WO2019198818A1 - Vehicle braking control device - Google Patents

Abstract

This brake control device is provided with: a simulator which imparts an operating force to an operating member; a master unit including a master chamber connected to a wheel cylinder, and a servo chamber which imparts a forward force to a master piston; a pressure regulating unit which introduces a regulating hydraulic pressure into the servo chamber; a regenerative coordination unit which includes an input piston linked to the operating member, and which has an input chamber connected to the simulator by way of a simulator fluid path; a first open/closed valve which is provided in the simulator fluid path and which has an open position providing communication between the input chamber and the simulator, and a closed position isolating the input chamber and the simulator; and a controller which controls the first open/closed valve. The controller determines "whether or not an operation is sudden" on the basis of an operation amount, and when the sudden operation is denied, drives the first open/closed valve to the open position, and when the sudden operation is affirmed, drives the first open/closed valve to the closed position.

Description

Brake control device for vehicle

The present invention relates to a vehicle braking control device.

The applicant has developed a braking control device for a vehicle as described in Patent Document 1. In this apparatus, in order to simplify and reduce the size of the mechanical regulator, “a mechanical type that sends out an output pressure from the output port according to the pilot pressure supplied to the pilot chamber based on the brake fluid pressure of the high pressure source”. A regulator, a switching unit connected to the pilot chamber, a first pilot pressure generator connected to the pilot chamber via the switching unit and supplying the first pilot pressure to the pilot chamber, and a pilot chamber via the switching unit A switching unit comprising: a second pilot pressure generator connected to supply the second pilot pressure to the pilot chamber; and a wheel cylinder that generates a braking force based on an output pressure supplied from an output port of the mechanical regulator. Is configured to supply either one of the first pilot pressure and the second pilot pressure to the pilot chamber.

The applicant has developed a braking control device as described in Patent Document 2 with further improvements. This device is composed of an “electric pump and an electromagnetic valve, and adjusts the brake fluid discharged from the electric pump to the adjusted hydraulic pressure by the electromagnetic valve, and introduces the adjusted hydraulic pressure into the rear wheel cylinder. ”And“ A master chamber composed of a master cylinder and a master piston and connected to the front wheel cylinder, and a forward movement in which the adjustment hydraulic pressure is introduced and which opposes the reverse force applied to the master piston by the master chamber A master unit having a servo chamber for applying a force to the master piston.

In this device, the brake fluid discharged from the electric pump is adjusted to the adjusted hydraulic pressure by the electromagnetic valve and introduced into the servo chamber and the rear wheel wheel cylinder. In this configuration, the electric pump is stopped during non-braking and is rotationally driven during braking. The braking control device is a so-called on-demand type. For this reason, it is desired to improve the boosting response during sudden braking.

JP 2013-107561 A Japanese Patent Application No. 2017-184272

An object of the present invention is to provide a braking control device for an on-demand type vehicle in which the boosting response can be improved.

The brake control device SC according to the present invention pumps the brake fluid (BF) to the wheel cylinder (CW) of the vehicle wheel (WH) according to the operation amount (Ba) of the vehicle brake operation member (BP). A braking torque is generated on the wheel (WH). The brake controller SC includes a simulator (SS) that applies an operation force (Fp) corresponding to the operation amount (Ba) to the brake operation member (BP), a master cylinder (CM), and a master piston (PM). The "master chamber (Rm) connected to the wheel cylinder (CW)" and "reverse force (Fb) applied to the master piston (PM) by the master chamber (Rm)" A master unit (YM) having a servo chamber (Rs) for applying a forward force (Fa) to the master piston (PM), and an electric pump for sucking the brake fluid (BF) from a reservoir (RV) of the vehicle DC) and electromagnetic valves (UA, UB, UC), and the brake fluid (BF) discharged from the electric pump (DC) is supplied by the electromagnetic valves (UA, UB, UC). A pressure regulating unit (YC) that adjusts the regulated fluid pressure (Pa, Pb, Pc) and introduces the regulated fluid pressure (Pa, Pb, Pc) into the servo chamber (Rs), and the braking operation member (BP) And an input chamber (Rn) connected to the simulator (SS) via a simulator fluid path (HS). The input piston (PK) is coupled to the input cylinder (CN). A regenerative cooperative unit (YK) in which a gap (Ks) between the master piston (PM) and the input piston (PK) is controlled by the adjustment hydraulic pressures (Pa, Pb, Pc) inside the chamber (Rn). A first open position provided in the simulator fluid path (HS) for communicating the input chamber (Rn) and the simulator (SS), and blocking the input chamber (Rn) and the simulator (SS) First closed A first on-off valve (VA) having a device, the electric pump (DC), the electromagnetic valves (UA, UB, UC), and a controller (ECU) for controlling the first on-off valve (VA). Prepare.

In the braking control device SC according to the present invention, the controller (ECU) determines whether or not the operation of the braking operation member (BP) is a sudden operation based on the operation amount (Ba), and When denying the sudden operation, the first on-off valve (VA) is driven to the first open position, and when affirming the sudden operation, the first on-off valve (VA) ) To the first closed position. For example, the controller (ECU) calculates an operation speed (dB) based on the operation amount (Ba), and when the operation speed (dB) is less than a predetermined speed (dx), the sudden operation is performed. If the operation speed (dB) is equal to or higher than the predetermined speed (dx), the sudden operation is affirmed.

According to the above configuration, in the sudden operation state, the first opening / closing valve VA is brought into the closed position, whereby the input chamber Rn is brought into a fluid locked state. Therefore, the operating force Fp of the braking operation member BP operated by the driver is transmitted to the master piston PM via the input chamber Rn, and the boosting response of the master cylinder hydraulic pressure Pm (that is, the braking hydraulic pressure Pw). Is improved.

1 is an overall configuration diagram for explaining a first embodiment of a vehicle braking control device SC according to the present invention. It is a control flow figure for explaining processing of pressure regulation control including regenerative cooperation control. It is a control flowchart for demonstrating the process at the time of sudden operation. It is a whole block diagram for demonstrating 2nd Embodiment of the braking control apparatus SC of the vehicle which concerns on this invention.

<Symbols of components and subscripts at the end of the symbols>
In the following description, components, arithmetic processing, signals, characteristics, and values having the same symbol, such as “ECU”, have the same function. The suffixes “i” to “l” attached to the end of the symbol relating to each wheel are comprehensive symbols indicating which wheel the wheel is associated with. Specifically, “i” indicates a right front wheel, “j” indicates a left front wheel, “k” indicates a right rear wheel, and “l” indicates a left rear wheel. For example, in each of the four wheel cylinders, they are expressed as a right front wheel wheel cylinder CWi, a left front wheel wheel cylinder CWj, a right rear wheel wheel cylinder CWk, and a left rear wheel wheel cylinder CWl. Further, the suffixes “i” to “l” at the end of the symbol can be omitted. When the subscripts “i” to “l” are omitted, each symbol represents a generic name of each of the four wheels. For example, “WH” represents each wheel, and “CW” represents each wheel cylinder.

The subscripts “f” and “r” attached to the end of the symbols related to the two braking systems are comprehensive symbols indicating which system of the front and rear wheels it is related to. Specifically, “f” indicates a front wheel system and “r” indicates a rear wheel system. For example, in the wheel cylinder CW of each wheel, they are expressed as a front wheel wheel cylinder CWf (= CWi, CWj) and a rear wheel wheel cylinder CWr (= CWk, CWl). Further, the suffixes “f” and “r” at the end of the symbol can be omitted. When the subscripts “f” and “r” are omitted, each symbol represents a generic name of the two braking systems. For example, “CW” represents a wheel cylinder in the front and rear braking systems.

<First Embodiment of Brake Control Device for Vehicle according to the Present Invention>
A first embodiment of a braking control device SC according to the present invention will be described with reference to the overall configuration diagram of FIG. In general vehicles, two fluid paths are employed to ensure redundancy. The fluid path is a path for moving the brake fluid BF that is the working fluid of the brake control device SC, and corresponds to a brake pipe, a fluid unit flow path, a hose, and the like. The inside of the fluid path is filled with the brake fluid BF. In the braking control device SC, a so-called front and rear type (also referred to as “H type”) is adopted as the two fluid paths. The front wheel system is connected to the front wheel cylinder CWf (= CWi, CWj), and the rear wheel system is connected to the rear wheel wheel cylinder CWr (= CWk, CWl). In the fluid path, the side close to the reservoir RV (the side far from the wheel cylinder CW) is called “upstream side” or “upper side”, and the side close to the wheel cylinder CW (the side far from the reservoir RV) is called “downstream”. Referred to as “side” or “bottom”.

The vehicle is provided with an electric motor GN for driving. That is, the vehicle is a hybrid vehicle or an electric vehicle. The electric motor GN for driving also functions as a generator (generator) for energy regeneration. For example, the generator GN is provided in the front wheel WHf. The electric motor / generator GN is controlled by a drive controller ECD.

In the braking control device SC, so-called regenerative cooperative control (cooperation between regenerative braking and friction braking) is performed. A vehicle including the braking control device SC includes a braking operation member BP, a wheel cylinder CW, a reservoir RV, and a wheel speed sensor VW.

Brake operation member (for example, brake pedal) BP is a member that the driver operates to decelerate the vehicle. By operating the braking operation member BP, the braking torque of the wheel WH is adjusted, and a braking force is generated on the wheel WH. Specifically, a rotating member (for example, a brake disc) KT is fixed to the vehicle wheel WH. A brake caliper is disposed so as to sandwich the rotating member KT, and a wheel cylinder CW is provided there. By increasing the pressure (braking fluid pressure) Pw of the brake fluid BF in the wheel cylinder CW, the friction member (for example, a brake pad) is pressed against the rotating member KT. Since the rotating member KT and the wheel WH are fixed so as to rotate integrally, a braking torque (resulting in friction braking force) is generated on the wheel WH by the frictional force generated at this time.

Reservoir (atmospheric pressure reservoir) RV is a tank for working fluid, in which braking fluid BF is stored. The lower portion of the reservoir RV is partitioned by a partition plate SK into a master reservoir chamber Ru connected to the master cylinder chamber Rm and a pressure regulating reservoir chamber Rd connected to the pressure regulating unit YC. In a state where the brake fluid BF is filled in the reservoir RV, the liquid level of the brake fluid BF is higher than the height of the partition plate SK. For this reason, the brake fluid BF can freely move between the master reservoir chamber Ru and the pressure regulation reservoir chamber Rd beyond the partition plate SK. On the other hand, when the amount of the brake fluid BF in the reservoir RV decreases and the liquid level of the brake fluid BF becomes lower than the height of the partition plate SK, the master reservoir chamber Ru and the pressure regulating reservoir chamber Rd become independent reservoirs. .

Each wheel WH is provided with a wheel speed sensor VW so as to detect the wheel speed Vw. The wheel speed Vw signal is used for independent braking control for each wheel, such as anti-skid control (control to suppress excessive deceleration slip of the wheel) and vehicle stabilization control (control to suppress excessive oversteer and understeer behavior). Is done. A vehicle body speed Vx is calculated based on each wheel speed Vw detected by the wheel speed sensor VW.

≪Brake control device SC≫
The braking control device SC includes an upper fluid unit YU and a lower fluid unit YL. Here, the upper fluid unit YU is a fluid unit closer to the master cylinder CM, and the lower fluid unit YL is a fluid unit closer to the wheel cylinder CW. The inside of each fluid unit YU, YL is made liquid-tight by the brake fluid BF. The upper fluid unit YU is controlled by the upper controller ECU, and the lower fluid unit YL is controlled by the lower controller ECL. The upper controller ECU and the lower controller ECL are connected via a communication bus BS so that each signal (sensor detection value, calculation value, etc.) is shared.

The upper fluid unit YU of the braking control device SC is composed of an operation amount sensor BA, an operation switch ST, a stroke simulator SS, a master unit YM, a pressure adjustment unit YC, and a regeneration coordination unit YK.

An operation amount sensor BA is provided so as to detect the operation amount Ba of the braking operation member (brake pedal) BP by the driver. As the operation amount sensor BA, an operation displacement sensor SP for detecting an operation displacement Sp of the braking operation member BP is provided. An operation force sensor FP is provided so as to detect the operation force Fp of the braking operation member BP. Further, a simulator hydraulic pressure sensor PS is provided as the operation amount sensor BA so as to detect the hydraulic pressure (simulator hydraulic pressure) Ps in the stroke simulator SS. An input hydraulic pressure sensor PN is provided so as to detect a hydraulic pressure (input hydraulic pressure) Pn in the input chamber Rn of the regeneration cooperative unit YK. The operation amount sensor BA is a general term for the above-described operation displacement sensor SP and the like, and as the braking operation amount Ba, at least one of the operation displacement Sp, the operation force Fp, the simulator hydraulic pressure Ps, and the input hydraulic pressure Pn is adopted. Is done. The detected braking operation amount Ba is input to the upper controller ECU.

The brake operation member BP is provided with an operation switch ST so as to detect whether or not the driver has operated the brake operation member BP. When the brake operation member BP is not operated (that is, during non-braking), the brake operation switch ST outputs an off signal as the operation signal St. On the other hand, when the braking operation member BP is operated (that is, during braking), an ON signal is output as the operation signal St. The braking operation signal St is input to the controller ECU.

A stroke simulator (simply referred to as “simulator”) SS is provided to generate an operation force Fp on the braking operation member BP. The simulator SS is connected between the reaction force chamber Ro and the first on-off valve VA in the simulator fluid path HS. Inside the simulator SS, a simulator piston Es and an elastic body (for example, compression spring) Ds are provided. When the brake fluid BF is moved into the simulator SS, the piston Es is pushed by the inflow brake fluid BF. Since force is applied to the piston in a direction to prevent the inflow of the brake fluid BF by the elastic body Ds, an operation force Fp when the brake operation member BP is operated is formed. In the simulator SS, an orifice Os is provided at the inlet of the brake fluid BF. Due to the damping generated at the orifice Os, the operating characteristics of the braking operation member BP are improved.

[Master unit YM]
The master unit YM adjusts the hydraulic pressure (front wheel braking hydraulic pressure) Pwf in the front wheel cylinder CWf via the master cylinder chamber Rm. The master unit YM includes a master cylinder CM, a master piston PM, and a master elastic body SM.

The master cylinder CM is a cylinder member having a bottom. The master piston PM is a piston member inserted into the master cylinder CM, and is movable in conjunction with the operation of the braking operation member BP. The interior of the master cylinder CM is divided into three hydraulic chambers Rm, Rs, and Ro by the master piston PM.

A groove portion is formed in the first inner peripheral portion Mw of the master cylinder CM, and two seals SL are fitted into the groove portion. The outer periphery (outer cylindrical surface) Mp of the master piston PM and the first inner peripheral portion (inner cylindrical surface) Mw of the master cylinder CM are sealed (sealed) by the two seals SL. The master piston PM can move smoothly along the central axis Jm of the master cylinder CM.

The master cylinder chamber (also simply referred to as “master chamber”) Rm is defined by “the first inner peripheral portion Mw and the first bottom portion (bottom surface) Mu of the master cylinder CM” and the first end portion Mv of the master piston PM. It is a partitioned hydraulic chamber. A master cylinder fluid path HM is connected to the master chamber Rm, and finally connected to the front wheel wheel cylinder CWf via the lower fluid unit YL.

The master piston PM is provided with a flange portion (flange) Tm. The inside of the master cylinder CM is divided into a servo hydraulic chamber (simply referred to as “servo chamber”) Rs and a reaction force hydraulic chamber (simply referred to as “reaction force chamber”) Ro by the collar portion Tm. Yes. A seal SL is provided on the outer peripheral portion of the collar portion Tm, and the collar portion Tm and the second inner peripheral portion Md of the master cylinder CM are sealed. The servo chamber Rs is a hydraulic chamber partitioned by “the second inner peripheral portion Md and the second bottom portion (bottom surface) Mt of the master cylinder CM” and the first surface Ms of the flange portion Tm of the master piston PM. . The master chamber Rm and the servo chamber Rs are arranged to face each other with the master piston PM (particularly, the collar portion Tm) interposed therebetween. A front wheel pressure adjusting fluid path HF is connected to the servo chamber Rs, and the adjusted hydraulic pressure Pa is introduced from the pressure adjusting unit YC.

The reaction force chamber Ro is a hydraulic chamber defined by the second inner peripheral portion Md of the master cylinder CM, the stepped portion Mz, and the second surface Mo of the flange portion Tm of the master piston PM. The reaction force chamber Ro is sandwiched between the master hydraulic pressure chamber Rm and the servo hydraulic pressure chamber Rs in the direction of the central axis Jm, and is positioned between them. Therefore, when the volume Vs of the servo chamber Rs is increased, the volume Vo of the reaction force chamber Ro is decreased. Conversely, when the servo chamber volume Vs is decreased, the reaction force chamber volume Vo is increased. A simulator fluid path HS is connected to the reaction force chamber Ro. The amount of the brake fluid BF in the upper fluid unit YU is adjusted by the reaction force chamber Ro.

A depression Mx is provided at the first end Mv of the master piston PM. A master elastic body (for example, a compression spring) SM is provided between the depression Mx and the first bottom Mu of the master cylinder CM. The master elastic body SM presses the master piston PM against the second bottom Mt of the master cylinder CM in the direction of the central axis Jm of the master cylinder CM. During non-braking, the stepped portion My of the master piston PM is in contact with the second bottom portion Mt of the master cylinder CM. The position of the master piston PM in this state is referred to as “initial position of the master unit YM”.

The through hole Ac is provided in the master cylinder CM between two seals SL (for example, cup seal). The through hole Ac is connected to the master reservoir chamber Ru via the replenishment fluid path HU. A through hole Ap is provided in the vicinity of the first end Mv of the master piston PM. When the master piston PM is in the initial position, the master chamber Rm is brought into communication with the reservoir RV (particularly, the master reservoir chamber Ru) through the through holes Ac and Ap and the supply fluid path HU.

The master chamber Rm has a biasing force Fb (referred to as “retreating force”) in the retreating direction Hb along the central axis Jm by its internal pressure (“master cylinder fluid pressure”, also referred to as “master fluid pressure”) Pm. Applies to the master piston PM. The servo chamber Rs applies an urging force Fa (referred to as “forward force”) opposite to the backward force Fb to the master piston PM by the internal pressure (that is, the introduced adjustment hydraulic pressure Pa). That is, in the master piston PM, the forward force Fa due to the hydraulic pressure Pv (= Pa) in the servo chamber Rs and the backward force Fb due to the hydraulic pressure (master hydraulic pressure) Pm in the master chamber Rm are in the direction of the central axis Jm. They face each other (facing) and are statically balanced. A master hydraulic pressure sensor PQ is provided so as to detect the master hydraulic pressure Pm. For example, the master hydraulic pressure sensor PQ can be provided in the master cylinder fluid path HM. Further, the master hydraulic pressure sensor PQ may be included in the lower fluid unit YL.

For example, the pressure receiving area (namely, the pressure receiving area of the servo chamber Rs) rs of the first surface Ms of the collar portion Tm is equal to the pressure receiving area (namely, the pressure receiving area of the master chamber Rm) rm of the first end Mv of the master piston PM. It is set to be equal. In this case, the hydraulic pressure Pa (resulting servo hydraulic pressure Pv) introduced into the servo chamber Rs and the hydraulic pressure Pm in the master chamber Rm are the same in a steady state. At this time, the forward force Fa (= Pa × rs) and the backward force Fb (= Pm × rm (+ SM elastic force)) are balanced.

[Pressure adjustment unit YC]
The pressure adjusting unit YC adjusts the hydraulic pressures Pwf and Pwr of the front and rear wheel cylinders CWf and CWr on demand. The pressure adjustment unit YC includes an electric pump DC, a check valve GC, a pressure adjustment valve UA, and an adjustment hydraulic pressure sensor PA. The pressure adjustment unit YC is an on-demand type (a function that is necessary when it is necessary without being prepared in advance).

The electric pump DC is composed of a set of one electric motor MC and one fluid pump QC. In the electric pump DC, the electric motor MC and the fluid pump QC are fixed so that the electric motor MC and the fluid pump QC rotate together. The electric pump DC (in particular, the electric motor MC) is a power source for increasing the brake fluid pressure Pw during control braking. The electric motor MC is controlled by the controller ECU.

The suction port Qs of the fluid pump QC is connected to the reservoir RV (particularly the pressure regulating reservoir chamber Rd) via the first reservoir fluid path HV. A pressure regulating fluid path HC is connected to the discharge port Qt of the fluid pump QC. By driving the electric pump DC (particularly, the fluid pump QC), the brake fluid BF is sucked from the first reservoir fluid path HV through the suction port Qs and discharged from the discharge port Qt to the pressure regulating fluid path HC. For example, a gear pump is employed as the fluid pump QC.

A check valve GC (also referred to as “check valve”) is interposed in the pressure regulating fluid path HC. The check valve GC allows the brake fluid BF to move from the first reservoir fluid path HV toward the pressure regulating fluid path HC, but to move from the pressure regulating fluid path HC toward the reservoir fluid path HV (ie, , Back flow of the brake fluid BF) is prevented. That is, the electric pump DC is rotated only in one direction. An end Bv of the pressure regulating fluid path HC opposite to the discharge part Qt is connected to the first reservoir fluid path HV.

A pressure regulating valve UA is provided in the pressure regulating fluid path HC. The pressure regulating valve UA is a linear solenoid valve (also referred to as “proportional valve” or “differential pressure valve”) whose valve opening amount (lift amount) is continuously controlled based on an energized state (for example, supply current). It is. The pressure regulating valve UA is controlled by the controller ECU based on the drive signal Ua. As the pressure regulating valve UA, a normally open type electromagnetic valve is employed.

The brake fluid BF is pumped up from the first reservoir fluid passage HV through the suction port Qs of the fluid pump QC and discharged from the discharge port Qt. Then, the brake fluid BF passes through the check valve GC and the pressure regulating valve UA, and is returned to the reservoir fluid path HV. In other words, the first reservoir fluid path HV and the pressure regulating fluid path HC form a reflux path (a fluid path in which the flow of the brake fluid BF returns to the original flow again), A valve GC and a pressure regulating valve UA are interposed in series.

When the electric pump DC is operating, the brake fluid BF is recirculated in the order of “HV → QC (Qs → Qt) → GC → UA → HV” as indicated by the broken arrow (A). (Ie, a “reflux path” is formed). When the pressure regulating valve UA is in a fully opened state (because it is a normally open type and not energized), the hydraulic pressure (adjusted hydraulic pressure) Pa in the regulated fluid path HC is substantially “0 (atmospheric pressure)”. When the energization amount to the pressure regulating valve UA is increased and the return path is throttled by the pressure regulating valve UA, the hydraulic pressure (adjusted hydraulic pressure) Pa between the fluid pump QC and the pressure regulating valve UA in the pressure regulating fluid path HC is “0. Is increased. The pressure adjusting fluid path HC is provided with an adjustment hydraulic pressure sensor PA so as to detect the adjustment hydraulic pressure Pa.

The pressure regulating fluid path HC is branched into the front wheel and rear wheel regulating fluid paths HF and HR at a portion Bc between the fluid pump QC and the pressure regulating valve UA. The front wheel pressure adjusting fluid path HF is connected to the servo chamber Rs of the master unit YM. Accordingly, the adjusted hydraulic pressure Pa adjusted by the pressure regulating valve UA is introduced (supplied) into the servo chamber Rs. Since the master cylinder CM is connected to the front wheel wheel cylinder CWf via the lower fluid unit YL, the adjustment hydraulic pressure Pa is indirectly introduced to the front wheel wheel cylinder CWf via the master cylinder CM. On the other hand, the rear wheel pressure adjusting fluid path HR is connected to the rear wheel wheel cylinder CWr via the lower fluid unit YL. Therefore, the adjustment hydraulic pressure Pa is directly introduced into the rear wheel hole cylinder CWr.

The pressure regulating unit YC is provided with a bypass fluid path HD that connects the reservoir RV and the servo chamber Rs in parallel with the pressure regulating fluid path HC. A check valve GD is interposed in the bypass fluid path HD. In the check valve GD, the flow of the brake fluid BF from the reservoir RV to the servo chamber Rs is allowed, but the reverse flow from the servo chamber Rs to the reservoir RV is blocked. When the braking operation member BP is suddenly operated, the master piston PM is moved in the forward direction Ha and the volume Vs of the servo chamber Rs is increased also by the driver's operation force. In this case, the amount of liquid corresponding to the volume increase of the servo chamber Rs caused by the operation of the driver is supplied via the bypass fluid path HD and the check valve GD.

[Regenerative cooperation unit YK]
The regenerative cooperative unit YK achieves cooperative control of friction braking and regenerative braking (referred to as “regenerative cooperative control”). For example, a state can be formed in which the braking operation member BP is operated by the regenerative coordination unit YK but the braking hydraulic pressure Pw is not generated. The regeneration cooperative unit YK includes an input cylinder CN, an input piston PK, an input elastic body SN, a first on-off valve VA, a second on-off valve VB, a stroke simulator SS, a simulator hydraulic pressure sensor PS, and an input hydraulic pressure sensor PN. Composed.

The input cylinder CN is a cylinder member having a bottom portion fixed to the master cylinder CM. The input piston PK is a piston member inserted into the input cylinder CN. The input piston PK is mechanically connected to the braking operation member BP via a clevis (U-shaped link) so as to interlock with the braking operation member BP. The input piston PK is provided with a flange portion (flange) Tn. An input elastic body (for example, a compression spring) SN is provided between the attachment surface Ma of the input cylinder CN to the master cylinder CM and the flange portion Tn of the input piston PK. The input elastic body SN presses the flange portion Tn of the input piston PK against the bottom Mb of the input cylinder CN in the direction of the central axis Jm.

During non-braking, the stepped portion My of the master piston PM is in contact with the second bottom portion Mt of the master cylinder CM, and the collar portion Tn of the input piston PK is in contact with the bottom portion Mb of the input cylinder CN. During non-braking, the gap Ks between the master piston PM (particularly the end face Mq) and the input piston PK (particularly the end face Mg) is set to a predetermined distance ks (referred to as “initial gap”) inside the input cylinder CN. Yes. That is, when the pistons PM and PK are in the position of the most backward direction Hb (referred to as “initial position” of each piston) (that is, during non-braking), the master piston PM and the input piston PK are separated by a predetermined distance ks. ing. Here, the predetermined distance ks corresponds to the maximum value of the regeneration amount Rg. When the regeneration cooperative control is executed, the gap (also referred to as “separation displacement”) Ks is controlled (adjusted) by the adjustment hydraulic pressure Pa.

When the braking operation member BP is stepped on from “Ba = 0”, the input piston PK is moved in the forward direction Ha from its initial position. At this time, if the adjustment hydraulic pressure Pa remains “0”, the master piston PM remains at the initial position, and therefore the gap Ks (the end surface Mg of the input piston PK and the master piston PM is increased as the input piston PK moves forward). The distance between the end face Mq) gradually decreases. On the other hand, when the adjustment hydraulic pressure Pa is increased from “0”, the master piston PM is moved in the forward direction Ha from the initial position. For this reason, the gap Ks can be adjusted independently of the braking operation amount Ba within the range of “0 ≦ Ks ≦ ks” by the adjustment hydraulic pressure Pa. That is, by adjusting the adjustment hydraulic pressure Pa, the gap Ks between the master piston PM and the input piston PK is adjusted, and regenerative cooperative control is achieved.

The input chamber Rn of the regeneration coordination unit YK and the reaction force chamber Ro of the master unit YM are connected by the simulator fluid path HS. A first on-off valve VA is provided in the simulator fluid path HS. The first on-off valve VA is a normally closed electromagnetic valve having a first open position and a first closed position. The reservoir fluid path HT is connected to a portion Bs between the first on-off valve VA and the reaction force chamber Ro of the simulator fluid path HS. The reservoir fluid path HT is provided with a second on-off valve VB. The second on-off valve VB is a normally open solenoid valve having a second open position and a second closed position. The first and second on-off valves VA and VB are two-position solenoid valves (also referred to as “on / off valves”) having an open position (communication state) and a closed position (blocking state). The first and second on-off valves VA and VB are controlled by the upper controller ECU based on the drive signals Va and Vb.

The simulator SS is connected to the simulator fluid path HS at a portion Bo between the first on-off valve VA and the reaction force chamber Ro. In other words, the input chamber Rn of the regeneration coordination unit YK is connected to the simulator SS by the simulator fluid path HS. When the regeneration cooperative control is executed, the first on-off valve VA is set to the open position, and the second on-off valve VB is set to the closed position. Since the second on-off valve VB is in the closed position, the flow path to the reservoir RV is blocked in the reservoir fluid path HT. Accordingly, the brake fluid BF is moved from the input chamber Rn of the input cylinder CN into the simulator SS. The piston Es of the simulator SS is applied with a force that prevents the inflow of the brake fluid BF by the elastic body Ds, so that an operation force Fp when the brake operation member BP is operated is generated.

The second reservoir fluid path HT is connected to the reservoir RV (particularly the pressure regulating reservoir chamber Rd). A portion of the second reservoir fluid path HT can be shared with the first reservoir fluid path HV. However, it is desirable that the first reservoir fluid path HV and the second reservoir fluid path HT are separately connected to the reservoir RV. The fluid pump QC sucks the brake fluid BF from the reservoir RV via the first reservoir fluid path HV. At this time, bubbles may be mixed in the first reservoir fluid path HV. For this reason, the second reservoir fluid path HT does not have a common part with the first reservoir fluid path HV and is separate from the first reservoir fluid path HV so as to avoid air bubbles from entering the input cylinder CN and the like. To the reservoir RV.

In the simulator fluid path HS between the first on-off valve VA and the reaction force chamber Ro, a simulator fluid pressure sensor PS is provided so as to detect the fluid pressure (referred to as “simulator fluid pressure”) Ps in the simulator SS. Further, an input hydraulic pressure sensor PN is provided in the simulator fluid path HS between the first on-off valve VA and the input chamber Rn so as to detect a hydraulic pressure (referred to as “input hydraulic pressure”) Pn in the input chamber Rn. It is done. The simulator hydraulic pressure sensor PS and the input hydraulic pressure sensor PN are one of the braking operation amount sensors BA described above. The detected hydraulic pressures Ps and Pn are input to the upper controller ECU as a braking operation amount Ba.

[Upper controller ECU]
The upper controller ECU controls the electric motor MC and the electromagnetic valves VA, VB, and UA based on the braking operation amount Ba, the operation signal St, and the adjustment hydraulic pressure (detection value) Pa. Specifically, the upper controller ECU calculates drive signals Va, Vb, Ua for controlling various electromagnetic valves VA, VB, UA. Similarly, a drive signal Mc for controlling the electric motor MC is calculated. Then, based on the drive signals Va, Vb, Ua, Mc, the electromagnetic valves VA, VB, UA and the electric motor MC are driven.

The upper controller (electronic control unit) ECU is network-connected to the lower controller ECL and other system controllers (drive controller ECD, etc.) via the in-vehicle communication bus BS. A regeneration amount (target value) Rg is transmitted from the upper controller ECU to the drive controller ECD through the communication bus BS so as to execute the regeneration cooperative control.

[Lower fluid unit YL]
The lower fluid unit YL is a known fluid unit including a master hydraulic pressure sensor PQ, a plurality of solenoid valves, an electric pump, and a low pressure reservoir. The lower fluid unit YL is controlled by the lower controller ECL. Wheel speed Vw, yaw rate, steering angle, longitudinal acceleration, lateral acceleration, and the like are input to the lower controller ECL. In the lower controller ECL, the vehicle body speed Vx is calculated based on the wheel speed Vw. Then, based on the vehicle speed Vx and the wheel speed Vw, anti-skid control is executed so as to suppress excessive deceleration slip (for example, wheel lock) of the wheel WH. Further, the lower controller ECL performs vehicle stabilization control (so-called ESC) that suppresses unstable behavior (excessive oversteer behavior, understeer behavior) of the vehicle based on the yaw rate. That is, the brake fluid pressure Pw of each wheel WH is individually controlled by the lower fluid unit YL. The calculated vehicle speed Vx is input to the upper controller ECU through the communication bus BS.

[Operation of braking controller SC]
When a vehicle start switch (for example, an ignition switch) is turned on, the first on-off valve VA is opened and the second on-off valve VB is closed. Therefore, during traveling of the vehicle, the input chamber Rn of the regeneration cooperative unit YK and the reaction force chamber Ro of the master unit YM are in communication with each other via the simulator fluid path HS and the first on-off valve VA. On the other hand, since the second on-off valve VB is in the closed position, the input chamber Rn and the reaction force chamber Ro are disconnected from the reservoir RV.

In non-braking (for example, when the operation of the braking operation member BP is not performed), the energization of the pressure regulating valve UA and the electric motor MC is not performed. At this time, the pistons PM and PN are pressed to their initial positions by the elastic bodies SM and SN, and the hydraulic chamber Rm of the master cylinder CM and the reservoir Ru of the reservoir RV are in communication with each other, and the master hydraulic pressure Pm Is “0 (atmospheric pressure)”.

When the braking operation member BP is operated (particularly at the start of control braking), the input piston PK is moved in the forward direction Ha. At this time, the amount of the brake fluid BF flowing out from the input chamber Rn flows into the simulator SS, and the operation force Fp of the brake operation member BP is formed.

When the vehicle deceleration is sufficient by the regenerative braking force by the generator GN, the state of “Pa = 0” is maintained. By operating the braking operation member BP, the input piston PK is moved in the forward direction Ha from its initial position. At this time, the adjustment hydraulic pressure Pa remains “0”, so the master piston PM is not moved. . Therefore, as the input piston PK advances, the gap Ks (the distance between the end surface Mg of the input piston PK and the end surface Mq of the master piston PM) gradually decreases.

When the vehicle deceleration is insufficient with the regenerative braking force by the generator GN, the controller ECU controls the pressure adjusting unit YC and the adjusted hydraulic pressure Pa is adjusted on demand. The adjusted hydraulic pressure Pa is applied to the servo chamber Rs through the front wheel pressure adjusting fluid passage HF. When the force (forward force) Fa in the forward direction Ha generated by the hydraulic pressure (referred to as “servo hydraulic pressure”) Pv (= Pa) in the servo chamber Rs becomes larger than the set load of the master elastic body SM, the master piston PM Is moved along the central axis Jm of the master cylinder CM. The master chamber Rm is blocked from the reservoir RV by the movement in the forward direction Ha. Further, when the adjustment hydraulic pressure Pa is increased, the brake fluid BF is pumped from the master cylinder CM toward the front wheel cylinder CWf at the master hydraulic pressure Pm. A force (retracting force) Fb in the retreating direction Hb is applied to the master piston PM by the master hydraulic pressure Pm. The servo chamber Rs generates a force (forward force) Fa in the forward direction Ha by the adjustment hydraulic pressure Pa so as to oppose (oppose) the backward force Fb. The master hydraulic pressure Pm is increased or decreased according to the increase or decrease of the adjustment hydraulic pressure Pa. As the adjustment hydraulic pressure Pa increases, the master piston PM is moved in the forward direction Ha from the initial position, but the gap Ks is set to a braking operation amount Ba within a range of “0 ≦ Ks ≦ ks” by the adjustment hydraulic pressure Pa. Are independently adjustable. That is, regenerative cooperative control is executed by adjusting the gap Ks by the adjustment hydraulic pressure Pa. The adjustment hydraulic pressure Pa is directly applied to the rear wheel wheel cylinder CWr through the rear wheel pressure adjusting fluid path HR and the lower fluid unit YL.

When the braking operation member BP is returned, the adjustment hydraulic pressure Pa is reduced. When the servo hydraulic pressure Pv (= Pa) becomes smaller than the master chamber hydraulic pressure Pm (= Pwf), the master piston PM is moved in the backward direction Hb. When the braking operation member BP is brought into a non-operating state, the master piston PM (particularly, the stepped portion My) comes into contact with the second bottom portion Mt of the master cylinder CM (initial position) by the elastic force of the compression spring SM. It is returned to.

It should be noted that during manual braking (power failure, etc.), the first and second on-off valves VA and VB are not energized. Accordingly, the first on-off valve VA is in the closed position and the second on-off valve VB is in the open position. The input chamber Rn is brought into a fluid lock state (sealed state) by the closed position of the first on-off valve VA so that the input piston PK and the master piston PM cannot be moved relative to each other. Further, the reaction force chamber Ro is connected to the reservoir RV through the second reservoir fluid path HT depending on the open position of the second on-off valve VB. For this reason, the volume Vo of the reaction force chamber Ro is reduced by the movement of the master piston PM in the forward direction Ha, but the liquid amount accompanying the volume reduction is discharged toward the reservoir RV. In conjunction with the operation of the brake operation member BP, the input piston PK and the master piston PM are moved together (that is, “Ks = 0”), and the brake fluid BF is transferred from the master chamber Rm to the front wheel wheel cylinder CWf. Pumped.

<Pressure control processing>
With reference to the control flow diagram of FIG. 2, processing of pressure regulation control including regenerative cooperative control will be described. “Pressure adjustment control” is drive control of the electric motor MC and the pressure adjustment valve UA for adjusting the adjustment hydraulic pressure Pa. The control algorithm is programmed in the upper controller ECU.

In step S110, the braking control device SC is initialized. In step S110, initial diagnosis of each component is executed. In step S120, energization is performed to the normally closed first open / close valve VA and the normally open second open / close valve VB. That is, when the start switch of the device is turned on, the first on-off valve VA is opened and the second on-off valve VB is closed. The on / off state of the first and second on-off valves VA and VB is not switched every time the braking operation is performed, but the first and second on-off valves VA and VB are always energized while the vehicle is running. Is called. Thereby, it is advantageous in terms of operating sound and the characteristics of the simulator SS can be stabilized.

In step S130, the braking operation amount Ba, the operation signal St, the adjustment hydraulic pressure (detection value) Pa, and the vehicle body speed Vx are read. The operation amount Ba is detected by an operation amount sensor BA (operation displacement sensor SP, input hydraulic pressure sensor PN, simulator hydraulic pressure sensor PS, etc.). The operation signal St is detected by the operation switch ST. The adjustment hydraulic pressure Pa is detected by an adjustment hydraulic pressure sensor PA provided in the pressure adjustment fluid path HC. The vehicle body speed Vx is acquired from the lower controller ECL via the communication bus BS. The vehicle body speed Vx may be calculated by the upper controller ECU based on the wheel speed Vw when the wheel speed Vw is input to the upper controller ECU.

In step S140, based on at least one of the braking operation amount Ba and the braking operation signal St, it is determined whether or not braking is being performed. For example, when the operation amount Ba is larger than the predetermined value bo, step S140 is affirmed and the process proceeds to step S150. On the other hand, when the operation amount Ba is equal to or smaller than the predetermined value bo, Step S140 is denied and the process returns to Step S130. Here, the predetermined value bo is a preset constant corresponding to the play of the braking operation member BP. When the operation signal St is on, the process proceeds to step S150, and when the operation signal St is off, the process returns to step S130.

In step S150, as shown in block X150, the required braking force Fd is calculated based on the operation amount Ba. The required braking force Fd is a target value of the total braking force F acting on the vehicle, and is a braking force obtained by combining the “friction braking force Fm by the braking controller SC” and the “regenerative braking force Fg by the generator GN”. The required braking force Fd is determined to be “0” when the operation amount Ba is in the range from “0” to the predetermined value bo according to the calculation map Zfd. When the operation amount Ba is equal to or greater than the predetermined value bo, the operation amount Ba increases. Accordingly, calculation is performed so as to monotonically increase from “0”.

In step S160, as indicated by a block X160, the maximum value (referred to as “maximum regenerative force”) Fx of the regenerative braking force is calculated based on the vehicle body speed Vx and the calculation map Zfx. The regeneration amount of the generator GN is limited by the rating of the power transistor (IGBT or the like) of the drive controller ECD and the battery charge acceptance. For example, the regeneration amount of the generator GN is controlled to a predetermined power (electric energy per unit time). Since the electric power (power) is constant, the regenerative torque around the wheel shaft by the generator GN is inversely proportional to the rotation speed of the wheel WH (that is, the vehicle body speed Vx). Further, when the rotational speed Ng of the generator GN decreases, the regeneration amount decreases. Furthermore, an upper limit is provided for the regeneration amount.

From the above, in the calculation map Zfx for the maximum regenerative force Fx, the maximum regenerative force Fx increases as the vehicle body speed Vx increases in the range where the vehicle body speed Vx is greater than or equal to “0” and less than the first predetermined speed vo. Is set as follows. Further, in the range where the vehicle body speed Vx is equal to or higher than the first predetermined speed vo and lower than the second predetermined speed vp, the maximum regenerative force Fx is determined as the upper limit value fx. When the vehicle body speed Vx is equal to or higher than the second predetermined speed vp, the maximum regenerative force Fx is set to decrease as the vehicle body speed Vx increases. For example, in the reduction characteristic of the maximum regenerative force Fx (characteristic of “Vx ≧ vp”), the relationship between the vehicle body speed Vx and the maximum regenerative force Fx is represented by a hyperbola (that is, the regenerative power is constant). Here, the predetermined values vo and vp are preset constants. Note that in the calculation map Zfx, the rotational speed Ng of the generator GN can be adopted instead of the vehicle body speed Vx.

In step S170, based on the required braking force Fd and the maximum regenerative force Fx, it is determined whether or not the required brake force Fd is equal to or less than the maximum regenerative force Fx. That is, it is determined whether or not the braking force Fd requested by the driver can be achieved only by the regenerative braking force Fg. If “Fd ≦ Fx” and step S170 is positive, the process proceeds to step S180. On the other hand, if “Fd> Fx” and step S170 is negative, the process proceeds to step S190.

In step S180, the required braking force Fd is determined as the regenerative braking force Fg. In step S180, the target friction braking force Fm is calculated to be “0”. The target friction braking force Fm is a target value of the braking force to be achieved by friction braking. In this case, friction braking is not employed for vehicle deceleration, and the required braking force Fd is achieved only by regenerative braking. In step S190, the regenerative braking force Fg is determined as the maximum regenerative force Fx. In step S190, the target friction braking force Fm is calculated based on the required braking force Fd and the maximum regenerative force Fx. Specifically, the target friction braking force Fm is determined by subtracting the maximum regenerative force Fx from the required braking force Fd. That is, the required braking force Fd is made up by the target friction braking force Fm, which is insufficient for the regenerative braking force Fg (= Fx).

In step S200, the regenerative amount Rg is calculated based on the regenerative braking force Fg. The regeneration amount Rg is a target value for the regeneration amount of the generator GN. The regeneration amount Rg is transmitted from the braking controller ECU to the drive controller ECD via the communication bus BS. In step S210, the target hydraulic pressure Pt is calculated based on the target value Fm of the friction braking force. The target hydraulic pressure Pt is a target value for the adjusted hydraulic pressure Pa. In step S210, the target friction braking force Fm is converted into a hydraulic pressure, and the target hydraulic pressure Pt is determined.

In step S220, it is determined whether or not an emergency operation process is necessary. If it is necessary, an emergency operation process is executed. The sudden operation process is a process for improving the pressure increase response of the brake fluid pressure Pw. Details of the emergency operation processing will be described later.

In step S230, the electric motor MC is driven to form a reflux of the brake fluid BF including the fluid pump QC. The electric motor MC (electric pump DC) is driven (rotated) even when “Pt = 0” during braking in order to ensure boosting response. In step S240, the pressure regulating valve UA is servo-controlled based on the target hydraulic pressure Pt and the adjusted hydraulic pressure (detected value of the regulated hydraulic pressure sensor PA) Pa so that the adjusted hydraulic pressure Pa approaches the target hydraulic pressure Pt. The In the servo control, feedback control is performed so that the actual value Pa matches the target value Pt.

<Sudden operation processing>
With reference to the control flow chart of FIG. 3, the processing at the time of sudden operation will be described. The “sudden operation process” is to improve the boosting response of the brake hydraulic pressure Pw when the braking operation member BP is suddenly operated by the driver (that is, during sudden braking). When the processing is not executed, the driver's operation is a “brake-by-wire” configuration separated from the brake fluid pressure Pw. However, during sudden braking, the driver's operation force (operation power) is reduced. This is used to improve the boosting response.

In step S310, the operation speed dB is calculated based on the operation amount Ba. Specifically, the operation speed dB is calculated by differentiating the operation amount Ba with respect to time. Here, the operation amount Ba is a state amount representing the degree of operation of the braking operation member BP, and is based on at least one of the operation displacement Sp, the operation force Fp, the input hydraulic pressure Pn, and the simulator hydraulic pressure Ps. Determined. Further, it is preferable that the operation displacement Sp is adopted as the operation amount Ba, and the operation speed dS (differential value of the operation displacement Sp) is calculated as the operation speed dB. The operation of the brake operation member BP is dynamically propagated in the order of “Sp → Pn → Ps”, but the operation displacement Sp is a state quantity closest to the brake operation member BP and is detected early in time. Is based on the state quantity being made.

In step S320, based on the operation speed dB, it is determined whether or not the operation of the braking operation member BP is a sudden operation. For example, the determination of the sudden operation is affirmed when the following two conditions (A1, A2) are both satisfied.
Condition A1: The operation speed dB is equal to or higher than the first predetermined speed dx. The first predetermined speed dx is a preset constant (predetermined value).
Condition A2: The operation amount Ba is equal to or greater than the predetermined amount bx. The predetermined amount bx is a preset constant (predetermined value).
If “dB ≧ dx and Ba ≧ bx”, step S320 is positive, and the process proceeds to step S330. On the other hand, “dB <dx or Ba <bx” is satisfied, step S320 is denied, and the process returns to step S310.

In step S330, the elapsed time Tz is calculated. The elapsed time Tz is the elapsed time from the time when the determination in step S320 is affirmed for the first time in a series of braking operations (that is, operations from the start of braking to the end of braking). In other words, the timer is activated and the elapsed time Tz is integrated in the calculation cycle in which the sudden operation is first determined.

In step S340, it is determined whether or not the termination condition for the sudden operation process is satisfied. The abrupt operation process is terminated when at least one of the following three conditions (B1 to B3) is satisfied.
Condition B1: The elapsed time Tz is equal to or longer than the predetermined time tz. The predetermined time tz is a preset constant (predetermined value).
Condition B2: The sudden operation was weakened. The operation speed dB is less than the second predetermined speed dy. Here, the second predetermined speed dy is a preset constant (predetermined value) smaller than the first predetermined speed dx (that is, “dy <dx”).
Condition B3: The braking operation is terminated. That is, “Ba = 0” was achieved.

If step S340 is negative, the process proceeds to step S350 and step S360, and the sudden operation process is executed. In the sudden operation process, the first on-off valve VA is closed at step S350. In step S360, the second on-off valve VB is set to the open position. The input chamber Rn is put into a containment state (that is, the input chamber Rn is fluid-locked) by the closed position of the first on-off valve VA. For this reason, the master piston PM is moved in the forward movement direction Ha by the input piston PK connected to the braking operation member BP. When the master piston PM is moved in the forward direction Ha, the volume Vo of the reaction force chamber Ro is reduced. When the second on-off valve VB is in the closed position, the brake fluid BF in the reaction force chamber Ro flows into the simulator SS. The simulator SS is provided with an elastic body Ds for generating the operation force Fp, and an orifice Os is provided at the entrance for improving the operation characteristics. The elastic body Ds and the orifice Os become a resistance against the inflow of the brake fluid BF. In order to avoid this resistance, the second on-off valve VB is opened, and the braking fluid BF in the reaction force chamber Ro is moved to the reservoir RV without resistance. Further, when the master piston PM is moved in the forward direction Ha, the volume Vs of the servo chamber Rs is increased. At this time, the servo chamber Rs needs to suck in the brake fluid BF. However, since the bypass fluid passage HD is provided so as to bypass the fluid pump QC, the bypass fluid passage HD and the check valve GD are provided. The brake fluid BF can be sucked through without any resistance.

When step S340 is affirmed, the process proceeds to step S370 and step S380, the sudden operation process is terminated, and the normal state is restored. That is, the first on-off valve VA is set to the open position, the fluid lock state is canceled, and the input chamber Rn and the simulator SS are connected. In addition, the second on-off valve VB is closed, and the hydraulic chambers Rn, Ro and the reservoir RV are disconnected.

In the calculation process at the time of sudden operation, the operating force Fp of the braking operation member BP operated by the driver is transmitted to the master piston PM through the input chamber Rn by closing the first on-off valve VA. Is done. During normal operation (that is, other than during sudden operation), the master piston PM is driven only by the adjustment hydraulic pressure Pa in the servo chamber Rs. However, when the sudden operation process is executed, the master piston PM is pressed in the forward direction Ha by the adjustment hydraulic pressure Pa and the driver's operation force Fp. For this reason, in the increase of the master hydraulic pressure Pm, the responsiveness is improved.

Since the pressure adjusting unit YC is an on-demand type, the electric pump DC is stopped during non-braking. Accordingly, when the braking operation member BP is suddenly operated, the increase in the adjustment fluid pressure Pa cannot keep up with the increase in the operation force Fp (the rise in the adjustment fluid pressure Pa is in contrast to the rise in the operation force Fp). Can be delayed). When the brake fluid BF is supplied from the reservoir RV to the servo chamber Rs through the fluid pump QC, the fluid pump QC acts as a fluid resistance. In order to avoid this, the bypass fluid passage HD is provided in parallel with the pressure regulation fluid passage HC including the pressure regulation valve UA. When the rising of the adjustment fluid pressure Pa is delayed, the servo chamber Rs can suck the brake fluid BF from the bypass fluid passage HD, so that the pressure increase response of the master fluid pressure Pm can be ensured. The bypass fluid path HD is provided with a check valve GD so as to prevent the movement of the brake fluid BF from the servo chamber Rs to the reservoir RV.

The simulator SS is provided with an elastic body Ds so as to generate an operating force Fp. In addition, the simulator SS is provided with an orifice Os so as to improve the operation characteristics by a damping effect. When the first and second on-off valves VA and VB are in the closed position, the master piston PM is moved in the forward direction Ha, and when the volume Vo of the reaction force chamber Ro is reduced, the corresponding braking fluid BF is It needs to be absorbed by the simulator SS. However, since the simulator SS is provided with the elastic body Ds and the orifice Os, these serve as inflow resistance of the brake fluid BF to the simulator SS. In the sudden operation process, since the second on-off valve VB is set to the open position, the braking fluid BF corresponding to the volume reduction of the reaction force chamber Ro is transferred to the reservoir RV through the simulator fluid path HS and the reservoir fluid path HT. Returned. Therefore, since the braking fluid BF in the reaction force chamber Ro is moved without resistance, the responsiveness of the master fluid pressure Pm can be effectively achieved.

<Second Embodiment of Braking Control Device SC>
A second embodiment of the braking control device SC will be described with reference to the overall configuration diagram of FIG. The braking control device SC according to the second embodiment is also configured to include a master unit YM, a regeneration coordination unit YK, a pressure adjustment unit YC, and a controller ECU. The master unit YM and the regeneration cooperative unit YK are the same as those in the first embodiment. In the first embodiment, the pressure adjusting unit YC is configured by one pressure adjusting valve UA, and the same hydraulic pressure (adjusted hydraulic pressure) Pa is supplied to the servo chamber Rs and the rear wheel cylinder CWr. Instead, in the second embodiment, the pressure regulating unit YC includes two pressure regulating valves UB and UC, and the controller ECU supplies the hydraulic pressure Pc supplied to the servo chamber Rs and the rear wheel wheel cylinder. The supply hydraulic pressure Pb to CWr is controlled independently and individually. Hereinafter, a description will be given focusing on differences from the first embodiment. In the second embodiment, the front wheel WHf is provided with a generator GN.

As in the first embodiment, in the second embodiment, the constituent members, arithmetic processing, signals, characteristics, and values that are given the same symbols have the same function. The suffix “i” to “l” at the end of the symbol is a comprehensive symbol indicating which wheel the wheel is associated with, “i” is the right front wheel, “j” is the left front wheel, “k” is the right rear wheel, “L” indicates the left rear wheel. When the subscripts “i” to “l” are omitted, each symbol represents a generic name of each of the four wheels. Subscripts “f” and “r” at the end of the symbol are general symbols indicating which of the front and rear wheels the two fluid paths (movement paths of the brake fluid BF) relate to. "" Indicates a front wheel system and "r" indicates a rear wheel system. When the subscripts “f” and “r” are omitted, it represents a generic name of two systems. In each fluid path, the “upstream side (or upper part)” is the side close to the reservoir RV, and the “downstream side (or lower part)” is the side close to the wheel cylinder CW.

[Other examples of pressure control unit YC]
The pressure adjustment unit YC includes an electric pump DC, a check valve GC, first and second pressure adjustment valves UB and UC, and first and second adjustment hydraulic pressure sensors PB and PC. The pressure adjusting unit YC adjusts the hydraulic pressure Pwf of the front wheel cylinder CWf and the hydraulic pressure Pwr of the rear wheel cylinder CWr independently and individually. Specifically, the braking hydraulic pressure Pwf of the front wheel WHf provided with the generator GN is adjusted to be equal to or lower than the braking hydraulic pressure Pwr of the rear wheel WHr not provided with the generator GN.

Similarly to the above, the electric pump DC is constituted by one electric motor MC and one fluid pump QC, which rotate together. In the fluid pump QC, the suction port Qs is connected to the first reservoir fluid path HV, and the discharge port Qt is connected to one end of the pressure regulating fluid path HC. A check valve GC is provided in the pressure regulating fluid path HC. The other end Bv of the pressure regulating fluid path HC is connected to the reservoir fluid path HV.

In the pressure regulating fluid path HC, two pressure regulating valves UB and UC are provided in series. Specifically, the first pressure regulating valve UB is provided in the pressure regulating fluid path HC. And the 2nd pressure regulation valve UC is arrange | positioned between the 1st pressure regulation valve UB and the site | part Bv. As with the pressure regulating valve UA, the first and second pressure regulating valves UB and UC are linear solenoid valves whose valve opening amount (lift amount) is continuously controlled based on an energized state (for example, supply current). Proportional valve, differential pressure valve). The first and second pressure regulating valves UB and UC are controlled by the controller ECU based on the drive signals Ub and Uc. As the first and second pressure regulating valves UB and UC, normally open solenoid valves are employed.

When the electric pump DC is driven, a reflux of the brake fluid BF of “HV → QC (Qs → Qt) → GC → UB → UC → HV” is formed. When the first and second pressure regulating valves UB and UC are in a fully opened state (because these are normally open types, when not energized), the hydraulic pressures (adjusted hydraulic pressures) Pb and Pc in the regulated fluid path HC are: Both are substantially “0 (atmospheric pressure)”. When the energization amount to the first pressure regulating valve UB is increased and the recirculation is throttled by the pressure regulating valve UB, the fluid pressure (first regulated fluid pressure) between the fluid pump QC and the first pressure regulating valve UB in the pressure regulating fluid path HC. Pb is increased from “0”. Further, when the energization amount to the second pressure regulating valve UC is increased and the recirculation is throttled by the pressure regulating valve UC, the hydraulic pressure (second pressure) between the first pressure regulating valve UB and the second pressure regulating valve UC in the pressure regulating fluid path HC. Adjustment hydraulic pressure) Pc is increased from “0”.

Since the first and second pressure regulating valves UB and UC are arranged in series with the pressure regulating fluid path HC, the second adjustment hydraulic pressure Pc adjusted by the second pressure regulating valve UC is the first adjustment hydraulic pressure Pb. It is as follows. In other words, the second adjustment hydraulic pressure Pc is adjusted to increase from “0 (atmospheric pressure)” by the second pressure adjustment valve UC, and the first adjustment hydraulic pressure Pb is adjusted to be the second by the first pressure adjustment valve UB. It adjusts so that it may increase from adjustment hydraulic pressure Pc. In the pressure adjusting unit YC, first and second adjustment hydraulic pressure sensors PB and PC are provided in the pressure adjustment fluid path HC so as to detect the first and second adjustment hydraulic pressures Pb and Pc.

The pressure regulating fluid path HC is branched to the rear wheel regulating fluid path HR at a portion Bh between the fluid pump QC and the first pressure regulating valve UB. The rear wheel pressure adjusting fluid path HR is connected to the rear wheel wheel cylinder CWr via the lower fluid unit YL. Accordingly, the first adjustment hydraulic pressure Pb is directly introduced (supplied) to the rear wheel hole cylinder CWr. Further, the pressure regulating fluid path HC is branched to the front wheel pressure regulating fluid path HF at a portion Bg between the first pressure regulating valve UB and the second pressure regulating valve UC. The front wheel pressure adjusting fluid path HF is connected to the servo chamber Rs. Accordingly, the second adjustment hydraulic pressure Pc is introduced (supplied) into the servo chamber Rs. Since the master cylinder CM is connected to the front wheel cylinder CWf via the lower fluid unit YL, the second adjustment hydraulic pressure Pc is indirectly introduced to the front wheel cylinder CWf via the master cylinder CM. The

As in the first embodiment, the pressure adjusting unit YC has a bypass fluid that connects the reservoir RV and the servo chamber Rs in parallel with the pressure adjusting fluid path HC so as to improve the pressure rising response at the time of sudden braking. Road HD is provided. A check valve GD is interposed in the bypass fluid path HD. In the check valve GD, the flow of the brake fluid BF from the reservoir RV to the servo chamber Rs is allowed, but the flow from the servo chamber Rs to the reservoir RV is blocked.

In the second embodiment, the first adjustment hydraulic pressure Pb and the second adjustment hydraulic pressure Pc are adjusted independently and separately within the range of “Pb ≧ Pc”. As a result, the regenerative cooperative control is executed in consideration of the front-rear distribution of the braking force, so that the deceleration and stability of the vehicle can be ensured and the regenerative energy can be maximized.

For example, when the required braking force Fd corresponding to the operation amount Ba is equal to or less than the regenerative braking force (maximum regenerative force) Fx that can be generated by the generator GN, the friction braking force is controlled to “Pb = Pc = 0”. Fm is not generated. Here, the required braking force Fd is a braking force for the entire vehicle, and is increased according to an increase in the operation amount Ba. When the operation amount Ba is increased and the regenerative braking force Fg exceeds the maximum regenerative force Fx (see block X160 in FIG. 2), the required braking force Fd cannot be achieved with the regenerative braking force Fg. In this case, the friction braking force Fmr of the rear wheel WHr is increased by the first adjustment hydraulic pressure Pb corresponding to the shortage of the regenerative braking force Fg with respect to the required braking force Fd (that is, “Fd−Fx”). At this time, “Pc = 0” remains, only the regenerative braking force is applied to the front wheels WHf, and no friction braking force Fmf is generated. The ratio (front / rear distribution ratio) Hf of the front wheel braking force to the total braking force is gradually decreased from 100% when the friction braking force Fmr of the rear wheel WHr is sequentially increased. When the operation amount Ba is further increased and the distribution ratio Hf reaches a predetermined ratio (constant) hf set in advance, the second adjustment hydraulic pressure Pc starts to increase from “0”. As the second adjustment hydraulic pressure Pc increases, the friction braking force Fmf of the front wheel WHf increases. For this reason, the front-rear distribution ratio Hf is maintained at the desired value hf while the regenerative braking force Fg maintains the maximum value Fx.

As described above, the front wheel hydraulic pressure Pwf and the rear wheel hydraulic pressure Pwr are individually adjusted by the first and second adjustment hydraulic pressures Pb and Pc. Specifically, as the operation amount Ba increases, “only the regenerative braking force Fg of the front wheel WHf by the generator GN” → “(regenerative braking force Fg of the front wheel WHf) + (friction of the rear wheel WHr by the first adjustment hydraulic pressure Pb). Braking force Fmr) ”→“ (regenerative braking force Fg of front wheel WHf) + (friction braking force Fmf of front wheel WHf due to second adjustment hydraulic pressure Pc) + (friction braking force Fmr of rear wheel WHr) ” The occurrence state of is transitioned. As a result, sufficient energy that can be regenerated is ensured, and the front-rear distribution of the braking force is made appropriate, so that the deceleration and stability of the vehicle can be ensured.

In the second embodiment, the same effects as in the first embodiment are obtained. That is, when a sudden operation is determined, the master piston PM is driven by the operating force Fp by the driver in addition to the second adjustment hydraulic pressure Pc by closing the first on-off valve VA. . For this reason, the boost response of the master hydraulic pressure Pm is improved. When the increase in the second adjustment hydraulic pressure Pc is delayed with respect to the increase in the operating force Fp, the brake fluid BF to the servo chamber Rs is supplied from the reservoir RV through the bypass fluid path HD. Since the fluid resistance is low in the movement of the brake fluid BF, the boosting response can be effectively improved. In addition, the simulator SS includes resistance elements such as the elastic body Ds and the orifice Os. However, during an emergency operation, the second on-off valve VB is opened, and the brake fluid BF from the reaction force chamber Ro is supplied to the fluid path. It is moved to the reservoir RV via HS and HT. The influence of the resistance element is avoided, and the boosting response can be improved efficiently.

<Third Embodiment of Braking Control Device SC>
Next, a third embodiment of the braking control device SC will be described. In the second embodiment, in a vehicle including the generator GN on the front wheel WHf, the first adjustment hydraulic pressure Pb is introduced into the rear wheel cylinder CWr, and the second adjustment hydraulic pressure Pc is supplied to the servo chamber Rs. The third embodiment is applied to a vehicle including a generator GN on the rear wheel WHr, the first adjustment hydraulic pressure Pb is supplied to the servo chamber Rs, and the second adjustment hydraulic pressure Pc is supplied to the rear wheel wheel cylinder CWr. . That is, in FIG. 4, the front wheel pressure regulating fluid path HF is connected to the part Bh, and the rear wheel pressure regulating fluid path HR is connected to the part Bg.

The rear wheel hydraulic pressure Pwr and the front wheel hydraulic pressure Pwf are individually adjusted by the first and second adjustment hydraulic pressures Pb and Pc. Specifically, as the operation amount Ba increases, “only the regenerative braking force Fg of the rear wheel WHr by the generator GN” → “(friction braking force Fmf of the front wheel WHf by the first adjustment hydraulic pressure Pb) + (of the rear wheel WHr). Regenerative braking force Fg) "→" (friction braking force Fmf of front wheel WHf due to second adjustment hydraulic pressure Pc) + (regenerative braking force Fg of rear wheel WHr) + (friction braking force Fmr of rear wheel WHr) "in this order. The generation state of the braking force is changed. As a result, sufficient energy that can be regenerated is ensured, and the front-rear distribution of the braking force is made appropriate, so that the deceleration and stability of the vehicle can be ensured. Further, in the response of the master hydraulic pressure Pm, the boost response of the master cylinder hydraulic pressure Pm (resulting in the brake hydraulic pressure Pw) is improved by driving the first and second on-off valves VA and VB.

<Action and effect>
The actions and effects of the braking control device SC according to the present invention will be summarized. The braking control device SC pumps the braking fluid BF to the wheel cylinder CW provided in the wheel WH according to the operation amount Ba of the braking operation member BP. As a result, braking torque is generated in the wheel WH. The braking control device SC includes a simulator SS, a master unit YM, a pressure adjustment unit YC, a regeneration coordination unit YK, a first on-off valve VA, and a controller ECU.

The simulator SS applies an operating force Fp according to the operation of the braking operation member BP to the braking operation member BP. The master unit YM is composed of a master cylinder CM and a master piston PM. The master unit YM includes a “master chamber Rm connected to the wheel cylinder CW” and a “servo chamber for applying a forward force Fa opposite to the reverse force Fb applied to the master piston PM by the master chamber Rm to the master piston PM. Rs "is provided. The pressure adjustment unit YC includes an electric pump DC that sucks the brake fluid BF from the reservoir RV, and electromagnetic valves UA, UB, and UC. In the pressure adjusting unit YC, the brake fluid BF discharged from the electric pump DC is adjusted to the adjusted hydraulic pressures Pa, Pb, Pc by the electromagnetic valves UA, UB, UC, and the adjusted hydraulic pressures Pa, Pb, Pc are adjusted to the servo chamber Rs. To be introduced. The regenerative cooperative unit YK includes an input piston PK that is linked to the braking operation member BP and an input cylinder CN. The regeneration coordination unit YK is provided with an input chamber Rn connected to the simulator SS via the simulator fluid path HS. Inside the input chamber Rn, the gap Ks between the master piston PM and the input piston PK is controlled by adjusting hydraulic pressures Pa, Pb, and Pc. In the input chamber Rn, the clearance Ks between the master piston PM and the input piston PK is controlled by the adjustment hydraulic pressures Pa, Pb, and Pc, thereby achieving regenerative cooperative control.

The first on-off valve VA is provided in the simulator fluid path HS. The first on-off valve VA is a normally closed on / off solenoid valve having a first open position for communicating the input chamber Rn and the simulator SS and a first closed position for blocking the input chamber Rn and the simulator SS. . The controller ECU controls the electric pump DC, the electromagnetic valves UA, UB, UC, and the first on-off valve VA. In the controller ECU, based on the operation amount Ba, “whether or not the operation of the braking operation member BP is a sudden operation” is determined. And when it is denied that it is sudden operation (namely, normal operation state), the 1st on-off valve VA is driven to the 1st open position. On the other hand, when it is affirmed that the operation is sudden (that is, in the sudden operation state), the first on-off valve VA is driven to the first closed position. For example, the controller ECU calculates an operation speed dB (for example, a differential value dS of the operation displacement Sp) based on the operation amount Ba (in particular, the operation displacement Sp of the braking operation member BP), and the operation speed dB is less than the predetermined speed dx. If it is, it is denied that the operation is sudden, and if the operation speed dB is equal to or higher than the predetermined speed dx, it is affirmed that the operation is sudden. Note that a condition for the operation amount Ba can be added so as to improve the accuracy of determination. That is, when “dB <dx or Ba <bx”, the normal operation state is determined, and when “dB ≧ dx and Ba ≧ bx”, the sudden operation state is determined. The predetermined speed dx and the predetermined amount bx are preset constants.

Since the electric pump DC is an on-demand type, the electric pump DC is not operated during non-braking (it is in a stopped state). In the sudden operation state, the input chamber Rn is brought into a fluid locked state by closing the first on-off valve VA. Thereby, the operating force Fp of the braking operation member BP operated by the driver is transmitted to the master piston PM via the input chamber Rn. The master piston PM is pressed in the forward direction Ha by the adjustment hydraulic pressures Pa, Pb, Pc and the driver's operation force Fp. For this reason, the response is improved as the master cylinder hydraulic pressure Pm (that is, the braking hydraulic pressure Pw) increases. In the normal operation state, the first on-off valve VA is closed, the input chamber Rn is in communication with the simulator SS and the reaction force chamber Ro, and the master piston PM is adjusted liquid in the servo chamber Rs. It is driven only by the pressures Pa, Pb, Pc.

The brake control device SC may be provided with a bypass fluid path HD and a check valve GD. The bypass fluid path HD is a fluid path that connects the reservoir RV and the servo chamber Rs. The check valve GD is provided in the bypass fluid path HD and allows the brake fluid BF to move from the reservoir RV to the servo chamber Rs, but prevents the brake fluid BF from moving from the servo chamber Rs to the reservoir RV.

When the braking operation member BP is suddenly operated, a situation may occur in which the adjustment fluid pressures Pa, Pb, and Pc are insufficiently increased with respect to the increase in the operation force Fp. A bypass fluid path HD is provided in parallel to the pressure regulating fluid path HC including the pressure regulating valves UA, UB, UC, and the reservoir RV and the servo chamber Rs are connected. Further, a check valve GD is provided in the bypass fluid path HD, and movement of “RV → Rs” is allowed in movement of the brake fluid BF, but movement of “Rs → RV” is prohibited. As a result, even when the rising of the adjustment fluid pressures Pa, Pb, and Pc is delayed, the brake fluid BF can flow into the servo chamber Rs via the bypass fluid passage HD, so that the master cylinder fluid pressure Pm increases. Pressure responsiveness can be ensured.

The braking controller SC (in particular, the master unit YM) is provided with a reaction force chamber Ro in which the volume Vo decreases when the volume Vs of the servo chamber Rs increases. The reaction force chamber Ro is connected to the simulator SS and the input chamber Rn via the simulator fluid path HS. The reservoir fluid path HT is connected between the first on-off valve VA and the reaction force chamber Ro of the simulator fluid path HS, and finally connected to the reservoir RV. The reservoir fluid path HT is provided with a second on-off valve VB. The second on-off valve VB is a normally open electromagnetic valve having a second open position that allows the reaction force chamber Ro and the reservoir RV to communicate with each other and a second closed position that blocks the reaction force chamber Ro and the reservoir RV. The second on-off valve VB is driven by the controller ECU to the second closed position when the sudden operation is denied, and to the second open position when the sudden operation is affirmed.

In the simulator SS, an elastic body Ds is provided so as to generate an operating force Fp. Further, in the simulator SS, an orifice Os is provided in the inflow hole of the brake fluid BF so as to maintain the operating characteristics favorably by the damping effect. When the master piston PM is moved in the forward direction Ha, the brake fluid BF is discharged from the reaction force chamber Ro. When the brake fluid BF flows into the simulator SS, fluid resistance due to the elastic body Ds and the orifice Os can occur. However, in the sudden operation state, the second on-off valve VB is set to the open position, and the braking fluid BF is returned from the reaction force chamber Ro to the reservoir RV through the fluid paths HS and HT. For this reason, when the master piston PM moves forward, the braking fluid BF in the reaction force chamber Ro is discharged without resistance, so that the responsiveness of the master fluid pressure Pm can be effectively achieved.

<Other embodiments>
Hereinafter, other embodiments will be described. In other embodiments, the same effects as described above are obtained.
In the above-described embodiment, the linear pressure regulating valves UA, UB, and UC are used in which the valve opening amount is adjusted according to the energization amount. For example, although the pressure regulating valves UA, UB, and UC are on / off valves, the opening and closing of the valves may be controlled by a duty ratio, and the hydraulic pressure may be linearly controlled.

In the above embodiment, the configuration of the disc type braking device (disc brake) is exemplified. In this case, the friction member is a brake pad, and the rotating member is a brake disk. Instead of the disc type braking device, a drum type braking device (drum brake) may be employed. In the case of a drum brake, a brake drum is employed instead of the caliper. The friction member is a brake shoe, and the rotating member is a brake drum.

In the above-described embodiment, the pressure regulating fluid path HC is connected to the first reservoir fluid path HV at the site Bv to form a reflux path. The pressure regulation fluid path HC is connected to the reservoir RV (particularly, the pressure regulation reservoir chamber Rd), and the reflux path may be formed including the reservoir RV (see the fluid path shown by the two-dot chain line in FIGS. 1 and 4). ). With this configuration, gas suction by the fluid pump QC can be suppressed.

In the above embodiment, the master cylinder CM is a single type having one master chamber Rm, and one of the front wheel cylinder CWf and the rear wheel cylinder CWr is connected to the master cylinder CM. The other of the front wheel cylinder CWf and the rear wheel cylinder CWr was connected to the pressure regulating fluid path HC. Instead, a tandem type is adopted as the master cylinder CM, one of the two hydraulic chambers of the master cylinder CM is connected to the front wheel cylinder CWf, and the other of the two hydraulic chambers of the master cylinder CM is the rear. It can be connected to a wheel wheel cylinder CWr. Further, in the configuration according to the first embodiment (in which the hydraulic pressure Pa is adjusted by one pressure regulating valve UA) in which the tandem type master cylinder CM is employed, instead of the front and rear fluid paths, a diagonal type ( A fluid path (also referred to as “X-type”) may be used. In addition, since the dimension of the longitudinal direction of the braking control device SC is shortened when the single master cylinder CM is adopted, it is preferable in terms of mountability on the vehicle.

In the above embodiment, the first on-off valve VA and the second on-off valve VB are energized while the start switch is on. Alternatively, after it is determined that “the brake is being performed”, the first on-off valve VA may be set to the open position and the second on-off valve VB may be set to the closed position. As described above, the determination during braking is performed based on at least one of the braking operation amount Ba and the operation signal St (see step S140 in FIG. 2).

Claims (4)

1. A vehicle braking control device that pumps braking fluid to a wheel cylinder of a wheel of the vehicle according to an operation amount of a braking operation member of the vehicle and generates a braking torque on the wheel,
   A simulator for applying an operation force corresponding to the operation amount to the braking operation member;
   It consists of a master cylinder and a master piston,
   A master chamber connected to the wheel cylinder; and a master unit having a servo chamber that applies a forward force to the master piston that opposes a reverse force applied to the master piston by the master chamber;
   An electric pump for sucking the brake fluid from a reservoir of the vehicle, and a solenoid valve;
   A pressure adjusting unit that adjusts the brake fluid discharged from the electric pump to an adjusted hydraulic pressure by the electromagnetic valve, and introduces the adjusted hydraulic pressure into the servo chamber;
   An input piston interlocked with the braking operation member, and an input cylinder,
   Having an input chamber connected to the simulator via a simulator fluid path;
   Inside the input chamber, a regenerative coordination unit in which a gap between the master piston and the input piston is controlled by the adjustment hydraulic pressure,
   A first on-off valve provided in the simulator fluid path, having a first open position for communicating the input chamber and the simulator, and a first closed position for blocking the input chamber and the simulator;
   A controller for controlling the electric pump, the electromagnetic valve, and the first on-off valve;
   The controller is
   Based on the operation amount, it is determined whether or not the operation of the braking operation member is a sudden operation,
   In the case of denying the sudden operation, the first on-off valve is driven to the first open position,
   A vehicle braking control device configured to drive the first on-off valve to the first closed position when it is affirmative that the operation is sudden.
2. The vehicle braking control device according to claim 1,
   The controller is
   Calculate the operation speed based on the operation amount,
   If the operation speed is less than a predetermined speed, deny the sudden operation,
   A vehicle braking control device configured to affirm that the sudden operation is performed when the operation speed is equal to or higher than the predetermined speed.
3. A braking control device for a vehicle according to claim 1 or 2,
   A bypass fluid path connecting the reservoir and the servo chamber;
   A check valve provided in the bypass fluid path and allowing movement of the brake fluid from the reservoir to the servo chamber, but preventing movement of the brake fluid from the servo chamber to the reservoir; Vehicle braking control device.
4. A vehicle braking control device according to any one of claims 1 to 3,
   A reaction force chamber connected to the simulator via the simulator fluid path and having a volume that decreases when the volume of the servo chamber increases;
   A reservoir fluid path connecting the simulator fluid path and the reservoir between the first on-off valve and the reaction force chamber;
   A second open / close valve provided in the reservoir fluid path and having a second open position for communicating the reaction force chamber and the reservoir, and a second closed position for blocking the reaction force chamber and the reservoir; Prepared,
   The controller is
   In the case of denying the sudden operation, the second on-off valve is driven to the second closed position,
   A braking control device for a vehicle configured to drive the second on-off valve to the second open position when affirmative that the operation is sudden.
   
   

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