform a detection-time operation that is an operation for detecting self-excited vibration of the target linear valve. The hydraulic brake system according to any one of items (2) to (9), further including a detection-time operation control unit that controls the motor.

  The mode of this section is a mode in which the self-excited vibration detection process can be automatically executed regardless of the operation of the brake operation member by the operator. Self-excited vibration can be detected when the target linear valve is actuated by the operator's operation. However, if self-excited vibration can be automatically detected as in this mode, self-excited vibration can be detected. Effective response to vibration becomes possible.

  (11) The pressure-increasing valve and the pressure-reducing valve so that the detection-time operation control unit executes the detection-time operation such that a hydraulic pressure difference before and after the operation of the target linear valve becomes a set hydraulic pressure difference. The hydraulic brake system according to item (10), wherein the hydraulic brake system is controlled.

  According to the aspect of this section, it is possible to detect the self-excited vibration by fixing one factor related to the occurrence of the self-excited vibration described above, and to perform an appropriate detection process. Note that by setting a plurality of different set hydraulic pressure differences, self-excited vibration corresponding to various hydraulic pressure differences can be detected.

  (12) The detection-time operation control unit executes the detection-time operation so that the hydraulic pressure change gradient in the operation of the target linear valve becomes a set hydraulic pressure change gradient. The hydraulic brake system according to (10) or (11), which controls the pressure reducing valve.

  According to the aspect of this section, it is possible to detect the self-excited vibration by fixing one factor related to the occurrence of the self-excited vibration described above, and to perform an appropriate detection process. In addition, by setting a plurality of different set hydraulic pressure change gradients, it is possible to detect self-excited vibration corresponding to various hydraulic pressure differences.

  (13) The hydraulic brake system according to any one of (1) to (12), wherein the hydraulic brake system is configured to be capable of executing at least the self-excited vibration elimination process as the anti-self-excited vibration process. Hydraulic brake system.

  A series of terms after this term is a term describing various modes capable of executing the self-excited vibration elimination processing.

(14) The valve control device comprises:
(13) having a canceling operation control unit that controls the pressure increasing valve and the pressure reducing valve so that the pressure increasing valve and the pressure reducing valve execute a canceling operation that is an operation for canceling the self-excited vibration of the target linear valve. The hydraulic brake system according to item.

  The mode described in this section is a mode in which the self-excited vibration canceling process can be executed by causing the pressure increasing valve and the pressure reducing valve to perform a predetermined operation.

  (15) The canceling operation control unit controls the pressure increasing valve and the pressure reducing valve so that the canceling operation is performed in which the front and rear of the closing portion of the canceling target linear valve are both pressurized. The hydraulic brake system according to item (14).

  The mode described in this section is a mode in which a canceling operation particularly effective for canceling the self-excited vibration caused by the bubbles can be executed. According to the elimination operation in this section, since the entire interior of the target linear valve is in a high pressure state, the disappearance of bubbles existing inside the linear valve, more specifically, disappearance due to the dissolution of the gas constituting the bubbles into the brake fluid. I can expect.

  (16) The cancellation operation control unit controls the pressure increasing valve and the pressure reducing valve so that the cancellation operation in which the target linear valve is opened and closed while the pressurized state is maintained is executed ( The hydraulic brake system as described in the item 15).

  The mode described in this section is a mode in which a canceling operation can be executed such that the linear valve is opened and closed after the target linear valve is in a pressurized state. According to the elimination operation of this section, the movement of the bubbles existing inside the target linear valve is promoted by the opening / closing operation of the linear valve, so that the effect of disappearance of the bubbles and the discharge of the bubbles can be expected.

(17) The hydraulic brake system includes a valve-reservoir shut-off valve that is controlled by the valve control device to shut off communication between the pressure reducing valve and the reservoir,
The elimination operation control unit controls the pressure increasing valve and the pressure reducing valve so that the elimination operation is executed in a state where the valve-reservoir shutoff valve is activated. The hydraulic brake system according to any one of the items).

  The valve-reservoir shutoff valve described in this section is a means for ensuring self-excited vibration cancellation processing by the cancellation operation, and according to the aspect of this section, for example, pressurization of the target linear valve described above It is possible to easily realize the state.

(18) The target linear valve is the pressure increasing valve,
The cancellation operation control unit controls the pressure increasing valve and the pressure reducing valve so that the pressure cancellation valve is closed and the cancellation operation in which the pressure increasing valve opens and closes is executed. Hydraulic brake system.

  The aspect described in this section is an aspect in which the elimination operation when the target linear valve is a pressure increasing valve is limited to a specific one. When the pressure reducing valve is a normally closed valve, it is not necessary to apply electric energy to the pressure reducing valve in order to maintain the pressurizing state of the pressure increasing valve. Therefore, the aspect of this section is an aspect excellent in terms of energy saving. It becomes.

(19) The hydraulic brake system includes a valve-reservoir shut-off valve that is controlled by the valve control device to shut off communication between the pressure reducing valve and the reservoir,
The target linear valve is the pressure increasing valve;
The cancellation operation control unit operates the valve-reservoir shut-off valve, and when the valve-reservoir shut-off valve is operated, the pressure-reducing valve is opened and the pressure-increasing valve is opened / closed. The hydraulic brake system according to the item (14), which controls the pressure increasing valve and the pressure reducing valve so that is executed.

  The aspect described in this section is an aspect in which the elimination operation when the target linear valve is a pressure increasing valve is limited to a specific one. More specifically, this is a mode in which the pressure-increasing valve is realized by operating the valve-reservoir shutoff valve.

  (20) The hydraulic brake system according to item (19), wherein the pressure reducing valve is a normally open valve.

  The mode described in this section is a mode in which when the pressure reducing valve is a normally open valve, the pressurization state of the pressure increasing valve is realized by operating the valve-reservoir shutoff valve. For example, when the pressure reducing valve is a normally open valve, in order to maintain the valve closed state, electric energy must be continuously supplied to the pressure reducing valve, so that the pressure reducing valve may be overloaded. high. According to the description in this section, since the pressurization state of the pressure increasing valve is realized not by the pressure reducing valve but by the valve-reservoir shutoff valve, it is possible to prevent the pressure reducing valve from being overloaded.

(21) The hydraulic brake system includes a valve-reservoir shut-off valve that is controlled by the valve control device and shuts off the communication between the pressure reducing valve and the reservoir,
The target linear valve is the pressure reducing valve;
The cancellation operation control unit operates the valve-reservoir shut-off valve, and when the valve-reservoir shut-off valve is operated, the cancel operation is performed such that the pressure increasing valve is opened and the pressure reducing valve is opened / closed. The hydraulic brake system according to the item (14), which controls the pressure increasing valve and the pressure reducing valve so that is executed.

  The mode described in this section is a mode when the target linear valve is a pressure reducing valve, and according to the mode of this section, the pressurizing state of the pressure reducing valve can be easily realized by using the valve-reservoir shutoff valve. .

(22) The valve control device comprises:
The self-excited valve that controls the pressure-increasing valve and the pressure-reducing valve so that the pressure-increasing valve and the pressure-reducing valve perform the operation during the self-excited vibration process, which is the operation for the processing when the anti-self-excited vibration process is performed. It has an operation control unit during vibration processing,
The operation control unit for the self-excited vibration processing is
When the self-excited vibration detection process is executed, the detection-time operation, which is an operation for detecting the self-excited vibration of the target linear valve by the pressure increasing valve and the pressure reducing valve, is executed as the anti-self-excited vibration process operation. And a detection operation control unit for controlling the pressure increasing valve and the pressure reducing valve, and a canceling operation in which the pressure increasing valve and the pressure reducing valve are actions for eliminating the self-excited vibration of the target linear valve. The hydraulic brake system according to any one of (1) to (21), which has at least one of a pressure increasing valve and a canceling operation control unit that controls the pressure reducing valve so as to be executed as an operation during processing.

  The aspect of this item is at least one of the operation at the time of detection of the pressure increasing valve and the pressure reducing valve executed in the self-excited vibration detecting process and the operation of canceling the pressure increasing valve and the pressure reducing valve executed in the self-excited vibration eliminating process Can be executed as an operation at the time of anti-excited vibration processing.

  (23) The hydraulic brake system according to (22), wherein the anti-excited vibration processing operation control unit includes a stop operation realizing unit that realizes the anti-excited vibration processing operation while the vehicle is stopped. .

  The above-described self-excited vibration processing operation of the pressure increasing valve and the pressure reducing valve usually involves a change in the wheel cylinder hydraulic pressure, so it is desirable not to be executed while the vehicle is running. According to the aspect described in this section, since it is possible to realize the operation at the time of anti-self-excited vibration processing while the vehicle is stopped, it is possible to cope with the self-excited vibration without affecting the running of the vehicle. It becomes.

  (24) The hydraulic brake system according to item (23), wherein the operation realizing unit at the time of stopping realizes the operation at the time of anti-excited vibration processing while the parking brake provided in the vehicle is operating.

  According to the aspect of this section, it is possible to realize the operation at the time of the above self-excited vibration processing in a state in which confirmation of stopping is obtained.

  (25) The hydraulic brake system according to (24), wherein the operation realizing unit at the time of stopping operates the parking brake to realize an operation at the time of anti-excited vibration processing.

  According to the aspect of this section, it is possible to execute the above-described self-excited vibration processing operation after creating a situation in which the stop state can be actively maintained, which is an aspect further advanced than the previous aspect. .

(26) A plurality of the brakes are provided corresponding to each of the plurality of wheels provided in the vehicle, and a plurality of the pressure increasing valves and the pressure reducing valves are provided corresponding to the wheel cylinders of the plurality of brakes. ,
The remaining operation of the plurality of brakes is performed so that the operation realizing unit at the time of stopping performs the anti-self-excited vibration process for the target linear valve corresponding to the wheel cylinder of one of the plurality of brakes. A brake force for maintaining the vehicle stop state is generated by the brake, and the pressure increasing valve and the pressure reducing valve corresponding to the wheel cylinder of the one brake are operated during the self-excited vibration process. A hydraulic brake system as set forth in (23).

  In the aspect described in this section, when executing the anti-self-excited vibration processing for the target linear valve corresponding to a certain wheel, the braking force necessary for stopping the vehicle is determined by the hydraulic brake system without using the parking brake. This is a mode in which the anti-self-excited vibration process can be executed. Furthermore, in another aspect, the braking force is applied to wheels other than the wheel corresponding to the target linear valve, and the self-excited vibration process for the target linear valve can be executed. In the aspect of this section, when the target self-excited vibration process is executed by sequentially changing the target linear valve for each wheel, the wheel to which the braking force is applied may be changed in accordance with the change. In addition, the braking force for maintaining the stopped state of the vehicle (hereinafter sometimes referred to as “required braking force when stopped”) is, for example, a vehicle having four wheels, front, rear, left, and right, other than the wheel corresponding to the target linear valve. Will be allocated to the three wheels. In this case, for example, in a hydraulic brake system in which the pressure reducing valve on the front wheel side is a normally closed linear valve and the pressure reducing valve on the rear wheel side is a normally open linear valve, the linear valves are overloaded. Therefore, it is desirable to increase the distribution of braking force on the front wheel side as much as possible. The required braking force at the time of stopping differs depending on the coefficient of friction μ between the tire and the road surface. For example, when the vehicle is stopped on a dry slope of 45 ° in general, the braking force is large so that the vehicle does not rotate and the vehicle starts to slide. It is desirable to do so.

  (27) The hydraulic brake system includes a valve-cylinder shut-off valve that is controlled by the valve control device and shuts off the communication between the pressure increasing valve and the pressure reducing valve and the wheel cylinder. The hydraulic brake system according to any one of the items.

  If the inter-cylinder shut-off valve described in this section is operated, the wheel cylinder hydraulic pressure can be prevented from changing even by the operation of the pressure increasing valve and the pressure reducing valve. Even during traveling, the above self-excited vibration processing, more specifically, the operation of the pressure increasing valve and the pressure reducing valve during the above self-excited vibration processing can be performed.

  (28) A travel-time operation realizing unit that realizes the operation during the self-excited vibration process in a state where the valve-cylinder shut-off valve is operated during travel of the vehicle. The hydraulic brake system according to item (27).

  The mode described in this section is a mode in which it is possible to execute the self-excited vibration processing while the vehicle is running by using the above-described valve-cylinder cutoff valve. If the anti-self-excited vibration process can be executed while the vehicle is running, the opportunities for executing the process can be increased, and more effective self-excited vibration can be dealt with.

  (29) The anti-self-excited vibration processing operation control unit includes a travel speed-based operation prohibiting unit that prohibits the anti-self-excited vibration processing operation when the vehicle traveling speed is lower than a set speed (28). The hydraulic brake system according to item.

  When the pressure increasing valve and the pressure reducing valve perform the operation during the self-excited vibration processing during vehicle travel, it is conceivable that the braking force of the wheel corresponding to the target linear valve cannot be obtained in an appropriate state. The aspect described in this section is an aspect that takes that into consideration. In the aspect of this section, when the vehicle traveling speed is relatively low, the brake operation by the driver is highly likely to be performed. Therefore, the operation during the self-excited vibration process is prohibited at a relatively low speed. In addition, when the self-excited vibration processing operation is a detection-time operation, even if self-excited vibration is generated by the operation, if the vehicle traveling speed is relatively high, the road surface and the tire The road noise, wind noise, etc. generated between the two are relatively large, and it is considered difficult for the driver to notice self-excited vibration. In the aspect of this section, it is possible to allow the execution of the above-described self-excited vibration processing operation only when traveling at a relatively high speed.

  (30) The anti-self-excited vibration processing operation control unit includes a braking operation possibility dependent operation prohibiting unit that prohibits the anti-self-excited vibration processing operation when the driver is highly likely to perform the braking operation (28 ) Or the hydraulic brake system according to item (29).

  When the pressure increasing valve and the pressure reducing valve perform the operation during the self-excited vibration processing during vehicle travel, it is conceivable that the braking force of the wheel corresponding to the target linear valve cannot be obtained in an appropriate state. In view of this, the aspect described in this section is configured to limit the operation during the self-excited vibration process. As described above, even when the vehicle is traveling at a low speed, it can be considered that there is a high possibility of a braking operation by the driver (hereinafter sometimes simply referred to as “braking operation”). For example, in the case where automatic control of a vehicle based on the distance between the vehicle and the object with a possibility of collision such as auto drive control (ACC (Adaptive Cruie Control), etc.), pre-crash safety control, etc. is executed The aspect of this section can be configured to limit the operation during anti-excited vibration processing based on the possibility of brake operation estimated based on information used in the automatic control.

(31) The wheel cylinder provided with a plurality of the brakes corresponding to each of the plurality of wheels provided in the vehicle, and the pressure increasing valve, the pressure reducing valve, and the valve cylinder shutoff valve included in each of the plurality of brakes. A plurality are provided corresponding to
The running operation realizing unit corresponds to the wheel cylinder of a part of the brakes in a state where the valve cylinder cutoff valve corresponding to the wheel cylinder of the part of the plurality of brakes is operated. In order to execute the counter-self-excited vibration process for the target linear valve, only the pressure-increasing valve and the pressure-reducing valve corresponding to the wheel cylinder of a part of the brake are operated during the counter-excited vibration process. The hydraulic brake system according to any one of (28) to (31).

  When the pressure increasing valve and the pressure reducing valve perform the operation during the self-excited vibration processing during vehicle travel, it is conceivable that the braking force of the wheel corresponding to the target linear valve cannot be obtained in an appropriate state. Therefore, when the self-excited vibration detection process for each target linear valve corresponding to each of the plurality of wheels provided in the vehicle is executed at the same time, when the driver performs a brake operation, for example, the operation There is a possibility that the target braking force may not be obtained in the initial stage of. More specifically, there is a possibility that only a braking force smaller than the target braking force can be obtained, and there is a possibility that the braking force becomes larger than the target braking force. The aspect described in this section has been made in view of that, and allows the self-excited vibration processing for only the target linear valve corresponding to only some of the wheels while the vehicle is running. It is. Specifically, for example, in a vehicle provided with four wheels on the front, rear, left and right, one of two pairs of wheels composed of two wheels positioned diagonally in consideration of the balance of braking force The self-excited vibration processing for the two target linear valves corresponding to one of them is allowed, and the self-excited vibration processing for the two target linear valves corresponding to the other is performed for the other of the two pairs of wheels. It should be prohibited.

  (32) The pressure increasing valve and the pressure reducing valve corresponding to the wheel cylinder of the part of the brake when the driver performs a braking operation while the valve control device is performing the operation for the self-excited vibration process. The operation based on the braking operation by the valve is prohibited, and the operation based on the braking operation by only the pressure increasing valve and the pressure reducing valve corresponding to the wheel cylinder of the brakes other than the part of the plurality of brakes is prohibited. The hydraulic brake system as set forth in (31), wherein the hydraulic brake system has a partial operation realization part during a braking operation to be realized.

  As described above, when the self-excited vibration detection process is executed at the same time, when the driver performs a braking operation, there is a possibility that a desired braking force cannot be obtained at the initial stage of the operation. . In view of this, in the aspect described in this section, the pressure increasing valve and the pressure reducing valve do not generate the braking force for the wheel executing the self-excited vibration processing operation, but only the braking force of the other wheel is generated. It is an aspect. In the aspect of this section, the braking force may not be generated for the wheel executing the anti-self-excited vibration processing operation during the driver's braking operation. For example, the braking operation is started. Although generation of the braking force is prohibited at the time, it is desirable to generate the braking force for the wheels when the braking force for the wheels becomes a target braking force. When generating braking force for some of the wheels, add at least part of the braking force that should be shared by the wheels for which generation of braking force is prohibited to the braking force of these some wheels. Therefore, it is desirable to compensate as much as possible the braking force acting on the entire vehicle.

  (41) A linear valve self-excited vibration detection method for detecting self-excited vibration of a linear valve based on periodic fluctuations in hydraulic pressure during operation of the linear valve.

  (42) The linear valve self-excited vibration detection method according to item (41), wherein self-excited vibration of the linear valve is detected by frequency analysis of a change in hydraulic pressure during operation of the linear valve.

  (43) The linear valve self-excited vibration detection method according to (42), wherein self-excited vibration of the linear valve is detected based on a peak frequency and intensity of a power spectrum obtained by the frequency analysis.

  The aspects described in the above three terms are aspects of the claimable invention that belong to the category of methods for detecting self-excited vibration of a linear valve. According to the detection method of the above aspect, the self-excited vibration of the linear valve can be easily detected. The explanation for the above three terms overlaps with the explanation in the aspect of the claimable invention relating to the hydraulic brake system described above, and the detailed explanation is omitted here.

  Hereinafter, embodiments of the claimable invention will be described in detail with reference to the drawings. In addition to the following examples, the claimable invention is implemented in various modes including various modifications and improvements based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. can do.

≪Configuration of hydraulic brake system≫
FIG. 1 shows a circuit diagram of a hydraulic brake system according to this embodiment. The hydraulic brake system includes a brake pedal 10 that is a brake operation member, a master cylinder 12, a brake actuator 14, a hydraulic brake 18 provided on each of four wheels 16, and the like. In the following description, when it is necessary to distinguish each wheel 16 individually, a subscript is added to the left front wheel 16FL, the right front wheel 16FR, the left rear wheel 16RL, the right rear wheel 16RR, and the like. Regarding the components of the brake system, if it is necessary to individually distinguish the components corresponding to the wheels 16, the same subscripts are attached. In addition, when it is necessary to distinguish the components corresponding to the left wheel and the right wheel individually, the subscripts L and R are attached.

  In this embodiment, the master cylinder 12 includes two pressurizing chambers 20L and 20R, and the hydraulic pressures generated in the pressurizing chambers 20L and 20R based on the depression of the brake pedal 10 are the master cylinder passages 22L and 22R, respectively. Thus, the hydraulic brakes 18FL and 18FR that brake the front wheels 16FL and 16FR are supplied to the wheel cylinders 24FL and 24FR, respectively. Further, the master cylinder 12 is provided with a reservoir 26 in which brake fluid is stored at atmospheric pressure, and the reservoir 26 and the pressurizing chambers 20L and 20R have a structure that allows and blocks communication therebetween. ing. Further, a stroke simulator 30 is connected to one master cylinder passage 22L via a simulator on / off valve 28 which is an electromagnetic on / off valve. The simulator open / close valve 28 is a normally closed valve, which is closed in a normal state where no current is supplied to the solenoid, shuts off the communication between the pressurizing chamber 20L and the stroke simulator 30, and is opened by supplying current to the solenoid. Thus, the pressurizing chamber 20L and the stroke simulator 30 are communicated to allow the brake fluid to flow from the master cylinder 12 to the stroke simulator 30.

  The brake actuator 14 controls the hydraulic pressure of each wheel cylinder 24 included in each brake 18 provided on each wheel 16. As shown in the figure, the brake actuator 14 includes two master cut valves 40, each of which is an electromagnetic on-off valve, a hydraulic pressure source device 42, which is a hydraulic pressure source, a hydraulic pressure control valve device 44, and two master cylinder pressure sensors 46. , Four wheel cylinder pressure sensors 48 are provided. The brake actuator 14 is disposed in the engine room of the vehicle in a state in which those constituent elements are integrally assembled to a box-shaped main body member (not shown). The brake actuator 14 is provided with a liquid temperature sensor 50 on the outer side surface of the main body member. The liquid temperature sensor considers the surface temperature of the main body member as the liquid temperature of the brake fluid, thereby adjusting the brake fluid temperature. It is supposed to detect.

  The hydraulic pressure source device 42 includes a pump 54 for pumping brake fluid from the reservoir 26 through the reservoir passage 52, a pump motor 56 (which is an electric motor) as a drive source for driving the pump 54, and a brake discharged from the pump 54. An accumulator 58 that stores liquid under pressure, a relief valve 60 that regulates the discharge pressure of the pump 54 to a set value or less, and a hydraulic pressure source pressure that is the discharge hydraulic pressure of the hydraulic pressure source device 42 (equal to the accumulator pressure) A hydraulic pressure source pressure sensor 62 is detected. The operation of the pump motor 56 is controlled such that the hydraulic pressure source pressure is within a set range.

  The four wheel cylinders 24 are connected to the hydraulic pressure source device 42 via a hydraulic pressure control valve device 44. The hydraulic pressure control valve device 44 is provided between the hydraulic pressure source device 42 and each wheel cylinder 24, and includes four linear boosters that control the inflow of brake fluid from the hydraulic pressure source device 42 to each wheel cylinder 24. Each of which includes a pressure valve 70 and four linear pressure-reducing valves 72 provided between the wheel cylinders 24 and the reservoirs 26 for controlling the flow of brake fluid from the wheel cylinders 24 to the reservoirs 26. The source device 42, specifically, the pump 54 and the accumulator 58 and the linear pressure increasing valve 70 are connected by a pressure increasing passage 74, and the linear pressure reducing valve 72 and the reservoir 26 are connected by a pressure reducing passage 76 and a reservoir passage 52. That is, one linear pressure increasing valve 70 and one linear pressure reducing valve 72 are provided for each of the four wheel cylinders 24, and each of the four sets of linear pressure increasing valves 70 and linear pressure reducing valves 72 is a wheel cylinder passage 78. To the wheel cylinder 24. From the above structure, the hydraulic pressures of the four wheel cylinders 24 can be controlled independently of each other.

  Note that the master cut valve 40 is a normally open electromagnetic opening / closing valve, which is opened in a normal state and communicates the pressurizing chambers 20L, 20R with the front wheel side wheel cylinders 24FL, 24FR. The current supply is closed to cut off their communication. The hydraulic pressure control of each wheel cylinder 24 by the hydraulic pressure control valve device 44 is performed when the master cylinder passage 22 is shut off by the master cut valve 40. The linear valve has a predetermined relationship between the hydraulic pressure difference between the upstream side and the downstream side and the supply current, and the valve opening pressure, the valve opening, etc. can be changed according to the increase or decrease of the supply current. It is a valve. Therefore, the linear pressure increasing valve 70 and the linear pressure reducing valve 72 can control the wheel cylinder hydraulic pressure, which is the hydraulic pressure of the wheel cylinder 24, to an arbitrary height by controlling the supply current, and the wheel cylinder hydraulic pressure can be continuously increased. It can be changed. Detailed structures of the linear pressure increasing valve 70 and the linear pressure reducing valve 72 will be described later.

  Furthermore, in this hydraulic brake system, the brake actuator 14 has four valve cylinder shut-offs that each cut off the communication between each wheel cylinder 24 and each linear pressure increasing valve 70 and linear pressure reducing valve 72 in each wheel cylinder passage 78. A valve 90 is provided. Furthermore, a valve-reservoir shutoff valve 92 that shuts off the communication between each wheel cylinder 24 and the reservoir 26 in the decompression passage 76 is provided. The valve cylinder shutoff valve 90 and the valve reservoir shutoff valve 92 are both normally open on-off valves, and are opened in the normal state to connect the wheel cylinders 24, the linear pressure increasing valves 70, and the linear pressure reducing valves 72. The wheel cylinders 24 and the reservoirs 26 are communicated with each other, but are closed by supplying current to the solenoids to block the communication. The purpose and mode of operation of the valve-cylinder cutoff valve 90 and the valve-reservoir cutoff valve 92 will be described in detail later.

  In addition, in the hydraulic brake system, an electric parking brake 94 is provided for each of the rear wheels 16RL and 16RR, and a wheel speed sensor 96 is provided for each wheel 16. The brake pedal 10 is provided with a stroke sensor 98 for detecting the operation stroke of the brake pedal 10. Furthermore, a stop-time processing mode selection switch 100, a stop-time processing start switch 102, travel, and the like that are operated by the driver to select and execute processing for self-excited vibration of the linear pressure increasing valve 70 and the linear pressure reducing valve 72 described later. A time processing necessity / unnecessity selection switch 104 is provided on the instrument panel.

  The hydraulic brake system includes a brake ECU (electronic control unit) 110 for controlling itself. The brake ECU 110 is a computer-based device, and the hydraulic pressure source device 42, the hydraulic pressure control valve device 44, and the like are controlled by the brake ECU 110. In this hydraulic brake system, the hydraulic pressure control device 44 is controlled so that the wheel cylinder hydraulic pressure corresponding to the driver's operation of the brake pedal 10 detected by the stroke sensor 98 is obtained, and the anti-skid control ( ABS), traction control (TRC), etc. are also executed. Incidentally, since it controls the linear pressure increasing valve 70 and the linear pressure reducing valve 72, it can be considered that it functions as a valve control device. As will be described in detail later, the brake ECU 110 can also execute processing for self-excited vibration of the linear pressure increasing valve 70 and the linear pressure reducing valve 72.

≪System configuration of vehicle including hydraulic brake system≫
This hydraulic brake system is connected to various other systems and devices on which the vehicle is mounted. If it demonstrates centering on the part relevant to claimable invention, as shown in FIG. 2, in this vehicle, brake ECU110 is control system LAN120 (Vehicle LAN (CAN). Other LAN is also the same). Are connected to the engine ECU 122, the auto drive ECU 124, the diagnosis ECU 126, and the gate away ECU 128. The autodrive ECU 124 is connected to the radar device 132 via the sensor LAN 130, and the gate-away ECU 128 is connected to the communication device 136 that is an in-vehicle communication device via the AV LAN 134 that is a network related to car navigation information and the like. .

  The autodrive ECU 124 identifies the preceding vehicle that travels ahead of the host vehicle based on the information of the radar device 132, recognizes the inter-vehicle distance from the preceding vehicle, the traveling speed of the preceding vehicle, and the like. With reference to the speed, control is performed to cause the host vehicle to follow the preceding vehicle while maintaining a predetermined inter-vehicle distance from the preceding vehicle. Specifically, for example, when approaching the preceding vehicle to some extent, a command is issued to the engine ECU 122 to limit the output of the engine, and when approaching further, the vehicle is braked to decelerate the vehicle. A command is issued to the ECU 110.

  The diagnosis ECU 126 executes a vehicle self-diagnosis process. For example, based on information from the brake ECU 110, the engine ECU 122, etc., abnormalities in various systems are detected, and the contents of the abnormalities are notified to the driver through indicators, displays, etc. provided on the instrument panel. As will be described in detail later, the diagnosis ECU 126 also executes a diagnosis process for self-excited vibrations of the linear pressure increasing valve 70 and the linear pressure reducing valve 72. More specifically, the diagnosis ECU 126 has a storage unit 138, and information about self-excited vibration is stored in the storage unit 138. Based on the stored information, the frequency of occurrence of self-excited vibration is determined, and the driver is notified of the occurrence of self-excited vibration based on the determination result. The information is transmitted to the outside of the vehicle through 136, and more specifically, to a support center that supports the vehicle (for example, a store that can maintain the vehicle). The transmitted information is subjected to analysis at the support center, and the result of the analysis is fed back to the diagnosis ECU 126 via the communication device 136.

≪Linear valve structure≫
The linear pressure increasing valve 70 and the front wheel side linear pressure reducing valves 72FL, 72FR (hereinafter, may be collectively referred to as “linear valves 70, 72FL, 72FR”) included in the hydraulic pressure control valve device 44 of the present hydraulic brake system are shown in FIG. As shown in FIG. 3, the normally closed solenoid valve includes a valve housing 160, a seat valve 162, and a solenoid 164. The seat valve 162 includes a valve seat 168, a valve element 170 provided on the plunger 172, and a spring 178 that biases the plunger 172 in a direction in which the valve element 170 is seated on the valve seat 168. The solenoid 164 includes a plunger 172, a solenoid coil 180, a resin coil holding member 182 that holds the solenoid coil 180, and a first magnetic path forming member 184 and a second magnetic path forming member 186 formed of a ferromagnetic material, respectively. It is comprised including. The plunger 172 can also be considered as a component of the seat valve 162.

  The valve housing 160 is configured by integrally assembling the first member 190 and the second member 192, and the second magnetic path forming member 186 is concentrically coupled to the second member 192 by the first member 190. Yes. The first member 190 has a thin bottomed cylindrical shape, and the second magnetic path forming member 186 is fitted and accommodated in the first member 190. The second member 192 has a generally hollow cylindrical shape, and is fitted in the first member 190 with a spacer 194 sandwiched between the second magnetic path forming member 186 at one end in the axial direction thereof. The first magnetic path forming member 184 covers the solenoid coil 180 and is fitted to the outside of the first member 190.

  The second member 192 has first ports 198 formed at two locations on the peripheral wall thereof. The first port 198 is connected to each wheel cylinder 24 by the wheel cylinder passage 78 in the linear pressure increasing valve 70, and is connected to the reservoir 26 by the pressure reducing passage 76 in the linear pressure reducing valves 72 FL and 72 FR on the front wheel side. The second member 192 is provided with an assembly member 200 for assembling the linear valves 70, 72FL, and 72FR. The assembly member 200 is provided with an opening (not shown) so that the brake fluid can be removed. Inflow to the wheel cylinder 24 or the reservoir 26 is allowed. The third member 202, which is still another member constituting the valve housing 160, is fitted to the other end of the second member 192, and a through hole formed through the third member 202 in the axial direction has a first hole. A 2-port 204 is configured. The second port 204 is connected to the hydraulic pressure source device 42 by the pressure increasing passage 76 in the linear pressure increasing valve 70, and the wheel cylinders 24 FL and 24 FR on the front wheel side by the wheel cylinder passage 78 in the linear pressure reducing valves 72 FL and 72 FR on the front wheel side. Connected to. The valve seat 168 is provided at the open end of the second port 204 on the first port 198 side.

  A valve hole 210 is formed between the second and third members 192 and 202 and the second magnetic path forming member 186, and a plunger 172 is fitted in the valve hole 210 so as to be movable in the axial direction. The plunger 172 is made of a ferromagnetic material, and is fitted into the valve hole 210 with a slight gap 216 between the plunger hole 172 and the valve chamber 218 on the valve seat 168 side of the plunger 172. The plunger chamber 220 is formed on the second magnetic path forming member 186 side.

  The plunger 172 is formed with a through-hole 222 that is located on one circumference centered on the axis thereof and extends through the plunger 172 in the axial direction at two locations separated in the diameter direction. The gap 216 and the through hole 222 constitute an in-valve communication passage 224 that allows the valve chamber 218 and the plunger chamber 220 to communicate with each other, and the plunger 172 moves quickly by the flow of brake fluid in the in-valve communication passage 224. can do. The plunger chamber 220 is always in communication with the wheel cylinder 24 or the reservoir 26 through the in-valve communication passage 224, the valve chamber 218, the first port 198, and the like. The plunger chamber 220 is on the low pressure side with respect to the valve seat 168 and the valve element 170. The movement limit of the plunger 172 toward the second magnetic path forming member 186 is defined by the shoulder surface of the plunger 172 contacting a contact surface 228 provided on the second magnetic path forming member 186. A thin plate 226 made of a non-magnetic material is provided on the shoulder surface to form a sticking prevention portion, ensuring a distance between the shoulder surface and the contact surface 228, and being attracted to the contact surface 228 by a magnetic attraction force. Further, the plunger 172 is prevented from sticking to the contact surface 228, and the separation from the contact surface 228 is improved.

  The plunger 172 is provided with a protrusion 232 protruding on the valve seat 168 side on the shaft center, and a hemispherical valve element 170 is integrally provided at the protruding end. The spring 178 is disposed between the plunger 172 and the second magnetic path forming member 186, and the plunger 172 is urged by the spring 178 in a direction in which the valve element 170 is seated on the valve seat 168. Therefore, in a state where no current is supplied to the solenoid 164, the plunger 172 is moved toward the valve seat 168 by the bias of the spring 178, and the valve element 170 is seated on the valve seat 168. , 72FL, 72FR are kept closed.

  When a current is supplied to the solenoid 164, a magnetic field is formed. Most of the magnetic field lines pass through the gap between the first magnetic path forming member 184, the second magnetic path forming member 186, the plunger 172, the plunger 172, and the second magnetic path forming member 186. In the plunger 172, in the linear pressure increasing valve 70, the hydraulic pressure difference between the hydraulic pressure of the hydraulic pressure source device 42 and the hydraulic pressure of the wheel cylinder 24 (hereinafter, such a hydraulic pressure difference may be referred to as “differential pressure”), In the front-wheel-side linear pressure reducing valves 72FL and 72FR, a force having a magnitude that is obtained by multiplying the differential pressure between the front-wheel wheel cylinders 24FL and 24FR and the reservoir 26 by the cross-sectional area of the seating portion of the valve element 170 with respect to the valve seat 168, and the spring 178 And the magnetic attraction force generated by the current supply to the solenoid 164 acts on the plunger 172 in the direction opposite to the biasing force of the spring 178, and the plunger 172 is axially moved. , The valve element 170 is moved away from the valve seat 168. Therefore, if the supply current to the solenoid 164 is set based on the target hydraulic pressure of the wheel cylinder 24 and the magnitude of the magnetic attractive force is controlled, the plunger 172 is retracted against the urging force of the spring 178, When the valve element 170 is separated from the valve seat 168, the linear valves 70, 72FL, 72FR are opened. Accordingly, the brake fluid is allowed to flow out from the hydraulic pressure source device 42 to the wheel cylinder 24, or the brake fluid is allowed to flow out from the front wheel side wheel cylinders 24FL and 24FR to the reservoir 26. Increased or decreased to hydraulic pressure. When the hydraulic pressure in the wheel cylinder 24 increases or decreases, the differential pressure decreases, and the plunger 172 is moved in the direction approaching the valve seat 168 by the bias of the spring 178, and the valve is reached when the target hydraulic pressure is reached. When the child 170 is seated on the valve seat 168, the linear valves 70, 72FL, 72FR are closed.

  Next, the rear wheel side linear pressure reducing valves 72RL and 72RR included in the hydraulic pressure control valve device 44 of the hydraulic brake system are normally provided with a valve housing 250, a seat valve 252 and a solenoid 254, as shown in FIG. Open solenoid valve. Since the linear pressure reducing valves 72RL, 72RR are designed under the same design concept as the linear valves 70, 72FL, 72FR, which are the normally closed solenoid valves, there are many parts in common with them. A brief description will be given.

  The seat valve 252 includes a valve seat 262 provided in a valve chamber 260 formed in the valve housing 250, a valve element 264 that can approach and separate from the valve seat 262, and a valve element 264 that is spaced from the valve seat 262. And a spring 266 that biases in the direction. The first port 268 and the second port 270 formed so as to open to the valve chamber 260 are connected to the reservoir 26 by the pressure reducing passage 76 and to the wheel cylinders 24RL and 24RR on the rear wheel side by the wheel cylinder passage 78, respectively. . The first port 268 is in an open state even when the valve element 260 is seated on the valve seat 262.

  The solenoid 254 includes a coil 272 fixed to the valve housing 250 and a plunger 276 disposed in the plunger chamber 274 formed in the valve housing 250 at a position spaced from the valve chamber 260. The valve housing 250 is provided with a guide hole 280 communicating with the valve chamber 260 and the plunger chamber 274, and a shaft 282 is disposed in the guide hole 280. The shaft 282 is provided in contact with the plunger 276, and the valve element 264 is provided integrally on the opposite side of the plunger 276, so that the shaft 282 is integrated with the valve element 264 in the axial direction as the plunger 276 moves. It is possible to move to.

  The linear pressure reducing valves 72RL and 72RR are arranged in a state in which a force corresponding to a differential pressure between the wheel cylinders 24RL and 24RR and the reservoir 26 is applied to the valve element 264. If a current is supplied to the solenoid 254, the plunger 276 is provided. Electromagnetic driving force is generated, and the valve element 264 is brought close to the valve seat 262. The valve opening degree is determined by the relationship between the force corresponding to the differential pressure, the spring biasing force, and the electromagnetic driving force. Thus, the hydraulic pressures of the wheel cylinders 24RL and 24RR can be continuously controlled.

≪Self-excited vibration of linear valve≫
The linear pressure increasing valve 70 and the linear pressure reducing valve 72 (hereinafter may be collectively referred to as “linear valves 70, 72”) have the possibility of generating self-excited vibration in their operation from the above-described structure. . There are various causes of the self-excited vibration, and the main one is the presence of bubbles inside the valve. The bubbles are considered to be generated when, for example, air dissolved in the brake fluid is discharged from the liquid as a gas, and remains inside the valve. More specifically, for example, the linear pressure increasing valve 70 and the front wheel side linear pressure reducing valves 72FL and 72FR are connected to the valve chamber 218 and the plunger chamber 220, and the rear wheel side linear pressure reducing valves 72RL and 72RR are connected to the valve chamber 260 and the plunger chamber 274, respectively. When bubbles remain, when the linear valves 70 and 72 are actuated, it is considered that the valve elements 170 and 264 and the plungers 172 and 276 pulsate and self-excited vibration is generated due to the influence of the bubbles. In the case of the self-excited vibration caused by bubbles, it can be considered that the linear pressure reducing valve 72 in which the inside of the valve chamber and the plunger chamber is unlikely to become high pressure is more likely to occur than the linear pressure increasing valve 70.

Such occurrence of self-excited vibration, the degree of vibration generated is dependent on the brake fluid temperature T _B which is a liquid temperature of the brake fluid. Generally speaking, self-excited vibration is likely to occur at high temperatures where the solubility of gaseous brake fluid is reduced. The presence or absence of self-excited vibration and the degree of vibration generated are the hydraulic pressure difference before and after the operation of the linear valves 70 and 72, that is, the difference between the pre-operation wheel cylinder pressure P _Cb and the post-operation wheel cylinder pressure _PCa. It depends on the hydraulic pressure difference ΔP _C before and after operation, which is the pressure. For example, as shown in FIG. 5 (a), whether to boosted until the wheel cylinder pressure P _C of the extent to which the linear increasing valve 70, depending under reduced pressure from how much the linear pressure reducing valve 72 the wheel cylinder pressure P _C, The presence or absence of self-excited vibration, the amplitude of vibration, the frequency, etc. are different. Furthermore, occurrence of self-excited vibration, the degree of vibration generated is dependent on the fluid pressure change gradient V _P in the operation of the linear valves 70, 72. For example, as shown in FIG. 5 (b), depending changing the wheel cylinder pressure P _C and at what rate of increase or decrease the speed of, and occurrence of self-excited vibration, the amplitude of vibration, the frequency may vary It is. Generally speaking, when the hydraulic pressure difference ΔP _C before and after operation is relatively large, and when the hydraulic pressure change gradient V _P is relatively large, self-excited vibration tends to occur. From the above, the brake fluid temperature T _B , the hydraulic pressure difference ΔP _C before and after the operation, and the hydraulic pressure change gradient V _P are parameters indicating the possibility of occurrence of self-excited vibration (hereinafter referred to as “self-excited vibration index parameter”). ”).

≪Anti-excited vibration process≫
In the hydraulic brake system, the self-excited vibrations of the linear valves 70 and 72 are taken into consideration, and the self-excited vibrations of the linear valves 70 and 72 are dealt with for each of the linear valves 70 and 72. The self-excited vibration process, which is a process for performing this, can be executed. More specifically, two processes of a self-excited vibration detection process that is a process for detecting self-excited vibration and a self-excited vibration cancellation process that is a process for eliminating the self-excited vibration can be executed. Further, in the present hydraulic brake system, the self-excited vibration processing can be executed even when the vehicle is stopped or when the vehicle is running. Hereinafter, each of the self-excited vibration detection process and the self-excited vibration cancellation process will be described, and execution of the counter-self-excited vibration process during stopping and traveling will be described.

(A) Self-excited vibration detection processing
i) Self-excited vibration detection method In the self-excited vibration detection process in the hydraulic brake system, the hydraulic pressure is periodically detected when the target linear valves 70 and 72 (hereinafter also referred to as “target linear valve”) are operated. The self-excited vibration detection method based on such fluctuations, more specifically, the wheel cylinder pressure P _C detected by the wheel cylinder pressure sensor 48 (the anti-self-excited vibration process during traveling, which will be described in detail later, is not necessarily the actual A method of detecting the self-excited vibration of the target linear valve based on a periodic fluctuation of the fluid pressure (which will be referred to as such) is adopted. More specifically, the frequency of the change in the wheel cylinder pressure P _C from the start to the end of the operation of the target linear valve is analyzed, and the periodic fluctuations in the wheel cylinder pressure P _C are identified. The excitation vibration is detected.

With reference to FIG. 6, In more detail, first, during the period until operating the start and end operation, very short time intervals (for example, several msec) the value of the wheel cylinder pressure P _C in is sampled. Then, by performing a fast Fourier transform processing on the sampled wheel cylinder pressure P _C of the data, obtains the power spectrum. For example, In operation, when there is variation in the wheel cylinder pressure P _C as shown in FIG. 6 (a) or FIG. 6 (b), the power spectrum obtained, for example, as shown in FIG. 6 (c) Become. Then, in the power spectrum, the peak Peak existing in the set frequency range Rf which is the set frequency f range is specified, and the peak intensity I _Peak which is the intensity I of the specified peak _Peak is set as the set intensity I _S ( If the threshold intensity is exceeded, it is determined that self-excited vibration is occurring. The set frequency range Rf and the set intensity I _S are designed to detect self-excited vibrations such that an event caused by self-excited vibrations such as vibration noise is not felt by the driver. In the self-excited vibration detection process, the occurrence of such a self-excited vibration pretends that the self-excited vibration has occurred and detects it.

self-excited vibration of the detection during the operation the linear valves 70, 72 ii) linear valve, it is possible to detect based on variations in the wheel cylinder pressure P _C by the operation of the brake pedal 10 by the driver, the hydraulic In the brake system, in the self-excited vibration detection process, in order to operate the target linear valve so as to realize the hydraulic pressure difference ΔP _C before and after the operation and the hydraulic pressure change gradient V _P set in advance without depending on the operation of the driver, The brake ECU 110 specifies the operating condition of the target linear valve, and the hydraulic control valve device 44 is controlled under the operating condition. The detection operation, which is the control operation of the linear valves 70 and 72 by such control, is a kind of operation at the time of anti-excited vibration, and the target linear valves 70 and 72 (hereinafter referred to as “target linear valve”). And every wheel 16 corresponding to the target linear valve (hereinafter sometimes referred to as “target wheel”). In the hydraulic brake system, when the target linear valve is the linear pressure increasing valve 70 and when the target linear valve is the linear pressure reducing valve 72, and in the case of the detection process while the vehicle is stopped and the case of the detection process while traveling, Since the mode of operation at the time of detection is different, the mode of operation at the time of detection will be described below by taking the case where the target wheel is the left front wheel 16FL as an example.

When the target linear valve is the linear booster valve 70FL in the self-excited vibration detection process while the vehicle is stopped, as shown in FIG. 7A, in the state where the master cut valve 40L is closed, the linear pressure reducing valve 72FL is while being a closed state, the linear pressure-increasing valve 70FL is, that the current supplied to it is controlled, the set hydraulic longitudinal fluid pressure difference [Delta] P _C, is operated such that the fluid pressure change gradient V _P is realized (Hereinafter, such an operation is referred to as a “control operation”, and a state in which the operation is being performed may be referred to as a “control operation state”). In the figure, ● represents the closed state realized by supplying current to the linear valve, and ☆ represents the control operation state (the same applies to other figures). Further, when the target linear valve is a linear pressure reducing valves 72FL, as shown in FIG. 7 (b), in the state where the master cut valve 40L is closed, once the wheel cylinder pressure P _C and the predetermined hydraulic pressure After that, the linear pressure increasing valve 72FL is closed, and in this state, the linear pressure reducing valve 72FL is controlled. On the other hand, in the self-excited vibration detection process during traveling, as shown in FIGS. 7C and 7D, the master cut valve 40L is closed and the left front wheel 16FL, which is the target wheel, is closed. In order to avoid the application of the braking force, the linear pressure-increasing valve 70FL is operated in a state in which the inter-cylinder shutoff valve 90FL corresponding to the wheel 16FL is operated and the inflow / outflow of the brake fluid to the wheel cylinder 24FL is prohibited. , The operation at the time of detection of the linear pressure reducing valve 72FL is executed. When the target linear valve is the linear pressure-increasing valve 70FL, as in the processing during the stop, as shown in FIG. 7 (c), the linear pressure-increasing valve 70FL is controlled while the linear pressure-reducing valve 72FL remains closed. it is operated, when the target linear valve is a linear pressure reducing valves 72FL, as shown in FIG. 7 (d), once the wheel cylinder pressure P _C is a predetermined fluid pressure, linear pressure-increasing valve 72FL are closed The valve state is set, and the linear pressure reducing valve 72FL is controlled. Since the brake fluid does not flow into or out of the wheel cylinder 24FL, the linear pressure increasing valve 70FL and the linear pressure reducing valve 72FL on the side that is not the target linear valve are supplementarily controlled to simulate the flow in and out. It may be operated. In addition, when the target wheels are the rear wheels 16RL and 16RR, the master cut valve 40 does not exist, and therefore the operation thereof is not executed.

As described above, the possibility of the occurrence of self-excited vibration depends on the hydraulic pressure difference ΔP _C before and after operation and the hydraulic pressure change gradient V _P that are self-excited vibration index parameters. In consideration of this, in the operation at the time of detection, three pre- and post-operation hydraulic pressure differences ΔP _C and hydraulic pressure change gradients V _P to be realized for the target linear valve are respectively set as three set hydraulic pressure differences and hydraulic pressure change gradients before and after the operation. Is set. Specifically, as for the hydraulic pressure difference before and after the set operation, as shown in FIG. 5A, three of ΔP _CS , ΔP _CM , and ΔP _CL are set in ascending order, and the set hydraulic pressure change gradient is set in ascending order. Three of V _PS , V _PM , and V _PL are set. Therefore, if the control operation under the condition of combining the hydraulic pressure difference before and after 1 set operation and the set hydraulic pressure change gradient of 1 is one control operation, nine types of one control operation are set for one target linear valve. Therefore, in executing the self-excited vibration detection process for one target linear valve, the nine types of one control operation are continuously executed (hereinafter, the continuous operation is referred to as “ It may be called “target linear valve control operation”). In addition, since there are two target linear valves, the linear pressure increasing valve 70 and the linear pressure reducing valve 72, in one target wheel, two self-excited vibration detection processes for one target wheel are performed. The target linear valve control operation for each of the target linear valves is continuously executed (hereinafter, the continuous operation may be referred to as “wheel control operation”). And since a vehicle has four object wheels, in execution of self-excited vibration processing about the whole vehicle, anti-wheel control operation for each of the four object wheels will be executed (hereinafter, referred to as “the self-excited vibration process”). These operations may be collectively referred to as “all control operations”).

Incidentally, the possibility of the occurrence of self-excited vibration is also dependent on the brake fluid temperature T _B. In consideration of the fact that, in the self-excited vibration detection processing of the present hydraulic braking system is adapted to be executed when the brake fluid temperature T _B is in the plurality of set temperature, the linear valve 70 , 72 is also executed when the set temperature is reached. The set brake fluid temperature is set to five temperatures, and is set to T _B1 , T _B2 , T _B3 , T _B4 , T _B5 (for example, 20, 40, 60, 80, 100 ° C.) in ascending order. . It should be noted that those settings brake fluid temperature, is the a actually in width value (e.g., ± 5 ° C.), the brake fluid temperature T _B, when the value in its width, the setting brake fluid It is assumed that it is warm.

iii) Self-excited vibration detection data The presence or absence of self-excited vibration is performed according to the above-described self-excited vibration detection method every time the one control operation is executed. That is, it is executed for each target linear valve and for each hydraulic pressure difference ΔP _C before and after operation and each hydraulic pressure change gradient V _P. The brake ECU 110 has a detection data temporary storage unit that temporarily stores self-excited vibration detection data as a result of the self-excited vibration detection process (see FIG. 22). Self-excited vibration detection data for each control operation is stored. Specifically, as shown in FIG. 8, self-excited vibration detection data for each target wheel and each target linear valve are the hydraulic pressure difference ΔP _C before and after each of the nine types of one control operation, associated with the variation gradient V _P, also detection processing are the data relating to the presence or absence of the self-excited vibration associated with the running brake fluid temperature T _B, the detection data temporary storage unit for each subject linear valve, It is configured as a storage area that can record data for all target wheels and target linear valves. When a series of self-excited vibration detection processing for all the target linear valves is executed, the brake ECU 110 stores the self-excited vibration detection data for all the target linear valves stored in the detection data temporary storage unit. The detected data set is transmitted to the diagnosis ECU 126. The diagnosis ECU 126 stores the one detection data set in association with the date and time when the data set is obtained in the period data storage unit (see FIG. 22) of the storage unit 138 provided in the diagnosis ECU 126. The period data storage unit stores self-excited vibration detection data in a set period (for example, one month) that is a period that is continuously set repeatedly from the time of purchase of the vehicle.

iv) Diagnosis process for self-excited vibration and process based on the diagnosis result In this hydraulic brake system, two diagnostic processes, a short-term diagnosis process and a long-term diagnosis process, are executed for the self-excited vibration of the linear valve. The short-term diagnosis process is executed when the brake ECU 110 executes a series of self-excited vibration detection processes for all the target linear valves described above. Specifically, using the self-excited vibration detection data for each control operation existing in the detection data temporary storage unit, it is detected for all the one control operation regardless of which target linear valve it is. This is performed by determining how many control operations the self-excited vibration is generated out of the presence or absence of the self-excited vibration. That is, in the short-term diagnosis processing, the self-excited vibration occurrence rate R _S in the one detection data set is specified, and the self-excited vibration occurrence rate R _S (hereinafter sometimes referred to as “short-term self-excited vibration occurrence rate R _S ”). However, when the set occurrence rate R _S1 (for example, 10%) is exceeded, it is diagnosed that the possibility of occurrence of self-excited vibration is high. In this hydraulic brake system, when it is diagnosed that the possibility of occurrence of self-excited vibration is high in the short-term diagnosis process, the self-excited vibration process described later is preferentially executed in the subsequent anti-excited vibration process. It has come to be.

The long-term diagnosis process, which is another diagnosis, is executed in the diagnosis ECU 126 every time the above-described set period expires. Specifically, the self-excited vibration detection data in the set period stored in the period data storage unit is used, and the condition regarding the self-excited vibration of the hydraulic brake system is “good”, “adjustment required”, Approved as one of three levels of “urgent adjustment”. Specifically, in all self-excited vibration detection data stored in the storage unit 138, the presence / absence of self-excited vibration detected for one control operation regardless of which target linear valve is the target. Of these, the self-excited vibration is generated for one control operation, that is, the long-term self-excited vibration occurrence rate R _L is specified and executed. When the long-term self-excited vibration occurrence rate R _L is equal to or less than the set occurrence rate R _L1 (for example, 10%), “good” is recognized. If the long-term self-excited vibration occurrence rate R _L exceeds the set occurrence rate R _L1 , it depends on whether or not the possibility of the self-excited vibration is high under the condition that the self-excited vibration is relatively difficult to occur. , “Adjustment required” or “Urgent adjustment required”. Specifically, when the set brake fluid temperature is equal to or lower than T _B3 , the long-term self-excited vibration occurrence rate R _T , which is the long-term self-excited vibration occurrence rate, and the long-term when the hydraulic pressure difference before and after the set operation is ΔP _CS and ΔP _CM. The low-pressure difference occurrence rate R _P , which is the self-excited vibration occurrence rate, and the low-gradient occurrence rate R _V , which is the long-term self-excited vibration occurrence rate when the set hydraulic pressure change gradient is V _PS , V _PM , respectively. When any of the occurrence rates R _T , R _P , R _V exceeds the set occurrence rate R ₁ (for example, 30%), it is recognized as “Necessary adjustment”, and the occurrence rate R _{When all of T 1} , R _P , and R _V are equal to or less than the set occurrence rate R ₁ , “adjustment required” is recognized.

  When the long-term diagnosis processing is completed, the self-excited vibration detection data for the set period is stored in the storage data storage unit (see FIG. 22) of the storage unit 138 together with the diagnosis result. In addition, when it is recognized as “adjustment required” or “adjustment required” in the long-term diagnosis processing, the diagnosis result and the self-excited vibration detection data for the set period are sent to the communication device 136 via the gate-away ECU 128. Then, the communication device 136 transmits the self-excited vibration information of the vehicle equipped with the hydraulic brake system to the support center. After the support center analyzes the self-excited vibration information and decides on the necessary measures, the support center will provide information on a specific maintenance department that can maintain the vehicle, and information that will prompt the customer to enter the department. And reply. The returned information is sent from the communication device 136 to the diagnosis ECU 126 via the gate-away ECU 128, and the diagnosis ECU 126 displays the information on a display provided on the instrument panel. When the diagnosis result is “Necessary adjustment”, the diagnosis ECU 126 is concerned that the driver may feel vibration sound or the like due to self-excited vibration, and “the vibration experienced by the driver”. A message stating that “the sound or the like does not affect the running performance of the vehicle” is displayed on the display. Incidentally, the self-excited vibration detection data stored in the storage data storage unit of the storage unit 138 is effective for adjustment of the hydraulic brake system in a department that performs the periodic inspection at the time of periodic inspection of the vehicle. Is used.

(B) Self-excited vibration elimination processing (linear valve elimination operation)
The self-excited vibration canceling process in the present hydraulic brake system is performed by controlling the hydraulic control valve device 44 by the brake ECU 110 so that the linear pressure increasing valve 70 and the linear pressure reducing valve 72 perform a canceling operation which is a predetermined operation. Done. Specifically, in the canceling operation, the linear valves 70 and 72 are controlled so that both the front and rear of the closing portion of the target linear valve are in a pressurized state. More specifically, referring to FIG. 3 and FIG. 4, before and after the portion constituted by the valve elements 170 and 264 included in the target linear valve and the valve seats 168 and 262 on which the valve elements 170 and 264 are seated. In other words, both the first port 198,268 side and the second port 204,270 side sandwiching the portion for blocking and adjusting the flow of the brake fluid are pressurized, and the valve chambers 218,260 and the plunger chamber of the target linear valve A control operation is performed so that pressures 220 and 274 are in a pressurized state. In such a state, when bubbles are present in the valve chambers 218 and 260 and the plunger chambers 220 and 274, the bubbles can be eliminated by dissolving the air constituting the bubbles in the brake fluid. It becomes. Further, in the canceling operation, the target linear valve is opened and closed in a state where the front and rear of the closing portion are pressurized. More specifically, the supply and non-supply of current to the target linear valve are repeated, and the plungers 172 and 276 are repeatedly operated a plurality of times. By such an operation, movement of bubbles inside the target linear valve and elimination of bubbles are promoted. The canceling operation of the linear valves 70 and 72 as described above is a kind of the anti-self-excited vibration processing operation similar to the above-described detection time operation, and is executed for each target linear valve and for each target wheel. In the cancellation operation, when the target linear valve is the linear pressure increasing valve 70 and the linear pressure reducing valve 72, in the case of the detection process during stopping and the detection process during traveling, the target wheel is the front wheels 16FL and 16FR. It differs depending on whether there is a rear wheel 16RL or 16RR. In the following, the canceling operation in each case will be specifically described by taking the case where the target wheel is the left front wheel 16FL and the case of the right rear wheel being 16RR as examples.

  When the target wheel is the front left wheel 16FL, which is the front wheel, when the self-excited vibration elimination process is performed while the vehicle is stopped, the following elimination operation is executed. When the target linear valve is the pressure-increasing linear valve 70FL, as shown in FIG. 9A, the linear pressure reducing valve 72FL remains in the closed state in the state where the master cut valve 40L is closed. The linear pressure increasing valve 70FL is opened and then the supply current is controlled, so that the above-described opening / closing operation of the linear pressure increasing valve 70FL is repeated (hereinafter, this operation is referred to as "repetitive opening / closing operation" The state in which the operation is performed may be referred to as a “repetitive opening / closing operation state”). In addition, (triangle | delta) in a figure shows a repeated opening / closing operation state (it is the same also in another figure). When the target linear valve is the linear pressure reducing valve 72FL, as shown in FIG. 9B, in the state where the master cut valve 40L is closed, the valve reservoir shutoff valve 92 is operated to close. By setting the valve state, the brake fluid is prevented from flowing out from the linear pressure reducing valve 72FL to the reservoir 26. In this state, the linear pressure increasing valve 70FL is opened by supplying a current. The linear pressure reducing valve 72FL is opened, and then the linear pressure reducing valve 72FL is repeatedly opened and closed. In addition, (circle) in a figure shows the valve opening state implement | achieved by supplying with an electric current (it is the same also in another figure). On the other hand, in the self-excited vibration elimination process during traveling, as shown in FIGS. 9C and 9D, the master cut valve 40L is closed and the left front wheel 16FL, which is the target wheel, is closed. In order to avoid the application of the braking force, the linear pressure-increasing valve 70FL is operated in a state in which the inter-cylinder shutoff valve 90FL corresponding to the wheel 16FL is operated and the inflow / outflow of the brake fluid to the wheel cylinder 24FL is prohibited. , The elimination operation of the linear pressure reducing valve 72FL is executed. When the target linear valve is the linear pressure-increasing valve 70FL, as in the processing during the stop, as shown in FIG. 9C, the linear pressure-increasing valve 70FL is opened while the linear pressure-reducing valve 72FL remains closed. Then, the linear pressure increasing valve 70FL is repeatedly opened and closed. When the target linear valve is the linear pressure reducing valve 72FL, the valve reservoir shutoff valve 92 is closed as shown in FIG. 9D, and in this state, the linear pressure increasing valve 70FL is opened. The linear pressure reducing valve 72FL is opened and then the linear pressure reducing valve 72FL is repeatedly opened and closed.

  When the target wheel is the right rear wheel 16RR that is the rear wheel side wheel, the following canceling operation is performed when the self-excited vibration canceling process is performed while the vehicle is stopped. When the target linear valve is a linear pressure-increasing valve 70RR, as shown in FIG. 10A, instead of the linear pressure reducing valves 72FL and 72FR when the front wheels 16FL and 16FR are the target wheels, the valve reservoir is shut off. The valve 92 is actuated to close the valve, the linear pressure reducing valve 72RR remains open, the linear pressure increasing valve 70RR is opened, and then the linear pressure increasing valve 70RR is repeatedly opened and closed. When the target linear valve is the linear pressure reducing valve 72RR, as shown in FIG. 10B, the valve reservoir shutoff valve 92 is operated as in the case where the front wheels 16FL, 16FR are the target wheels. The valve is closed, the linear pressure increasing valve 70RR is opened while the linear pressure reducing valve 72RR remains open, and then the linear pressure reducing valve 72RR is repeatedly opened and closed. On the other hand, in the self-excited vibration elimination process during traveling, as shown in FIGS. 10C and 10D, the valve-to-cylinder cutoff valve 90RR is the same as in the case where the front wheels 16FL and 16FR are the target wheels. Is operated to close the valve, and the elimination operation of the linear pressure increasing valve 70RR and the linear pressure reducing valve 72RR is executed. Similar to the processing while the vehicle is stopped, when the target linear valve is the linear pressure increasing valve 70RR, as shown in FIG. 10C, the valve reservoir shutoff valve 92 is closed and the linear pressure reducing valve 72RR is opened. The linear pressure increasing valve 70RR is opened while the valve is in the valve state, and then the linear pressure increasing valve 70RR is repeatedly opened and closed. When the target linear valve is the linear pressure reducing valve 72RR, the valve reservoir shutoff valve 92 is closed as shown in FIG. 10D, and in this state, the linear pressure reducing valve 72RR is opened. In this state, the linear pressure increasing valve 70RR is opened, and then the linear pressure reducing valve 72RR is repeatedly opened and closed. When the target wheels are the rear wheels 16RL and 16RR, the valve reservoir shut-off valve 92 is closed instead of the linear pressure reducing valves 72RL and 72RR when the target linear valve is the pressure increasing linear valve 70RL or 70RR. Since the linear pressure reducing valves 72RL and 72RR are normally open linear valves, there is a risk that the linear pressure reducing valves 72RL and 72RR are overloaded by the supply current for maintaining the valve closed state. This is to reduce the amount.

  In the above cancellation operation, when the target wheels are the front wheels 16FL and 16FR, the valve-reservoir shutoff valve 92 is not operated when the target linear valve is the linear pressure increasing valve 70FL or 70FR. However, when the self-excited vibration elimination processing of two or more target linear valves is executed simultaneously with a plurality of wheels 16 as target wheels, the valve reservoir shutoff valve 92 is operated to close the valve. In this state, the canceling operation using the linear pressure increasing valves 70FL and 70FR as the target linear valve may be executed.

(C) Anti-self-excited vibration process while the vehicle is stopped In the hydraulic brake system, it is possible to execute anti-self-excited vibration processing when the vehicle is stopped. In this case, the parking brake 94 is activated because it is necessary to execute the anti-self-excited vibration process while securing a braking force (hereinafter sometimes referred to as “stop braking force”) for maintaining the vehicle's stopped state. In other words, the parking brake 94 is applied, or it depends on one or more of the hydraulic brakes 18 provided on each wheel 16 without depending on the parking brake 94. When the stop braking force is ensured, the self-excited vibration process, specifically, the operation of the linear valves 70 and 72 during the self-excited vibration can be executed. In this hydraulic brake system, which one of the above two states is used as a permissible condition for anti-self-excited vibration processing when the vehicle is stopped (hereinafter, sometimes referred to as “allowing processing when the vehicle is stopped”). It is possible to select, and by the selection, it is possible to select a stop time processing mode which is a mode of anti-self-excited vibration processing (hereinafter also referred to as “stop time processing”) at the time of stop. The selection is made possible by switching of the stop time processing mode selection switch 100 by the driver. It should be noted that the operation at the time of stationary self-excited vibration, that is, the self-excited vibration processing is arbitrarily performed by the driver, and is started by operation of the stop-time processing start switch 102 by the driver.

  If the stop time processing mode is a parking brake dependent mode in which the stop time processing permission condition is that the parking brake 94 is operating, the parking brake 94 is set by the driver when the stop time processing is started. When the brake ECU 110 is not operated, the brake ECU 110 determines that, and controls the parking brake 94 to operate it. In the parking brake relying mode, the stopping braking force by the parking brake 94 is ensured, so that the stopping braking force by the hydraulic brake 18 is not required. Therefore, in the stop-time process in the parking brake dependent mode, the anti-self-excited vibration process for each wheel having each of the four wheels 16 as a target wheel is performed at the same time. That is, the operation at the time of the self-excited vibration of the linear valves 70 and 72 for each of the four wheels 16 as target wheels is executed at the same time.

  When the stop time processing mode is a hydraulic brake dependent mode in which securing of the braking force by the hydraulic brake 18 is a permissible stop time processing condition, the brake ECU 110 controls the hydraulic pressure when the stop time processing is started. By controlling the valve device 44, the braking force during stopping is secured by the three wheels 16 excluding one target wheel. In this case, the total braking force applied to the three wheels 16 is such that, for example, the wheels 16 do not rotate even when the vehicle is stopped on a dry road (μ = 1) with an inclination angle of 45 °. Moreover, in order to consider the overload of the linear pressure reducing valves 72RL and 72RR which are normally open valves, the sharing of the braking force by the hydraulic brakes 18FL and 18FR on the front wheels side is made as large as possible. . As described above, in the stop time processing in the hydraulic brake dependent mode, only one wheel 16 is set as a target wheel at a certain time, and the self-excited vibration processing for the wheel 16, that is, the self-excitation of the linear valves 70 and 72. Operation during excitation vibration is executed. Then, every time the counter-self-excited vibration process for the wheel 16 is completed, the target wheels are sequentially changed, so that the counter-self-excited vibration process for all four wheels 16 is executed.

  When a predetermined operation is performed on the vehicle by the driver while the stop time process is being executed, the stop time process is immediately interrupted by the brake ECU 110. More specifically, the stop-time process is interrupted when an operation that can be considered to start the vehicle, such as a release operation of the parking brake 94, is performed. In this case, the brake ECU 110 knows which wheel 16 has completed the anti-self-excited vibration process, and when the anti-self-excited vibration process is executed next, the brake ECU 110 has not completed the process. The process is executed from the self-excited vibration process, and the self-excited vibration process for all the wheels 16 is completed as one unit.

(D) Anti-self-excited vibration process during traveling In this hydraulic brake system, even when the vehicle is traveling, the anti-excited vibration process, that is, the operation during the self-excited vibration process of the linear valves 70 and 72 is performed. It is possible to execute. Whether or not it is necessary to execute the anti-self-excited vibration process during traveling (hereinafter sometimes referred to as “traveling process”) is arbitrarily determined by the driver. This is performed by switching the processing necessity / unnecessary selection switch 104. In addition, since the processing at the time of travel causes a brake operation delay or the like when a brake operation by the driver, that is, the operation of the brake pedal 10 is performed, the processing condition at the time of traveling, which is a predetermined permissible condition, is satisfied. Only when it is running. Specifically, when the vehicle is traveling at a low speed, or when the vehicle ahead is relatively close, the brake operation by the driver is likely to be performed. In order to prohibit the operation of the valves 70 and 72 during the self-excited vibration process, “the vehicle travel speed v must be equal to or higher than the set speed v ₁ ” and “the arrival time to the preceding vehicle as information from the autodrive ECU 124. “T _r (distance obtained by dividing the inter-vehicle distance by the relative speed with respect to the vehicle ahead) is equal to or longer than the set time t _R1 ” is the above-described processing condition for traveling.

  In the running process, a brake operation by the driver during execution is scheduled, and only the processing operation at the time of anti-excited vibration for two wheels 16 that are a part of the four wheels 16 is executed at one time. Have been to. That is, the four wheels 16 are divided into two wheel pairs, and only one self-excited vibration process is performed for each of the two wheels 16 constituting one wheel pair as target wheels. -ing Specifically, considering that the braking force that can be generated immediately after the brake operation is not as small as possible and the balance of the braking force, etc., the left front wheel 16FL and the right rear wheel 16RR that exist in diagonal positions, respectively. One of the self-excited vibration processing with each of the target wheels as a target wheel and the self-excited vibration processing with each of the right front wheel 16FR and the left rear wheel 16RL as the target wheels is executed at one time, and one of the processes is completed After that, the other process is executed at one time after the one process.

  If a brake operation is performed by the driver during the running process, or if the previous running process permission condition is not satisfied, the running process, that is, the running operation of the linear valves 70 and 72 is performed. The brake ECU 110 is immediately interrupted. When the brake operation is performed, only the linear valves 70 and 72 corresponding to the two wheels 16 for which the self-excited vibration process is not executed are controlled. Thereby, the braking force for the wheels 16 is secured. Incidentally, in that case, it is also possible to execute control to increase the braking force of the two wheels 16 from the normal time so as to compensate the braking force by the four wheels 16 at the normal time. On the other hand, with respect to the two wheels 16 that have been subjected to anti-excited vibration processing, the linear valves 70 and 72 provided on them are immediately in a normal operation state, that is, the hydraulic brake 18 is connected to the brake pedal 10. Returning to an operating state capable of exhibiting an appropriate braking force in accordance with the operation of (2), after that, an appropriate braking force is applied similarly to the previous two wheels 16. When the running process is interrupted, as in the case of the stopping process described above, the brake ECU 110 knows which wheel 16 the anti-self-excited vibration process has been completed. When the self-excited vibration process is executed, the process is executed from the self-excited vibration process for the wheels 16 that are not completed, and the self-excited vibration process for all the wheels 16 is completed as one unit. -ing

≪Flow of anti-excited vibration processing≫
(A) Anti-self-excited vibration processing program The anti-self-excited vibration processing in the hydraulic brake system is performed by executing the anti-self-excited vibration processing program shown in the flowchart of FIG. This program is repeatedly executed while the ignition switch of the vehicle is in the ON state, except for the case of interruption described later. The flow of the anti-self-excited vibration process in the hydraulic brake system will be described below along the flowchart.

In the self-excited vibration processing program, first, in step 1 (hereinafter abbreviated as “S1”, the same applies to other steps), it is determined whether or not the stop-time process start switch 102 has been operated by the driver. If the vehicle is operated, it is determined in S2 that the vehicle is stopped depending on whether or not the vehicle speed v obtained based on the wheel speed sensor 96 is zero. If it is determined that the vehicle is stopped, it is determined in S3 whether or not the stop time processing mode is set to the parking brake dependent mode based on the operation state of the stop time processing mode selection switch 100. When the parking brake dependent mode is selected, the parking brake dependent stop processing of S4 is executed. When the parking brake dependent mode is not set, that is, when the hydraulic brake dependent mode is selected, the hydraulic brake dependent stop of S5 is performed. Processing is executed. If it is determined in S2 that the vehicle is not stopped, it is determined in S6 whether or not it is necessary to execute the running process based on the operating state of the running process necessity / unnecessary selection switch 104. . If it is determined that the travel time process is necessary, in S7, whether or not the travel time processing permission condition is satisfied, that is, the vehicle travel speed v is equal to or higher than the set speed v ₁ and the automatic drive is performed. When the arrival time t _R to the preceding vehicle, which is information from the ECU 124, is equal to or greater than the set time t _R1, it is determined that the travel-time processing permission condition is satisfied, and the travel-time processing in S8 is executed. If execution of the running process is not required, or if the above-described running allowance condition is not satisfied, one execution of this program ends. In other words, in this self-excited vibration processing program, either the hydraulic brake-based stop processing or the parking brake-based stop processing according to the driver's selection is performed as a driver's start operation while the vehicle is stopped. In addition, it is executed based on the travel time, and the travel time process is performed during travel by the driver.

  The hydraulic brake dependent stop processing at S5, the parking brake dependent stop processing at S4, and the travel processing at S8 are shown in flowcharts in FIGS. 12 (a), 12 (b), and 12 (c), respectively. This is performed by executing a hydraulic brake-based stop processing routine, a parking brake-based stop processing routine, and a travel processing routine. In any of these routine processes, it is determined whether to perform a self-excited vibration detection process or a self-excited vibration cancellation process as the anti-self-excited vibration process. This determination is made based on a cancellation process execution flag, which will be described later. When the flag is OFF, the hydraulic brake-based stoppage self-excited vibration detection process in S12 and the parking brake in S22, respectively. When the dependent stop self-excited vibration detection process and the running self-excited vibration detection process of S32 are executed and the flag is in the ON state, the hydraulic brake dependent stop self-excited vibration cancellation process of S13, The self-excited vibration canceling process at the time of parking brake reliance stop at S23 and the self-excited vibration canceling process at the time of traveling at S33 are executed. That is, when it is necessary to perform self-excited vibration cancellation processing, the cancellation processing execution flag is turned on. In this case, the hydraulic brake dependent stop processing, the parking brake dependent stop processing, and the traveling processing are performed. In any of the processes, the self-excited vibration cancellation process is preferentially executed over the self-excited vibration detection process. Hereinafter, the self-excited vibration detection process and the self-excited vibration cancellation process executed in the three processes will be sequentially described.

i) Processing at the time of hydraulic brake-based stopping The self-excited vibration detection processing at S12 in the processing at the time of hydraulic brake-based stopping is performed by executing the hydraulic brake-based stopping self-excited vibration detection processing subroutine shown in the flowchart of FIG. Done. In this subroutine, first, in step S101, the target linear valve counter Cv, the hydraulic pressure difference condition counter Ccp, and the hydraulic pressure change gradient condition counter Ccv are reset. The target linear valve counter Cv is a counter for specifying which of the linear pressure increasing valve 70 and the linear pressure reducing valve 72 is the target linear valve. In the subsequent processing, when Cv = 0, the linear pressure increasing valve 70 is set. However, when Cv = 1, the linear pressure reducing valve 72 is specified as the target linear valve. Hydraulic pressure difference condition counter Ccp is a counter for specifying the operation before and after hydraulic pressure difference [Delta] P _C of the target linear valve in the detection during the operation where the above-mentioned, in the process of post, is [Delta] P _CS in the case of Ccp = 0, Ccp ΔP _CM is specified as the hydraulic pressure difference ΔP _C before and after operation, respectively, when Δ = 1, and ΔP _CL when Ccp = 2. The hydraulic pressure change gradient condition counter Ccv is a counter for specifying the hydraulic pressure change gradient V _P of the target linear valve in the above-described detection operation. When Ccv = 0, V _PS is Ccv = 1. If the V _PM is CCV = 2 of V _PL when are respectively specified above liquid pressure variation gradient V _P. These counters are reset to Cv = 0, Ccp = 0, and Ccv = 0, respectively.

Next, in S102, the brake fluid temperature T _B based on the detection value of the liquid temperature sensor 50, whether either set the brake fluid temperature T _B1 through T _B5 mentioned above is determined. If either is, in S103, is certified to the brake fluid temperature T _B in the case where any of its settings brake fluid temperature T _B1 through T _B5 is self-excited vibration detection is performed, the self-excited vibration detection processing Executed. If none of the set brake fluid temperatures T _{B1 to} T _B5 falls, the driver is notified in S104 by displaying on the display provided on the instrument panel that the self-excited vibration detection process is not executed. This subroutine ends.

  In the self-excited vibration detection process according to this subroutine, only one wheel 16 of the four wheels 16 is the target wheel at one time. Therefore, when the self-excited vibration detection process is executed, the target wheel is determined in S105. The target wheel is specified based on the counter Cw. In the target wheel counter Cw, Cw = 0 indicates the left front wheel 16FL, Cw = 1 indicates the right rear wheel 16RR, Cw = 2 indicates the right front wheel 16FR, and Cw = 3 indicates the left rear wheel 16RL. . The target wheel counter Cw is reset only when the ignition switch is turned on and Cw = 0. However, at the beginning of this subroutine, it is not reset, and in S105, the counter value at that time is set. The corresponding wheel 16 is specified as the target wheel. Incidentally, by the above handling of the target wheel counter Cw, the anti-self-excited vibration process is performed with four wheels 16 as one set, and the execution of the anti-self-excited vibration process program is temporarily resumed and then resumed. In this case, the process is resumed from the anti-excited vibration process for the wheel 16 that has not been executed.

Next, in S106, the linear valves 70 and 72 corresponding to the three wheels 16 excluding the one target wheel specified in S105 are operated, and the vehicle is stopped by the braking force applied to the three wheels. The braking force for maintaining the above is ensured. Subsequently, in S107, the target linear valve for the target wheel is specified based on the counter value of the target linear valve counter Cv, and based on the hydraulic pressure difference condition counter Ccp and the hydraulic pressure change gradient condition counter Ccv, The operating conditions of the linear valves 70 and 72 for the target wheel are specified. In S108, the operation at the time of detection of the linear valves 70 and 72 of one target wheel for detecting the self-excited vibration of the specified target linear valve is executed according to the specified operation condition, and the target wheel is made to operate. based on the detected value of the corresponding wheel cylinder pressure sensor 48, variation data of the wheel cylinder pressure P _C in the midst of the detection during operation is obtained. Note that the specific mode of operation at the time of detection differs depending on the target wheel and target linear valve as described above, and at the time of detection of the mode according to the target wheel and target linear valve described above. Operation is performed. Next, in S109, based on the obtained fluctuation data, according to the self-excited vibration detection method described above, the presence / absence of self-excited vibration for the target linear valve that has been subjected to the analysis calculation process and identified is identified. In S110, the presence or absence of the self-excited vibration is the self-excited vibration detection data stored in the storage area corresponding to the target linear valve and the operation condition of the detection data temporary storage unit described above. Updated.

In subsequent S111, it is determined whether or not the hydraulic pressure change gradient condition counter Ccv is the upper limit counter value Ccv _LIM (= 2 is set). If the upper limit counter value Ccv _LIM is not reached, in S112, the hydraulic pressure change gradient condition counter The counter Ccv is counted up, and the processes of S107 to S110 are repeated. If it is the upper limit counter value Ccv _LIM , the hydraulic pressure change gradient condition counter Ccv is reset in S113. Subsequently, in S114, it is determined whether or not the hydraulic pressure difference condition Ccp is the upper limit counter value Ccp _LIM (set to = 2). If it is not the upper limit counter value Ccp _LIM , the hydraulic pressure difference condition counter Ccp is set in S115. Counting up, and the processing of S107 to S113 is repeated. If the upper limit counter value Ccp _LIM is reached, the hydraulic pressure difference condition counter Ccp is reset in S116. Then, in subsequent S117, it is determined whether the target linear valve counter Cv is the upper limit counter value Cv _LIM (= 1 is set). If it is not the upper limit counter value Cv _LIM , the target linear valve counter Cv is determined in S118. Is counted up, and the processing of S107 to S116 is repeated. If the upper limit counter value Cv _LIM is reached, the target linear valve counter Cv is reset in S119. By repeating such a process, for each target wheel, for each of the linear pressure increasing valve 70 and the linear pressure reducing valve 72, each of the nine conditions obtained by combining the set hydraulic pressure difference condition and the hydraulic pressure change gradient condition is set. The presence or absence of self-excited vibration is detected.

Subsequently, in S120, the target wheel counter Cw is, when whether or not a limit counter value Cw _LIM (set to 3 in this subroutine) is determined, not the upper limit counter value Cw _LIM is The target wheel counter Cw is counted up, and the processes of S105 to S119 are repeated. That is, the target wheel is changed, and the detection processing for the presence or absence of self-excited vibration is performed for each of the linear pressure increasing valve 70 and the linear pressure reducing valve 72 of the changed target wheel under the above nine conditions. . When the upper limit counter value Cw _LIM is reached, the target wheel counter Cw is reset in S122. That is, the detection of the presence or absence of self-excited vibrations for all target wheels, that is, the recognition of the presence or absence of a series of self-excited vibrations for all the linear valves 70 and 72 has been performed. Complete. Then, in S123, the fact that the self-excited vibration detection process has been completed is displayed on the instrument panel display, and the driver is notified accordingly.

After the self-excited vibration detection process is completed, a short-term diagnosis process is executed in S124. This short-term diagnosis processing is performed by executing a short-term diagnosis subroutine whose flowchart is shown in FIG. More specifically, first, in S131, the presence or absence of self-excited vibrations under all the above operating conditions of all the linear valves 70 and 72 currently stored in the detection data temporary storage unit, that is, all the linear valves A set of self-excited vibration detection data relating to the presence or absence of self-excited vibration in all control operations 70 and 72 is read out. Next, in S132, the short-term self-excited vibration occurrence rate R _S described above is specified based on the read data. Subsequently, in S133, it is determined whether or not the short-term self-excited vibration occurrence rate R _S exceeds the above-described set occurrence rate R _S1, and if so, in S134, the elimination processing execution flag described above is determined. However, it is provided on the instrument panel as an indication that the self-excited vibration canceling process is executed in the next anti-self-excited vibration process. When the cancellation processing indicator is turned on, the driver is notified of this. If it is determined in S133 that the set occurrence rate R _S1 is not exceeded, S134 and S135 are skipped. In S136, the self-excited vibration detection data stored in the detection data temporary storage unit is transmitted to the storage unit 138 of the diagnosis ECU 126, and the execution of this subroutine ends. The transmitted data is stored in the above-described period data storage unit included in the storage unit 138.

  The self-excited vibration canceling process of S13 in the hydraulic brake dependent stop process is performed by executing the hydraulic brake dependent stop self-excited vibration canceling subroutine shown in the flowchart of FIG. In this subroutine, first, in S151, the target linear valve counter Cv is reset. Even in the self-excited vibration elimination processing according to this subroutine, only one wheel 16 of the four wheels 16 is set as the target wheel at one time. Therefore, in the subsequent S152, as in the previous self-excited vibration detection processing, the target wheel counter Cw The target wheel is specified based on the above, and in S153, the braking force for maintaining the vehicle in the stopped state is secured by the braking force applied to the three wheels 16 excluding the specified one target wheel. Subsequently, in S154, the target linear valve for the target wheel is specified based on the counter value of the target linear valve counter Cv. In the next S155, the self-excited vibration of the specified target linear valve is eliminated. The cancellation operation of the linear valves 70 and 72 of one specific wheel is executed. In addition, the specific mode of the canceling operation is different depending on the target wheel and the target linear valve as described above, similarly to the operation at the time of detection, and the mode according to the target wheel and the target linear valve described above. The canceling operation is executed.

In subsequent S156, it is determined whether the target linear valve counter Cv is the upper limit counter value Cv _LIM . If the upper limit counter value Cv _LIM is not determined, the target linear valve counter Cv is counted up in S157, and the processes of S154 and S155 are performed. Repeated. If the upper limit counter value Cv _LIM is reached, the target linear valve counter Cv is reset in S158. By such repeated processing, a control operation for eliminating self-excited vibration is executed for each linear pressure increasing valve 70 and linear pressure reducing valve 72 of one target wheel. Subsequently, in S159, the target wheel counter Cw is, when whether or not a limit counter value Cw _LIM (set to 3 in this subroutine) is determined, not the upper limit counter value Cw _LIM is In S160, the target wheel counter Cw is counted up, and the processing of S152 to S158 is repeated. That is, the target wheel is changed, and the self-excited vibration canceling process is performed for each of the linear pressure increasing valve 70 and the linear pressure reducing valve 72 of the changed target wheel. When the upper limit counter value Cw _LIM is reached, the target wheel counter Cw is reset in S161, and the above-described cancellation processing indicator that is turned on is turned off in S162, thereby self-excited vibration. The driver is notified that the cancellation process has been completed.

ii) Processing at parking brake dependent stop processing The self-excited vibration detection processing at S22 in the parking brake dependent stop processing is performed by executing a parking brake dependent stop-time self-excited vibration detection processing subroutine shown in the flowchart of FIG. In this subroutine, similarly to the detection process relying on the hydraulic brake, first, in S201, the target linear valve counter Cv, the hydraulic pressure difference condition counter Ccp, and the hydraulic pressure change gradient condition counter Ccv are reset. Next, in S202, the brake fluid temperature T _B is, whether either set the brake fluid temperature T _B1 through T _B5 mentioned above is determined, if any, in S203, the brake fluid temperature If T _B is recognized and the self-excited vibration detection process is executed and does not correspond to any of the set brake fluid temperatures T _{B1 to} T _B5 , the instrument panel indicates that the self-excited vibration detection process is not executed in S204. Is displayed on the display provided to the driver, and the processing of this subroutine is completed.

  In the self-excited vibration detection process according to this subroutine, since it is assumed that the braking force for maintaining the stopped state of the vehicle depends on the parking brake 94, when the self-excited vibration detection process is performed, in S205, It is determined whether or not the parking brake 94 is operated. If the parking brake 94 is not operated, in S206, the parking brake 94 is operated and a braking force for maintaining the stopped state of the vehicle is secured. .

In the self-excited vibration detection processing according to this subroutine, all four wheels 16 are set as target wheels, and detection processing for all the wheels 16 is performed at the same time. Therefore, the target wheel specifying process is not executed, and in the subsequent S207, the target linear valve is specified based on the counter value of the target linear valve counter Cv as in the case of the detection process relying on the hydraulic brake. Based on the hydraulic pressure difference condition counter Ccp and the hydraulic pressure change gradient condition counter Ccv, the operating condition of the target linear valve is specified. In S208, the operation at the time of detection of the linear valves 70 and 72 for detecting the self-excited vibration of the specified target linear valve corresponds to each wheel 16 and each target linear valve according to the specified operation condition. In an embodiment, the four wheels 16 are executed at the same time. Then, based on the detected value of each of the four wheel cylinder pressure sensor 48, variation data of each wheel cylinder pressure P _C in the midst of the detection during operation is obtained. Next, in S209, in the same manner as the detection process relying on the hydraulic brake, according to the above-described self-excited vibration detection method, the analysis calculation process based on each obtained variation data is performed, and the self-excitation for all target linear valves is performed. The presence or absence of vibration is certified. In S210, the presence or absence of these self-excited vibrations is stored as self-excited vibration detection data in the storage area corresponding to the operation condition of each target linear valve in the detection data temporary storage unit described above. Is updated.

  The subsequent processing of S211 to S219 is the same processing as the processing of S111 to S119 in the detection processing that relies on the hydraulic brake, and the description here will be omitted. For each of the pressure increasing valve 70 and the linear pressure reducing valve 72, the presence or absence of self-excited vibration under each of the nine conditions obtained by combining the set hydraulic pressure difference condition and hydraulic pressure change gradient condition is detected. Subsequently, in S220, it is determined that the presence or absence of a series of self-excited vibrations for all target linear valves has been made, and the target wheel counter Cw is reset, as in the detection process relying on the hydraulic brake, in S221. , A notification process to the effect that the self-excited vibration detection process has been completed is performed, and a short-term diagnosis process is performed in S222 by executing a short-term diagnosis subroutine whose flowchart is shown in FIG.

  The self-excited vibration canceling process of S23 in the parking brake dependent stopping process is performed by executing the parking brake dependent stopping self-excited vibration canceling process subroutine shown in the flowchart of FIG. In this subroutine, first, in S231, the target linear valve counter Cv is reset as in the case of the cancellation process relying on the hydraulic brake. Next, in the same manner as in the detection process, it is determined in S232 whether or not the parking brake 94 is operated. If not, the parking brake 94 is operated in S233. Since the self-excited vibration cancellation processing by this subroutine is also performed on the four wheels 16 at the same time, the target wheel identification processing is not performed, and in subsequent S234, based on the counter value of the target linear valve counter Cv, The target linear valve for each wheel 16 is specified, and in the next S235, the elimination operation of the linear valves 70 and 72 for eliminating the self-excited vibration of the specified target linear valve is performed for each wheel 16, each target linear valve. The four wheels 16 are executed at the same time. By subsequent S236 to S238, the canceling operation for the four wheels 16 whose target linear valves have been changed is repeated, and the execution of the self-excited vibration canceling process for all the target linear valves is completed. Then, in S239, the target wheel counter Cw is reset, and in the subsequent S240, the above-described canceling process indicator that has been turned on is turned off to notify the driver that the self-excited vibration canceling process has been completed. .

iii) Traveling time process The self-excited vibration detection process of S32 in the traveling time process is performed by executing a traveling time self-excited vibration detection process subroutine shown in the flowchart of FIG. Since the self-excited vibration detection process by this subroutine has many parts similar to the process of the self-excited vibration detection process subroutine at the time of the hydraulic brake-based stop shown in the flowchart of FIG. 13, only the different parts will be described. .

In the process according to the subroutine are the detection process in the traveling of the vehicle, the notification to the driver when the brake fluid temperature T _B is not in the set brake fluid temperature T _B1 through T _B5, i.e., the detection process is The notification process (S104) not to be executed is omitted, and the application of braking force to the wheels 16 that are not the target wheels (S106) is not executed.

In the detection processing at the time of traveling, two of the two wheel pairs, that is, one of the wheel pair of the left front wheel 16FL and the right rear wheel 16RR and the wheel pair of the right front wheel 16FR and the left rear wheel 16RL are included in one of them. The self-excited vibration detection processing for the wheels 16, that is, the operation at the time of detection of the linear valves 70 and 72 of the wheels 16 is executed at the same time. Therefore, in the target wheel identification process in S304, when the target wheel counter Cw is Cw = 0, the self-excited vibration is applied to the former wheel pair, and when Cw = 2, the self-excited vibration is applied to the latter wheel pair. Detection processing is executed. Then, the upper limit counter value Cw _LIM in S318 is set to Cw _LIM = 2, and in S319, the target wheel counter Cw is counted up by two.

  The self-excited vibration elimination process of S33 in the running process is performed by executing a running self-excited vibration elimination subroutine shown in the flowchart of FIG. Since the self-excited vibration elimination processing by this subroutine has many parts similar to the processing of the self-excited vibration elimination sub-routine at the time of stopping based on the hydraulic brake shown in the flowchart of FIG. 15, if only different parts are described, detection Similar to the processing, the application of the braking force to the wheels 16 that are not the target wheels (S153) is not executed, and the cancellation processing for the two wheels is performed at the same time, and the target wheel counter Cw is the detection processing. Are handled in the same way as

(B) Anti-self-excited vibration process execution management program The anti-self-excited vibration process execution management program is not always executed, but is executed under the control of the anti-self-excited vibration process execution management program shown in the flowchart of FIG. This management program is repeatedly executed while the ignition switch is in the ON state, and can be executed in parallel with the anti-self-excited vibration processing program. Below, the process by the management program is demonstrated sequentially according to a flowchart.

  In the processing by the self-excited vibration processing execution management program, first, in S41, it is determined that a predetermined reason for interruption has occurred. If a reason for interruption occurs, in S42, as the interruption processing, Execution is interrupted immediately. The reason for the interruption is that the accelerator pedal was operated by the driver in the case of hydraulic brake-based stop processing, and the parking brake 94 was released by the driver in the case of parking brake-based stop processing. In the case of the running process, the brake pedal 10 is operated by the driver.

  If the interruption process has been performed, it is determined in S43 whether or not the interrupted anti-self-excited vibration process is a running process. If it is not a running process, that is, a stop process, a return process is executed in S44. In this return processing, the so-called normal control state, that is, the linear valves 70 and 72 are controlled and actuated, and the braking force for each of the wheels 16 becomes the braking force corresponding to the driver's braking operation at that time. It is returned to such a state. Next, in S45, the driver is notified that the anti-self-excited vibration process has been interrupted by being displayed on a display provided on the instrument panel.

When it is determined in S43 that the suspended self-excited vibration process is a process during traveling, normal control for the pair of wheels 16 that are the target wheels at that time is prohibited in S46. And a braking force by normal control for the pair of wheels 16 is not generated. With this process, when a braking operation is performed during the running process, only the braking force for the pair of wheels 16 that are not the target wheels is generated. Next, in S47, the operating state of the linear valves 70 and 72 corresponding to the pair of wheels 16 that are the target wheels is returned to a state in which normal control can be performed. That is linear increasing valve 70 is closed, corresponding to their wheels 16, the linear pressure reducing valve 72 is opened, once the wheel cylinder pressure P _C of their wheels 16 is the atmospheric pressure. Thereafter, in S48, a command is issued to the effect that the normal control for the pair of wheels 16 that are the target wheels can be executed. By this processing, the braking force for each of the wheels 16 is also made the braking force by the normal control.

  After the return processing as described above is executed, the step counter of the anti-self-excited vibration processing program is reset in S49, and the execution of the program is resumed in S50. The anti-self-excited vibration processing program that is resumed by these processes is executed from the beginning thereof.

(C) Long-term diagnosis processing program The long-term diagnosis processing using the detection data obtained by the self-excited vibration detection processing is performed by the diagnosis ECU 126 executing the long-term diagnosis processing program shown in the flowchart of FIG. This process is executed every time the set period described above expires. Hereinafter, the processing of the long-term diagnosis processing program will be sequentially described along the flowchart.

In the processing by the long-term diagnosis processing program, first, in S61, the anti-self-excited vibration detection data in the set period stored in the period data storage unit provided in the storage unit 138 of the diagnosis 126 is read. Next, in S62, based on the data, the long-term self-excited vibration occurrence rate R _L , the low liquid temperature occurrence rate R _T , the low hydraulic pressure difference occurrence rate R _P , and the low gradient time described above for the set period. The occurrence rate R _V is specified by being calculated. Next, in S63, it is determined whether or not the long-term self-excited vibration occurrence rate R _L is equal to or less than the set occurrence rate R _L1 . If it is equal to or less than the set occurrence rate R _L1 , the condition regarding the self-excited vibration of the linear valves 70 and 72 is determined to be “good” in S64. When the set occurrence rate R _L1 is exceeded, in S65 to S67, each of the low solution temperature occurrence rate R _T , the low fluid pressure difference occurrence rate R _P , and the gradient occurrence rate R _V is set. whether it exceeds the rate R ₁ is determined. If none of them exceeds the set occurrence rate R ₁ , the condition is determined as “necessary adjustment” in S68, and if any of them exceeds the set occurrence rate R ₁ , S69 In S70, the condition is recognized as “immediately necessary adjustment”, and in S70, as described above, “the vibration sound felt by the driver does not affect the running performance of the vehicle”. A message is displayed on the instrument panel display to notify the driver.

  After these authorization processes are completed, in S71, a process for transmitting the detection data stored in the period data storage unit together with the long-term diagnosis result obtained by the authorization process to the support center via the communication device 136. Further, in S 72, the long-term diagnosis result and the detection data are stored in a storage data storage unit provided in the storage unit 138 of the diagnosis ECU 126. In this way, the processing by the long-term diagnosis processing program is completed.

<Functional configuration of control device>
In this hydraulic brake system, it can be considered that the brake ECU 110 and the diagnosis ECU 126 connected to each other by the control system LAN 120 constitute a control device for anti-excited vibration processing for the linear valves 70 and 72. The control device can be considered to have a functional configuration as shown in FIG. Hereinafter, the functional configuration will be described with reference to the drawing.

In addition to the normal operation control unit 302, the control device 300 controls the operation of the hydraulic control valve device 44 in the brake ECU 110 so that the braking force on each wheel 16 becomes the braking force corresponding to the driver's operation of the brake pedal 10. In addition, an anti-self-excited vibration process operation control unit 304 is provided for controlling the operation of the hydraulic control valve device 44 during the anti-self-excited vibration process. Specifically, the anti-self-excited vibration processing operation control unit 304 includes a detection-time operation control unit 306 as a functional unit that executes the detection-time operation by the processes of S108, S208, and S306 in each self-excited vibration detection processing subroutine. The excitation vibration cancellation processing subroutine includes a cancellation operation control unit 308 as a functional unit that executes the cancellation operation by the processes of S155, S235, and S334. Furthermore, the stop operation realization part 310 comprised including the function part which implement | achieves the control action of the linear valves 70 and 72 in the stop time process of S4 and S5 by the determination process of S1-S3, and S1, S6, S7 And a running operation realizing unit 312 including a functional unit that realizes the control operation of the linear valves 70 and 72 in the running process of S8 by the determination process. In addition, a braking operation possibility dependence operation prohibiting unit 314 is provided as a functional unit that prevents the control operation of the linear valves 70 and 72 from being executed in the traveling processing of S8 by the determination processing of S7. As a functional unit for preventing the control operation of the linear valves 70 and 72 from being executed when the vehicle travel speed v is lower than the set speed v ₁ , a travel speed-based operation prohibition unit 316 is provided. The brake ECU 110 corresponds to the two wheels 16 that are the target wheels when there is a brake operation by the driver during the process of S46 in the anti-self-excited vibration process execution management program, that is, the process during traveling. The operation part 318 at the time of braking operation is used as a function part that prohibits the operation by the normal control of the linear valves 70 and 72 and operates only the linears 70 and 72 corresponding to the two wheels 16 other than the target wheel by the normal control. Have. Furthermore, the brake ECU 110 includes a self-excited vibration analysis certification unit 320 as a functional unit that executes analysis processing and certification processing for detecting self-excited vibration in S109, S209, and S307 in each self-excited vibration detection subroutine, and self-excited vibration detection. And a detected data temporary storage unit 322 as a part for temporarily storing data.

  Further, the control device 300 includes a storage unit 138 in the diagnosis ECU 126, and the storage unit 138 includes the period data storage unit 330 and the saved data storage unit 332 described above. Further, in the diagnosis ECU 126, the diagnosis unit 334 is used as a function unit for executing the diagnosis process of the condition of the hydraulic brake system related to the self-excited vibration by the long-term diagnosis process program. Each of the transmission units 336 is provided as a functional unit that executes processing for transmitting vibration detection data to the support center via the communication device 136.

  In this hydraulic brake system, a self-excited vibration detection device is configured including a wheel cylinder hydraulic pressure sensor 48 corresponding to each wheel 16 and a self-excited vibration analysis authorization unit 320, and a detection data temporary storage unit 322 of the brake ECU 110. , The storage unit 138 of the diagnosis ECU 126 is configured to store the detection result of the self-excited vibration, and the transmission unit 336 and the communication device 136 of the diagnosis ECU 126 are included to detect the self-excited vibration. The detection result transmitting device is configured to transmit to the outside of the vehicle.

It is a circuit diagram which shows the hydraulic brake system of an Example. FIG. 2 is a block diagram schematically showing a system configuration of a vehicle on which the hydraulic brake system of FIG. 1 is mounted. It is sectional drawing which shows the linear pressure | voltage rise valve and the front wheel side linear pressure | voltage reduction valve which comprise the hydraulic pressure control valve apparatus of the hydraulic brake system of FIG. It is sectional drawing which shows the rear-wheel side linear pressure-reduction valve which comprises the hydraulic control valve apparatus of the hydraulic brake system of FIG. It is a conceptual graph for demonstrating the hydraulic pressure difference before and behind a hydraulic pressure and the hydraulic pressure change gradient which are parameters which index the possibility of occurrence of self-excited vibration. It is a graph which shows notionally the situation of fluid pressure change in case self-excited vibration has occurred, and the power spectrum obtained by frequency analysis about the fluid pressure change. It is a figure which shows the operation state in the self-excited vibration detection process of the linear pressure increasing valve and linear pressure reducing valve with which the hydraulic brake system of FIG. 1 is provided as an example when the left front wheel is the target wheel. It is a conceptual diagram which shows the automatic vibration detection data as a detection result of a self-excited vibration detection process. It is a figure which shows the operation state in the self-excited vibration cancellation process of the linear pressure increasing valve and linear pressure reducing valve with which the hydraulic brake system of FIG. 1 is provided as an example when the left front wheel is the target wheel. It is a figure which shows the operation state in the self-excited vibration cancellation process of the linear pressure increasing valve and linear pressure reducing valve with which the hydraulic brake system of FIG. 1 is provided as an example when the right rear wheel is the target wheel. It is a flowchart which shows the self-excited vibration processing program performed in brake ECU with which the hydraulic brake system of FIG. 1 is provided. 12 is a flowchart showing each of a hydraulic brake dependent stop processing routine, a parking brake dependent stop processing routine, and a running processing routine executed in the anti-self-excited vibration processing program of FIG. FIG. 13 is a flowchart showing a hydraulic brake dependent stoppage self-excited vibration detection processing subroutine executed in the hydraulic brake dependency stoppage processing routine of FIG. FIG. 12 is a flowchart showing a short-term diagnosis processing subroutine executed in each of the hydraulic brake-based stoppage self-excitation vibration detection processing subroutine, the parking brake-based stoppage self-excitation vibration detection processing subroutine, and the travel time self-excitation vibration detection processing subroutine shown in FIG. It is. FIG. 13 is a flowchart showing a self-excited vibration elimination processing subroutine for hydraulic brake dependent stopping executed in the hydraulic brake dependent stopping processing routine of FIG. FIG. 13 is a flowchart showing a parking brake dependent stoppage self-excited vibration detection processing subroutine executed in the parking brake dependency stop processing routine of FIG. FIG. 13 is a flowchart showing a self-excited vibration elimination processing subroutine for parking brake dependent stopping executed in the parking brake dependent stopping processing routine of FIG. FIG. 13 is a flowchart showing a traveling self-excited vibration detection processing subroutine executed in the traveling processing routine of FIG. FIG. 13 is a flowchart showing a traveling self-excited vibration elimination processing subroutine executed in the traveling processing routine of FIG. It is a flowchart which shows the anti-self-excited vibration process execution management program performed in brake ECU with which the hydraulic brake system of FIG. 1 is provided. It is a flowchart which shows the long-term diagnostic processing program performed in diagnosis ECU with which the hydraulic brake system of FIG. 1 is provided. It is a functional block diagram regarding control of the anti-self-excited vibration process of the hydraulic brake system of FIG.

Explanation of symbols

10: Brake pedal 12: Master cylinder 14: Brake actuator 16: Wheel 18: Hydraulic brake 24: Wheel cylinder 26: Reservoir 40: Master cut valve 42: Fluid pressure source device 44: Fluid pressure control valve device 48: Wheel cylinder pressure Sensor 70: Linear pressure increasing valve 72: Linear pressure reducing valve 90: Valve cylinder shutoff valve 92: Valve reservoir shutoff valve 94: Parking brake 110: Brake ECU 124: Auto drive ECU 126: Diagnostics ECU 136: Communication device 138: Memory Portion 160: Valve housing 162: Seat valve 164: Solenoid 168: Valve seat 170: Valve element 172: Plunger 218: Valve chamber 220: Plunger chamber 250: Valve housing 252: Seat valve 254: Solenoid 260: Valve chamber 262 Valve seat 264: Valve 274: Plunger chamber 276: Plunger 300: Control device 302: Normal operation control unit 304: Operation control unit during anti-excited vibration processing 306: Operation control unit during detection 308: Cancellation operation control unit 310: Stop Operation realization unit 312: Operation realization unit during travel 314: Brake operation possibility dependent operation prohibition unit 316: Travel speed dependency operation prohibition unit 318: Partial operation implementation unit during braking operation 320: Self-excited vibration analysis certification unit 322: Detection Temporary data storage unit 330: Period data storage unit 332: Stored data storage unit 334: Diagnosis unit 336: Transmission unit

Claims (9)

A brake having a wheel cylinder for braking the wheel, a hydraulic pressure source, a reservoir, a pressure increasing valve provided between the wheel cylinder and the hydraulic pressure source, and between the wheel cylinder and the reservoir A hydraulic brake system including a provided pressure reducing valve and a valve control device that controls the pressure increasing valve and the pressure reducing valve,
At least one of the pressure increasing valve and the pressure reducing valve is a linear valve,
For a target linear valve that is at least one of the linear valves, self-excited vibration detection processing that is a process for detecting self-excited vibration of the target linear valve, and elimination of self-excited vibration of the target linear valve A hydraulic brake system configured to be capable of executing a self-excited vibration process that is at least one of a self-excited vibration canceling process that is a process for the purpose.   The hydraulic brake system is configured to be capable of executing at least the self-excited vibration detection process as the anti-self-excited vibration process, and the hydraulic pressure is periodically changed when the target linear valve is operated. The hydraulic brake system according to claim 1, further comprising a self-excited vibration detecting device that detects self-excited vibration of the target linear valve by detecting the self-excited vibration.   The hydraulic brake system according to claim 2, wherein the hydraulic brake system is configured to execute the self-excited vibration detection process when the brake fluid temperature is a set fluid temperature.   The hydraulic brake system is configured to be capable of executing at least the self-excited vibration canceling process as the anti-self-excited vibration process, and the valve control device includes the pressure increasing valve and the pressure reducing valve. 4. The canceling operation control unit that controls the pressure increasing valve and the pressure reducing valve so as to execute a canceling operation that is an operation for canceling the self-excited vibration of the target linear valve. Hydraulic brake system. The hydraulic brake system includes a valve-reservoir shutoff valve that is controlled by the valve control device to shut off communication between the pressure reducing valve and the reservoir;
5. The liquid according to claim 4, wherein the canceling operation control unit controls the pressure increasing valve and the pressure reducing valve so that the canceling operation is executed in a state where the valve-reservoir shutoff valve is operated. Pressure brake system. The valve control device is
The self-excited valve that controls the pressure-increasing valve and the pressure-reducing valve so that the pressure-increasing valve and the pressure-reducing valve perform the operation during the self-excited vibration process, which is the operation for the processing when the anti-self-excited vibration process is performed. It has an operation control unit during vibration processing,
The operation control unit for the self-excited vibration processing is
When the self-excited vibration detection process is executed, the detection-time operation, which is an operation for detecting the self-excited vibration of the target linear valve by the pressure increasing valve and the pressure reducing valve, is executed as the anti-self-excited vibration process operation. And a detection operation control unit for controlling the pressure increasing valve and the pressure reducing valve, and a canceling operation in which the pressure increasing valve and the pressure reducing valve are actions for eliminating the self-excited vibration of the target linear valve. The hydraulic brake system according to any one of claims 1 to 5, further comprising at least one of a pressure increasing valve and a canceling operation control unit that controls the pressure reducing valve so as to be executed as a processing operation.   The hydraulic brake system according to claim 6, wherein the anti-excited vibration processing operation control unit includes a stop operation realizing unit that realizes the anti-excited vibration processing operation while the vehicle is stopped.   The hydraulic brake system includes a valve-cylinder shut-off valve that is controlled by a control device to shut off the communication between the pressure-increasing valve and the pressure-reducing valve and the wheel cylinder, and the operation control unit for the self-excited vibration process is a vehicle. 8. The hydraulic brake system according to claim 6, further comprising a travel-time operation realizing unit that realizes the anti-self-excited vibration processing operation in a state in which the valve-cylinder shut-off valve is operated during travel. A linear valve self-excited vibration detection method for detecting self-excited vibration of a linear valve based on periodic fluctuations in hydraulic pressure during operation of the linear valve.

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