JP2014213628A - Vehicle brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate brake force equal to an engine brake properly even in a case that regenerative brake force cannot be generated and defect of a friction brake system, which is normally used as the brake force equal to an engine brake is generated.SOLUTION: When an accelerator pedal and a brake pedal are not operated, brake force equal to an engine brake of a vehicle having an internal combustion engine is generated by generating regenerative brake force by a motor generator. When a battery for charging regenerative power is fully charged, a motor cylinder device 16 drives disk brake mechanisms 30a-30d, and the brake force equal to an engine brake can be generated by friction brake force. In this case, when abnormality of a motor 72 or the like of the motor cylinder device 16 is detected, a vehicle behavior stabilization device 18 is directly controlled to drive the disk brake mechanisms 30a-30d, and the friction brake force generates the brake force equal to the engine brake.

Description

  The present invention relates to a vehicle braking system.

  In an electric vehicle or the like, when neither an accelerator pedal nor a brake pedal is operated, a braking force equivalent to an engine brake in a normal gasoline vehicle is generated by a regenerative braking force by a driving motor. The generation of such regenerative braking force equivalent to engine braking is in line with the engine braking of gasoline automobiles.

However, when the battery that stores the electric power generated by regeneration is fully charged, regenerative braking force cannot be generated.
Therefore, it is known that when such a full charge of the battery occurs, the friction braking force by the friction brake is operated and the braking force equivalent to the engine brake is generated by the friction braking force instead of the regenerative braking force. (See Patent Document 1).

JP-A-10-271605

However, when the braking force is generated by a friction brake system such as an electric servo brake system instead of the regenerative braking force, if the friction brake system has a defect (such as a drive motor failure), the brake will suddenly come off. There's a problem.
Therefore, the present invention can not generate regenerative braking force, and can properly generate braking force equivalent to engine brake even when a defect occurs in a friction brake system normally used as braking force equivalent to engine brake. It is an object of the present invention to provide a vehicle braking system that can be made to operate.

In order to solve the above-described problems, according to one aspect of the present invention, there is provided a friction braking force generation unit that generates a friction braking force of a vehicle with hydraulic pressure, and a first motor that is electrically driven to operate the friction braking force generation unit with hydraulic pressure. A first hydraulic pressure generation unit, a second hydraulic pressure generation unit that hydraulically communicates with the first hydraulic pressure generation unit and operates the friction braking force generation unit with hydraulic pressure, and an operation state of an accelerator pedal. When the accelerator pedal and the brake pedal are in the non-operating state by the detection of the accelerator state detecting unit for detecting, the brake state detecting unit for detecting the operation state of the brake pedal, and the accelerator state detecting unit and the brake state detecting unit An engine brake in a vehicle driven by an internal combustion engine is generated by the regenerative braking force generated by the electric motor driving the vehicle and the friction braking force generated by the friction braking force generation unit driven by the first hydraulic pressure generation unit. A first braking force control unit that generates a braking force equivalent to a key, an abnormality detection unit that detects occurrence of an abnormality related to the generation of the friction braking force by the first braking force control unit, and the abnormality detection unit When the occurrence of the abnormality is detected and in the non-operating state, the engine is generated by the regenerative braking force and the friction braking force generated by the friction braking force generation unit by the second hydraulic pressure generation unit. And a second braking force control unit that generates a braking force equivalent to a brake.
According to the present invention, even if an abnormality relating to the generation of the friction braking force by the first braking force control unit occurs, such as an abnormality in the first hydraulic pressure generation unit, the second braking force control unit includes the internal combustion engine. Therefore, it is possible to generate a braking force equivalent to the engine brake in the vehicle and appropriately generate a braking force equivalent to the engine brake.

In the case of the above invention, the vehicle further includes a shift position detecting unit that detects a shift position of the transmission of the vehicle, and the second braking force control unit applies the friction braking force that varies depending on the shift position. You may make it generate | occur | produce by a 2nd braking force control part.
According to the present invention, it is possible to cope with a case where it is necessary to generate a braking force corresponding to an engine brake that differs depending on the shift position.

In the case of the above-described invention, the second control device further includes: a storage amount detection unit that detects a storage amount of a battery that stores power regenerated by the electric motor; and a vehicle speed detection unit that detects a vehicle speed of the vehicle. When the power control unit detects that the shift position detection unit is in a shift position where the braking force corresponding to the engine brake when the shift position detection unit is in the non-operating state is larger than that in the travel range, the power storage amount detection unit When the detected amount of stored electricity is greater than or equal to a predetermined amount, the friction braking force generated by the second friction braking force generator is increased as the vehicle speed detected by the vehicle speed detector increases. You may make it gradually approach the thing in the case of a travel range.
According to the present invention, the friction braking force is increased when the amount of charge stored in the battery increases and the regenerative braking force cannot be generated even when the engine is in a shift position where the braking force equivalent to the engine brake is larger than that in the traveling range. It can approach according to the thing in the said traveling range.

In the case of the above invention, the second braking force control unit makes the friction braking force generated by the second braking force control unit larger than the friction braking force generated by the first braking force control unit.
According to the present invention, when an abnormality relating to the generation of the friction braking force by the second braking force control unit occurs, the friction braking force by the second braking force control unit is changed to the friction by the first braking force control unit. By making it larger than the braking force and expanding the braking force equivalent to the engine brake, it is possible to be careful in traveling.

  According to the present invention, even when a regenerative braking force cannot be generated and a defect occurs in a friction brake system that is normally used as a braking force equivalent to an engine brake, the braking force equivalent to the engine brake is appropriately generated. It is possible to provide a vehicle braking system that can be provided.

FIG. 1 is a system diagram of an essential part of a vehicle according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a vehicle brake system according to an embodiment of the present invention. FIG. 3 is a block diagram showing electrical connection of a control device for a vehicle brake system according to an embodiment of the present invention. FIG. 4 is a block diagram showing electrical connection of a control device for a vehicle brake system according to an embodiment of the present invention. FIG. 5 is a block diagram showing an electrical connection of a control device for a vehicle brake system according to an embodiment of the present invention. FIG. 6 is a flowchart of processing executed by the control device for the vehicle brake system according to the embodiment of the present invention. FIG. 7 is a flowchart of processing executed by the control device for the vehicle brake system according to the embodiment of the present invention. FIG. 8 is a flowchart of processing executed by the control device for the vehicle brake system according to the embodiment of the present invention. FIG. 9 is a graph illustrating the relationship between the acceleration applied to the vehicle and the vehicle speed with respect to the processing executed by the control device for the vehicle brake system according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a main part system diagram of a vehicle 100 according to the present embodiment. The vehicle 100 is, for example, an electric vehicle, and includes a pair of left and right front wheels 2aR and 2aL provided on the front side of the vehicle 100, and a pair of left and right rear wheels 2bR and 2bL provided on the rear side of the vehicle 100. A motor generator 3 serving as an electric motor is connected to the front wheel axle 4 connected to the left and right front wheels 2aR and 2aL by a torque transmission mechanism. The vehicle 100 may be a four-wheel drive vehicle or a rear wheel drive vehicle, or may be configured as a hybrid vehicle provided with the motor / generator 3, a fuel cell vehicle, or the like. A differential mechanism provided on the front wheel axle 4 is not shown.

  The motor / generator 3 serves as both a vehicle driving motor and a regeneration generator. A battery 5 as a secondary battery supplies power to the motor / generator 3 by an inverter 6 as a power source of the motor / generator 3. Further, at the time of deceleration, the motor / generator 3 converts the deceleration energy into electric power to be regenerated, and the battery 5 stores the regenerated generated electric power. During this regeneration, the motor / generator 3 generates a regenerative braking force.

  The control device 7 is mainly composed of a microcomputer, and controls power running and regeneration of the vehicle by the motor / generator 3. The control device 8 is configured around a microcomputer and controls a vehicle brake system 10 described later. The control device 9 is also configured around a microcomputer, and controls a vehicle brake system 10 to be described later. The control device 8 and the control device 9 are respectively involved in different controls of the vehicle brake system 10 (described later). Moreover, each part of the control apparatuses 7-9 and a vehicle can communicate with each other by CAN (Controller Area Network).

  FIG. 2 is a schematic configuration diagram of the vehicle brake system 10. First, the hydraulic path will be described. The connection port 20a of the input device 14 and the connection point A1 are connected by the first piping tube 22a with reference to the connection point A1 in FIG. The port 24a and the connection point A1 are connected by the second piping tube 22b, and the introduction port 26a of the vehicle behavior stabilization device 18 and the connection point A1 are connected by the third piping tube 22c.

  With reference to another connection point A2 in FIG. 2, the other connection port 20b of the input device 14 and the connection point A2 are connected by the fourth piping tube 22d, and the other output port 24b of the motor cylinder device 16 is connected. The connection point A2 is connected by the fifth piping tube 22e, and the other introduction port 26b of the vehicle behavior stabilization device 18 and the connection point A2 are connected by the sixth piping tube 22f.

  The vehicle behavior stabilization device 18 is provided with a plurality of outlet ports 28a to 28d. The first outlet port 28a is connected to the wheel cylinder 32FR of the disc brake mechanism 30a provided on the right front wheels 2aR and 2aL by the seventh piping tube 22g. The second outlet port 28b is connected to the wheel cylinder 32RL of the disc brake mechanism 30b provided on the left rear wheel 2bR, 2bL by the eighth piping tube 22h. The third outlet port 28c is connected to the wheel cylinder 32RR of the disc brake mechanism 30c provided on the right rear wheel 2bR, 2bL by the ninth piping tube 22i. The fourth outlet port 28d is connected to the wheel cylinder 32FL of the disc brake mechanism 30d provided on the left front wheels 2aR and 2aL by the tenth piping tube 22j.

  In this case, brake fluid (brake fluid) is supplied to the wheel cylinders 32FR, 32RL, 32RR, 32FL of the disc brake mechanisms 30a-30d by the piping tubes 22g-22j connected to the outlet ports 28a-28d, As the hydraulic pressure in the wheel cylinders 32FR, 32RL, 32RR, 32FL increases, each wheel cylinder 32FR, 32RL, 32RR, 32FL is operated, and the corresponding wheel (right front wheel 2aR, left rear wheel 2bL, right rear wheel 2bR). Friction braking force is applied to the left front wheel 2aL).

  The input device 14 includes a tandem master cylinder 34 that can generate hydraulic pressure by operating the brake pedal 12 by the driver, and a first reservoir 36 attached to the master cylinder 34. In the cylinder tube 38 of the master cylinder 34, a second piston 40a and a first piston 40b that are spaced apart by a predetermined distance along the axial direction of the cylinder tube 38 are slidably disposed. The second piston 40 a is disposed close to the brake pedal 12 and is connected to the brake pedal 12 via the push rod 42. Further, the first piston 40b is arranged farther from the brake pedal 12 than the second piston 40a.

  A pair of cup seals 44a and 44b are respectively attached to the outer peripheral surfaces of the second piston 40a and the first piston 40b via an annular step portion. Back chambers 48a and 48b communicating with supply ports 46a and 46b, which will be described later, are formed between the pair of cup seals 44a and 44b, respectively. Further, a spring member 50a is disposed between the second piston 40a and the first piston 40b, and another spring member 50b is disposed between the first piston 40b and the front end portion of the cylinder tube 38. Is done.

  The cylinder tube 38 of the master cylinder 34 is provided with two supply ports 46a and 46b, two relief ports 52a and 52b, and two output ports 54a and 54b. In this case, each supply port 46 a (46 b) and each relief port 52 a (52 b) are provided so as to join and communicate with a reservoir chamber (not shown) in the first reservoir 36.

  Further, in the cylinder tube 38 of the master cylinder 34, a second pressure chamber 56a and a first pressure chamber 56b for generating a brake fluid pressure corresponding to the depression force of the driver depressing the brake pedal 12 are provided. The second pressure chamber 56a is provided so as to communicate with the connection port 20a via the second hydraulic pressure path 58a, and the first pressure chamber 56b communicates with the other connection port 20b via the first hydraulic pressure path 58b. To be provided.

  A pressure sensor Pm is disposed between the master cylinder 34 and the connection port 20a upstream of the second hydraulic pressure path 58a, and a normally open type is provided downstream of the second hydraulic pressure path 58a. A second shut-off valve 60a composed of a (normally open) solenoid valve is provided. This pressure sensor Pm detects the hydraulic pressure upstream of the second shutoff valve 60a on the master cylinder 34 side on the second hydraulic pressure path 58a.

Between the master cylinder 34 and the other connection port 20b, on the upstream side of the first hydraulic pressure path 58b, a first shutoff valve 60b composed of a normally open type (normally open type) solenoid valve is provided. A pressure sensor Pp is provided on the downstream side of the first hydraulic pressure path 58b. The pressure sensor Pp detects the hydraulic pressure downstream of the wheel cylinders 32FR, 32RL, 32RR, 32FL from the first shutoff valve 60b on the first hydraulic pressure path 58b.
The normal open in the second shut-off valve 60a and the first shut-off valve 60b is a valve configured such that the normal position (the position of the valve body at the time of demagnetization (non-energization)) is in the open position (normally open). Say. In FIG. 2, the second shut-off valve 60a and the first shut-off valve 60b show the state at the time of excitation (the same applies to the third shut-off valve 62 described later).

A branch hydraulic pressure path 58c branched from the first hydraulic pressure path 58b is provided in the first hydraulic pressure path 58b between the master cylinder 34 and the first shutoff valve 60b, and the branched hydraulic pressure path 58c includes A third shut-off valve 62 composed of a normally closed type (normally closed type) solenoid valve and a stroke simulator 64 are connected in series. The normal close in the third shut-off valve 62 refers to a valve configured such that the normal position (the position of the valve body at the time of demagnetization (non-energization)) is in the closed position (normally closed).
The stroke simulator 64 is disposed on the first hydraulic pressure path 58b and closer to the master cylinder 34 than the first shutoff valve 60b. The stroke simulator 64 is provided with a hydraulic pressure chamber 65 communicating with the branch hydraulic pressure path 58c, and the brake fluid derived from the first pressure chamber 56b of the master cylinder 34 can be absorbed via the hydraulic pressure chamber 65. Is provided.

The stroke simulator 64 is a simulator piston that is urged by a first return spring 66a having a high spring constant, a second return spring 66b having a low spring constant, and first and second return springs 66a and 66b arranged in series. 68, the pedal reaction force increasing gradient is set low when the brake pedal 12 is first depressed and the pedal reaction force is set high when the brake pedal 12 is depressed late, so that the pedal feeling of the brake pedal 12 is equivalent to that of the existing master cylinder. It is provided as follows.
The hydraulic pressure path is roughly classified into a second hydraulic pressure system 70a that connects the second pressure chamber 56a of the master cylinder 34 and the plurality of wheel cylinders 32FR and 32RL, a first pressure chamber 56b of the master cylinder 34, and a plurality of pressure paths. The first hydraulic system 70b is connected to the wheel cylinders 32RR and 32FL.

  The second hydraulic system 70a includes a second hydraulic path 58a that connects the output port 54a of the master cylinder 34 (cylinder tube 38) and the connection port 20a in the input device 14, and the connection port 20a of the input device 14 and the motor cylinder. Piping tubes 22a and 22b that connect the output port 24a of the device 16, piping tubes 22b and 22c that connect the output port 24a of the motor cylinder device 16 and the introduction port 26a of the vehicle behavior stabilization device 18, and vehicle behavior stabilization It is comprised by piping tubes 22g and 22h which connect the derivation | leading-out ports 28a and 28b of the control apparatus 18, and each wheel cylinder 32FR and 32RL, respectively.

  The first hydraulic system 70b includes a first hydraulic path 58b that connects the output port 54b of the master cylinder 34 (cylinder tube 38) in the input device 14 and the other connection port 20b, and another connection port of the input device 14. Piping tubes 22d and 22e for connecting 20b and the output port 24b of the motor cylinder device 16; piping tubes 22e and 22f for connecting the output port 24b of the motor cylinder device 16 and the introduction port 26b of the vehicle behavior stabilization device 18; , And pipe tubes 22i and 22j for connecting the outlet ports 28c and 28d of the vehicle behavior stabilization device 18 and the wheel cylinders 32RR and 32FL, respectively.

  The motor cylinder device 16 is an electric brake device that generates brake fluid pressure by driving the second slave piston 88a and the first slave piston 88b in the axial direction by the driving force of the electric motor 72. In the motor cylinder device 16, the moving direction (in the direction of arrow X1 in FIG. 2) of the second slave piston 88a and the first slave piston 88b when generating (raising) the brake fluid pressure is set to “front” and vice versa. The direction (arrow X2 direction in FIG. 2) is “rear”.

  The motor cylinder device 16 includes a cylinder portion 76 having a second slave piston 88a and a first slave piston 88b that are movable in the axial direction, and a motor 72 for driving the second slave piston 88a and the first slave piston 88b. And a driving force transmission unit 73 for transmitting the driving force of the motor 72 to the second slave piston 88a and the first slave piston 88b.

The second slave piston 88a is formed integrally with the second cylindrical member 88a1 fixed along the outer periphery of the second slave piston 88a in the front-rear direction of the second slave piston 88a. Then, as the second cylindrical member 88a1 slides inside the cylinder portion 76, the second slave piston 88a is driven in the front-rear direction. The first slave piston 88b is also formed integrally with the first cylindrical member 88b1 fixed along the outer periphery of the first slave piston 88b in front of the first slave piston 88b. Then, as the first cylindrical member 88b1 slides inside the cylinder portion 76, the first slave piston 88b is driven in the front-rear direction.
The driving force transmission unit 73 includes a gear mechanism (deceleration mechanism) 78 that transmits the rotational driving force of the motor 72, and a ball screw structure 80 that converts this rotational driving force into a linear driving force of a ball screw shaft (screw) 80a. And a driving force transmission mechanism 74 including

  The cylinder part 76 includes a substantially cylindrical cylinder body 82 and a second reservoir 84 attached to the cylinder body 82. The second reservoir 84 is connected to the first reservoir 36 attached to the master cylinder 34 of the input device 14 by a piping tube 86, and the brake fluid stored in the first reservoir 36 is passed through the piping tube 86 to the second reservoir 84. 84 is provided so as to be supplied in the inside.

  As described above, the second slave piston 88a and the first slave piston 88b that are spaced apart from each other by a predetermined distance in the axial direction of the cylinder body 82 are provided in the cylinder body 82 so as to be driven. The ball screw shaft 80a is disposed close to the ball screw shaft 80a, contacts the front end of the ball screw shaft 80a, and is displaced integrally with the ball screw shaft 80a in the direction of the arrow X1 or X2. The first slave piston 88b is arranged farther from the ball screw structure 80 side than the second slave piston 88a.

  A slave cup seal 90a (seal member) that seals between the outer peripheral surface of the second cylindrical member 88a1 fixed to the second slave piston 88a and the driving force transmission mechanism 74 in a liquid-tight manner is provided on the cylinder portion 76 side. . In addition, a slave cup seal 90b (seal member) is also provided on the cylinder portion side so as to be separated from the slave cup seal 90a, and a reservoir port 92a, which will be described later, communicates with the slave cup seal 90a and the slave cup seal 90b. A flow path opening is provided. A second return spring 96a is provided between the second slave piston 88a and the first slave piston 88b. Further, on the opposite side of the slave cup seal 90b in the slave cup seal 90a, a slave cup seal 90e (seal member) and a liquid reservoir 91 are provided on the cylinder portion 76 side. By providing the slave cup seal 90e and the liquid reservoir 91, a more liquid-tight seal can be achieved.

  On the other hand, a slave cup seal 90c (seal member) that provides a fluid-tight seal between the outer peripheral surface of the first cylindrical member 88b1 fixed to the first slave piston 88b and a first hydraulic pressure chamber 98b described later is a cylinder portion. It is arranged on the 76 side. Further, the second hydraulic pressure chamber 98a, which will be described later, is liquid-tightly sealed by the slave cup seal 90b and the slave cup seal 90c.

  In addition, a slave cup seal 90d (seal member) that seals the first hydraulic chamber 98b in a liquid-tight manner is provided on the cylinder portion 76 side, apart from the slave cup seal 90c. Furthermore, between the slave cup seal 90c and the slave cup seal 90d, a flow path port communicating with a reservoir port 92b described later is provided. A first return spring 96b is disposed between the first slave piston 88b and the lid member 82c that closes the opening of the cylinder body 82 (that is, the opening provided at the front end of the cylinder portion 76).

The cylinder body 82 of the cylinder portion 76 is provided with two reservoir ports 92a and 92b and two output ports 24a and 24b. In this case, the reservoir port 92 a (92 b) is provided so as to communicate with the reservoir chamber in the second reservoir 84.
Further, in the cylinder body 82, a second hydraulic pressure chamber 98a for generating a brake hydraulic pressure output from the output port 24a to the wheel cylinders 32FR and 32RL side, and the other output port 24b to the wheel cylinders 32RR and 32FL side. A first hydraulic pressure chamber 98b for generating the output brake hydraulic pressure is provided.

  Further, a regulating means 102 for regulating the sliding range of the first slave piston 88b is provided between the first slave piston 88b and the lid member 82c that closes the opening of the cylinder portion 76. This prevents overreturn of the first slave piston 88b to the second slave piston 88a side. In particular, at the time of backup in which braking is performed with the brake fluid pressure generated in the master cylinder 34, when one system fails, Failure is prevented. Further, a restricting means 103 for restricting the maximum separation distance and the minimum separation distance between the first slave piston 88b and the second slave piston 88a is also provided between the first slave piston 88b and the second slave piston 88a.

  The regulating means 102 slides inside the cylindrical member 102b, the cylindrical member 102b fixed between the cylinder main body 82 and the lid member 82c via the flange portion 102b1, and the first slave piston 88b and the connecting member And a first regulating piston 102a connected by 102a1. That is, the flange portion 102b1 constituting the restricting means 102 is sandwiched and fixed between the cylinder body 82 (that is, the cylinder portion 76) and the lid member 82c by screwing or the like (not shown). And the sliding range of the 1st slave piston 88b connected to the 1st control piston 102a is controlled because the 1st control piston 102a slides in the cylindrical member 102b.

  Further, the regulating means 103 is connected to the first slave piston 88b and fixed to the cylindrical member 103b, slides inside the cylindrical member 103b, and is connected by the second slave piston 88a and the connecting member 103a1. And a second regulating piston 103a. And the sliding range of the 2nd slave piston 88a connected to the 2nd control piston 103a is controlled because the 2nd control piston 103a slides in the cylindrical member 103b.

  The vehicle behavior stabilization device 18 controls the second hydraulic system 70a connected to the disc brake mechanisms 30a, 30b (the wheel cylinder 32FR, the wheel cylinder 32RL) of the right front wheels 2aR, 2aL and the left rear wheels 2bR, 2bL. A second brake system 110a and a first brake system 110b that controls a first hydraulic system 70b connected to the disc brake mechanisms 30c, 30d (wheel cylinder 32RR, wheel cylinder 32FL) of the right rear wheel 2bR and the left front wheel 2aL. Have.

In addition, the combination of the connection between the second brake system 110a and the first brake system 110b and each of the disc brake mechanisms 30a, 30b, 30c, and 30d is not limited to the combination described above, and two independent systems are secured. For example, the following combinations are possible. That is, although not shown, the second brake system 110a is composed of a hydraulic system connected to the disc brake mechanism provided on the left front wheel 2aL and the right front wheel 2aR, and the first brake system 110b is composed of the left rear wheel 2bL and A hydraulic system connected to a disc brake mechanism provided on the right rear wheel 2bR may be used. Further, the second brake system 110a includes a hydraulic system connected to a disc brake mechanism provided on the right front wheel 2aR and the right rear wheel 2bR on one side of the vehicle body, and the first brake system 110b includes the left front wheel 2aL on the vehicle body side. And a hydraulic system connected to a disc brake mechanism provided on the left rear wheel 2bL. The second brake system 110a is composed of a hydraulic system connected to a disc brake mechanism provided on the right front wheel 2aR and the left front wheel 2aL. The first brake system 110b is connected to the right rear wheel 2bR and the left rear wheel 2bL. A hydraulic system connected to the provided disc brake mechanism may be used.
Since the second brake system 110a and the first brake system 110b have the same structure, the corresponding parts in the second brake system 110a and the first brake system 110b are assigned the same reference numerals, and the second brake system The description of the first brake system 110b will be added in parentheses as appropriate, with a focus on the description of the system 110a.

  The second brake system 110a (first brake system 110b) has a first common hydraulic pressure path 112 and a second common hydraulic pressure path 114 that are common to the wheel cylinders 32FR and 32RL (32RR and 32FL). The vehicle behavior stabilization device 18 includes a regulator valve 116 including a normally open type solenoid valve disposed between the introduction port 26a and the first common hydraulic pressure path 112, and the introduction port disposed in parallel with the regulator valve 116. A first check valve 118 that permits the flow of brake fluid from the 26a side to the first common hydraulic pressure passage 112 side (blocks the flow of brake fluid from the first common hydraulic pressure passage 112 side to the introduction port 26a side); The first in-valve 120 formed of a normally open type solenoid valve disposed between the first common hydraulic pressure path 112 and the first outlet port 28a, and the first outlet port 28a disposed in parallel with the first inlet valve 120. Allows the brake fluid to flow from the side to the first common hydraulic pressure path 112 side (from the first common hydraulic pressure path 112 side to the first guide A second check valve 122 (which blocks the flow of brake fluid to the port 28a side) and a second valve comprising a normally open solenoid valve disposed between the first common hydraulic pressure path 112 and the second outlet port 28b. The in-valve 124 and the second in-valve 124 are arranged in parallel to allow the brake fluid to flow from the second outlet port 28b side to the first common hydraulic path 112 side (second outlet from the first common hydraulic path 112 side). And a third check valve 126 that prevents the flow of brake fluid to the port 28b side.

Further, the vehicle behavior stabilization device 18 includes a first out valve 128 including a normally closed type solenoid valve disposed between the first outlet port 28a and the second common hydraulic pressure path 114, and a second outlet port 28b. And the second common hydraulic pressure path 114, a second out valve 130 comprising a normally closed type solenoid valve, a reservoir 132 connected to the second common hydraulic pressure path 114, and a first common hydraulic pressure It is arranged between the path 112 and the second common hydraulic pressure path 114 and allows the brake fluid to flow from the second common hydraulic pressure path 114 side to the first common hydraulic pressure path 112 side (first common hydraulic pressure path). The fourth check valve 134 is disposed between the fourth check valve 134 and the first common hydraulic pressure path 112 (which blocks the flow of brake fluid from the 112 side to the second common hydraulic pressure path 114 side). A pump 136 that supplies brake fluid from the two common hydraulic pressure paths 114 to the first common hydraulic pressure path 112, a suction valve 138 and a discharge valve 140 provided before and after the pump 136, and a motor M that drives the pump 136. And a suction valve 142 formed of a normally closed solenoid valve disposed between the second common hydraulic pressure path 114 and the introduction port 26a.
In the second brake system 110a, the brake fluid generated in the second hydraulic chamber 98a of the motor cylinder device 16 is output from the output port 24a of the motor cylinder device 16 on the hydraulic pressure path close to the introduction port 26a. A pressure sensor Ph for detecting pressure is provided. A detection signal detected by the pressure sensor Ph is introduced into the control device 9.

  FIG. 3 is a block diagram showing electrical connection of the control device 7. The control device (FI / MG-ECU) (ECU: Electronic Control Unit) 7 detects an operation state (opening degree) of an accelerator pedal (not shown) of the vehicle 100 via an interface (not shown). An accelerator position sensor 201 serving as a part, a brake pedal stroke sensor 202 that detects an operation state (operation amount) of the brake pedal 12 by a driver, and a battery state detection that detects a state of charge (SOC) of the battery 5 A sensor 203 is connected. The control device 7 is connected to a motor / generator 3, a battery 5, and an inverter 6. Furthermore, as described above, the control device 7 can communicate with the control devices 8 and 9. The control device 7 performs powering of the vehicle 100, various controls for regeneration, charging control of the battery 5, and the like.

  FIG. 4 is a block diagram showing electrical connection of the control device 8. An accelerator position sensor 201, a brake pedal stroke sensor 202, and a battery state detection sensor 203 are connected to the control device 8 (ESB ECU) via an interface (not shown). Further, the control device 8 is connected to a motor 72 of a motor cylinder device (electric brake device) 16 and various valves such as the input device 14 described above (for convenience, the valves 209 are generally shown in FIG. 3). Has been. Further, as described above, the control device 8 can communicate with the control devices 7 and 9. The control device 8 controls a motor cylinder device (electric brake device) 16 (motor 72) serving as a first hydraulic pressure generating unit that electrically drives the wheel cylinders 32FL, 32RR, 32RL, and 32FR. Later).

  FIG. 5 is a block diagram showing electrical connection of the control device 9. The control device 9 (VSA ECU) receives a steering angle sensor 204 for detecting a rotation angle of a steering wheel (not shown) of the vehicle 100 and rotation speeds of four wheels 2aR, 2aL, 2bR, 2bL via an interface (not shown). A wheel speed sensor 205 that individually detects each wheel, a yaw rate acting on the vehicle 100, a yaw rate / lateral G sensor 206 that detects lateral G, and a select lever position that serves as a shift position detection unit that detects the shift position of the transmission of the vehicle 100 A sensor 207 and a vehicle speed sensor 210 serving as a vehicle speed detection unit that detects the vehicle speed of the vehicle 100 are connected. Further, the aforementioned accelerator position sensor 201, brake pedal stroke sensor 202, and battery state detection sensor 203 are connected to the control device 9. Further, the control device 9 includes the motor M of the vehicle behavior stabilization device 18 described above, various valves of the vehicle behavior stabilization device 18 and the like (generally shown in FIG. 4 as valves 208 for convenience). The pressure sensor Ph of the vehicle behavior stabilization device 18 is connected. Furthermore, as described above, the control device 9 can communicate with the control devices 7 and 8. The control device 9 is in fluid pressure (hydraulic) communication with the motor cylinder device 16 and is a vehicle behavior stabilization device 18 serving as a second fluid pressure generating unit that electrically drives the wheel cylinders 32FL, 32RR, 32RL, and 32FR. (Motor M, valves 208, etc.) are controlled (details will be described later).

  Next, the operation of the brake system of the vehicle 100 will be described. When the vehicle brake system 10 functions normally, the second shut-off valve 60a and the first shut-off valve 60b, which are normally open type solenoid valves, are closed by excitation, and the first shut-off solenoid valve, which is a normally closed type solenoid valve. The 3 shut-off valve 62 is opened by excitation (see FIG. 2). Accordingly, since the second hydraulic pressure system 70a and the first hydraulic pressure system 70b are blocked by the second cutoff valve 60a and the first cutoff valve 60b, the brake hydraulic pressure generated in the master cylinder 34 of the input device 14 is applied to the disc brake. It is not transmitted to the wheel cylinders 32FR, 32RL, 32RR, 32FL of the mechanisms 30a to 30d.

  At this time, the brake hydraulic pressure generated in the first pressure chamber 56b of the master cylinder 34 is transmitted to the hydraulic pressure chamber 65 of the stroke simulator 64 via the branch hydraulic pressure path 58c and the third shut-off valve 62 in the valve open state. Is done. The simulator piston 68 is displaced against the spring force of the return springs 66a and 66b by the brake hydraulic pressure supplied to the hydraulic pressure chamber 65, so that the stroke of the brake pedal 12 is allowed and a pseudo pedal reaction is achieved. A force is generated and applied to the brake pedal 12.

  In such a system state, when the control device 8 detects the depression of the brake pedal 12 by the driver by the brake pedal stroke sensor 202, the control device 8 drives the motor 72 of the motor cylinder device 16, and the driving force of the motor 72 is changed to the driving force. 2 is transmitted through the transmission mechanism 74, and the second slave piston 88a and the first slave piston 88b are displaced in the direction of arrow X1 in FIG. 2 against the spring force of the second return spring 96a and the first return spring 96b. Let Due to the displacement of the second slave piston 88a and the first slave piston 88b, the brake fluid in the second fluid pressure chamber 98a and the first fluid pressure chamber 98b is pressurized so as to be balanced, and a target brake fluid pressure is generated.

  The brake hydraulic pressures in the second hydraulic pressure chamber 98a and the first hydraulic pressure chamber 98b in the motor cylinder device 16 are discs via the first and second inlet valves 120 and 124 in the valve open state of the vehicle behavior stabilization device 18. Friction braking force required for each wheel 2aR, 2aL, 2bR, 2bL is transmitted to the wheel cylinders 32FR, 32RL, 32RR, 32FL of the brake mechanisms 30a-30d, and the wheel cylinders 32FR, 32RL, 32RR, 32FL are operated. Is granted.

  In other words, in the vehicle brake system 10, when the motor cylinder device 16 that functions as an electric brake device and the control device 8 that performs by-wire control are operating normally, the driver depresses the brake pedal 12 so that the brake fluid pressure is reduced. In the state where the connection between the master cylinder 34 generating the disc and the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, 32FL) for braking each wheel is shut off by the second shutoff valve 60a and the first shutoff valve 60b, A so-called brake-by-wire brake system in which the disc brake mechanisms 30a to 30d are operated with the brake fluid pressure generated by the motor cylinder device 16 becomes active.

  Further, the control device 9 performs behavior control corresponding to a side slip or the like while the vehicle 100 is traveling. That is, the control corresponds to a situation in which the rear portion of the vehicle 100 skids with a sharp handle while the vehicle 100 is traveling, or the vehicle 100 skids without being bent. Such a situation such as the vehicle 100 skidding can be detected by the control device 9 using the steering angle sensor 204, the wheel speed sensor 205, the yaw rate / lateral G sensor 206, and the like. Further, the operation amount of the brake pedal 12 at that time is also detected by the brake pedal stroke sensor 202 or the like. Then, the control device 9 detects the hydraulic pressure with the pressure sensor Ph of the vehicle behavior stabilization device 18 and controls the motor M and valves 208 of the vehicle behavior stabilization device 18 to control the left and right front wheels 2aR, 2aL, The friction braking force of the four wheels of the left and right rear wheels 2bR and 2bL is individually controlled. That is, the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, 32FL) are individually controlled. Thus, the behavior control of the vehicle 100 is performed by generating a friction braking force corresponding to a skid or the like while the vehicle 100 is traveling by the vehicle behavior stabilization device 18 (details are omitted because it is publicly known). Thus, the vehicle brake system 10 can directly drive and control the vehicle behavior stabilization device 18 separately from the motor cylinder device 16 by the control device 9.

  By the way, in the vehicle 100 which is an electric vehicle, when neither an accelerator pedal (not shown) nor the brake pedal 12 is operated, a braking force equivalent to an engine brake in a normal gasoline vehicle is applied to the regeneration by the motor / generator 3. Generated by power. The generation of a regenerative braking force equivalent to the engine brake of a vehicle driven by such an internal combustion engine follows the engine brake of a gasoline automobile.

However, when the battery 5 that stores electric power generated by regeneration is fully charged (SOC is 100%), the regenerative braking force cannot be generated.
Therefore, when the control device 7 detects that the battery 5 is fully charged by the battery state detection sensor 203, the control device 7 stops charging the battery 5 with the regenerative braking force by the motor / generator 3. The inverter 6 and the like are controlled so that the motor / generator 3 does not regenerate power.

  FIG. 6 is a flowchart illustrating the regeneration control performed by the motor / generator 3 in this case performed by the control device 7. First, the control device 7 (FI / MG-ECU) determines whether an accelerator pedal (not shown) or the brake pedal 12 is operated by the accelerator position sensor 201 and the brake pedal stroke sensor 202. (Steps S1, S2). When neither an accelerator pedal (not shown) nor the brake pedal 12 is operated (Yes in Step S1, Yes in S2), the battery state detection sensor 203 sets the amount of power stored in the battery 5 to a predetermined amount. Whether or not the battery is fully charged in the present embodiment (the same applies hereinafter) is determined (step S3). When the battery 5 is not fully charged (No in step S3), the battery 5, the inverter 6 and the like are controlled to generate the regenerative braking force by charging the battery 5 with the electric power generated by the motor / generator 3 ( Step S4). When the battery 5 is fully charged (Yes in step S3), the regenerative braking force is stopped by controlling the battery 5, the inverter 6 and the like so that the motor / generator 3 does not charge the battery 5 (step S3). S5). Then, it notifies the control devices 8 and 9 that the regeneration has ended (step S6).

In step S5, since the regenerative braking force disappears, the braking force corresponding to the engine brake in the vehicle equipped with the internal combustion engine is lost.
Therefore, in the vehicle 100 of the present embodiment, the control device 8 (ESB ECU) cooperates with the control device 7 (FI / MG-ECU), and engine braking in a gasoline vehicle is performed by friction braking force instead of regenerative braking force. Control is performed to generate a considerable friction braking force. FIG. 7 is a flowchart for explaining such control contents.

  First, the control device 8 (ESB ECU) starts the process of FIG. 7 when the regenerative braking force of the battery 5 stops and receives a notification (step S6) from the control device 7 (FI / MG-ECU). . First, it is determined whether or not there is no abnormality in the generation of friction braking force by the motor cylinder device (electric brake device) 16 (step S14). Thereby, an abnormality detection unit is realized. Specifically, it can be determined whether or not the motor 72 has a failure, or the occurrence of the abnormality can be determined when the vehicle 100 does not decelerate even though the friction braking force is generated. . If it is determined that there is an abnormality (Yes in step S14), the control device 9 (VSA ECU) is notified of this (step S15), and the process returns to step S11.

  When it is determined that there is no abnormality (No in Step S14), the motor cylinder device (electric brake device) 16 (the motor 72) is controlled to disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, 32FL). ) Is generated to generate a friction braking force (step S16). As a result, a braking force equivalent to an engine brake in a vehicle driven by the internal combustion engine is generated by the friction braking force. As described above, in the control of FIGS. 6 and 7, the regenerative braking force and the friction braking force are selectively used as the braking force corresponding to the engine brake in the vehicle driven by the internal combustion engine depending on whether or not the battery 5 is fully charged. Thus, the control devices 7 and 8 realize the first braking force control unit.

  When the control device 9 is notified in step S15, the control device 9 (VSA ECU) starts the following processing. FIG. 8 is a flowchart of processing executed by the control device 9 in this case. First, the control device 9 determines whether or not the shift position of the transmission of the vehicle 100 is in the travel range (D range) using the select lever position sensor 207 (step S25). When the shift position is in the D range (Yes in step S25), the first braking mode is executed (described later) (step S26). When the shift position is in a range (B range) for selecting to increase the braking force equivalent to engine braking in a vehicle equipped with an internal combustion engine compared to the D range (Yes in step S27), the second braking is performed. The mode is executed (described later) (step S28).

  In both the first braking mode and the second braking mode described above, the control device 9 (VSA ECU) does not go through the motor cylinder device (electric brake device) 16, and the motor M of the vehicle behavior stabilization device 18 The valves 208 are directly controlled to drive the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, 32FL) and generate a braking force equivalent to an engine brake in a vehicle driven by an internal combustion engine as a friction braking force. It is a mode to make it.

  As described above, when the regeneration cannot be performed and the generation of the friction braking force by the motor cylinder device (electric brake device) 16 is abnormal (Yes in step S14), the vehicle behavior stabilization device 18 is directly used. Is controlled to generate friction braking force. Thus, even when there is an abnormality in the generation of the friction braking force by the motor cylinder device (electric brake device) 16, the above-described regenerative braking force and the friction braking force by directly controlling the vehicle behavior stabilizing device 18 are obtained. By properly using it, a braking force equivalent to an engine brake in a vehicle driven by an internal combustion engine can be maintained. Thus, the control devices 7 and 9 realize a second braking force control unit.

In this case, as compared with the case of FIG. 7 in which the control device 8 controls the motor cylinder device (electric brake device) 16 to generate the friction braking force, the vehicle behavior stabilization device 18 is directly controlled to generate the friction braking force. In the case of FIG. 8 in which the friction is generated, the friction braking force is increased.
FIG. 9 is a graph for explaining the relationship between the acceleration applied to the vehicle 100 and the vehicle speed. In FIG. 9, the vertical axis indicates the acceleration applied to the vehicle 100. That is, when the acceleration is greater than 0, the motor / generator 3 performs powering. Further, the case where the acceleration is an acceleration (deceleration) smaller than 0 corresponds to the case where regeneration is performed by the motor / generator 3 in principle. The vehicle speed increases from 0 to the right.

  FIG. 9 shows a case where a braking force equivalent to an engine brake in a vehicle driven by the internal combustion engine is generated in the vehicle 100 which is an electric vehicle without operating an accelerator pedal (not shown) and the brake pedal 12. The relationship between the acceleration applied to the vehicle 100 and the vehicle speed is shown. Here, the description will be focused on the first braking mode (step S26) and the second braking by the friction braking force generated by directly controlling the vehicle behavior stabilizing device 18 shown in FIG. Regarding the mode (step S28), the regenerative braking force and the friction braking force generated by controlling the motor cylinder device (electric brake device) 16 will also be described.

  Reference numeral 251 indicates a braking force equivalent to an engine brake in a vehicle driven by an internal combustion engine when the shift position of the transmission of the vehicle 100 is in the D range. In this case, the braking force corresponding to the engine brake is gradually increased as the vehicle speed increases, so that the deceleration applied to the vehicle 100 gradually increases. As described above, if the battery 5 is fully charged and the motor cylinder device (electric brake device) 16 is abnormal (Yes in step S14), the friction braking force generated by directly controlling the vehicle behavior stabilizing device 18 is generated. Thus, the braking force indicated by reference numeral 251 is generated. This is the operation of the first braking mode (step S26) described above.

If the battery 5 is not fully charged, regenerative braking force is generated (step S4). In this case, the regenerative braking force may be smaller than 251 or the same as long as it is in the D range.
Further, when there is no abnormality in the motor cylinder device (electric brake device) 16 (No in step S14) and the motor cylinder device 16 is driven to generate a friction braking force (step S16), the friction braking force is D If it is a range, it makes it smaller than the case of the code | symbol 251 which is the 1st braking mode.

  Reference numeral 252 indicates the regenerative braking force in the B range when the battery 5 is not fully charged. Also in this case, as the vehicle speed increases, the braking force corresponding to the engine brake described above is gradually increased so that the deceleration applied to the vehicle 100 gradually increases according to the vehicle speed. In this case, because of the B range, the braking force is increased and the deceleration is increased compared to the case of the D range denoted by reference numeral 251.

  On the other hand, when the battery 5 is fully charged in the B range, the regenerative braking force is not generated and the friction braking force is generated. In this case, if there is an abnormality as described above (Yes in step S14), the friction braking force is as indicated by reference numeral 253. That is, if the battery 5 is fully charged and there is an abnormality in the motor cylinder device (electric brake device) 16 (Yes in step S14), the code is generated by the friction braking force generated by directly controlling the vehicle behavior stabilizing device 18. The braking force shown at 253 is generated. This is the operation of the second braking mode (step S28) described above.

  The friction braking force in the case of the reference numeral 253 gradually approaches the braking force of the reference numeral 251 as the vehicle speed increases from the magnitude of the braking force in the reference numeral 252, and finally the first braking force in the case of the D range. The braking force is the same as that in the case of reference numeral 251 which is the braking mode. That is, compared with the B range when the battery 5 is not fully charged (reference numeral 252), the B range when the battery 5 is fully charged has a braking force equivalent to the engine brake of the vehicle driven by the internal combustion engine. In the area where the vehicle speed is high, it is the same as in the D range.

Even when the battery 5 is fully charged in the B range, if there is no abnormality in the motor cylinder device (electric brake device) 16 described above (No in step S14), the motor cylinder device 16 is driven to cause friction. A braking force is generated (step S16). The friction braking force in this case is smaller than that in the case of the friction braking force in the second braking mode indicated by reference numeral 253.
Note that the control of the regenerative braking force and the friction braking force described above with reference to FIG. 9 is performed by the control devices 7 to 9 when the vehicle speed of the vehicle 100, the shift position of the transmission, and the battery 5 are fully charged. It can be performed by referring to a control map prepared in advance depending on whether or not.

  In the above description, an example in which three control devices (ECUs) 7 to 9 cooperate to control regenerative braking and friction braking (processing in FIGS. 6 to 8) has been described. You may make it perform the process of FIGS. 6-8 by two control apparatuses (ECU).

  According to the present embodiment, when the battery 5 is fully charged and regenerative braking force cannot be generated, even if an abnormality occurs in the motor cylinder device 16 (such as the motor 72), the vehicle behavior stabilization device 18 is directly driven. Thus, it is possible to generate a braking force equivalent to an engine brake in a vehicle equipped with an internal combustion engine and to appropriately generate a braking force equivalent to the engine brake (steps S26 and S28).

  Also, when it is necessary to generate a braking force equivalent to engine braking that differs depending on the shift position depending on whether the shift position of the transmission is in the D range or the B range (steps S25 to S28), an appropriate response can be made. Yes (reference numerals 251 to 253 in FIG. 9).

  In this case, when the battery 5 is fully charged and the regenerative braking force cannot be generated, and when the B range is reached in which the braking force equivalent to the engine brake in the vehicle equipped with the internal combustion engine is larger than that in the D range (step). S28) As the vehicle speed increases, the friction braking force can be gradually brought closer to that in the D range (in the case of reference numeral 253 in FIG. 9).

Further, in a situation where the abnormality of the motor cylinder device 16 (the motor 72, etc.) has occurred, the friction braking force equivalent to the engine brake generated by directly driving the vehicle behavior stabilization device 18 is normal in the motor cylinder device 16. In such a case, it is possible to increase the braking force equivalent to the engine brake by making the friction braking force generated via the motor cylinder device 16 larger, so that traveling can be cautious.
Note that the magnitude of the braking force corresponding to the engine brake in the vehicle equipped with the internal combustion engine, which is generated by the above-described regenerative braking force and friction braking force, is set in advance for each vehicle type.

3 Motor generator
7 Control device (first and second braking force control unit)
8. Control device (first braking force control unit)
9 Control device (second braking force control unit)
16 Motor cylinder device (first hydraulic pressure generator)
18 Vehicle behavior stabilization device (second hydraulic pressure generator)
30a-30d Disc brake mechanism (friction braking force generator)
100 vehicle 201 accelerator opening sensor (accelerator state detection unit)
202 Brake pedal stroke sensor (brake state detector)
203 battery state detection sensor (charge storage amount detection unit)
207 Select lever position sensor (shift position detector)
210 Vehicle speed sensor (vehicle speed detector)

Claims (4)

A friction braking force generating section for generating the friction braking force of the vehicle by hydraulic pressure;
A first hydraulic pressure generator that is electrically driven to operate the friction braking force generator with hydraulic pressure;
A second hydraulic pressure generator that hydraulically communicates with the first hydraulic pressure generator and operates the friction braking force generator with hydraulic pressure;
An accelerator state detector for detecting the operation state of the accelerator pedal;
A brake state detector for detecting the operation state of the brake pedal;
When the accelerator pedal and the brake pedal are not operated by the detection of the accelerator state detection unit and the brake state detection unit, the regenerative braking force by the electric motor that drives the vehicle and the driving of the first hydraulic pressure generation unit A first braking force control unit that generates a braking force equivalent to an engine brake in a vehicle driven by an internal combustion engine by the friction braking force generated by the friction braking force generation unit by
An abnormality detection unit for detecting occurrence of an abnormality related to the generation of the friction braking force by the first braking force control unit;
The friction braking force generated in the friction braking force generation unit by the regenerative braking force and the second hydraulic pressure generation unit in the non-operating state when the abnormality detection unit detects the occurrence of the abnormality. A second braking force control unit that generates a braking force equivalent to the engine brake;
A vehicle braking system comprising: A shift position detecting unit for detecting a shift position of the transmission of the vehicle;
2. The vehicle braking system according to claim 1, wherein the second braking force control unit causes the second braking force control unit to generate the friction braking force that varies depending on the shift position. A storage amount detection unit that detects a storage amount of a battery that stores power regenerated by the electric motor; and
A vehicle speed detector for detecting the vehicle speed of the vehicle;
Further comprising
When the second braking force control unit detects that the shift position detection unit is in a shift position where the braking force equivalent to the engine brake when in the non-operating state is larger than that in the traveling range, When the storage amount detected by the storage amount detection unit is greater than or equal to a predetermined amount, the second friction braking force generation unit generates the vehicle as the vehicle speed detected by the vehicle speed detection unit increases. The vehicle braking system according to claim 2, wherein the friction braking force is gradually brought closer to that in the traveling range.   The said 2nd braking force control part makes the said friction braking force to generate larger than the said friction braking force to generate | occur | produce in the said 1st braking force control part, The any one of Claims 1-3 characterized by the above-mentioned. The braking system for a vehicle according to one item.

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