JP2021011215A - Vehicular brake control device - Google Patents

Abstract

To avoid an inconvenient situation occurring when a normally-closed type solenoid valve is in valve-closing failure, in a brake control device equipped with the normally-closed type solenoid valve for manual braking.SOLUTION: A brake control device includes: first and second connection paths that connect first and second liquid pressure chambers of a master cylinder and first and second wheel cylinders; normally-opened type first and second separation valves that are provided in the first and second connection paths; first and second fluid pumps that are driven by an electric motor; first and second reflux paths that connect first and second discharge portions and first and second suction portions of the first and second fluid pump; normally-opened type first and second pressure regulating valves that are provided in the first and second reflux paths and adjust a braking liquid discharged by the first and second fluid pumps to first and second adjusted liquid pressures; first and second communication paths that connect the first and second connection paths with the first and second reflux paths; normally-closed type first and second communication valves that are provided in the first and second communication paths; and a controller that drives the electric motor, the first and second pressure regulating valves, the first and second separation valves, and the first and second communication valves.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a vehicle braking control device.

In Patent Document 1, for the purpose of "providing a highly practical vehicle braking system", "a hydraulic brake device 32 is provided on one of the front wheels and the rear wheels, and an electric brake is provided on the other of the front wheels and the rear wheels." A pump 60 for pressurizing and supplying the hydraulic fluid to the wheel cylinder of the wheel brake 46 and a control holding valve for holding the hydraulic fluid pressure in a controllable manner by providing a device and supplying the actuator unit 44 of the hydraulic braking device to the wheel cylinder. A practical vehicle braking system that takes advantage of the advantages of each of the hydraulic braking device and the electric braking device is realized. The hydraulic braking device is applied to one of the front wheels and the rear wheels. Since the hydraulic braking force can be controlled only by the holding control valve, the vehicle braking system including the hydraulic braking device becomes a compact system. "

In Patent Document 1, regarding the actuator unit 44, "In the master liquid passage 50, there are two normally open type master cut valves 56, two pumps 60 corresponding to two systems, and a motor 62 for driving those pumps 60. A control holding valve 64, which is two electromagnetic linear valves corresponding to two systems, and two normally closed type shutoff valves 66 arranged in series with the control holding valve 64 are included. During normal operation, the master cut valve 56 and the shutoff valve 66 are in the closed state and the valve open state, respectively. The pump 60 is driven by the motor 62, and the pressure is adjusted by the control of the control holding valve 64. The liquid is supplied to the wheel brake 46. In the case of electrical failure, the master cut valve 56 and the shutoff valve 66 are set to the valve open state and the valve closed state, respectively, and the actuator is operated from the master cylinder 42. The hydraulic fluid supplied to the unit 44 will be supplied to the wheel brake 46. "

In Patent Document 1, the actuator unit (also referred to as "fluid unit") increases the pressure (braking fluid pressure) of the wheel cylinders provided on one of the front wheels and the rear wheels, and the fluid unit is the front and rear wheels. It is also possible to adjust the braking fluid pressure. However, in the device described in Patent Document 1, the working fluid (also referred to as “braking fluid”) discharged by the fluid pump 60 circulates in the return path 72, and the shutoff valve 66 and the control hold in the return path 72. The valves 64 are arranged in series. In the normally closed type shutoff valve 66, when the power supply to the actuator unit 44 is completely cut off, the braking fluid from the master cylinder is supplied to the wheel cylinder without being returned to the reservoir 48, and the driver's It is provided for manual braking only by operating force.

For example, assume that one of the two shutoff valves 66 fails in the closed state. In this situation, when the master cut valve 56 is closed, the braking fluid may be excessively supplied to the wheel cylinder, and the hydraulic pressure (braking fluid pressure) in the wheel cylinder may be unnecessarily increased. Further, when the master cut valve 56 is in the open state, the braking fluid is supplied not only to the wheel cylinder but also to the master cylinder. As a result, the operating force of the brake pedal 40 is increased, and the driver may feel uncomfortable.

JP-A-2018-052225

An object of the present invention is a case where a solenoid valve fails to close in a vehicle braking control device provided with a normally closed solenoid valve so that manual braking is possible even if the power supply is completely cut off. It is also to provide something that can avoid inconvenient situations.

The vehicle braking control device according to the present invention is a brake-by-wire type that generates an operating force (Fp) on a braking operation member (BP) by a stroke simulator (SS), and is the first of the "tandem type master cylinder (CM)". , The first and second connection paths (HS1, HS2) connecting the second hydraulic chamber (Rm1, Rm2) and the first and second wheel cylinders (CW1, CW2), and "the first and second The normally open type first and second separation valves (VM1, VM2) provided in the connection path (HS1, HS2) and the first and second fluid pumps (HP1, HP2) driven by an electric motor (MT). ) ”And“ The first and second discharge portions (Bt1, Bt2) of the first and second fluid pumps (HP1, HP2) and the first and first of the first and second fluid pumps (HP1, HP2). 2 The first and second return passages (HK1, HK2) connecting the suction units (Bs1, Bs2) and the first and second return passages (HK1, HK2) provided in the first and second return passages (HK1, HK2). Two normally open type first and second pressure regulating valves (UA1, UA2) that adjust the pressure of the braking fluid (BF) discharged by the two fluid pumps (HP1, HP2) to the first and second adjusting hydraulic pressures (Pp1, Pp2). ) ”And“ the first and second connecting paths (HR1, HR2) connecting the first and second connecting paths (HS1, HS2) and the first and second return paths (HK1, HK2) ”. , "The normally closed first and second connecting valves (VR1, VR2) provided in the first and second connecting paths (HR1, HR2)" and "The electric motor (MT), the first and first The two pressure control valves (UA1, UA2), the first and second separation valves (VM1, VM2), and the controller (ECU) for driving the first and second communication valves (VR1, VR2) are provided. ..

In the brake-by-wire type braking control device, a normally closed solenoid valve is provided in each braking system so that the braking fluid from the master cylinder is not returned to the reservoir during manual braking. When these solenoid valves are closed, the wheel cylinder hydraulic pressure (braking fluid pressure) is increased only by the operating force of the driver. According to the above configuration, when one of the two normally closed solenoid valves (communication valves VR1 and VR2) fails to close, the brake fluid BF recirculates in the return path including the solenoid valve that fails to close. Since it is not hindered, an unnecessary increase in braking fluid pressure or an increase in operating force as described above can be avoided. In addition, appropriate hydraulic servo control can be performed in the reflux path, including the valve closing valve that has not failed.

In the vehicle braking control device according to the present invention, the electric motor (MT) has first and second motor coils (CL1, CL2). Then, the controller (ECU) drives the first motor coil (CL1), the first pressure regulating valve (UA1), the first separation valve (VM1), and the first communication valve (VR1). Drives the first control unit (EC1), the second motor coil (CL2), the second pressure regulating valve (UA2), the second separation valve (VM2), and the second communication valve (VR2). The second control unit (EC2) "is included.

According to the above configuration, since the electric system of the braking control device is made redundant (duplicated), even if a part of the controller ECU, the electric motor MT, etc. malfunctions, all the wheel WHs are immediately set to manual braking. Cannot be switched. As a result, sufficient vehicle deceleration can be ensured when the braking control device SC is partially out of order.

It is an overall block diagram for demonstrating the embodiment of the brake control device SC of a vehicle. It is the schematic for demonstrating the configuration example of the controller ECU and the electric motor MT. It is a matrix diagram for demonstrating the operation of a controller ECU.

<Symbols of components, subscripts at the end of symbols>
In the following description, components, elements, signals, etc. with the same symbol, such as "CW", have the same function. The subscripts "1" and "2" added to the end of the symbols relating to the two braking systems are comprehensive symbols indicating which system they are related to, and "1" is one braking system ("1"). (Also referred to as "first braking system BK1"), "2" indicates the other braking system (also referred to as "second braking system BK2"). For example, in the two pressure chambers (also referred to as "hydraulic chambers") of the tandem type master cylinder CM, the one connected to the first braking system BK1 is the first hydraulic chamber Rm1 and is connected to the second braking system BK2. What is done is the second hydraulic chamber Rm2. The subscripts "1" and "2" may be omitted. When the subscripts "1" and "2" are omitted, the symbols represent generic names. For example, "Rm" represents a hydraulic chamber.

In the connection path HS described later, the side closer to the master cylinder CM (or the side far from the wheel cylinder CW) is referred to as "upper part", and the side closer to the wheel cylinder CW is referred to as "lower part". Further, in the return path HK where the braking fluid BF circulates, the side of the fluid pump HP near the discharge portion Bt is called the "upstream side (upstream portion)", and the side far from the discharge portion Bt (remote side) is the "downstream side". (Downstream) ".

<Embodiment of vehicle braking control device>
An embodiment of the braking control device SC according to the present invention will be described with reference to the overall configuration diagram of FIG. In the embodiment, of the two fluid paths (braking systems), the first braking system BK1 is connected to the wheel cylinder CW1 of the first wheel WH1, and the second braking system BK2 is the wheel cylinder of the second wheel WH2. Connected to CW2. For example, as the two fluid paths, a so-called front-rear type (also referred to as "type II") is adopted. In this case, the first braking system BK1 is a braking system related to the front wheels, and the first hydraulic chamber Rm1 is connected to the two front wheel cylinders. Further, the second braking system BK2 is a braking system related to the rear wheels, and the second hydraulic chamber Rm2 is connected to the two rear wheel wheel cylinders. Here, the "fluid path" is a path for moving the braking liquid BF, which is a working liquid, and corresponds to a braking pipe, a flow path of a fluid unit, a hose, and the like.

The vehicle equipped with the braking control device SC is provided with a braking operation member BP, a rotating member KT, a wheel cylinder CW, a master reservoir RV, a master cylinder CM, a braking operation amount sensor BA, and a wheel speed sensor VW.

The braking operation member (for example, the brake pedal) BP is a member operated by the driver to decelerate the vehicle. By operating the braking operation member BP, the braking torque Tq 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 wheel WH of the vehicle. Then, the brake caliper is arranged so as to sandwich the rotating member KT.

The brake caliper is provided with a wheel cylinder CW. By increasing the pressure (braking fluid pressure) Pw of the braking fluid BF in the wheel cylinder CW, the friction member (for example, the 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 Tq is generated in the wheel WH by the frictional force generated at this time. Then, a braking force (friction braking force) is generated on the wheel WH by the braking torque Tq.

The master reservoir (also referred to as "atmospheric pressure reservoir") RV is a tank for the working liquid, and the braking liquid BF is stored in the tank. The master cylinder CM is mechanically connected to the braking operation member BP via a brake rod RD or the like. As the master cylinder CM, a tandem type is adopted. Inside the master cylinder CM, two hydraulic chambers Rm1 and Rm2 are formed by the primary piston PG and the secondary piston PH. When the braking operation member BP is not operated, the first and second hydraulic chambers Rm1 and Rm2 (also referred to as “master cylinder chamber”) of the master cylinder CM and the master reservoir RV are in a communicating state.

When the braking operation member BP is operated, the primary, secondary pistons PG, and PH in the master cylinder CM are pushed in the forward direction Ha, and the master cylinder chamber (hydraulic chamber) Rm (= Rm1, Rm2) becomes the master reservoir. It is cut off from RV. Further, when the operation of the braking operation member BP is increased, the pistons PG and PH are moved in the forward direction Ha, the volume of the hydraulic chamber Rm is reduced, and the braking fluid (working fluid) BF is discharged from the master cylinder CM. Will be done. When the operation of the braking operation member BP is reduced, the pistons PG and PH are moved in the backward direction Hb, the volume of the hydraulic chamber Rm is increased, and the braking liquid BF is returned toward the master cylinder CM.

The first hydraulic chamber Rm1 and the first wheel cylinder CW1 of the tandem type master cylinder CM are connected by a first connecting fluid passage HS1 (simply also referred to as a "first connecting passage"). Further, the second hydraulic chamber Rm2 and the second wheel cylinder CW2 are connected by a second connecting fluid passage HS2 (simply also referred to as a "second connecting passage"). One end of the first and second connection paths HS1 and HS2 is connected to the master cylinder CM (particularly, the hydraulic chambers Rm1 and Rm2). The first and second connection paths HS1 and HS2 are branched into two at the branch portions Bb1 and Bb2, and are connected to the first and second wheel cylinders CW1 and CW2.

The braking operation amount sensor BA detects the operation amount Ba of the braking operation member (brake pedal) BP by the driver. Specifically, as the braking operation amount sensor BA, the master cylinder hydraulic pressure sensor PM (= PM1, PM2) that detects the hydraulic pressure (master cylinder hydraulic pressure) Pm (= Pm1, Pm2) in the hydraulic pressure chamber Rm, braking. At least one of the operation displacement sensor SP that detects the operation displacement Sp of the operation member BP and the operation force sensor FP that detects the operation force Fp of the braking operation member BP is adopted. That is, the operation amount sensor BA is a general term for the master cylinder hydraulic pressure sensor PM, the operation displacement sensor SP, and the operation force sensor FP, and the operation amount Ba is the master cylinder hydraulic pressure Pm, the operation displacement Sp, and the operation force. It is a general term for Fp.

The wheel speed sensor VW detects the wheel speed Vw, which is the rotation speed of each wheel WH. The signal of the wheel speed Vw is adopted for anti-lock brake control or the like that suppresses the locking tendency of the wheel WH. Each wheel speed Vw detected by the wheel speed sensor VW is input to the controller ECU. In the controller ECU, the vehicle body speed Vx is calculated based on the wheel speed Vw.

≪Brake control device SC≫
The braking control device SC is composed of a stroke simulator SS, a simulator valve VS, a fluid unit HU, and a controller ECU.

A stroke simulator (simply also referred to as “simulator”) SS is provided to generate an operating force Fp on the braking operating member BP. In other words, the operating characteristics of the braking operation member BP (relationship of the operating force Fp with respect to the operating displacement Sp) are formed by the simulator SS. The simulator SS is connected to the master cylinder CM (for example, the second hydraulic chamber Rm2). A simulator piston and an elastic body (for example, a compression spring) are provided inside the simulator SS. When the brake fluid BF is moved from the second hydraulic chamber Rm2 into the simulator SS, the simulator piston is pushed by the inflowing brake fluid BF. Since a force is applied to the simulator piston in a direction of blocking the inflow of the braking liquid BF by the elastic body, when the braking operating member BP is operated, an operating force Fp corresponding to the operating displacement Sp is generated.

A simulator valve VS is provided between the second hydraulic chamber Rm2 and the simulator SS. The simulator valve VS is a normally closed solenoid valve (on / off valve) having an open position and a closed position. In the "on / off valve", the open position and the closed position are selectively realized. When the braking control device SC is activated, the simulator valve VS is opened, and the master cylinder CM and the simulator SS are in a communicating state. If the capacity of the second hydraulic chamber Rm2 is sufficiently larger than the capacity of the second wheel cylinder CW2, the simulator valve VS may be omitted. Further, the simulator SS may be connected to the first hydraulic pressure chamber Rm1. In this case, the simulator valve VS is provided in the first braking system BK1.

The fluid unit HU includes first and second master cylinder valves VM1, VM2, first and second master cylinder hydraulic pressure sensors PM1, PM2, first and second fluid pumps HP1, HP2, electric motor MT, first and first. 2 Low-voltage reservoirs RW1, RW2, 1st, 2nd pressure regulating valves UA1, UA2, 1st and 2nd communication valves VR1, VR2, 1st and 2nd adjusting fluid pressure sensors PP1, PP2, 1st and 2nd inlet valves VI1 , VI2, and the first and second outlet valves VO1 and VO2 are included.

A first master cylinder valve VM1 (also referred to as a “separation valve”) is provided in the first connection path HS1. The second master cylinder valve (separation valve) VM2 is provided in the second connection path HS2 at the lower part of the portion Bf where the simulator SS is connected to the second connection path HS2. The first and second separation valves VM1 and VM2 are normally open solenoid valves (on / off valves) having an open position and a closed position. When the braking control device SC is started, the first and second separation valves VM1 and VM2 are closed, and the master cylinder CM and the first and second (front wheels, rear wheels) wheel cylinders CW1 and CW2 are disconnected (non-communication). State). That is, the connection between the master cylinder CM and the first and second wheel cylinders CW1 and CW2 is separated by the closed positions of the first and second separation valves VM1 and VM2.

The first and second master cylinders are located above the first and second separation valves VM1 and VM2 so as to detect the hydraulic pressures (master cylinder hydraulic pressures) Pm1 and Pm2 of the first and second hydraulic chambers Rm1 and Rm2. Hydraulic pressure sensors PM1 and PM2 are provided. The master cylinder hydraulic pressure sensor PM (= PM1, PM2) corresponds to the manipulated variable sensor BA, and the master cylinder hydraulic pressure Pm corresponds to the manipulated variable Ba. Since the first and second master cylinder hydraulic pressures Pm1 and Pm2 are substantially the same, any one of the first and second master cylinder hydraulic pressure sensors PM1 and PM2 may be omitted. it can.

In the first braking system BK1, the first fluid pump HP1 is provided in the first reflux fluid path HK1 (also referred to as “first reflux path”). The first return passage HK1 is a fluid passage provided in parallel with the first connection passage HS1 and connects the suction portion Bs1 and the discharge portion Bt1 of the first fluid pump HP1. The first fluid pump HP1 is driven by an electric motor MT. The electric motor MT and the first fluid pump HP1 are fixed so that the first fluid pump HP1 and the electric motor MT rotate integrally. When the electric motor MT is rotationally driven, the reflux KN1 of the braking fluid BF (flow of “Bt1 → Bv1 → Bw1 → Bx1 → Bs1 → Bt1”) is generated in the first reflux path HK1 as shown by the broken line arrow. Here, "reflux" means that the braking fluid BF circulates and returns to the original flow again. The first return path HK1 is provided with a check valve (also referred to as a “check valve”) so that the braking fluid BF does not flow back.

The first pressure regulating valve UA1 is provided in the first reflux path HK1. The first pressure regulating valve UA1 is a linear solenoid valve (also referred to as a "proportional valve" or a "differential pressure valve") in which the valve opening amount (lift amount) is continuously controlled. A normally open solenoid valve is adopted as the first pressure regulating valve UA1. The first reflux KN1 is throttled by the first pressure regulating valve UA1, and the hydraulic pressure on the upstream side of the first pressure regulating valve UA1 (at the hydraulic pressure between the discharge portion Bt1 of the first fluid pump HP1 and the first pressure regulating valve UA1). Yes, Pp1 (referred to as "first adjusting fluid pressure") is adjusted. In other words, the pressure of the braking fluid BF discharged by the first fluid pump HP1 is adjusted to the first adjusting hydraulic pressure Pp1 by the first pressure regulating valve UA1.

The first return path HK1 is connected to the first connection path HS1 via the first connecting path HR1. In other words, the first connecting path HR1 is the lower Bu1 of the separation valve VM1 of the first connecting path HS1 (the portion between the first separation valve VM1 and the first wheel cylinder CW1) and the first recirculation path HK1. 1 It is a fluid path connecting the upstream side of the pressure regulating valve UA1 (the portion Bv1 between the first discharge portion Bt1 and the first pressure regulating valve UA1). The first communication valve VR1 is provided in the first communication path HR1. The first communication valve VR1 is a normally closed solenoid valve (on / off valve) having an open position and a closed position. When the braking control device SC is activated, the first communication valve VR1 is opened, and the first connection path HS1 and the first return path HK1 are in a communicating state. That is, the braking fluid BF adjusted to the first adjusting hydraulic pressure Pp1 is supplied to the first wheel cylinder CW1 by the opening position of the first contact valve VR1.

Similar to the configuration according to the first braking system BK1, in the second braking system BK2, the second fluid pump HP2 is provided in the second recirculation fluid path HK2 (also referred to as “second recirculation path”). The second return passage HK2 is a fluid passage that connects the suction portion Bs2 and the discharge portion Bt2 of the second fluid pump HP2. The second fluid pump HP2 is driven by the electric motor MT. When the electric motor MT is rotationally driven, the reflux KN2 of the braking fluid BF (flow of "Bt2 → Bv2 → Bw2 → Bx2 → Bs2 → Bt2") is generated in the second reflux path HK2 as shown by the broken line arrow. A check valve is provided in the second return passage HK2 so that the braking fluid BF does not flow back.

A second pressure regulating valve UA2 is provided in the second reflux path HK2. The second pressure regulating valve UA2 is a linear solenoid valve whose valve opening amount (lift amount) is continuously controlled. A normally open solenoid valve is adopted as the second pressure regulating valve UA2. The second reflux KN2 is throttled by the second pressure regulating valve UA2, and the hydraulic pressure on the upstream side of the second pressure regulating valve UA2 (at the hydraulic pressure between the discharge portion Bt2 of the second fluid pump HP2 and the second pressure regulating valve UA2). Yes, Pp2 (referred to as "second adjusting fluid pressure") is adjusted. In other words, the pressure of the braking fluid BF discharged by the second fluid pump HP2 is adjusted to the second adjusting hydraulic pressure Pp2 by the second pressure regulating valve UA2.

The second return path HK2 is connected to the second connecting path HS2 via the second connecting path HR2. In other words, the second connecting path HR2 is the lower Bu2 of the separation valve VM2 of the second connecting path HS2 (the portion between the second separation valve VM2 and the second wheel cylinder CW2) and the second return path HK2. 2 It is a fluid path connecting the upstream side of the pressure regulating valve UA2 (at the portion Bv2, between the second discharge portion Bt2 and the second pressure regulating valve UA2). A second communication valve VR2 is provided on the second communication path HR2. The second communication valve VR2 is a normally closed solenoid valve (on / off valve) having an open position and a closed position. When the braking control device SC is activated, the second communication valve VR2 is opened, and the second connection path HS2 and the second return path HK2 are in a communicating state. That is, the braking fluid BF adjusted to the second adjusting hydraulic pressure Pp2 is supplied to the second wheel cylinder CW2 by the opening position of the second connecting valve VR2.

In order to supply the braking fluid BF to the first and second fluid pumps HP1 and HP2, the first and second low-pressure reservoirs RW1 and RW2 are provided in the first and second reflux paths HK1 and HK2 at the sites Bx1 and Bx2. Be connected. A reservoir piston is provided inside the cylinder of the low-pressure reservoir RW (= RW1, RW2). The inside of the cylinder is divided by the reservoir piston into first and second liquid chambers Rw1 and Rw2 (also referred to as "first and second reservoir chambers") filled with the braking liquid BF and a gas chamber filled with gas. ing. Inside the liquid chambers Rw1 and Rw2, compression springs are housed so as to press the reservoir piston toward the gas chamber.

At the start of driving the fluid pump HP (= HP1, HP2), the braking liquid BF is sucked from the low pressure reservoir RW (particularly, the liquid chamber Rw). That is, when the brake fluid BF is supplied from the low pressure reservoir RW (= RW1, RW2), the reflux KN1 and KN2 of the brake fluid BF are formed in the reflux paths HK1 and HK2. The first and second low-pressure reservoirs RW1 and RW2 are arranged in the vicinity of the suction portions Bs1 and Bs2 of the fluid pumps HP1 and HP2. Therefore, in the fluid pump HP, the suction performance of the braking fluid BF is improved.

In order to reduce the volume and size of the low pressure reservoir RW, the first and second reflux paths HK1 and HK2 are connected to the master reservoir RV via the first and second reservoir paths HV1 and HV2 (indicated by the broken line). May be connected. In this case, at the initial stage of driving the fluid pump HP (that is, when the rotation speed of the electric motor MT increases from "0" and at the start of braking), the braking fluid BF first receives the low-pressure reservoir RW (particularly). , Reservoir Rw). Since the fluid resistance and the like are small in boosting the braking fluid BF, its responsiveness is improved. Then, when the supply of the braking fluid BF from the low-pressure reservoir RW is restricted, the braking fluid BF is supplied from the master reservoir RV. In the fluid pump HP, if the suction of the braking fluid BF is sufficiently from the master reservoir RV, the low pressure reservoir RW may be omitted.

When the operation of the braking operation member BP is started, the electric motor MT is driven. At this time, the solenoid valves VS, VR1 and VR2 are opened, and the solenoid valves VM1 and VM2 are closed. When the rotation of the electric motor MT is started, the first and second fluid pumps HP1 and HP2 discharge the brake fluid BF, and the first and second reflux KN1 and KN2 which are the circulating flows of the brake fluid BF are generated. When the first and second pressure regulating valves UA1 and UA2 are energized, the opening amounts of the normally open type first and second pressure regulating valves UA1 and UA2 are reduced, and the flow of the braking fluid BF is throttled. Due to the orifice effect at this time, the first and second adjusting hydraulic pressures Pp1 and Pp2 are independently adjusted so as to increase from "0". The first and second connecting paths HS1 and HS2 are provided with first and second adjusting hydraulic pressure sensors PP1 and PP2 so as to detect the first and second adjusting hydraulic pressures Pp1 and Pp2.

In the first and second connection paths HS1 and HS2, the configurations from the branch portions Bb1 and Bb2 to the lower part (the side closer to the wheel cylinder CW) are the same. An inlet valve VI (= VI1, VI2) is provided in the connection path HS (= HS1, HS2). As the inlet valve VI, a normally open type on / off solenoid valve is adopted.

The lower parts Bg1 and Bg2 of the inlet valve VI (that is, between the inlet valve VI and the wheel cylinder CW) are connected to the first and second pressure reducing paths HG1 and HG2. The decompression passages HG1 and HG2 are connected to the low pressure reservoirs RW1 and RW2 (or the master reservoir RV). An outlet valve VO (= VO1, VO2) is provided in the decompression passage HG (= HG1, HG2). As the outlet valve VO, a normally closed on / off solenoid valve is adopted.

In order to reduce the hydraulic pressure (braking fluid pressure) Pw in the wheel cylinder CW by anti-lock braking control or the like, the inlet valve VI is closed and the outlet valve VO is opened. The inflow of the braking fluid BF from the inlet valve VI is blocked, the braking fluid BF in the wheel cylinder CW flows out to the low pressure reservoir RW (or the master reservoir RV), and the braking fluid pressure Pw is reduced. Further, in order to increase the braking fluid pressure Pw, the inlet valve VI is opened and the outlet valve VO is closed. The outflow of the braking fluid BF to the low pressure reservoir RW (or master reservoir RV) is prevented, the adjusting hydraulic pressure Pp is introduced into the wheel cylinder CW, and the braking hydraulic pressure Pw is increased. Further, in order to maintain the hydraulic pressure (braking fluid pressure) Pw in the wheel cylinder CW, both the inlet valve VI and the outlet valve VO are closed. That is, by controlling the solenoid valves VI and VO, the braking fluid pressure Pw (that is, braking torque Tq) can be independently adjusted by the wheel cylinder CW of each wheel WH.

An electric motor MT and solenoid valves UA, VM, VR, VS, VI, and VO are controlled by a controller (also referred to as an "electronic control unit") ECU. The controller ECU includes an electric circuit board on which a microprocessor MP or the like is mounted, and a control algorithm programmed in the microprocessor MP. The controller ECU is network-connected to a controller (electronic control unit) of another system such as a driving support controller via an in-vehicle communication bus BS.

The controller ECU controls the electric motor MT and the solenoid valve (VM, etc.) based on various signals (Ba, Pp, Vw, etc.). Specifically, the motor drive signal Mt for controlling the electric motor MT is calculated based on the control algorithm in the microprocessor MP. Similarly, the solenoid valve drive signals Ua, Vm, Vr, Vs, Vi, and Vo for controlling the solenoid valves UA, VM, VR, VS, VI, and VO are calculated. Then, the electric motor and a plurality of solenoid valves are driven based on these drive signals (Vm, Mt, etc.).

In the braking control device SC, when the operation of the device is proper, the operating characteristics of the braking operating member BP are formed by the simulator SS. For example, when the front and rear brake systems are adopted as the two braking systems, the hydraulic pressures of the first (front wheel) and second (rear wheel) braking systems BK1 and BK2 (that is, front wheels, rear wheel cylinders CW1 and CW2). (Brake fluid pressures Pw1 and Pw2) are independently (individually) adjusted by the first and second adjustment hydraulic pressures Pp1 and Pp2 (hereinafter, referred to as "independent control").

Regenerative cooperative control is performed in an electric vehicle (electric vehicle, hybrid vehicle, etc.) equipped with an electric motor for traveling (also a "generator for energy regeneration") on at least one of the front wheels and the rear wheels. In this case, the braking torque Tq1 of the first wheel WH1 (front wheel) and the braking torque Tq2 of the second wheel WH2 (rear wheel) are separately controlled by this independent control. As a result, the amount of energy regeneration can be increased and the vehicle stability during braking can be improved. Here, the "regenerative cooperative control" efficiently converts the kinetic energy of the moving vehicle into electric energy by coordinating the regenerative braking force of the generator and the frictional braking force of the braking fluid pressure Pw. It is to convert to.

When the power supply of the braking control device SC is completely lost, the simulator valves VS, the first and second communication valves VR1 and VR2 are closed, and the first and second separation valves VM1 and VM2 are opened. .. That is, the operating characteristics of the braking operating member BP are formed by the rigidity of the brake caliper, the friction material, and the like. Further, the braking liquid BF is pumped from the master cylinder CM to the first and second wheel cylinders CW1 and CW2 only by the driver's operating force Fp (muscle force), and the vehicle is decelerated by the manual braking of the four wheels WH. .. Here, "manual braking" is braking performed only by the muscular strength of the driver. Further, the wheel cylinder hydraulic pressure (braking fluid pressure) increased by manual braking is called "manual hydraulic pressure".

In the braking control device SC, even if one of the normally closed first and second communication valves VR1 and VR2 fails in the closed state, the brake fluid BF can be circulated in the return path on the failed side. Is. Therefore, an excessive increase in the braking fluid pressure or an increase in the operating force of the BP may not cause a sense of discomfort. Further, in the braking system including the communication valve in which the valve closing failure has occurred, the separation valve can be opened and manual braking can be performed. On the other hand, in the braking system including the other (normal side) of the first and second communication valves VR1 and VR2, the braking fluid BF discharged by the fluid pump is adjusted by the pressure regulating valve, so that the vehicle deceleration is preferably adjusted. Can be secured.

<Configuration of electric motor MT, controller ECU, etc.>
The configuration of the electric motor MT, the controller ECU, and the like in consideration of redundancy will be described with reference to the schematic diagram of FIG.

The electric motor MT includes two winding sets (first and second motor coils) CL1 and CL2. For example, a three-phase brushless motor is adopted as the electric motor MT. The brushless motor MT is provided with a rotation angle sensor KA that detects the rotor position (rotation angle) Ka of the motor. Three-phase (U-phase, V-phase, W-phase) winding sets (motor coils) are formed on the first and second motor coils CL1 and CL2 of the brushless motor MT, respectively. That is, the electric motor MT is provided with two systems of three-phase motor coils (first and second motor coils) CL1 and CL2. Based on the rotation angle (actual value) Ka, the energization directions (that is, the excitation directions) of the two three-phase motor coils CL1 and CL2 are sequentially switched, and the brushless motor MT is rotationally driven. In order to ensure redundancy, two sets of detection units may be adopted for the rotation angle sensor KA.

The actual rotation angle Ka is a known method (for example, a method of energizing 120 degrees to detect a zero cross of the induced voltage, a method of using a neutral point potential, a method of using an estimated induced voltage of a dq rotating coordinate model, αβ. It can be estimated by applying an extended Kalman filter to a fixed coordinate model, or using a state observer). Therefore, when the rotation angle Ka is estimated and calculated, the rotation angle sensor KA may be omitted.

The controller ECU is composed of two control units (first and second control units) EC1 and EC2. The first control unit EC1 includes a first microprocessor MP1 and a first drive circuit DR1. Further, the second control unit EC2 includes a second microprocessor MP2 and a second drive circuit DR2. The first and second microprocessors MP1 and MP2 are programmed with a control algorithm for controlling an electric motor MT and a solenoid valve (UA, VM, etc.). Signals (detected values, calculated values, etc.) are shared between the first microprocessor MP1 and the second microprocessor MP2. The first and second drive circuits DR1 and DR2 are controlled based on the calculation results of the first and second microprocessors MP1 and MP2. Electric circuits are formed in the first and second drive circuits DR1 and DR2 by switching elements (power semiconductor devices such as MOS-FETs and IGBTs). The electric motor MT and the solenoid valve (UA, VM, etc.) are energized by the first and second drive circuits DR1 and DR2, and they are driven. As described above, the controller ECU (= MP + DR) and the electric motor MT are electrically duplicated.

A first configuration example of the controller ECU and the like will be described with reference to FIG. 2A. In the first configuration example, the first control unit EC1 (that is, the first drive circuit DR1) causes the first motor coil (motor coil of the first system of the two systems) CL1, the first pressure regulating valve UA1, and the first separation. The valve VM1, the first communication valve VR1, the first inlet valve VI1, and the first outlet valve VO1 are energized. Further, by the second control unit EC2 (that is, the second drive circuit DR2), the second motor coil (the motor coil of the second system of the two systems) CL2, the second pressure regulating valve UA2, the second separation valve VM2, and the second 2 The communication valve VR2, the second inlet valve VI2, the second outlet valve VO2, and the simulator valve VS are energized. Therefore, even if one of the first control unit EC1 and the second control unit EC2 malfunctions (for example, when an electrical failure occurs), the other control unit (drive) operates properly. Since the electric motor MT and the pressure regulating valve UA are driven by the circuit or the like), the hydraulic pressure servo control can be continued. Here, the "hydraulic servo control" means that the first and second target hydraulic pressures Pt1 and Pt2 calculated based on the braking operation amount Ba and the like are combined with the actual first and second adjustment hydraulic pressures Pp1 and Pp2 ( = Pw1 and Pw2) are matched. For example, in hydraulic servo control, it is determined that the target hydraulic pressures Pt1 and Pt2 increase as the braking operation amount Ba increases, and the deviation between the target hydraulic pressures Pt1 and Pt2 and the adjusted hydraulic pressures Pp1 and Pp2 (detected values). The amount of electricity supplied to the first and second pressure regulating valves UA1 and UA2 is feedback-controlled so that the value approaches "0".

A second configuration example of the controller ECU and the like will be described with reference to FIG. 2 (b). In the second configuration example, the first control unit EC1 (that is, the first drive circuit DR1) causes the first motor coil (first system motor coil) CL1, the first pressure regulating valve UA1, the first separation valve VM1, and the first. 1 The communication valve VR1 is energized. Further, by the second control unit EC2 (that is, the second drive circuit DR2), the second motor coil (second system motor coil) CL2, the second pressure regulating valve UA2, the second separation valve VM2, the second communication valve VR2, and the second 1. The second inlet valves VI1, VI2, the first and second outlet valves VI1, VO2, and the simulator valve VS are energized.

In the second configuration example, all the inlet valve VI and the outlet valve VO are controlled by the second control unit EC2. In the second configuration example, as in the first configuration example, even if one of the first control unit EC1 and the second control unit EC2 becomes malfunctioning, the other that operates properly. Hydraulic servo control can be continued (that is, redundancy is ensured) by the control unit (drive circuit, etc.).

In addition, in the second configuration example, the first and second inlet valves VI1 and VI2, and the first and second outlet valves VO1 and VO2 are controlled by the second control unit EC2. Alternatively, as shown by the broken line, the first and second inlet valves VI1, VI2, the first and second outlet valves VO1 and VO2 may be controlled by the first control unit EC1. This is based on the fact that in the hydraulic pressure control of each wheel independently such as anti-lock brake control, each wheel speed Vw is compared and the inlet valve VI and the outlet valve VO related to each wheel WH are individually driven. .. That is, although information is shared between the first control unit EC1 and the second control unit EC2, the inlet valve VI and the outlet valve VO are any one of the first and second control units EC1 and EC2. On the other hand, driving is more suitable for anti-lock brake control and the like.

In the first and second configuration examples, the simulator valve VS is energized and driven by the second control unit EC2. The control unit on the side that drives the simulator valve VS is called a "specific side control unit", and the control unit on the side that does not drive the simulator valve VS is called a "non-specific side control unit". Therefore, in the first and second configuration examples, the first control unit EC1 is the non-specific side control unit, and the second control unit EC2 is the specific side control unit. Further, the simulator valve VS may be driven by the first control unit EC1. In this case, the first control unit EC1 is the specific side control unit, and the second control unit EC2 is the non-specific side control unit.

<Operation of controller ECU>
With reference to the matrix diagram of FIG. 3, the controller ECU will be described when the operation is proper / malfunction. During normal braking (during service braking), the inlet valve VI and the outlet valve VO are not energized, so they are omitted in the matrix diagram.

A case where both the first and second control units EC1 and EC2 operate properly will be described with reference to FIG. 3A. In this case, the first control unit EC1 energizes the first motor coil CL1, the first pressure regulating valve UA1, the first separation valve VM1, and the first communication valve VR1. The second control unit EC2 energizes the second motor coil CL2, the second pressure regulating valve UA2, the second separation valve VM2, the second communication valve VR2, and the simulator valve VS. As a result, the electric motor MT is rotationally driven by the first and second motor coils CL1 and CL2. The first and second pressure regulating valves UA1 and UA2 throttle the first and second reflux KN1 and KN2 of the braking fluid BF, and the first and second adjusting hydraulic pressures Pp1 and Pp2 are individually adjusted (that is,). Independent control is achieved). The first and second separation valves VM1 and VM2 are closed, and the master cylinder CM and the first and second wheel cylinders CW1 and CW2 are brought into a non-communication state. The first and second communication valves VR1 and VR2 are opened, and the first and second braking fluid pressures Pw1 and Pw2 are adjusted by the first and second adjusting hydraulic pressures Pp1 and Pp2. The simulator valve VS is opened, and the operating force Fp of the braking operation member BP is generated by the simulator SS. When the first and second control units EC1 and EC2 are normal, the electric motor MT may be driven by any one of the first and second motor coils CL1 and CL2.

A case where the second control unit EC2 operates properly but the first control unit EC1 is malfunctioning will be described with reference to FIG. 3B. In this case, since the first control unit EC1 (non-specific side control unit) is malfunctioning, the first motor coil CL1, the first pressure regulating valve UA1, the first separation valve VM1, and the first communication valve VR1 are energized. Not done. Therefore, the first pressure regulating valve UA1 and the first separation valve VM1 are opened, and the first communication valve VR1 is closed. The second control unit EC2 (specific side control unit) energizes the second motor coil CL2, the second pressure regulating valve UA2, the second separation valve VM2, and the second communication valve VR2. However, the second control unit EC2, which is the specific side control unit, does not energize the simulator valve VS. The electric motor MT is driven by the second motor coil CL2, and refluxs KN1 and KN2 of the braking fluid BF are generated in the first and second reflux paths HK1 and HK2. The second reflux KN2 is throttled by the second pressure regulating valve UA2 to adjust the second adjusting hydraulic pressure Pp2. At this time, the second separation valve VM2 is closed, the second communication valve VR2 is opened, and the simulator valve VS is closed. Therefore, the second braking fluid pressure Pw2 is adjusted by the second adjusting hydraulic pressure Pp2. The first hydraulic chamber Rm1 of the master cylinder CM is directly connected to the first wheel cylinder CW1, and the first braking hydraulic pressure Pw1 is adjusted by the muscular strength (manual braking) of the driver. At this time, the simulator valve VS is closed, and the braking fluid BF from the second hydraulic chamber Rm2 is not consumed by the simulator SS, so that the secondary piston PH is not moved in the forward direction Ha. As a result, manual braking (that is, increase in manual hydraulic pressure) is effectively performed on the first wheel WH1 (first braking system BK1), and the second wheel WH2 (second braking system BK2) is on the second wheel. 2 The hydraulic servo control is executed by the control unit EC2.

A case where the first control unit EC1 operates properly but the second control unit EC2 is malfunctioning will be described with reference to FIG. 3C. In this case, since the second control unit EC2 is malfunctioning, the second motor coil CL2, the second pressure regulating valve UA2, the second separation valve VM2, the second communication valve VR2, and the simulator valve VS are not energized. .. The second pressure regulating valve UA2 and the second separation valve VM2 are in the valve open state, and the second communication valve VR2 and the simulator valve VS are in the valve closed state. The first control unit EC1 energizes the first motor coil CL1, the first pressure regulating valve UA1, the first separation valve VM1, and the first communication valve VR1. The electric motor MT is driven by the first motor coil CL1, and reflux KN1 and KN2 of the braking fluid BF are generated in the first and second reflux paths HK1 and HK2. The first reflux KN1 is throttled by the first pressure regulating valve UA1 to adjust the first adjusting hydraulic pressure Pp1. At this time, the first separation valve VM1 is closed and the first communication valve VR1 is opened. Therefore, the first braking fluid pressure Pw1 is adjusted by the first adjusting hydraulic pressure Pp1. That is, in the first braking system BK1, the hydraulic servo control is executed by the first control unit EC1. On the other hand, in the second braking system BK2, since the simulator valve VS is closed, the braking fluid BF from the second hydraulic chamber Rm2 is not consumed by the simulator SS. Therefore, the manual hydraulic pressure is effectively increased in the second wheel cylinder CW2.

In the above hydraulic servo control, if either one of the first control unit EC1 and the second control unit EC2 malfunctions, the first and second control units EC1 and EC2 are appropriate. It is preferable that the target hydraulic pressure Pt with respect to the braking operation amount Ba is calculated to be larger than that in the case of operation. Specifically, when the first control unit EC1 is malfunctioning, only the difference between the first target hydraulic pressure Pt1 when it operates properly and the braking hydraulic pressure (manual hydraulic pressure) by manual braking is the second. The target hydraulic pressure Pt2 is determined to be large. On the contrary, when the second control unit EC2 is malfunctioning, it is determined that the first target hydraulic pressure Pt1 increases by the difference between the second target hydraulic pressure Pt2 and the manual hydraulic pressure when it operates properly. Will be done. As a result, the shortage of vehicle deceleration when any one of the first and second control units EC1 and EC2 malfunctions can be appropriately compensated.

<Summary of embodiments and their actions / effects>
The brake control device SC is a brake-by-wire type that generates an operating force Fp on the braking operation member BP by the stroke simulator SS. Hereinafter, the embodiments and their actions / effects will be summarized.

The braking control device SC includes "first and second connecting paths HS1 and HS2 for connecting the first and second hydraulic chambers Rm1 and Rm2 of the tandem type master cylinder CM to the first and second wheel cylinders CW1 and CW2. "," The first and second separation valves VM1 and VM2 of the normally open type provided in the first and second connection paths HS1 and HS2 "and" The first and second fluid pumps HP1 driven by the electric motor MT. , HP2 "and" the first and second discharge parts Bt1, Bt2 and the first and second fluid pumps HP1 and HP2 of the first and second fluid pumps HP1 and HP2, and the first and second suction parts Bs1 and Bs2. The pressure of the braking fluid BF provided in the first and second recirculation passages HK1 and HK2 and discharged by the first and second fluid pumps HP1 and HP2 is the pressure of the first and second recirculation passages HK1 and HK2. "Normally open type 1st and 2nd pressure regulating valves UA1 and UA2" that adjust to the 1st and 2nd adjusting fluid pressures Pp1 and Pp2, and "1st and 2nd connection paths HS1, HS2 and 1st and 2nd return paths". "First and second connecting paths HR1 and HR2 connecting HK1 and HK2" and "normally closed first and second connecting valves VR1 and VR2 provided in the first and second connecting paths HR1 and HR2" , "Electric motor MT, first and second pressure regulating valves UA1, UA2, first and second separation valves VM1, VM2, and controller ECU for driving the first and second communication valves VR1 and VR2" are provided. Be done.

In the brake-by-wire type braking control device, the braking fluid BF pumped from the first and second hydraulic chambers Rm1 and Rm2 of the master cylinder CM is the first and second low-pressure reservoirs RW1 and RW2 (or master reservoir RV). A normally closed type solenoid valve is provided in each of the first and second braking systems BK1 and BK2 so as not to be returned to the above. When these solenoid valves are closed, the hydraulic pressures (braking fluid pressures) Pw1 and Pw2 of the first and second wheel cylinders CW1 and CW2 are increased by manual braking. As in Patent Document 1, when two normally closed solenoid valves are provided in series with the first and second pressure regulating valves UA1 and UA2 in the first and second reflux passages HK1 and HK2, the two normally closed solenoid valves are provided. When one of the closed solenoid valves fails to close, the reflux of the braking fluid BF is hindered in the reflux path including the solenoid valve that fails to close the valve. As a result, there may be a problem of unnecessary increase in braking fluid pressure or increase in operating force. Further, since it becomes difficult to drive the electric motor rotationally, it may be difficult to execute appropriate hydraulic servo control in the return path including the solenoid valve which has not failed to close the valve.

On the other hand, in the braking control device SC according to the present invention, the normally closed solenoid valves (communication valves) VR1 and VR2 are the first and second connecting paths HR1 and HR2 (first and second connecting paths HS1 and HS2). It is provided in the fluid passage connecting the first and second reflux passages HK1 and HK2). Therefore, even if one of the first and second communication valves VR1 and VR2 fails to close, the first and second reflux KN1 and KN2 are dammed up in the first and second reflux paths HK1 and HK2. (That is, the brake fluid BF is continuously circulated). Therefore, manual braking is accurately performed in the braking system on the side of the first and second communication valves VR1 and VR2 where the valve closing failure occurs. Further, the hydraulic servo control is executed in the braking system of the first and second communication valves VR1 and VR2 on the side where the valve closing failure does not occur. That is, in the braking control device SC according to the present invention, all the above-mentioned problems can be solved.

In the braking control device SC, the electric motor MT has first and second motor coils CL1 and CL2. Then, the controller ECU includes "the first motor coil CL1, the first pressure regulating valve UA1, the first separation valve VM1, and the first control unit EC1 for driving the first communication valve VR1" and "the second motor coil CL2, The second control valve UA2, the second separation valve VM2, and the second control unit EC2 for driving the second communication valve VR2 ”are included.

The electric motor MT is electrically duplicated by two motor coils (first and second motor coils) CL1 and CL2, and the controller ECUs for driving them are the first and second control units EC1 and EC2 (for example, It is duplicated by two drive circuits DR1 and DR2). Further, the first control unit EC1 drives the first pressure regulating valve UA1, the first separation valve VM1, and the first communication valve VR1, and the second control unit EC2 drives the second pressure regulating valve UA2 and the second separation valve VM2. , And the second communication valve VR2 is driven. When the first control unit EC1 is malfunctioning, the first braking fluid pressure Pw1 is pressurized by manual braking only by the driver's muscle strength, and the second braking hydraulic pressure Pw2 is increased by the hydraulic pressure servo control in the second braking system BK2. It will be adjusted. On the other hand, when the second control unit EC2 is out of order, the first braking hydraulic pressure Pw1 is adjusted by the hydraulic pressure servo control in the first braking system BK1, and the second braking hydraulic pressure Pw2 is the manual hydraulic pressure according to the muscle strength of the driver. Is pressurized to. Since the electric system of the braking control device SC is redundant (duplicated), even if a part of the controller ECU, the electric motor MT, or the like malfunctions, all the wheel WH cannot be immediately switched to manual braking. As a result, sufficient vehicle deceleration can be ensured when the braking control device SC is partially out of order.

The braking control device SC is a normally closed type that is provided between the stroke simulator SS and the first hydraulic chamber Rm1 or the second hydraulic chamber Rm2 and is energized by the first control unit EC1 or the second control unit EC2. A simulator valve VS is provided. Then, when the operation of the first and second control units EC1 and EC2 is appropriate, the specific side control unit that drives the simulator valve VS among the first and second control units EC1 and EC2 is a simulator. Of the first and second control units EC1 and EC2, the non-specific side control unit, which is the side that does not energize the simulator valve VS, energizes the valve VS and operates the specific side control unit properly. When the operation is not good, the specific side control unit is configured not to energize the simulator valve VS.

When any one of the first and second control units EC1 and EC2 malfunctions, the simulator valve VS is closed. The braking fluid BF in the hydraulic chamber Rm is not consumed in the simulator SS, and the entire amount of the braking fluid BF pumped from the hydraulic chamber Rm is supplied to the wheel cylinder CW that requires manual braking. Therefore, efficient manual braking can be achieved.

In the braking control device SC, the four inlet valve VIs and the outlet valve VO are driven by the second control unit EC2. Antilock braking control is performed based on each wheel speed Vw. Although information is shared between the first and second microprocessors MP1 and MP2, information transmission delays and the like can be avoided by being driven by either the first or second control unit EC1 or EC2. And the anti-lock braking control can be performed more efficiently. Further, since the stability of the vehicle is improved by securing the lateral force of the rear wheel WH2, it is preferable that all the inlet valve VI and the outlet valve VO are driven by the second control unit EC2. In this configuration, when the first control unit EC1 is malfunctioning, anti-lock braking control on the rear wheel WH2 can be executed.

In the above-described embodiment of the braking control device SC, the two braking systems BK1 and BK2 have been described assuming a front-rear type. Then, the operation of the specific side control unit among the first and second control units EC1 and EC2 is appropriate, and the operation of the first and second control units EC1 and EC2 that is not the specific side control unit is performed. In the case of malfunction, the specific side control unit did not energize the simulator valve VS. When the front-rear braking system is adopted, the simulator valve is used when the front wheel system (that is, the first braking system BK1) is hydraulically controlled by hydraulic servo and the rear wheel system (that is, the second braking system BK2) is manually braked. When the VS is closed, the operating force depends on the specifications of the braking device (master cylinder CM, pressure receiving area of wheel cylinder CW, effective braking radius of rotating member KT, fluid path, brake caliper, rigidity of friction material, etc.). The operating displacement Sp may be too small with respect to the Fp (so-called "short stroke"). In other words, the "short stroke" means that the operating force Fp with respect to the operating displacement Sp becomes excessive. In order to solve this short stroke problem, the specific side control unit is set to the first control unit EC1 and the non-specific side control unit is set to the second control unit EC2 (that is, the first control unit EC1 causes the simulator valve VS. Is driven). Then, when the second control unit EC2 is malfunctioning and the first control unit EC1 is normal, the simulator valve VS is energized by the first control unit EC1 and the simulator valve VS is opened. To. Since the braking fluid BF from the master cylinder CM flows into the simulator SS, the above-mentioned short stroke problem can be solved.

Further, depending on the specifications of the braking device, the front wheel system (that is, the first braking system BK1) is set to manual braking, and the rear wheel system (that is, the second braking system BK2) is controlled by hydraulic servo. However, the operating displacement Sp may become too small (short stroke) with respect to the operating force Fp. In a vehicle equipped with a braking device having such specifications, when any one of the first and second control units EC1 and EC2 is out of order and the specific side control unit is normal. , The simulator valve VS is energized and the simulator valve VS is opened.

In the above-described embodiment, the two braking systems BK1 and BK2 are assumed to be of the front-rear type, but instead of the front-rear type, the two braking systems BK1 and BK2 are of the diagonal type (also referred to as "X type"). Things can be adopted. In this case, the first braking system BK1 (Rm1, HS1, etc.) is connected to the right front wheel and left rear wheel wheel cylinders, and the second braking system BK2 (Rm2, HS2, etc.) is connected to the left front wheel and right rear wheel wheel cylinders. Be connected. The same effect as described above can be obtained in the diagonal type braking control device SC.

When a diagonal type braking system is adopted, the problem of the short stroke is unlikely to occur. Therefore, when the operation of the specific side control unit is proper and the operation of the side other than the specific side control unit is malfunctioning. It is preferable that the specific side control unit does not energize the simulator valve VS. However, in the braking control device of the specifications that causes the above-mentioned short stroke problem, the specific side control unit is normal even when any one of the first and second control units EC1 and EC2 is out of order. If is, the simulator valve VS is energized and the simulator valve VS is opened.

Even in the diagonal type braking control device SC, the execution of the anti-lock brake control is that the four inlet valve VI and the outlet valve VO are driven by one of the first and second control units EC1 and EC2. Is suitable for. In the diagonal type braking control device SC, even in a vehicle in which regenerative cooperative control is executed, independent control is not adopted so that the first adjustment hydraulic pressure Pp1 and the second adjustment hydraulic pressure Pp2 are the same. Hydraulic pressure servo control is performed (that is, "Pw1 = Pw2").

SC ... Braking control device, BP ... Braking operation member, CM ... Master cylinder, Rm1, Rm2 ... 1st and 2nd hydraulic chambers (master cylinder chamber), SS ... Stroke simulator, CW1, CW2 ... 1st and 2nd wheels Cylinder, RV ... Master reservoir, RW1, RW2 ... 1st, 2nd low pressure reservoir, BA ... Operation amount sensor, PM1, PM2 ... 1st, 2nd master cylinder hydraulic pressure sensor, HP1, HP2 ... 1st, 2nd fluid Pump, ECU ... Controller (electronic control unit), EC1, EC2 ... 1st, 2nd control unit, MT ... Electric motor, CL1, CL2 ... 1st, 2nd motor coil, UA1, UA2 ... 1st, 2nd adjustment Pressure valve, VM1, VM2 ... 1st, 2nd separation valve (master cylinder valve), VR1, VR2 ... 1st, 2nd communication valve, VS ... Simulator valve, VI ... Inlet valve, VO ... Outlet valve, HP1, HP2 ... 1st and 2nd fluid pumps, KN ... Circulation of braking liquid (working liquid), HS1, HS2 ... 1st and 2nd connection paths, HR1, HR2 ... 1st and 2nd connecting paths, HK1, HK2 ... 1st, Second return path.

Claims (2)

A brake-by-wire type vehicle braking control device that generates operating force on braking operation members using a stroke simulator.
The first and second connection paths connecting the first and second hydraulic chambers of the tandem type master cylinder and the first and second wheel cylinders,
The normally open type first and second separation valves provided in the first and second connection paths, and
The first and second fluid pumps driven by an electric motor,
The first and second return passages connecting the first and second discharge portions of the first and second fluid pumps and the first and second suction portions of the first and second fluid pumps, and
A normally open type first and second pressure regulating valve provided in the first and second reflux passages and adjusting the pressure of the braking fluid discharged by the first and second fluid pumps to the first and second adjusting hydraulic pressures. When,
The first and second connecting paths connecting the first and second connecting paths and the first and second return paths, and
The normally closed first and second communication valves provided in the first and second communication paths, and
A controller for driving the electric motor, the first and second pressure regulating valves, the first and second separation valves, and the first and second communication valves.
A vehicle braking control device. In the vehicle braking control device according to claim 1,
The electric motor has first and second motor coils.
The controller
A first control unit that drives the first motor coil, the first pressure regulating valve, the first separation valve, and the first communication valve.
A second control unit that drives the second motor coil, the second pressure regulating valve, the second separation valve, and the second communication valve.
A vehicle braking control device that includes.