JP2012210879A - Brake actuator - Google Patents

Abstract

A brake actuator capable of reducing the cost of a brake system is provided.
An introduction port 26b and an introduction port 26a connected to a first pressure chamber 56b and a second hydraulic pressure chamber 56a in a tandem master cylinder 34, a motor, and a motor, respectively, are connected to a second brake system 110a and a first brake system 110b. Pressure sensors Pp for detecting downstream pressures of the first shutoff valve 60b, the second shutoff valve 60a, and the first shutoff valve 60b that shut off the flow of brake fluid from the introduction ports 26c and 26d that connect the cylinder device 16 and the master cylinder 34. The pressure sensor Pm for detecting the upstream pressure of the second cutoff valve 60a, the stroke simulator 64, and the third cutoff valve 62 are integrally configured.
[Selection] Figure 2

Description

  The present invention relates to a brake actuator applicable to a by-wire brake system.

  The By Wire brake system converts the driver's braking operation into an electrical signal, and uses that signal to activate an external pressure source to apply the necessary braking force to the wheel (wheel cylinder). It is done. In addition, between the external pressure source and the wheel, the slip of the wheel is excessive during control or braking so that the hydraulic pressure from the external pressure source is increased or decreased to a size corresponding to the operation amount of the brake pedal. There have been proposed various ones equipped with a brake actuator for performing anti-lock control to prevent the occurrence (see, for example, Patent Document 1).

JP 2006-007874 A

  However, in a conventional brake system including a brake actuator, a valve, a stroke simulator, a sensor, and the like that block the hydraulic pressure from the master cylinder from being applied to the brake actuator are provided in the housing constituting the master cylinder. There has been a problem in that the liquid path has to be processed for each of the housing constituting the cylinder and the housing constituting the brake actuator, resulting in high costs. Further, a harness and a connector for electrically connecting the valve and the sensor have to be provided for each housing, which is also expensive in this respect.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a brake actuator capable of reducing the cost of the brake system.

  The present invention is connected to four output ports each connected to a wheel cylinder provided corresponding to each wheel of the vehicle, and to a first hydraulic pressure chamber and a second hydraulic pressure chamber in a tandem master cylinder, respectively. The first input port, the second input port, the normally open first shut-off valve that shuts off the first input port and the output port, and the second input port and the output port are shut off. A normally open second shut-off valve, a stroke simulator provided upstream of the first shut-off valve or the second shut-off valve in one of the first input port and the second input port, and the stroke simulator A normally closed pedal force shut-off valve that selectively opens communication with the first input port or the second input port, and a supply fluid path between the first shut-off valve and the wheel cylinder, And a third input port that is connected to a supply liquid path between the second cutoff valve and the wheel cylinder, and selectively connects an external pressure source, and the first input port includes the first cutoff valve. A first pressure sensor provided on the downstream side of the second pressure sensor, a second pressure sensor provided on the upstream side of the second shut-off valve at the second input port, and a supply valve connected to the supply liquid path via the suction valve, A pump that sucks and pressurizes hydraulic fluid that passes through the suction valve or hydraulic fluid from a low-pressure source, supplies the hydraulic fluid to the supply liquid passage, a regulator valve that adjusts the differential pressure upstream and downstream of the pump, and the wheel cylinder A normally closed pressure reducing valve that depressurizes the wheel cylinder by moving the hydraulic fluid to the low pressure source side, and selectively shuts off the supply liquid path and the wheel cylinder. And Hirakishiki pressure valve, the characterized in that it comprises integrated.

  In the present invention, a configuration including a regulator valve, a normally closed pressure reducing valve, a normally open pressure valve, a pump, etc., and valves (first cutoff valve, second cutoff valve, pedal force cutoff valve), stroke simulator, sensors, etc. The first pressure sensor and the second pressure sensor are integrated. This eliminates the need to provide the valves and sensors in the master cylinder, so that mass-produced products can be used as the master cylinder, and the oil passage (hydraulic pressure passage) is all processed on the brake actuator side. Therefore, the cost can be reduced. In addition, since the electrodes of the valves and sensors and the housing provided on the master cylinder side can be concentrated on the brake actuator, the cost can be further reduced.

  As a result, the number of harnesses and connectors connecting the first shut-off valve, the second shut-off valve, the stroke simulator, the pedal force shut-off valve, the first pressure sensor and the second pressure sensor, which have been provided separately, can be reduced, and the cost can be reduced. It becomes.

  Further, by providing a third input port for connecting an external pressure source (corresponding to the motor cylinder device described in the embodiment), it can be easily applied to a system (bilateral brake system) including a by-wire type brake actuator. In addition, a reaction force can be generated by a stroke simulator when driven by a by-wire system.

  Further, in a state where the third input port is mechanically closed, the first shut-off valve and the second shut-off valve are closed and the pedal force shut-off valve is opened, based on a detection signal of the second pressure sensor, And an internal by-wire control means for controlling the detection value of the first pressure sensor to be a value corresponding to the detection signal of the second pressure sensor by driving the pump and the regulator valve. To do.

  According to this, a by-wire type vehicle brake system can be realized while applying an appropriate reaction force without using a special external pressure source (hydraulic pressure generating means). That is, even in a configuration in which an external pressure source is not connected to the third input port, by closing the first shutoff valve and the second shutoff valve and opening the pedal effort shutoff valve, the reaction force is generated by the stroke simulator, A braking force can be generated by controlling the regulator valve. Accordingly, it is possible to easily cope with a mode in which a by-wire type brake is required due to an external request, such as a regenerative brake system.

  ADVANTAGE OF THE INVENTION According to this invention, the brake actuator which can aim at the cost reduction of a brake system can be provided.

It is a figure showing the arrangement composition in vehicles of the brake system for vehicles to which the brake actuator concerning one embodiment of the present invention was applied. 1 is a schematic configuration diagram of a vehicle brake system. The brake actuator which concerns on this embodiment is shown, (a) is a front view, (b) is a side view, (c) It is a top view. It is a disassembled perspective view which shows the brake actuator which concerns on this embodiment. It is a flowchart which shows the braking method in the brake system for vehicles provided with the brake actuator which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a diagram showing an arrangement configuration in a vehicle of a vehicle brake system to which a brake actuator according to an embodiment of the present invention is applied. Note that the front, rear, left and right directions of the vehicle V are indicated by arrows in FIG. The vehicle brake system 10 is provided so as to be mountable on various vehicles including, for example, an automobile driven only by an engine (internal combustion engine), a hybrid automobile, an electric automobile, and a fuel cell automobile.

  The vehicle brake system 10 including the brake actuator 18 according to the present embodiment includes a by-wire type brake system that transmits an electric signal to operate the brake and a fail-safe type for normal use. As described above, both the conventional hydraulic brake system that transmits the hydraulic pressure and operates the brake is provided.

  As shown in FIG. 1, the brake actuator 18 is connected to the master cylinder device 14 and the motor cylinder device 16 (external pressure source) to constitute the vehicle brake system 10. The vehicle brake system 10 can be applied to any of front-wheel drive vehicles, rear-wheel drive vehicles, and four-wheel drive vehicles.

  Here, the master cylinder device 14 is applied to a right-hand drive vehicle, and is fixed to the right side of the dashboard 2 in the vehicle width direction via a bolt or the like. The master cylinder device 14 may be applied to a left-hand drive vehicle.

  The motor cylinder device 16 is disposed, for example, on the left side in the vehicle width direction opposite to the master cylinder device 14 and is attached to a vehicle body such as a left side frame via a mounting bracket (not shown). The motor cylinder device 16 may be configured to generate the brake fluid pressure based not only on an electric signal corresponding to a driver's brake operation but also on an electric signal corresponding to another physical quantity. The electrical signal corresponding to the other physical quantity is, for example, an ECU (Electronic Control Unit) that uses a sensor or the like to determine the situation around the vehicle V without relying on the driver's brake operation, as in an automatic brake system. A signal for avoiding a collision of the vehicle V and the like.

  The brake actuator 18 suppresses, for example, an ABS (anti-lock brake system) function for preventing wheel lock during braking, a TCS (traction control system) function for preventing wheel slipping during acceleration, and a side slip during turning. For example, it is attached to the vehicle body via a bracket at the right front end in the vehicle width direction. The brake actuator 18 may have a function having only an ABS function for preventing wheel lock during braking.

  Further, the brake actuator 18 is connected to a master cylinder through piping tubes 22a and 22b in a structure mounting chamber R in which a structure 3 such as an engine and a traveling motor provided in front of the dashboard 2 of the vehicle V is mounted. It is connected to the device 14, is connected to the motor cylinder device 16 via the pipes 22c and 22d, and the master cylinder device 14 and the motor cylinder device 16 are arranged separately from each other.

  FIG. 2 is a schematic configuration diagram of the vehicle brake system.

  The brake actuator 18 is provided with four lead-out ports (output ports) 28a, 28b, 28c, and 28d. The outlet port 28a is connected to the wheel cylinder 32FR of the disc brake mechanism 30a provided on the right front wheel by the piping tube 22g. The lead-out port 28b is connected to a wheel cylinder 32RL of the disc brake mechanism 30b provided on the left rear wheel by the piping tube 22h. The lead-out port 28c is connected to the wheel cylinder 32RR of the disc brake mechanism 30c provided on the right rear wheel by the piping tube 22i. The lead-out port 28d is connected to the wheel cylinder 32FL of the disc brake mechanism 30d provided on the left front wheel by the 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, and 32FL increases, each wheel cylinder 32FR, 32RL, 32RR, and 32FL operates, and the corresponding wheel (right front wheel, left rear wheel, right rear wheel, left front wheel). ) Is applied with braking force. The detailed configuration of the brake actuator 18 will be described after the master cylinder device 14 and the motor cylinder device 16 are described.

  The master cylinder 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 from each other 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.

  Instead of providing the cup seals 44a and 44b on the outer peripheral surfaces of the second piston 40a and the first piston 40b, packings may be provided on the inner peripheral surface of the cylinder tube 38, respectively.

  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 46a (46b) and each relief port 52a (52b) are provided so as to join and communicate with a reservoir chamber (not shown) in the first reservoir 36, respectively.

  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 output port 54a, and the first pressure chamber 56b is provided so as to communicate with the output port 54b.

  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 driving force transmission unit 73 converts a gear mechanism (deceleration mechanism) 78 that transmits the rotational driving force of the motor 72, and converts this rotational driving force into a linear driving force along the axial direction of the ball screw shaft (screw) 80a. And a driving force transmission mechanism 74 including a ball screw structure 80.

  The gear mechanism 78 includes a pinion gear 78a fixed to the output shaft of the motor 72, an idle gear 78b meshed with the pinion gear 78a, and a ring gear 78c meshed with the idle gear 78b.

  The ball screw structure 80 is provided with a nut 80c that rotates by receiving the rotational driving force of the motor 72, and is engaged (screwed) with the nut 80c so as to be movable in the axial direction, and the front end thereof is the second slave piston 88a. And a ball screw shaft 80a (screw) that presses the second slave piston 88a (piston) and a ball 80b (see FIG. 2) that is arranged to roll in a thread groove on the ball screw shaft 80a. ing.

  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 master cylinder device 14 by a piping tube 86, and the brake fluid stored in the first reservoir 36 is supplied to the second reservoir 84 via the piping tube 86. It is provided so as to be supplied into the reservoir 84.

  In the cylinder body 82, a second slave piston 88a and a first slave piston 88b that are spaced apart from each other by a predetermined distance along the axial direction of the cylinder body 82 are slidably disposed. The second slave piston 88a is disposed close to the ball screw structure 80, 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.

  An annular guide piston 230 that provides a fluid-tight seal between the outer peripheral surface of the second slave piston 88a and the driving force transmission mechanism 74 and guides the second slave piston 88a so as to be movable in the axial direction thereof. It arrange | positions so that the outer peripheral surface of 2 slave piston 88a may be opposed. A slave cup seal 90 c is attached to the inner peripheral surface of the guide piston 230. A slave cup seal 90b is attached to the outer peripheral surface on the front end side of the second slave piston 88a via an annular stepped portion. A second back chamber 94a communicating with a reservoir port 92a described later is formed between the slave cup seal 90c and the slave cup seal 90b. A second return spring 96a is disposed between the second slave piston 88a and the first slave piston 88b.

  On the other hand, a pair of slave cup seals 90a and 90b are mounted on the outer peripheral surface of the first slave piston 88b via an annular stepped portion. A first back chamber 94b communicating with a reservoir port 92b described later is formed between the pair of slave cup seals 90a and 90b. A first return spring 96b is disposed between the first slave piston 88b and the front end portion of the cylinder body 82.

  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.

  A regulating means 100 is provided between the second slave piston 88a and the first slave piston 88b to regulate the maximum and minimum separation distance between the second slave piston 88a and the first slave piston 88b. The first slave piston 88b is provided with a stopper pin 102 that restricts a sliding range of the first slave piston 88b and prevents an overreturn to the second slave piston 88a side. At the time of backup when braking with the brake fluid pressure generated at 34, the failure of another system is prevented when one system fails.

  The brake actuator 18 includes a second brake system 110a that controls the disc brake mechanisms 30a and 30b (the wheel cylinder 32FR and the wheel cylinder 32RL) for the right front wheel and the left rear wheel, and the disc brake mechanisms 30c and 30d for the right rear wheel and the left front wheel. (First brake system 110b for controlling (wheel cylinder 32RR, wheel cylinder 32FL), second cutoff valve (normally open type second cutoff valve) 60a, first cutoff valve (normally open type first cutoff valve) 60b, A third shutoff valve (normally closed pedal force shutoff valve) 62, a stroke simulator 64, a pressure sensor (first pressure sensor) Pp, and a pressure sensor (second pressure sensor) Pm are provided.

  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 includes a hydraulic system connected to a disc brake mechanism provided on the left front wheel and the right front wheel, and the first brake system 110b includes the left rear wheel and the right rear wheel. It may be a hydraulic system connected to a disc brake mechanism provided in the. Further, the second brake system 110a includes a hydraulic system connected to a disc brake mechanism provided on the right front wheel and the right rear wheel on one side of the vehicle body, and the first brake system 110b includes the left front wheel and the left rear wheel on the vehicle body side. A hydraulic system connected to a disc brake mechanism provided on the wheel may be used. The second brake system 110a includes a hydraulic system connected to a disc brake mechanism provided on the right front wheel and the left front wheel, and the first brake system 110b includes a disc provided on the right rear wheel and the left rear wheel. A hydraulic system connected to the 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 common first common hydraulic pressure path (supply liquid path) 112 and a second common hydraulic pressure path (with respect to the wheel cylinders 32FR and 32RL (32RR and 32FL)). Supply liquid path) 114.

  The second brake system 110a includes a regulator valve 116 including a normally open solenoid valve disposed between the introduction port 26a and the first common hydraulic pressure path 112, and the introduction port 26a disposed in parallel with the regulator valve 116. The first check permits the flow of brake fluid (hydraulic fluid) from the 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). A valve 118, a first in-valve (normally open type pressurizing valve) 120 including a normally open type solenoid valve disposed between the first common hydraulic pressure path 112 and the first outlet port 28a; The brake fluid is allowed to flow from the first outlet port 28a side to the first common hydraulic pressure path 112 side in parallel with the first outlet port 28a (first common port). A normal valve disposed between the second check valve 122 (which blocks the flow of brake fluid from the hydraulic pressure path 112 side to the first outlet port 28a side) and the first common hydraulic path 112 and the second outlet port 28b. A second in-valve (normally-open pressurizing valve) 124 composed of an open-type solenoid valve and a brake fluid flow from the second outlet port 28b side to the first common hydraulic path 112 side arranged in parallel with the second in-valve 124. And a third check valve 126 that permits flow (blocks the flow of brake fluid from the first common hydraulic pressure path 112 side to the second outlet port 28b side).

  Further, the second brake system 110a includes a first out valve (normally closed pressure reducing valve) 128 formed of a normally closed solenoid valve disposed between the first outlet port 28a and the second common hydraulic pressure path 114, Connected to the second common hydraulic pressure path 114 and a second out valve (normally closed pressure reducing valve) 130 consisting of a normally closed solenoid valve disposed between the second outlet port 28 b and the second common hydraulic pressure path 114. The reservoir (low pressure source) 132, the first common hydraulic pressure path 112, and the second common hydraulic pressure path 114 are disposed between the second common hydraulic pressure path 114 side and the first common hydraulic pressure path 112 side. A fourth check valve 134 that allows the brake fluid to flow (blocks the brake fluid from the first common hydraulic pressure passage 112 side to the second common hydraulic pressure passage 114 side), and the fourth check valve 1. 4 and the first common hydraulic pressure path 112, a pump 136 that supplies brake fluid from the second common hydraulic pressure path 114 side to the first common hydraulic pressure path 112 side, and provided before and after the pump 136. A suction valve 138 and a discharge valve 140, a motor M for driving the pump 136, a suction valve 142 comprising a normally closed solenoid valve disposed between the second common hydraulic pressure path 114 and the introduction port 26a, Is provided.

  The second shut-off valve 60a is a normally open solenoid valve, and is provided in a second hydraulic pressure path (supply liquid path) 58a that connects the second brake system 110a and the introduction port 26a. In the second hydraulic pressure path 58a, a pressure sensor Pm is provided on the upstream side of the second shutoff valve 60a. 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.

  The first shutoff valve 60b is a normally open type solenoid valve, and is provided in a first hydraulic pressure path (supply liquid path) 58b that connects the first brake system 110b and the introduction port 26b. In the first hydraulic pressure path 58b, a pressure sensor Pp is provided on the downstream side of the first shutoff valve 60b. The pressure sensor Pp detects the hydraulic pressure downstream of the wheel cylinders 32RR and 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).

  The third shut-off valve 62 is a normally closed type (normally closed) solenoid valve, and is provided in a branch hydraulic pressure path 58e that branches from the first hydraulic pressure path 58b. A stroke simulator 64 is connected in series with the third shut-off valve 62 in the branch hydraulic pressure path 58e. 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 58e, 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. Provided.

  The stroke simulator 64 is a simulator 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 the first and second return springs 66a and 66b arranged in series. A piston 68, the pedal reaction force increase gradient is set low when the brake pedal 12 is 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 to become.

  The first hydraulic pressure path 58b is provided with a third hydraulic pressure path 58d that branches downstream from the first cutoff valve 60b and is connected to the introduction port 26d. The second hydraulic pressure path 58a is provided with a fourth hydraulic pressure path 58c that branches downstream from the second cutoff valve 60a and is connected to the introduction port 26c.

  FIG. 3 shows a brake actuator according to the present embodiment, where (a) is a front view, (b) is a side view, and (c) is a top view. FIG. 4 is an exploded perspective view showing the brake actuator according to the present embodiment.

  As shown in FIG. 3, the brake actuator 18 includes a housing 200 in which a flow path (liquid path) and the like are formed, a control device 300 (see FIG. 3C), a control box 400 that houses the control device 300, and a motor. It is comprised with M.

  The housing 200 is made of a substantially rectangular parallelepiped aluminum alloy casting or the like, and has a flow path (not shown) corresponding to the second brake system 110a and the first brake system 110b (see FIG. 2). A known method can be adopted for forming the flow path. Although not shown, a flow path (hydraulic pressure path) shown in the brake actuator 18 of FIG. 2 is formed in the housing 200.

  The housing 200 is formed with the introduction ports 26a, 26b, 26c, and 26d on the surface 200a to which the motor M is attached (see FIG. 3A). Further, the outlet ports 28a, 28b, 28c, and 28d are formed on the upper surface 200b of the housing 200 (see FIG. 3C). The motor M serves as a power source for the pump 136 (see FIG. 2), and is provided in the housing 200. Further, the motor M includes a terminal (not shown), and this terminal is connected to a connection terminal (not shown) provided in the control device 300.

  The control box 400 is formed in a substantially rectangular parallelepiped shape by a synthetic resin material that covers a surface 200c (see FIG. 4) opposite to the surface 200a to which the motor M is attached. Further, a connector portion 301 having terminals of a power supply line and a control line is provided on the side surface of the control box 400 (see FIG. 3B). A connector (not shown) provided in the harness is connected to the connector portion 301.

  As shown in FIG. 4, the housing 200 is formed with a mounting hole 202 in which the first shut-off valve 60b, the second shut-off valve 60a, and the third shut-off valve 62 are attached to the surface 200c on the side where the control box 400 is attached. The Further, a mounting hole 203 for mounting the pressure sensors Pp and Pm is formed in the surface 200c of the housing 200. Further, a mounting hole 201 to which the regulator valve 116, the first in valve 120, the second in valve 124, the first out valve 128, and the second out valve 130 are attached is formed in the surface 200c of the housing 200. The first cutoff valve 60b, the second cutoff valve 60a, the third cutoff valve 62, the regulator valve 116, the first in valve 120, the second in valve 124, the first out valve 128, the second out valve 130, and the pressure sensor Pp. , Pm is attached in a state in which a part (terminal portion) protrudes from the surface 200c of the housing 200.

  Further, a mounting hole 204 into which a component (reference numerals 66a, 66b, 68: see FIG. 2) of the stroke simulator 64 is formed is formed in the surface (lower surface) 200d of the housing 200. Further, a mounting hole 205 to which the pump 136 is mounted is formed in the surface (side surface) 200e of the housing 200. Although not shown, a mounting hole to which the other pump 136 is similarly attached is formed on the other side surface of the housing 200. The housing 200 is also formed with mounting holes (not shown) to which the reservoirs 132 and 132 are mounted.

  The control box 400 includes a first shut-off valve 60b, a second shut-off valve 60a, a third shut-off valve 62, pressure sensors Pp and Pm, a regulator valve 116, a first in valve 120, a second in valve 124, a first out valve 128, a first The two-out valve 130 is fixed to the surface 200c of the housing 200 so as to cover it. The control box 400 includes a first shut-off valve 60b, a second shut-off valve 60a, a third shut-off valve 62, a regulator valve 116, a first in valve 120, a second in valve 124, a first out valve 128, a second An electromagnetic coil (not shown) for driving the out valve 130 is provided. The control device 300 in the control box 400 is configured to be connected to an electromagnetic coil (not shown) or a terminal of the motor M.

  The control device 400 includes a CPU (Central Processing Unit), a ROM (Read Only Memory) storing a program, a RAM (Random Access Memory), an input / output unit, and the like mounted on an electronic circuit board, and a pressure sensor Pm. , Pp detection values (upstream hydraulic pressure, downstream hydraulic pressure), the first shut-off valve 60b, the second shut-off valve based on the detected values of the stroke sensor S (see FIG. 2) for detecting the operation amount of the brake pedal 12. 60a, the third shutoff valve 62, the regulator valve 116, the first in valve 120, the second in valve 124, the first out valve 128, the second out valve 130, and the motor M are controlled.

  An unillustrated power source (battery) is disposed near the brake actuator 18. As a result, the distance between the valves (the first cutoff valve 60b, the second cutoff valve 60a, the third cutoff valve 62), the sensors (pressure sensors Pm, Pp), and the motor M can be shortened. Can be prevented, and the performance of the valves, sensors, and motor M can be prevented from deteriorating.

  The vehicle brake system 10 including the brake actuator 18 according to the present embodiment is basically configured as described above. Next, the function and effect 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 energized to be closed, and a third shut-off type solenoid valve is used. The shut-off valve 62 is opened by excitation (see FIG. 2). Accordingly, since the second hydraulic pressure path 58a and the first hydraulic pressure path 58b of the brake actuator 18 are shut off via the second shutoff valve 60a and the first shutoff valve 60b, the brake fluid pressure generated in the master cylinder 34 is reduced. There is no transmission to the wheel cylinders 32FR, 32RL, 32RR, 32FL of the disc brake mechanisms 30a-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 58e 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. As a result, it is possible to obtain a brake feeling that is comfortable for the driver.

  In such a system state, when the control device 300 detects the depression of the brake pedal 12 by the driver, the control device 300 drives the motor 72 of the motor cylinder device 16 and transmits the driving force of the motor 72 via the driving force transmission mechanism 74. Then, the second slave piston 88a and the first slave piston 88b are displaced in the direction of the arrow X1 in FIG. 2 against the spring force of the second return spring 96a and the first return spring 96b. 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 to generate a desired brake fluid pressure.

  The brake hydraulic pressure in the second hydraulic pressure chamber 98a and the first hydraulic pressure chamber 98b in the motor cylinder device 16 is applied to the disc brake mechanism 30a via the first and second in-valves 120 and 124 in the valve open state of the brake actuator 18. To 30d wheel cylinders 32FR, 32RL, 32RR, 32FL, and the wheel cylinders 32FR, 32RL, 32RR, 32FL are operated to apply a desired braking force to each wheel.

  In other words, in the vehicle brake system 10 according to the present embodiment, the driver steps on the brake pedal 12 when the motor cylinder device 16 that functions as an external pressure source and the control device 300 that controls by-wire are operable. Thus, the communication between the master cylinder 34 that generates the brake fluid pressure and the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, and 32FL) that brake each wheel is communicated by the second cutoff valve 60a and the first cutoff valve 60b. In the shut-off state, a so-called brake-by-wire type 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. For this reason, in this embodiment, for example, it can be suitably applied to a vehicle such as an electric vehicle that does not have negative pressure due to an internal combustion engine that has been used for a long time.

  The operation of the second brake system 110a and the first brake system 110b (at the time of VSA control) by the brake actuator 18 will be described. Since the second brake system 110a and the first brake system 110b have the same configuration, the following description will be given with reference to the second brake system 110a.

  When the driver depresses the brake pedal 12, the regulator valve 116 is demagnetized and opened, the first in valve 120 and the second in valve 124 are demagnetized, and the first out valve 128 and the second out valve 130 are opened. Demagnetizes and closes. Therefore, the brake fluid pressure output from the output ports 24a and 24b of the motor cylinder device 16 in operation passes from the regulator valve 116 to the wheel cylinders 32FR and 32RL via the first in-valve 120 and the second in-valve 124 that are opened. Supplied and braking force is applied to the wheels.

  When the driver is not stepping on the brake pedal 12 and the pump 136 is driven by the motor M with the suction valve 142 excited and opened, the pump 136 is sucked from the motor cylinder device 16 through the suction valve 142. The brake fluid (hydraulic fluid) pressurized in step 1 is supplied to the regulator valve 116, the first in valve 120, and the second in valve 124. Therefore, by exciting the regulator valve 116 and adjusting the opening degree, the brake fluid pressure in the first common fluid pressure path 112 is regulated, and the first in-valve 120 and the second in-valve are opened by exciting the brake fluid pressure. By selectively supplying the wheel cylinders 32FR and 32RL via 124, the braking force can be individually controlled even when the driver does not step on the brake pedal 12.

  Therefore, the braking force of the four wheels can be individually controlled by the brake actuator 18 to increase the turning performance by increasing the braking force of the inner turning wheel, or to improve the straight running stability performance by increasing the braking force of the outer turning wheel. it can.

  Further, when the driver steps on the brake pedal 12 suddenly to avoid a collision, the brake fluid pressure generated by the motor cylinder device 16 is further increased by the pump 136, and the wheel is driven by the increased brake fluid pressure. Maximum braking force is generated in the cylinders 32FR, 32RL, 32RR, 32FL. That is, when the regulator valve 116 is energized and closed, and the pump 136 is driven by the motor M, the brake fluid pressure generated by the motor cylinder device 16 is sucked into the pump 136 via the suction valve 142 and further pressurized there. In this state, it is supplied to the wheel cylinders 32FR, 32RL, 32RR, 32FL via the first in-valve 120 and the second in-valve 124, thereby assisting the driver's braking operation and generating a large braking force for avoiding a collision. be able to.

  In addition, when the driver depresses the brake pedal 12 and detects that the left front wheel has a tendency to lock by stepping on the low friction coefficient road, for example, based on the output of a wheel speed sensor (not shown), The first in-valve 120 of the first brake system 110b is excited and closed, and the first out valve 128 is excited and opened to release the brake fluid pressure of the left front wheel wheel cylinder 32FL to the reservoir 132. After reducing the pressure to a predetermined pressure, the brake fluid pressure of the left front wheel wheel cylinder 32FL is maintained by demagnetizing the first out valve 128 and closing it. As a result, when the lock tendency of the left front wheel wheel cylinder 32FL is resolved, the first in-valve 120 is demagnetized to open the brake fluid pressure from the output port 24b of the motor cylinder device 16 to the left front wheel. The braking force is increased by supplying the cylinder 32FL to a predetermined pressure.

  When the left front wheel becomes locked again due to this pressure increase, ABS (anti-lock brake) that minimizes the braking distance while suppressing the lock on the left front wheel by repeating the pressure reduction → hold → pressure increase.・ System) Control can be performed.

  The ABS control when the left front wheel wheel cylinder 32FL tends to lock has been described above. However, the right rear wheel wheel cylinder 32RR, the right front wheel wheel cylinder 32FR, and the left rear wheel wheel cylinder 32RL tend to lock. The ABS control can be performed in the same manner.

  While the above-described VSA control (including ABS control) is executed, the first shut-off valve 60b and the second shut-off valve 60a are maintained in the closed state, so that the hydraulic pressure change due to the operation of the brake actuator 18 is kicked. It is possible to prevent transmission from the master cylinder 34 to the brake pedal 12 as a back.

  On the other hand, when the motor cylinder device 16 or the like becomes inoperable, the second shut-off valve 60a and the first shut-off valve 60b are opened, the third shut-off valve 62 is closed, and the first in-valve is closed. 120, 120 and the second in valves 124, 124 are automatically opened, and the first out valves 128, 128 and the second out valves 130, 130 are automatically closed, so that the master cylinder 34 The generated brake fluid pressure is transmitted to the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, and 32FL), and the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, and 32FL) are operated. The so-called traditional hydraulic brake system becomes active.

  In the brake actuator 18 according to the present embodiment, control based on the flowchart shown in FIG. 5 is performed. Hereinafter, the control in a state where the motor cylinder device 16 is disconnected from the introduction ports 26c and 26d and the introduction ports 26c and 26d are mechanically closed will be described. The state of being mechanically closed includes a state in which the motor cylinder device 16 is not attached to the brake actuator 18 (a state in which the introduction ports 26c and 26d are plugged), and a state in which the motor cylinder device 16 has failed. Etc. In the braking method described below, the internal by-wire control means is started when the driver of the vehicle V turns on an ignition switch IG (not shown).

  First, in step S1, the control device 300 transmits a closing instruction to the first cutoff valve 60b and the second cutoff valve 60a, and puts the first cutoff valve 60b and the second cutoff valve 60a into a closed state. Due to this valve closing, the upstream side (master cylinder 34 side) and the downstream side (wheel cylinders 32FR, 32RL, 32RR, 32FL side) of the first cutoff valve 60b and the second cutoff valve 60a cannot transmit the hydraulic pressure to each other. Is cut off. That is, the upstream hydraulic pressure (upstream hydraulic pressure) is not transmitted as the downstream hydraulic pressure (downstream hydraulic pressure), but the downstream hydraulic pressure can be set and controlled independently of the upstream hydraulic pressure. become.

  In addition, the control device 300 transmits an opening instruction to the third shut-off valve 62, so that the third shut-off valve 62 is opened. When the third shut-off valve 62 is opened, the stroke simulator 64 applies an appropriate reaction force to the brake pedal 12 while absorbing the brake fluid that flows as the brake pedal 12 is operated.

  In step S2, the control device 300 determines whether or not the stroke sensor (operation amount detection means) S has detected a brake operation (brake operation amount). If a brake operation amount greater than or equal to a predetermined value corresponding to the operation of the brake pedal (brake operation unit) 12 by the driver is detected (Yes in step S2), the process proceeds to step S3, and if not detected (step S2, No), step S2 is repeated.

  In step S <b> 3, the control device 300 acquires the value of the upstream hydraulic pressure Pu (upstream hydraulic pressure value) generated by the brake pedal operation by the driver. The upstream fluid pressure Pu (upstream fluid pressure value) can be detected by the pressure sensor Pm. In addition, based on the brake operation amount (depression operation amount) of the brake pedal 12 detected by the stroke sensor (operation amount detection means) S, estimation is performed using the correspondence relationship between the brake operation amount and the upstream hydraulic pressure value that has been obtained in advance. May be.

  In step S4, the control device 300 sets a target value (target downstream hydraulic pressure) of the downstream hydraulic pressure Pd generated downstream of the first cutoff valve 60b and the second cutoff valve 60a. The target downstream hydraulic pressure can be determined based on the value of the pressure sensor Pm (upstream hydraulic pressure value). That is, for example, the control device 300 includes a map (which is obtained in advance by experiment, simulation, or the like) such that the target downstream hydraulic pressure increases as the upstream hydraulic pressure value increases, and the target downstream hydraulic pressure is determined based on this map. Set the pressure.

  In step S5, the control device 300 controls the brake actuator 18 (first brake system 110b, second brake system 110a). That is, the control device 300 drives the motor M to operate the pumps 136 and 136 and controls the regulator valves 116 and 116 so that the target downstream hydraulic pressure set in step S4 is reached.

  That is, when the pump 136 is driven by the motor M, the brake fluid (hydraulic fluid) pressurized by the pump 136 is supplied to the regulator valve 116, the first in-valve 120, and the second in-valve 124. Accordingly, the first in-valve that regulates the brake fluid pressure in the first common hydraulic pressure passage 112 by exciting the regulator valve 116 and adjusting the opening, and opens the brake fluid pressure to a predetermined opening by excitation. By supplying the wheel cylinders 32FR, 32RL, 32RR, 32FL via the 120 and the second in-valve 124, a braking force corresponding to the target downstream pressure can be applied to each wheel. Whether or not the target downstream pressure has been reached can be determined based on the pressure sensor Pp.

  In step S6, the control device 300 determines whether or not the ignition switch IG has been turned off by the driver. If it is determined that the ignition switch IG has been turned off (Yes), the control device 300 ends the series of braking methods (end) and is turned off. If it is determined that it is not (No), the process returns to step S2.

  In the above-described braking method (brake system) in which the introduction ports 26c and 26d are mechanically closed, the configuration in which the braking force is applied based on the power of only the motor M has been described as an example. The configuration is not limited, and a configuration in which a braking force due to regeneration is taken into consideration with respect to the braking force due to the above-described hydraulic pressure (hydraulic braking force) may be employed. For example, the control device 300 determines the braking force (regenerative braking force) by regeneration based on the amount of brake operation, the amount of electricity (charge, electric power) stored in a high-voltage battery (not shown), the current maximum value of charging current, and the like. calculate. Further, the control device 300 calculates the hydraulic braking force by subtracting the calculated regenerative braking force from the total braking force. Thus, by setting (distributing) the hydraulic braking force in consideration of the regenerative braking force, the hydraulic braking force can be reduced and the power consumption of the motor M can be reduced. This distribution method is an example, and the present invention is not limited to this, and various distribution methods can be applied.

  The regenerative braking force is, for example, a brake that generates a braking force by causing a motor (travel motor) to function as a generator and recovering kinetic energy during travel as electrical energy in a hybrid vehicle or an electric vehicle. It is a kind.

  Further, in the braking method in a state where the introduction ports 26c and 26d are mechanically closed, even if the power supply fails, the second cutoff valve 60a and the first cutoff valve 60b automatically open, and the third cutoff valve The valve 62 is automatically closed, the first in valve 120 and the second in valve 124 are automatically opened, and the first out valve 128 and the second out valve 130 are automatically closed. Therefore, the brake hydraulic pressure generated in the second pressure chamber 54a and the first pressure chamber 54b of the master cylinder 34 is not absorbed by the stroke simulator 64, and the second cutoff valve 60a, the first cutoff valve 60b, and the first in-valve. The wheel cylinders 32FR, 32RL, 32RR, 32FL of each wheel can be operated through the 120 and the second in-valve, and the braking force can be generated without any trouble.

  As described above, in the brake actuator 18 according to the present embodiment, the second brake system 110a and the first brake system 110b include the first cutoff valve 60b, the second cutoff valve 60a, the third cutoff valve 62, and the pressure sensor Pm. , Pp, and the stroke simulator 64 are integrally configured. As a result, the mass-produced master cylinder 34 (master cylinder device 14) can be used.

  Further, according to the present embodiment, as shown in FIGS. 3 and 4, the oil passage (the first hydraulic pressure passage 58b, the second hydraulic pressure passage 58a, the third hydraulic pressure passage 58d, the fourth hydraulic pressure passage 58c, Since all the processing of the second brake system 110a and the first brake system 110b) can be performed on the housing 200 side, the cost can be reduced. That is, in this embodiment, the number of holes (oil passages) to be formed is smaller than in the conventional case where the oil passage machining in the master cylinder side housing and the oil passage machining in the brake actuator side housing are performed. Since only the increase is required, the manufacturing process is simplified and the cost can be reduced as compared with processing the oil passage for each housing.

  Furthermore, according to the present embodiment, electrodes of the valves (first cutoff valve 60b, second cutoff valve 60a, third cutoff valve 62) and sensors (pressure sensors Pm, Pp) are provided on the conventional master cylinder 34 side. Since the provided housing can be concentrated on the housing 200 of the brake actuator 18, the cost can be reduced. As a result, it is possible to reduce the first shut-off valve 60b, the second shut-off valve 60a, the third shut-off valve 62, the stroke simulator 64, the pressure sensor Pm, the harness for the pressure sensor Pp, and the connectors that have been provided separately. become. Moreover, since the harness can be bundled, the strength of the harness can be increased.

  Further, by providing the introduction ports 26c and 26d (third input port) for connecting the motor cylinder device 16 (external pressure source), the system (the vehicle brake system 10) including the by-wire type brake actuator 18 is provided. Can be applied. Thus, the reaction force can be generated by the stroke simulator 64 when driving by the by-wire type.

  Further, in the present embodiment, the first shutoff valve 60b and the second shutoff valve 60a are closed and the third shutoff valve 62 is opened while the introduction ports 26c and 26d are mechanically closed, and the pressure sensor Pm is detected. A control device 300 (internal by-wire control means) for controlling the detection value of the pressure sensor Pp to be a value corresponding to the detection signal of the pressure sensor Pm by driving the pump 136 and the regulator valve 116 based on the signal. Prepare. Thereby, even if a special external actuator such as the motor cylinder device 16 is not used, the master cylinder device 14 is connected to the brake actuator 18 so that an appropriate reaction force is applied by the stroke simulator 64 while the by-wire type. The vehicle brake system can be realized. Accordingly, it is possible to easily cope with a mode in which by-wire braking is required by an external request such as a regenerative braking system.

  In the above-described embodiment, the motor cylinder device 16 has been described as an example of the external pressure source. However, the present invention is not limited to this. For example, a pump that pumps brake fluid from a reservoir, and a drive source for the pump And an accumulator 124 that stores brake fluid discharged from the pump under pressure.

  In the above-described embodiment, the case where the brake actuator 18 is disposed in the vicinity of the right front portion of the structure mounting chamber R (see FIG. 1) has been described as an example. However, the present invention is not limited to this position. The structure arrange | positioned in the dashboard 2 may be sufficient.

10 Brake system for vehicle 14 Master cylinder device 16 Motor cylinder device (external pressure source)
18 Brake actuator 26a Introduction port (second input port)
26b Introduction port (first input port)
26c, 26d Introduction port (third input port)
28a, 28b, 28c, 28d Derivation port (output port)
32FR, 32RL, 32RR, 32FL Wheel cylinder 34 Master cylinder 56a Second pressure chamber (second hydraulic chamber)
56b First pressure chamber (first hydraulic chamber)
58a Second hydraulic pressure path (supply liquid path)
58b First hydraulic pressure path (supply liquid path)
60a Second shutoff valve (normally open second shutoff valve)
60b First shutoff valve (normally open first shutoff valve)
62 3rd shut-off valve (normally closed pedal force shut-off valve)
64 Stroke simulator 110a Second brake system 110b First brake system 112 First common hydraulic path (supply liquid path)
114 Second common hydraulic path (supply liquid path)
116 Regulator valve 120 First in valve (normally open pressure valve)
124 Second In Valve (Normally Opening Pressure Valve)
128 First out valve (normally closed pressure reducing valve)
130 Second out valve (Normally closed pressure reducing valve)
132 Reservoir (low pressure source)
136 Pump 142 Suction valve 200 Housing 300 Control device (internal by wire control means)
Pp Pressure sensor (first pressure sensor)
Pm pressure sensor (second pressure sensor)
M motor

Claims (2)

Four output ports each connected to a wheel cylinder provided corresponding to each wheel of the vehicle;
A first input port and a second input port respectively connected to the first hydraulic pressure chamber and the second hydraulic pressure chamber in the tandem master cylinder;
A normally-open first shutoff valve that shuts off between the first input port and the output port;
A normally open second shutoff valve that shuts off between the second input port and the output port;
A stroke simulator provided on the upstream side of the first shut-off valve or the second shut-off valve in one of the first input port and the second input port;
A normally closed pedal force shut-off valve that selectively opens communication between the stroke simulator and the first input port or the second input port;
First connected to a supply liquid path between the first shut-off valve and the wheel cylinder and a supply liquid path between the second shut-off valve and the wheel cylinder, and selectively connected to an external pressure source. 3 input ports,
A first pressure sensor provided downstream of the first shutoff valve at the first input port;
A second pressure sensor provided upstream of the second shut-off valve at the second input port;
A pump connected to the supply liquid path via a suction valve, and sucking and pressurizing the hydraulic fluid or low-pressure source hydraulic fluid via the suction valve, and supplying the pump to the supply liquid path;
A regulator valve that adjusts the differential pressure upstream and downstream of the pump;
A normally closed pressure reducing valve that depressurizes the wheel cylinder by moving the hydraulic fluid of the wheel cylinder to the low pressure source side;
A brake actuator, comprising: a normally-open pressurizing valve that selectively blocks between the supply liquid passage and the wheel cylinder.   In a state where the third input port is mechanically closed, the first shut-off valve and the second shut-off valve are closed and the pedaling force shut-off valve is opened. Based on the detection signal of the second pressure sensor, the pump And an internal by-wire control means for controlling the detection value of the first pressure sensor to be a value corresponding to the detection signal of the second pressure sensor by driving the regulator valve. Item 4. The brake actuator according to item 1.

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