JP2008137603A - Brake fluid pressure control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress vibration of a control valve arranged in the discharge side of a pump caused by a resonance phenomenon based on pulsation of brake fluid. <P>SOLUTION: When an electric current value held in peak hold circuits 72a to 72d at the time of a pressure intensifying mode exceeds a reference electric current value, the resonance phenomenon is assumed occurring and pulse is outputted. Specifically, pulses of an electric current value of a control current carried to a solenoid of a first pressure intensifying control valve 17 are increased/decreased. Basically, with respect to the solenoid of the first pressure intensifying control valve 17, a control current of an electric current value generating a pressure difference is carried and a control current of a holding electric current value is carried so that the first pressure intensifying control valve 17 momentarily becomes the cut-off state by contact of a valve element with a valve seat. Thus, the valve element and a plunger are pressed against the valve seat side, and vibration of the valve element and the plunger is stopped even when the resonance phenomenon occurs caused by the pulsation of the brake fluid discharged by the pump 19. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a brake fluid pressure control device for a vehicle that executes brake fluid pressure control such as anti-skid control (ABS control) and traction control (TCS control).

  2. Description of the Related Art Conventionally, there is an anti-skid control device that avoids wheel lock by controlling a braking force generated on a wheel based on wheel slip. Regarding such an anti-skid control device, for example, Patent Document 1 discloses a difference between a pressure (M / C pressure) of a master cylinder (M / C) and a pressure (W / C pressure) of a wheel cylinder (W / C). By calculating a pressure and outputting a control signal corresponding to the differential pressure to a pressure increase control valve composed of a normally open control valve that controls the pressure increase of the wheel cylinder of each wheel, the pressure is increased. It has been proposed to increase the wheel cylinder pressure smoothly by changing the pressure difference between the upstream and downstream of the pressure control valve linearly (steplessly).

Specifically, by linearly adjusting the value of the current flowing through the pressure increase control valve, the pressure increase control valve functions as a linear valve that generates a differential pressure between the upstream and downstream sides. That is, when the current value flowing through the pressure increase control valve is adjusted, the distance between the valve body and the valve seat provided in the pressure increase control valve is controlled, and the throttling effect generated between the valve body and the valve seat is changed. Since the differential pressure corresponding to the effect can be maintained, the pressure increase control valve can function as a linear valve.
JP 2003-19952 A

  However, when the brake fluid stored in the reservoir is discharged by the pump, if the frequency of the pulsation of the discharged brake fluid matches the natural frequency of the pressure increase control valve, a large hydraulic pulsation occurs due to the resonance phenomenon. . That is, there is a problem in that the valve body and plunger of the pressure increase control valve vibrate due to pulsation, and excessive vibration noise is generated.

  Although the pressure increase control valve has been described here, a control valve disposed between the M / C and the pressure increase control valve in order to execute TCS control or side slip prevention control (ESC (Electronic Stability Control)). With respect to the above, when functioning as a linear valve during TCS control or ESC, the same problem as described above occurs due to the pulsation of the brake fluid discharged by the pump.

  The present invention has been made in view of the above points, and an object of the present invention is to make it possible to suppress a control valve disposed on the discharge side of a pump from vibrating due to a resonance phenomenon based on pulsation of brake fluid.

  In order to achieve the above object, according to the first aspect of the present invention, when the pressure increasing mode in the brake fluid pressure control is selected, the current value of the control current flowing through the control valve of the target wheel is detected. Current detection means (125), determination means (130) for determining whether or not the current value of the control current exceeds a reference current value that is a threshold value for occurrence of a resonance phenomenon, and the current value of the control current is the reference current A normal output means (135) for executing a normal output process for flowing a control current so as to linearly change the differential pressure with respect to the solenoid of the control valve of the target wheel when the value does not exceed the value, and the current value of the control current Pulse output means (140) for executing a pulse output process for increasing or decreasing the control current in a pulsed manner so that the interval between the valve body and the valve seat becomes zero or the maximum value when the current exceeds the reference current value; Have It is characterized.

  In this way, when the current value of the control current exceeds the reference current value, the pulse output means increases or decreases the control current in a pulse manner so that the distance between the valve body and the valve seat is zero or the maximum value. Execute the pulse output process. Thereby, it becomes possible to suppress that the control valve arranged on the discharge side of the pump vibrates due to a resonance phenomenon based on pulsation. Thereby, generation | occurrence | production of an excessive vibration sound can be suppressed, and it becomes possible to perform control which maintains a wheel cylinder pressure more correctly.

  For example, as shown in claim 2, the pulse output means can alternately change the current value that makes the interval between the valve body and the valve seat zero, the current that makes the maximum value, and the current value of the control current. .

  According to a third aspect of the present invention, the pulse output means can continue the pulse output process during the pressure increasing mode when the current value of the control current exceeds the reference current value. In this way, the pulse output process may be continued during the pressure increasing mode, or the pulse output process may be executed every time the current value of the control current exceeds the reference current value.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
A first embodiment of the present invention will be described. FIG. 1 shows an overall configuration of a vehicle brake control system 1 to which a first embodiment of the present invention is applied. FIG. 2 is a diagram showing a part of the circuit configuration in the brake control system 1.

  As shown in FIG. 1, the brake control system 1 includes a brake pedal 11, a booster 12, an M / C 13, W / Cs 14, 15, 34, and 35, and a brake fluid pressure control actuator (hereinafter referred to as “brake hydraulic pressure control actuator”). , A brake ACT) 50, a brake ECU 70, and the like.

  A brake pedal 11 as a brake operation member that is depressed by a driver when applying braking force to the vehicle is connected to a booster 12 and an M / C 13 that are sources of brake fluid pressure, and the driver depresses the brake pedal 11. Then, the pedaling force is boosted by the booster 12, and the master pistons 13a and 13b disposed in the M / C 13 are pressed. Thereby, the same M / C pressure is generated in the primary chamber 13c and the secondary chamber 13d defined by the master pistons 13a and 13b.

  The M / C 13 is provided with a master reservoir 13e having passages communicating with the primary chamber 13c and the secondary chamber 13d. The master reservoir 13e supplies brake fluid into the M / C 13 through the passage, or stores excess brake fluid in the M / C 13. Note that each passage is formed to have a diameter that is much smaller than the diameter of each main pipeline extending from the primary chamber 13c and the secondary chamber 13d. An orifice effect is exhibited when the brake fluid flows into the tank.

  The M / C pressure generated in the M / C 13 is transmitted to each W / C 14, 15, 34, 35 through the brake ACT50.

  The brake ACT 50 includes a first piping system 50a and a second piping system 50b. The first piping system 50a controls the brake fluid pressure applied to the left front wheel FL and the right rear wheel RR, and the second piping system 50b controls the brake fluid pressure applied to the right front wheel FR and the left rear wheel RL. X piping is constituted by these two piping systems of the first and second piping systems 50a, 50b.

  Hereinafter, the first and second piping systems 50a and 50b will be described. However, since the first piping system 50a and the second piping system 50b have substantially the same configuration, the first piping system 50a will be described here. The description of the second piping system 50b is omitted with reference to the first piping system 50a.

  The first piping system 50a includes a pipeline A serving as a main pipeline that transmits the above-described M / C pressure to the W / C 14 provided in the left front wheel FL and the W / C 15 provided in the right rear wheel RR. ing. A W / C pressure can be generated in each of the W / Cs 14 and 15 through the pipe A.

  Further, the pipe line A is provided with a first differential pressure control valve 16 composed of a control valve capable of controlling two positions in the communication / differential pressure state. The first differential pressure control valve 16 is in a communicating state in the normal brake state, and when a current is supplied to the solenoid (armature), the valve position is in a differential pressure state. At the valve position of the differential pressure state in the first differential pressure control valve 16, the M from the W / C 14, 15 side is only when the brake fluid pressure on the W / C 14, 15 side becomes a predetermined level or higher than the M / C pressure. Brake fluid flow is allowed only to the / C13 side. For this reason, the W / C 14 and 15 side is always maintained so as not to be higher than the M / C 13 side by a predetermined pressure or more, and the respective pipelines are protected.

  The pipe A branches into two pipes A1 and A2 downstream of the first differential pressure control valve 16 on the W / C 14 and 15 side. One of the two pipes A1 and A2 is provided with a first pressure increase control valve 17 for controlling the increase of the brake fluid pressure to the W / C 14, and the other is an increase of the brake fluid pressure to the W / C 15. A second pressure increase control valve 18 is provided for controlling the pressure.

  The first and second pressure increase control valves 17 and 18 are constituted by two-position solenoid valves that can control the communication / blocking state. When the first and second pressure increase control valves 17 and 18 are controlled to be in communication, the M / C pressure or the brake fluid pressure generated by the discharge of brake fluid from a pump 19 described later is applied to the W / C 14 and 15. be able to.

  The first and second pressure-increasing control valves 17 and 18 have a well-known structure, and although not shown, basically, during normal braking by the operation of the brake pedal 11 performed by the driver, that is, the first and second pressure control valves. 2. When the control current to the solenoid provided in the pressure-increasing control valves 17 and 18 is zero (when no power is supplied), the valve body and the plunger always move so as to contact the sleeve in the opposite direction to the valve seat. It is a normally open type in which the valve element is controlled to be in a shut-off state when the control current is passed to the solenoid by the ABS control (when energized), but the control current is large when energized. By adjusting the length (current value), it also functions as a linear valve that generates a predetermined differential pressure between upstream and downstream.

  The first differential pressure control valve 16 and the first and second pressure increase control valves 17 and 18 are provided with safety valves 16a, 17a and 18a, respectively, in parallel. The safety valve 16a of the first differential pressure control valve 16 reduces the M / C pressure to W / C14 when the driver depresses the brake pedal 11 when the valve position of the first differential pressure control valve 16 is in the differential pressure state. , 15 so as to be able to transmit. The safety valves 17a and 18a of the pressure increase control valves 17 and 18 are returned to the brake pedal 11 by the driver, particularly when the pressure increase control valves 17 and 18 are controlled to be shut off during ABS control. In some cases, the W / C pressure of the left front wheel FL and the right rear wheel RR is provided so as to be able to be reduced corresponding to this return operation.

  In the pipeline A, the first and second pressure increase control valves 17 and 18 and the pipeline B serving as a pressure-reducing pipeline connecting the pressure regulating reservoir 20 between the W / Cs 14 and 15 are controlled in communication / blocking states. A first pressure-reducing control valve 21 and a second pressure-reducing control valve 22 each including a two-position electromagnetic valve that can be provided are respectively provided. The first and second pressure reduction control valves 21 and 22 are always cut off during normal braking.

  A conduit C serving as a reflux conduit is disposed so as to connect the pressure regulating reservoir 20 and the conduit A serving as the main conduit. This pipe C is provided with a self-priming pump 19 driven by a motor 60 so as to suck and discharge brake fluid from the pressure regulating reservoir 20 toward the M / C 13 side or the W / C 14, 15 side. Yes.

  A safety valve 19 a is provided on the discharge port side of the pump 19 so that high-pressure brake fluid is not applied to the pump 19. A fixed capacity damper 23 is disposed on the discharge side of the pump 19 in the pipe C in order to reduce the pulsation of the brake fluid discharged by the pump 19.

  And the pipe line D used as an auxiliary pipe line is provided so that the pressure regulation reservoir 20 and M / C3 may be connected. Brake fluid is sucked from the M / C 13 by the pump 19 through this pipeline D and discharged to the pipeline A, so that the brake is applied to the W / C 14 and 15 side during brake fluid pressure control such as TCS control and ESC. The liquid can be supplied to increase the W / C pressure of the target wheel.

  The pressure regulating reservoir 20 is connected to the pipeline D and receives the brake fluid from the M / C 3 side, and receives the brake fluid that is connected to the pipelines B and C and escapes from the W / Cs 14 and 15. In addition, a reservoir hole 20b for supplying brake fluid to the suction side of the pump 19 is provided and communicates with the reservoir chamber 20c. A ball valve 20d is disposed inside the reservoir hole 20a. The ball valve 20d is provided with a rod 20f having a predetermined stroke for moving the ball valve 20d up and down separately from the ball valve 20d.

  Also, in the reservoir chamber 20c, there are a piston 20g interlocking with the rod 20f, and a spring 20h that generates a force for pressing the piston 20g toward the ball valve 20d to push out the brake fluid in the reservoir chamber 20c. Is provided.

  The pressure regulating reservoir 20 configured as described above is configured such that when a predetermined amount of brake fluid is stored, the ball valve 20d is seated on the valve seat 20e and the brake fluid does not flow into the pressure regulating reservoir 20. . For this reason, more brake fluid than the suction capacity of the pump 19 does not flow into the reservoir chamber 20c, and no high pressure is applied to the suction side of the pump 19.

  On the other hand, as described above, the second piping system 50b has substantially the same configuration as the first piping system 50a. That is, the first differential pressure control valve 16 and the safety valve 16a correspond to the second differential pressure control valve 36 and the safety valve 36a. The first and second pressure increase control valves 17 and 18 and the safety valves 17a and 18a correspond to the third and fourth pressure increase control valves 37 and 38 and the safety valves 37a and 38a, respectively. , 22 correspond to the third and fourth decompression control valves 41, 42, respectively. The pressure regulating reservoir 20 and the components 20a to 20h correspond to the pressure regulating reservoir 40 and the components 40a to 40h. The pump 19 and the safety valve 19a correspond to the pump 39 and the safety valve 39a. The damper 23 corresponds to the damper 43. Further, the pipeline A, the pipeline B, the pipeline C, and the pipeline D correspond to the pipeline E, the pipeline F, the pipeline G, and the pipeline H, respectively. As described above, the hydraulic piping structure of the brake ACT 50 is configured.

  The brake ECU 70 corresponds to the brake fluid pressure control device of the present invention, and is constituted by a well-known microcomputer having a CPU, ROM, RAM, I / O, and the like. Perform processing such as computation. Motors for driving the control valves 16 to 18, 21, 22, 36 to 38, 41 and 42 and the pumps 19 and 39 in the brake ACT 50 configured as described above based on the electrical signal from the brake ECU 70. Current supply control to 60 is executed. Thereby, control of the W / C pressure generated in each W / C 14, 15, 34, 35 is performed.

  For example, when a control current is supplied from the brake ECU 70 to the motor 60 and the solenoid for driving the control valve, the brake ACT 50 sets a route of the brake pipe in the brake ACT 50 according to the supplied current. The brake fluid pressure corresponding to the set brake pipe path is generated in the W / Cs 14, 15, 34, and 35 so that the braking force generated in each wheel can be controlled.

  Further, in the brake control system 1 of the present embodiment, as shown in FIG. 2, the current value of the current supplied to the solenoid of each pressure increase control valve 17, 18, 37, 38 is detected with respect to the brake ECU 70. Peak hold circuits 72a to 72d for holding the peak values of the current values detected by the current detectors 71a to 71d and the current detectors 71a to 71d are provided. The peak value of the current value held in each of the peak hold circuits 72a to 72d is transmitted to the brake ECU 70.

  Although not shown, the brake control system 1 is provided with a wheel speed sensor for each of the wheels FL, FR, RL, and RR, and a detection signal of the wheel speed sensor is input to the brake ECU 70. It has become. Based on the detection signal of the wheel speed sensor, the brake ECU 70 obtains the wheel speed and the vehicle body speed of each wheel, and when the slip ratio expressed as the deviation between the vehicle body speed and the wheel speed reaches a predetermined value, the ABS control is performed. The brake fluid pressure control such as the above is executed.

  As described above, the brake control system 1 of the present embodiment is configured. Next, the operation by the brake control system 1 will be described. Since the basic operation in the brake control system 1 is the same as the conventional operation, the operation in the ABS control related to the features of the present invention will be described here.

  In the brake ECU 70, the vehicle body speed and the wheel speed are obtained, and the slip ratio of each wheel is obtained based on these. Then, if there is a wheel whose slip rate exceeds a predetermined threshold value, ABS control is started with that wheel as a control target wheel. In the ABS control, an applied voltage for driving the motor 60 is output from the brake ECU 70, and control modes such as a pressure reducing mode, a holding mode, and a pressure increasing mode are appropriately set according to the situation of the wheel to be controlled. Various control valves are controlled according to the control mode. Hereinafter, the operation during the ABS control will be described by taking as an example the case where the left front wheel FL is a wheel to be controlled.

  First, when the decompression mode is set, decompression processing is executed. In this decompression process, the brake ECU 70 outputs an electrical signal that causes the first pressure increase control valve 17 of the left front wheel FL to be shut off and the first pressure reduction control valve 21 to be in a communication state. As a result, the M / C 13 and the W / C 14 are disconnected, the W / C 14 and the pressure regulating reservoir 20 are in communication, and the brake fluid for pressurizing the W / C 14 corresponding to the left front wheel FL is regulated. The reservoir 20 escapes to the reservoir chamber 20c. As a result, the W / C 14 of the left front wheel FL is depressurized.

  Subsequently, when the decompression mode is performed for a desired time, the holding mode is set. When this holding mode is set, a holding process is executed. In this holding process, the brake ECU 70 outputs an electrical signal that causes the first pressure increase control valve 17 of the left front wheel FL to be in the shut-off state and the first pressure reduction control valve 21 to be in the shut-off state. As a result, the M / C 13 and the W / C 14 are disconnected, and the W / C 14 and the pressure regulating reservoir 20 are also disconnected, and the W / C generated by the W / C 14 corresponding to the left front wheel FL. Pressure is maintained.

  When the wheel speed of the left front wheel FL recovers and the slip ratio exceeds the pressure increase start threshold, the pressure increase mode is set. When this pressure increasing mode is set, the pressure increasing process is executed. In this pressure increase process, the first pressure increase control valve 17 of the left front wheel FL is linearly driven, and an electrical signal that causes the first pressure decrease control valve 21 to be shut off is output. At this time, the linear drive of the first pressure increase control valve 17 is controlled so as to be a differential pressure desired to be generated between the upstream and downstream of the first pressure increase control valve 17, that is, between the M / C 13 and the W / C 14. The current is set to a current value corresponding to the estimated differential pressure value, and the control current is supplied to the solenoid of the first pressure increase control valve 17. Then, the control current to the first pressure increase control valve 17 is reduced, and the valve of the first pressure increase control valve 17 is at a position where the actual differential pressure generated between the M / C 13 and the W / C 14 is obtained. Balances with the body's magnetic attraction. Thereafter, the control current is gradually reduced, so that the W / C 14 corresponding to the left front wheel FL is gradually (steplessly) increased.

  At this time, in order to generate a desired differential pressure in the first pressure increase control valve 17, a differential pressure estimated value is obtained, and a current value of the first pressure increase control valve 17 corresponding to the differential pressure estimated value is obtained. . The method for obtaining this differential pressure estimated value is the same as the conventional method, and the difference between the M / C pressure estimated value and the W / C pressure estimated value is used as the differential pressure estimated value.

  When performing such an ABS control operation, in the present embodiment, in the pressure increasing mode, the first to fourth pressure increasing control valves are caused by a resonance phenomenon based on the pulsation of the brake fluid discharged from the pumps 19 and 39 in the pressure increasing mode. In order to suppress the vibration generated in 17, 18, 37, 38, the brake ECU 70 performs a vibration suppression control process. FIG. 3 is a flowchart showing details of the vibration suppression control process, and the vibration suppression control process will be described with reference to this figure. Note that the vibration suppression control process shown in this figure is executed for each wheel, and is repeatedly executed every predetermined calculation cycle when an ignition switch (not shown) is switched from OFF to ON.

  First, in step 100, it is determined whether or not ABS control is being performed. For example, an ABS control flag is set when ABS control is started, and the above determination is made by checking whether or not this ABS control flag is set. Here, the process proceeds to step 105 and subsequent steps only when the ABS control is being performed.

  In step 105, mode selection is performed. As described above, when the ABS control is started, the control mode of the pressure reduction mode, the holding mode, and the pressure increase mode is set, so it is determined which of these control modes is set. .

  At this time, when the pressure reduction mode or the holding mode is set, that is, when the pressure increasing mode is not set, the process proceeds to step 110 or step 115, and the pressure reduction processing or holding mode executed when the pressure reduction mode is set. The holding process that is executed when is set is executed. Then, as described above, the W / C 14 of the left front wheel FL that is the wheel to be controlled is depressurized or retained by the decompression process or the retention process.

  If the pressure increasing mode is set, the process proceeds to step 120, and the pressure increasing process is executed. As described above, the pressure increasing process is a process for gradually increasing the W / C 14 of the left front wheel FL to be controlled. For example, the current value of the first pressure increase control valve 17 corresponding to the estimated differential pressure value obtained from the difference between the estimated M / C pressure value and the estimated W / C pressure value is obtained. Is supplied to the solenoid of the first pressure increase control valve 17. Then, a process of gradually decreasing the control current is performed.

  Thereafter, the process proceeds to step 125, and a current value reading process is performed. Specifically, since the peak value of the current value detected by the current detection unit 71a is held by the peak hold circuit 72a, the current value held by the peak hold circuit 72a is read. The current value held in the peak hold circuit 72a is reset when a mode other than the pressure increasing mode is set, and the peak value of the current value during the pressure increasing mode is peaked every time the pressure increasing mode is set. It is held by the hold circuit 72a.

  Then, it progresses to step 130 and it is determined whether the read electric current value exceeds the reference electric current value. This process is a process for detecting the resonance phenomenon. The reference current value here is a predetermined value, and is large enough to suppress the vibration generated in the first pressure increase control valve 17 due to the resonance phenomenon based on the pulsation of the brake fluid discharged from the pump 19. It becomes a threshold value for determining whether or not. For example, the reference current value is set to about 1.1A. If a negative determination is made in this step, it is assumed that no resonance phenomenon has occurred. For this reason, the routine proceeds to step 135, where normal output processing, that is, processing for outputting the current value of the first pressure increase control valve 17 obtained in step 120 as usual, is executed, and then the processing ends.

  On the other hand, if a negative determination is made in step 130, it is assumed that a resonance phenomenon has occurred. For this reason, the process proceeds to step 140 to perform a pulse output process. The pulse output process means a process of increasing or decreasing the current value of the control current flowing through the solenoid of the first pressure increase control valve 17 in a pulse manner. In the case of the present embodiment, basically, the control current having the current value obtained in step 120 is supplied to the solenoid of the first pressure increase control valve 17, but for example, in a pulse every calculation cycle, in other words, during the calculation cycle. The first pressure-increasing control is performed with a control current having a holding current value (maximum current value) such that the first pressure-increasing control valve 17 comes into contact with the valve body and the valve seat instantaneously only during a part of time. Flow through solenoid of valve 17. In this way, since the valve body and the plunger are pressed against the valve seat side, the vibration of the valve body and the plunger can be stopped even if a resonance phenomenon caused by the pulsation of the brake fluid discharged from the pump 19 occurs. . Thereafter, the process is terminated.

  The effects when the vibration suppression control process is executed and when the vibration suppression control process is not executed will be described with reference to a normal time when the resonance phenomenon based on the pulsation of the brake fluid discharged from the pump 19 does not occur during the ABS control. 4A is a timing chart in a normal state, FIG. 4B is a timing chart when the vibration suppression control process is executed, and FIG. 4C is a timing chart when the vibration suppression control process is not executed.

  As shown in FIG. 4A to FIG. 4C, if a wheel speed decreases with respect to the vehicle body speed and a slip ratio increases and there is a wheel that exceeds a predetermined threshold, ABS control is performed using that wheel as a control target wheel. Is started. In the ABS control, the pressure reduction mode, the holding mode, and the pressure increase mode control mode are set in order.

  That is, as in the normal state shown in FIG. 4A, when the pressure reducing mode and the holding mode are set, the control that is sent to the solenoid of the first pressure increasing control valve 17 to turn off the first pressure increasing control valve 17. The current value of the current is set to the holding current value. When the pressure-increasing mode is set, the control current is changed so that the pressure difference between the upstream and downstream sides of the first pressure-increasing control valve 17, that is, between the M / C 13 and the W / C 14, is generated. A predetermined current value is set according to the estimated value, and the control current is supplied to the solenoid of the first pressure increase control valve 17. That is, the current value of the control current is reduced, and the valve body moves to the valve body position where the current value corresponds to the actual differential pressure generated between the M / C 13 and the W / C 14, and the first increase occurs. The magnetic attraction force of the valve body of the pressure control valve 17 is balanced with the fluid force applied to the valve body against it. Thereafter, the control current is gradually reduced to gradually open the throttle between the valve element and the valve seat, and the W / C 14 corresponding to the left front wheel FL is gradually (steplessly) increased.

  In this ABS control pressure increasing mode, when the resonance phenomenon based on the pulsation of the brake fluid discharged from the pump 19 occurs, if the vibration suppression control process is not executed, the valve is caused by vibration as shown in FIG. 4C. The valve body position, which was stable due to the balance between the magnetic attraction force and the fluid force at the desired position from the seat, is repeatedly moved rapidly, and the W / C pressure is greatly amplified by the movement of the throttle. To do.

  On the other hand, when the vibration suppression control process is performed, as shown in FIG. 4B, the first pressure increase control valve 17 contacts the valve body and the valve seat in a shut-off state in a pulsed manner every calculation cycle. A control current having such a holding current value is supplied to the solenoid of the first pressure increase control valve 17. After passing the minute holding current value, the original control current is restored, the current value is gradually decreased, and the W / C 14 is gradually increased. For this reason, even if the valve body and the plunger are pressed against the valve seat side and a resonance phenomenon due to the pulsation of the brake fluid discharged from the pump 19 occurs, the vibration of the valve body and the plunger can be stopped.

  As described above, in the brake control system 1 of the present embodiment, the first to fourth pressure increase control valves 17, 18 arranged on the discharge side of the pumps 19, 39 are performed by executing the vibration suppression control process. It is possible to suppress the vibration of the vibrations 37 and 38 due to the resonance phenomenon based on the pulsation of the brake fluid. Thereby, generation | occurrence | production of an excessive vibration sound can be suppressed, and it becomes possible to perform control which maintains a W / C pressure correctly with a desired pressure.

(Second Embodiment)
A second embodiment of the present invention will be described. In the present embodiment, the flow of the control current when the vibration suppression control process is executed is changed from the first embodiment. Therefore, since the structure of the brake control system 1 and the process executed by the ECU 50 are the same, only different parts will be described.

  In the present embodiment, the pulse output process in step 140 of the vibration suppression control process described in the first embodiment is performed in a different form. That is, in the present embodiment, basically, the control current having the current value obtained in step 120 is supplied to the solenoid of the first pressure increase control valve 17, and for example, the first pressure increase control valve is pulsed at every calculation cycle. By setting the control current to be applied to the solenoid 17 to zero, the distance between the valve body and the valve seat is maximized. In this way, since the valve body and the plunger are pressed against the tip position side of the sleeve opposite to the valve seat, the valve body and the plunger even if a resonance phenomenon caused by the pulsation of the brake fluid discharged from the pump 19 occurs. The vibration of the plunger can be stopped.

  FIG. 5 is a timing chart when such vibration suppression control processing is executed. As shown in this figure, when the pressure increasing mode is set, the pressure increasing mode is set, and the current value of the control current corresponds to the differential pressure desired to be generated between the upstream and downstream of the first pressure increasing control valve 17. The W / C 14 corresponding to the left front wheel FL is gradually increased in a stepless manner.

  When a resonance phenomenon based on the pulsation of the brake fluid discharged from the pump 19 occurs in the pressure increase mode of the ABS control, as shown in FIG. 5, the first pressure increase control valve 17 is pulsed at every calculation cycle. The current value of the control current flowing through the solenoid is set to zero. For this reason, even if the valve body and the plunger are pressed to the tip position side of the sleeve and a resonance phenomenon caused by the pulsation of the brake fluid discharged from the pump 19 occurs, the vibration of the valve body and the plunger can be stopped. Thereby, the effect similar to 1st Embodiment is acquired.

(Third embodiment)
A third embodiment of the present invention will be described. In this embodiment, the flow of the control current when executing the vibration suppression control process is changed from that in the first embodiment. Therefore, since the structure of the brake control system 1 and the process executed by the ECU 50 are the same, only different parts will be described.

  Also in this embodiment, the pulse output process in step 140 of the vibration suppression control process described in the first embodiment is performed in a different form. That is, in this embodiment, when it is assumed that a resonance phenomenon has occurred, the pulse pressure increase that has been conventionally performed in the pressure increase mode of the ABS control is performed. Specifically, the control current passed to the solenoid of the first pressure increase control valve 17 is alternately switched between zero and a holding current value, and when the interval between the valve body and the valve seat is maximized, the valve body and the valve Alternating with the time of making the seat contact. In this way, since the valve body and the plunger are pressed against the tip position side of the valve seat or sleeve, even if a resonance phenomenon caused by the pulsation of the brake fluid discharged from the pump 19 occurs, the vibration of the valve body and the plunger Can be stopped.

  FIG. 6 is a timing chart when such vibration suppression control processing is executed. As shown between T1 and T2 in this figure, when the pressure increasing mode is set, the current value of the control current is generated between the upstream and downstream of the first pressure increasing control valve 17 at the T1 timing. By gradually decreasing from the corresponding value, the W / C 14 corresponding to the left front wheel FL is gradually (steplessly) increased.

  When a resonance phenomenon based on the pulsation of the brake fluid discharged from the pump 19 occurs between T1 and T11 in the pressure increasing mode of the ABS control, as shown in FIG. 1 The value of the control current flowing through the solenoid of the pressure increase control valve 17 is alternately switched between zero and the holding current value. Therefore, even if the valve body and the plunger are pressed against the valve seat or the front end position of the sleeve and a resonance phenomenon due to the pulsation of the brake fluid discharged from the pump 19 occurs, the vibration of the valve body and the plunger can be stopped. it can. Since the first pressure increase control valve 17 is in the communication state during the period when the current value is zero, the M / C pressure is added to the W / C 14 and the W / C pressure increases. When the current value switches to the holding current value, the increased W / C pressure is held. By repeating such switching of the current value, the W / C pressure increases toward the M / C pressure stepwise. Thereby, the effect similar to 1st Embodiment is acquired.

(Fourth embodiment)
A fourth embodiment of the present invention will be described. In the first to third embodiments, the vibrations of the first to fourth pressure increase control valves 17, 18, 37 and 38 are suppressed, but in the present embodiment, the first and second differential pressure control valves 16 and 36 are suppressed. Suppresses vibration.

  At the time of ABS control, the first and second differential pressure control valves 16 and 36 are basically always in communication with each other, so that the valve body and the plunger are pressed against the sleeve tip position side and the brake 19 discharges. The resonance phenomenon caused by the pulsation of the liquid does not occur. However, since the brake fluid is discharged from the pumps 19 and 39 while the first and second differential pressure control valves 16 and 36 are in a differential pressure state during TCS control and ESC, the first and second differential pressure control valves 16 and 36 may also cause the above problem due to the resonance phenomenon.

  For this reason, with respect to the first and second differential pressure control valves 16 and 36 as well, the vibration suppression control process is executed in the same manner as in the above embodiments, so that the first and second differential pressure control valves 16 and 36 are pumped. Even if a resonance phenomenon caused by the pulsation of the brake fluid discharged from the valve 19 occurs, the vibration of the valve body and the plunger can be stopped. Thereby, the effect similar to 1st Embodiment is acquired. Note that regarding the vibration suppression control processing in the present embodiment, step 100 in the flowchart of FIG. 3 shown in the first embodiment may be read as TCS control or ESC.

(Other embodiments)
In the first to fourth embodiments, the occurrence of the resonance phenomenon is detected based on the peak value of the actual current value held in the peak hold circuits 72a to 72d. The median value of the current value is actually gradually reduced. For example, the control current value (that is, the indicated value) is decreased to about 1.0 to 0.3 A with a gradient that matches the road surface condition. On the other hand, the amplitude of the current value of the control current when the resonance phenomenon occurs is, for example, about 0.4 A, so that the amplitude is 0 with respect to the indicated value that changes the value of the reference current value serving as the threshold value. It is sufficient to add a half 0.1A of 0.2A smaller than .4A and shift from 1.1 to 0.4A. Further, in order to easily determine the reference current value, 1.1 A is obtained by adding 0.1 A to the initial indicated value 1.0 A in consideration that the pump pulsation almost always exists from the start timing of pressure increase. It may be fixed.

  In the first to fourth embodiments, when the resonance phenomenon is detected, the pulse output process is executed until the end of the period of the pressure increasing mode, that is, until the mode is switched to the decreasing mode. Each time the process is performed, the current value held in the peak hold circuits 72a to 72d may be reset again to determine whether or not the pulse output process is required for each control cycle.

  The steps shown in each figure correspond to means for executing various processes.

1 shows an overall configuration of a brake control system 1 according to a first embodiment of the present invention. FIG. 2 is a diagram showing a part of a circuit configuration in the brake control system 1. It is the flowchart which showed the detail of the vibration suppression control process. It is a timing chart at the normal time when the resonance phenomenon does not occur during ABS control. Timing chart when a vibration suppression control process is executed when a resonance phenomenon occurs during ABS control Timing chart when vibration suppression control processing is not executed when a resonance phenomenon occurs during ABS control It is a timing chart at the time of performing the vibration suppression control process demonstrated in 2nd Embodiment of this invention. It is a timing chart at the time of performing the vibration suppression control process demonstrated in 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Brake fluid pressure control system, 11 ... Brake pedal, 13 ... M / C,
16, 36 ... differential pressure control valve, 17, 18, 37, 38 ... pressure increase control valve,
21, 22, 41, 42 ... decompression control valve, 50 ... actuator for brake fluid pressure control,
50a, 50b ... first and second piping systems, 70 ... brake ECU,
71a-71d ... current detection unit, 72a-72d ... peak hold circuit.

Claims (3)

When the brake fluid pressure control condition is established in any of the plurality of wheels (FR to RL), the brake (19, 39) sucks and discharges the brake fluid and the brake disposed on the discharge side of the pump The brake fluid pressure applied to the wheel cylinders (14, 15, 34, 35) during control of the control valve is set in advance as a control current flowing through the solenoid of the control valve (16-18, 36-38) of the target wheel for hydraulic pressure control. The distance between the valve body and the valve seat of the control valve is adjusted by controlling based on the pressure increase gradient, and the side connected to the master cylinder (13) with respect to the control valve and the wheel cylinder A brake fluid pressure control device that linearly changes the differential pressure on the connected side,
Current detection means (125) for detecting an actual current value flowing through a solenoid of the control valve of the target wheel when a pressure increasing mode in the brake fluid pressure control is selected;
Determination means (130) for determining whether or not the actual current value exceeds a reference current value that is a threshold value for occurrence of a resonance phenomenon;
When the actual current value does not exceed the reference current value, a normal output process is performed in which the control current is flowed so as to linearly change the differential pressure with respect to the solenoid of the control valve of the target wheel. Output means (135);
When the actual current value exceeds the reference current value, a pulse output process is performed to increase or decrease the control current in a pulse manner so that the interval between the valve body and the valve seat is zero or the maximum value. And a brake output pressure control means (140). The pulse output means changes the current value of the control current alternately between a current value that makes the interval between the valve body and the valve seat zero and a current value that makes the maximum value. A brake control device for a vehicle as described in 1. 5. The pulse output means continues the pulse output process during the pressure increasing mode when the current value exceeds the reference current value. 6. The brake fluid pressure control device described in 1.

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