JP2014094625A - Brake control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology that is effective in reliably detecting a hydraulic pressure output from a master cylinder when a brake operation is performed in a brake control system for applying braking force to wheels.SOLUTION: A brake control device 10 includes: plural pressure sensors that can detect a hydraulic pressure output by a working fluid stored in a master cylinder 100 when a brake operation of a brake pedal is performed and that include at least one pressure sensors 232 and 233 disposed in a second connection path 230 which connects a reactive force chamber 110 to a stroke simulator 120 without communicating with first connection paths 210 and 220; and a control unit 300 that controls the hydraulic pressure of the working fluid which is supplied from a power source 261 to wheel cylinders 12, 13, 14, and 15, according to the hydraulic pressures detected by the plural pressure sensors, when the brake operation of the brake pedal 11 is performed in a state that master cut valves 211 and 221 are cut off.

Description

  The present invention relates to a brake control device for applying a braking force to a wheel.

Patent Documents 1 and 2 below disclose an example of this type of brake control device.
The brake control device disclosed in Patent Document 1 is a device applied to a so-called “brake-by-wire” system, and stores a working fluid supplied to a wheel cylinder of a wheel in a master housing. A master cylinder having a chamber, a stroke simulator for generating a reaction force according to the brake operation of the brake pedal, and a master cut valve provided to be openable and closable on a connection path connecting the cylinder chamber and the wheel cylinder ing. According to this brake control device, the hydraulic fluid supplied from the power source to the wheel cylinders according to the hydraulic pressure output from the master cylinder chamber when the brake pedal is operated with the master cut valve shut off. The hydraulic pressure is controlled, and a desired braking force is applied to the wheel.
Further, in the brake control device disclosed in Patent Document 2, a reaction force chamber for storing the hydraulic fluid supplied to the stroke simulator is provided in the master housing of the master cylinder separately from the master cylinder chamber.

JP 2007-185999 A JP 2012-066692 A

  By applying the structure of the reaction force chamber disclosed in Patent Document 2 to the brake control device disclosed in Patent Document 1, it is possible to improve the fail-safe property, reduce the cost of the device, and improve the brake feeling. Have sex. On the other hand, in this case, the piston for pressurizing the hydraulic fluid in the master cylinder chamber hardly moves during the brake operation. Therefore, when the hydraulic pressure output from the master cylinder chamber at the time of brake operation is detected and the hydraulic pressure of the hydraulic fluid supplied from the power source to the wheel cylinder is controlled using this detected value, the control is appropriate. Can not be executed. Therefore, when designing this brake control device, there is a demand for a technique for optimizing the braking force applied to the wheels by reliably detecting the hydraulic pressure output from the master cylinder during brake operation.

  The present invention has been made in view of the above points, and one of its purposes is to ensure the hydraulic pressure output from the master cylinder during brake operation in a brake control device for applying braking force to wheels. It is to provide an effective technique for detection.

In order to achieve the above object, a brake control device according to the present invention is mounted on a vehicle and includes a master cylinder, a master cut valve, a power source, a plurality of pressure sensors, and a control unit.
The master cylinder has a master cylinder chamber, a reaction force chamber, and a master cylinder piston in the master housing. The master cylinder chamber functions to store hydraulic fluid supplied to a wheel cylinder for applying a braking force to the wheels. The reaction force chamber functions to store hydraulic fluid supplied to a stroke simulator for generating a reaction force according to the brake operation of the brake pedal. The master cylinder piston is configured as a piston member provided between the master cylinder chamber and the reaction force chamber so that the hydraulic fluid in the master cylinder chamber can be pressurized by the fluid pressure in the reaction force chamber. The master cut valve is provided to be openable and closable in a first connection path that connects the master cylinder chamber and the wheel cylinder. The master cut valve functions to switch between a supply state in which the hydraulic fluid stored in the master cylinder chamber is supplied to the wheel cylinder and a cutoff state in which the supply is shut off. The power source is provided outside the master cylinder and functions to pressurize the hydraulic fluid with a predetermined power and supply it to the wheel cylinder. Each of the plurality of pressure sensors can detect the hydraulic pressure output when the brake pedal is operated by the hydraulic fluid stored in the master cylinder. The plurality of pressure sensors include at least one pressure sensor provided in the second connection path that connects the reaction force chamber and the stroke simulator without communicating with the first connection path. In this case, the plurality of pressure sensors may be configured only by the pressure sensor provided in the second connection path, or may be provided in the first connection path or other paths in the pressure sensor provided in the second connection path. It may be configured by adding a provided pressure sensor. When the brake pedal is operated with the master cut valve shut off, the controller controls the hydraulic pressure of the hydraulic fluid supplied from the power source to the wheel cylinder according to the hydraulic pressure detected by the plurality of pressure sensors. Control. In this case, by using a plurality of pressure sensors, it is possible to deal with a malfunction of the pressure sensor and to ensure a certain level of reliability regarding pressure detection information used for control.

  In the shut-off state of the master cut valve, even if the brake operation of the brake pedal is performed, the master cylinder piston for pressurizing the hydraulic fluid in the master cylinder chamber hardly moves. Therefore, when the hydraulic pressure in the master cylinder chamber is reliably detected as the brake operating pressure and used for controlling the power source, the hydraulic pressure of the hydraulic fluid supplied from the power source to the wheel cylinder cannot be properly controlled. Therefore, by providing at least one pressure sensor in the second connection path, the hydraulic pressure output from the reaction force chamber of the master cylinder when the brake pedal is operated can be reliably detected by the pressure sensor. That is, the arrangement structure of the pressure sensor for reliably detecting the hydraulic pressure output from the master cylinder when the brake pedal is operated is optimized. The control unit can correctly derive the target value of the braking parameter (for example, the target deceleration of the vehicle) according to the pressure detection value of the pressure sensor, and is supplied from the power source to the wheel cylinder according to the derived result. The hydraulic pressure of the hydraulic fluid can be controlled appropriately. As a result, a desired braking force is applied to the wheels.

  In the brake control device according to the present invention, it is preferable that the plurality of pressure sensors include at least two pressure sensors provided in the second connection path. Thereby, one pressure sensor can be used for backup of the other pressure sensor.

  In the above-described brake control device according to the present invention, it is preferable that the plurality of pressure sensors include at least one pressure sensor provided in the first connection path. Thereby, in addition to the pressure sensor provided in the second connection path, the pressure sensor provided in the first connection path can be used to detect the hydraulic pressure output from the master cylinder when the brake pedal is operated. it can.

  In the configuration in which the pressure sensor is provided in the first connection path in addition to the pressure sensor in the second connection path, when the brake pedal is operated with the master cut valve shut off, the input piston approaches the master cylinder piston. While operating to pressurize the hydraulic fluid in the reaction force chamber, the master cylinder piston preferably operates in the opposite direction to the input piston to pressurize the hydraulic fluid in the master cylinder chamber before contacting the input piston. The input piston is configured as a piston member that is connected to the brake pedal and disposed opposite to the master cylinder piston with the reaction force chamber interposed in the master housing of the master cylinder. In this case, it is preferable to employ an operating mechanism that operates the master cylinder piston in a direction opposite to the input piston before the input piston contacts the master cylinder piston during a brake operation. This operating mechanism is for operating the master cylinder piston with this hydraulic pressure even when the hydraulic pressure of the hydraulic fluid in the reaction force chamber is relatively low. This can be realized by a structure that makes it smaller (smaller diameter structure), a structure that relatively increases the separation distance between the input piston and the master cylinder piston, and the like. Thereby, the hydraulic pressure output from the master cylinder can be reliably detected by both the pressure sensor of the first connection path and the pressure sensor of the second connection path during the brake operation of the brake pedal.

  In a configuration in which a pressure sensor is provided in the first connection path in addition to the pressure sensor in the second connection path, the control unit corrects the hydraulic pressure detected by at least one pressure sensor provided in the first connection path. The braking parameter of the vehicle is preferably derived using the corrected hydraulic pressure. Typical vehicle braking parameters include vehicle deceleration, wheel torque and braking force, hydraulic pressure supplied to the wheel cylinder, and the like. In this case, the hydraulic pressure detected by the pressure sensor in the first connection path is less likely to increase than the hydraulic pressure detected by the pressure sensor in the second connection path with respect to the depression operation of the brake pedal (depression operation). Therefore, it is effective to correct the hydraulic pressure obtained from the pressure sensor of the first connection path. For this correction, it is typically preferable to use an arithmetic expression or a correction map stored in advance in the control unit.

  In the above-described brake control device according to the present invention, the second connection path includes an atmosphere non-communication region that does not communicate with the atmosphere when the brake pedal is operated, and at least of two pressure sensors provided in the second connection path. One is preferably provided in the atmosphere non-communication region. By providing a pressure sensor in the atmosphere non-communication region, the atmospheric pressure is not detected by the pressure sensor, and the hydraulic pressure output from the reaction force chamber can be reliably detected when the brake is operated.

  In the above brake control device according to the present invention, it is preferable that both of the two pressure sensors provided in the second connection path are provided in the atmosphere non-communication region. This makes it possible to reliably detect the hydraulic pressure output from the reaction force chamber when the brake is operated, and to back up with the other pressure sensor when a failure occurs in one of the pressure sensors.

  The above-described brake control device according to the present invention includes an on-off valve provided to be openable and closable in the second connection path, and the atmosphere non-communication area by the upstream area between the reaction force chamber and the on-off valve in the second connection path. Is preferably configured. The control unit preferably corrects the hydraulic pressure detected by the pressure sensor provided in the atmosphere non-communication region, and derives the braking parameter of the vehicle using the corrected hydraulic pressure. In this case, the on-off valve acts as a throttle when the hydraulic fluid flows from the reaction force chamber to the stroke simulator through the second connection path. Therefore, the pressure sensor installed in the upstream region of the on-off valve in the second connection path is more susceptible to the depression speed of the brake pedal than the pressure sensor installed in the downstream region of the on-off valve. For example, when the brake pedal is suddenly depressed by the driver, the pressure detection value by the pressure sensor in the upstream region of the on-off valve becomes larger than the pressure detection value by the pressure sensor in the downstream region of the on-off valve. Accordingly, if the target deceleration is derived using the detected pressure value as the brake operating pressure, the target deceleration also increases, and therefore the brake pedal depression speed has an influence on the brake feeling. On the other hand, the pressure sensor installed in the downstream area of the on / off valve is the pressure sensor in the upstream area of the on / off valve even if the brake pedal is suddenly depressed by the driver. Not as affected. Therefore, in order to derive the target deceleration, the fluid pressure output from the reaction force chamber is reliably detected when the brake is applied by using the pressure detection value correction value that is easily affected by the brake pedal depression speed. it can.

  In the above-described brake control device according to the present invention, it is preferable that a stroke simulator is provided in the master housing of the master cylinder. Thereby, the compactness of the brake control device can be achieved.

  As described above, according to the present invention, in the brake control device that applies a braking force to the wheel, it is possible to reliably detect the hydraulic pressure output from the master cylinder when the brake is operated.

It is a figure showing the schematic structure of brake control device 10 of one embodiment of the present invention. It is a figure which shows schematic structure of the brake control apparatus 20 which concerns on the example of a change of the brake control apparatus 10 in FIG. It is a figure which shows schematic structure of the brake control apparatus 30 which concerns on the example of a change of the brake control apparatus 10 in FIG. It is a figure which shows schematic structure of the brake control apparatus 40 which concerns on the example of a change of the brake control apparatus 30 in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a brake control device 10 according to an embodiment of the “brake control device” of the present invention. The brake control device 10 is mounted on a vehicle to control the braking force applied to the wheels, and is a device applied to a so-called “brake-by-wire” system. The components of the brake control device 10 are roughly divided into a master cylinder 100, a hydraulic pressure actuator 200, and a control unit 300. In the following description, a case where hydraulic fluid (typically hydraulic fluid) is used as an example of a medium for operating the brake control device 10 is described. In FIG. 1 and other drawings, the left direction in the drawing is defined as a first direction D1, and the right direction in the drawing is defined as a second direction D2 opposite to the first direction D1.

  The master cylinder 100 includes master housings 101 and 102 that form a long cylindrical housing, and a plurality of components are accommodated in a space in the master housings 101 and 102. The plurality of components include an input piston 104, a first master cylinder piston 106, a second master cylinder piston 108, coil springs 105, 107, 109, and a stroke simulator 120. In particular, with respect to the longitudinal direction (first direction D1) of the master housings 101 and 102, the input piston 104, the first master cylinder piston 106, and the second master cylinder piston 108 are arranged in this order from the right side in FIG. This master cylinder 100 corresponds to a “master cylinder” of the present invention.

  The input piston 104 is connected to the brake pedal 11 via the input rod 103, and is disposed to face the first master cylinder piston 106 with a reaction force chamber 110 to be described later interposed therebetween. This input piston 104 corresponds to the “input piston” of the present invention. A coil spring 105 is interposed between the input piston 104 and the master housing 102. For this reason, in the operating state in which the brake operation (depression operation) of the brake pedal 11 is performed by the vehicle occupant, the input rod 103 receives a load in the first direction D1 by the pedaling force applied to the brake pedal 11. At this time, the input piston 104 is pressed in the first direction D1 by the input rod 103 against the elastic biasing force of the coil spring 105, and the input rod 103 and the input piston 104 move to their respective operating positions. On the other hand, in the initial state where the brake operation of the brake pedal 11 is released, the input rod 103 and the input piston 104 both move from the operating position in the second direction D2 according to the elastic biasing force of the coil spring 105. Return to.

  A reaction force chamber 110 is defined by the input piston 104, the first master cylinder piston 106 and the master housing 102. The reaction force chamber 110 is configured as a space for storing hydraulic fluid supplied to the stroke simulator 120. That is, the reaction force chamber 110 is connected to the introduction port 121 of the stroke simulator 120 through the connection path 230. For this reason, the input piston 104 moves in the first direction D1 against the elastic biasing force of the coil spring 105 during the brake operation of the brake pedal 11, and the distance from the first master cylinder piston 106 becomes relatively small. When the proximity operation is performed as described above, the hydraulic fluid in the reaction force chamber 110 is pressurized. The hydraulic fluid pressurized in the reaction chamber 110 is introduced into the inlet 121 of the stroke simulator 120 through the connection path 230. This reaction force chamber 110 corresponds to the “reaction force chamber” of the present invention.

  A first master cylinder chamber 111 is defined by the first master cylinder piston 106, the second master cylinder piston 108 and the master housing 101. A coil spring 107 is interposed between the first master cylinder piston 106 and the second master cylinder piston 108. For this reason, when the first master cylinder piston 106 and the second master cylinder piston 108 move toward each other against the elastic biasing force of the coil spring 107, the volume of the first master cylinder chamber 111 relatively decreases. . As a result, the hydraulic fluid stored in the first master cylinder chamber 111 is pressurized.

  Similarly, a second master cylinder chamber 112 is defined by the opposing space of the second master cylinder piston 108, the closing member 101a, and the master housing 101. A coil spring 109 is interposed between the second master cylinder piston 108 and the closing member 101a. For this reason, when the second master cylinder piston 108 moves in the first direction D1 (the direction opposite to the first master cylinder piston 106) against the elastic biasing force of the coil spring 109, the volume of the second master cylinder chamber 112 becomes relative. Decrease. As a result, the hydraulic fluid stored in the second master cylinder chamber 112 is pressurized.

  These two master cylinder chambers 111 and 112 are configured as spaces for storing hydraulic fluid supplied to the wheel cylinders 12, 13, 14, and 15 for applying a braking force to each of the four wheels. These two master cylinder chambers 111 and 112 correspond to the “master cylinder chamber” of the invention, and the master cylinder pistons 106 and 108 provided in the master cylinder chamber correspond to the “master cylinder piston” of the invention. In this case, the wheel cylinder 12 is a wheel cylinder for the left front wheel, the wheel cylinder 13 is a wheel cylinder for the right front wheel, the wheel cylinder 14 is a wheel cylinder for the left rear wheel, and the wheel cylinder 15 is the right rear wheel. This is a wheel cylinder. These wheel cylinders 12, 13, 14, and 15 correspond to the “foil cylinder” of the present invention.

  The first master cylinder chamber 111 and the wheel cylinders 12, 13, 14, 15 are connected through a connection path 210. For this reason, the hydraulic fluid pressurized in the first master cylinder chamber 111 can be introduced into the wheel cylinders 12, 13, 14, 15 through the connection path 210. On the other hand, the connection path 210 is provided with a first master cut valve 211 that is controlled to be opened and closed by the controller 300. The first master cut valve 211 has a supply state in which the hydraulic fluid stored in the first master cylinder chamber 111 is supplied to the wheel cylinders 12, 13, 14, and 15 through the connection path 210 and is cut off from the supply state. It functions as a switching valve that switches between the shut-off states. The connection path 210 corresponds to the “first connection path” of the present invention, and the first master cut valve 211 provided in the connection path 210 corresponds to the “master cut valve” of the present invention.

  The control unit 300 is configured by a microcomputer having a CPU, ROM, RAM, and the like as main components, and the control unit 300 functions to control at least the hydraulic pressure actuator 200. That is, the control unit 300 may be a control unit dedicated to the hydraulic pressure actuator 200, or may be combined with another control target control unit of the vehicle. The control unit 300 corresponds to the “control unit” of the present invention.

  Similar to the connection path 210, the second master cylinder chamber 112 and the wheel cylinders 12, 13, 14, 15 are connected through the connection path 220. For this reason, the hydraulic fluid pressurized in the second master cylinder chamber 112 can be introduced into the wheel cylinders 12, 13, 14, 15 through the connection path 220. On the other hand, the connection path 220 is provided with a second master cut valve 221 that is controlled to be opened and closed by the controller 300. The second master cut valve 221 has a supply state in which the hydraulic fluid stored in the second master cylinder chamber 112 is supplied to the wheel cylinders 12, 13, 14, 15 through the connection path 220 and the supply is cut off. It functions as a switching valve that switches between the shut-off states. The connection path 220 corresponds to the “first connection path” of the present invention, and the second master cut valve 211 provided in the connection path 220 corresponds to the “master cut valve” of the present invention.

  The stroke simulator 120 has a space 122 defined by the master housing 101, and the first movable piston 123, the second movable piston 124, and the closing member 101b are accommodated in the space 122. In particular, with respect to the first direction D1, the first movable piston 123, the second movable piston 124, and the closing member 101b are arranged in this order from the right side in FIG. A coil spring 125 is interposed between the first movable piston 123 and the second movable piston 124, and a coil spring 126 is interposed between the second movable piston 124 and the closing member 101b. As a result, when the driver operates the brake pedal 11, the first movable piston 123 causes the hydraulic pressure of the hydraulic fluid introduced into the space 122 from the inlet 121 of the stroke simulator 120, that is, the hydraulic pressure of the reaction force chamber 110. Is pressed against the elastic biasing force of the coil spring 125 in the first direction D1. Thereafter, when the amount of depression of the brake pedal 11 by the driver increases and the hydraulic pressure in the reaction force chamber 110 further increases, the first movable piston 123 is moved to the second movable piston 124 as the hydraulic fluid pressure in the space 122 increases. Then, the second movable piston 124 is pressed in the first direction D1 against the elastic biasing force of the coil spring 125. At this time, the hydraulic pressure generated in the reaction force chamber 110 is transmitted to the driver as a brake reaction force at the time of brake operation via the input piston 104, the input rod 103, and the brake pedal 11. This stroke simulator 120 corresponds to the “stroke simulator” of the present invention. The stroke simulator 120 is configured as a stroke simulator chamber provided in the master housing 101 of the master cylinder 100 so that the brake control device 10 can be made compact.

  The connection path 230 connects the reaction force chamber 110 and the introduction port 121 of the stroke simulator 120 without communicating with the connection paths 210 and 220. This connection path 230 corresponds to the “second connection path” of the present invention. An opening / closing valve 231 and pressure sensors 232 and 233 that are controlled to be opened and closed by the controller 300 are provided in this connection path 230 between the reaction force chamber 110 and the introduction port 121 in order from the reaction force chamber 110 side. . This connection path 230 further branches off from the introduction port 121 of the stroke simulator 120 and extends to the pressurizing chamber 113. The pressurizing chamber 113 is an annular space defined by the first master cylinder piston 106 and the master housing 101, and the second master cylinder piston 106 is subjected to the second pressure by the hydraulic pressure of the working fluid supplied from the reaction force chamber 110. It fulfills the function of urging in the direction D2. For this reason, in the state where the on-off valve 231 is controlled to close, the hydraulic pressure of the working fluid in the reaction force chamber 110, that is, the hydraulic pressure in the upstream region of the on-off valve 231 in the connection path 230 is not supplied to the stroke simulator 120 (transmission). Not) Therefore, the on-off valve 231 is also referred to as a simulator cut valve that cuts off the supply of hydraulic pressure to the stroke simulator 120 side. On the other hand, in the state in which the opening / closing valve 231 is controlled to open, the hydraulic pressure of the hydraulic fluid in the reaction force chamber 110 (the hydraulic pressure in the upstream region of the opening / closing valve 231 in the connection path 230) is the opening / closing valve 231 in the connection path 230. Are supplied (transmitted) to both the stroke simulator 120 and the pressurizing chamber 113 in the downstream region. In this case, the hydraulic pressure in the downstream region is detected by the two pressure sensors 232 and 233, and the pressure detection information is transmitted to the control unit 300. By using at least these two pressure sensors, it is possible to cope with the problem of one of the pressure sensors, and to ensure a certain level of reliability regarding the pressure detection information used for the control for applying braking force to the wheels.

  The connection path 240 branches from the downstream of the on-off valve 231 in the connection path 230 and is connected to a compartment 114 formed by the master housing 101 and the input piston 104. The compartment 114 communicates with the atmosphere through an opening 115 provided in the master housing 101. The connection path 240 is provided with an on / off valve 241 that is controlled to open and close by the control unit 300. For this reason, in the state where the on-off valve 231 is controlled to close, the hydraulic pressure of the hydraulic fluid in the compartment 114 (the hydraulic pressure in the downstream area of the on-off valve 241 in the connection path 240) becomes atmospheric pressure. On the other hand, in a state in which the on-off valve 241 is controlled to open, the hydraulic pressure in the upstream region of the on-off valve 241 in the connection path 240 and the hydraulic pressure in at least the downstream region of the on-off valve 231 in the connection path 230 are both atmospheric pressure. become.

  The connection path 250 is connected to a compartment 116 formed by the master housings 101 and 102 and the first master cylinder piston 106. This compartment 116 communicates with the atmosphere via a reservoir 251.

  The connection path 260 is a path that connects the reservoir 251 in which the hydraulic fluid is stored and the wheel cylinders 12, 13, 14, and 15. The connection path 260 is provided with a pump 261 and an accumulator 261a. The pump 261 is driven by an electric motor controlled by a control signal from the control unit 300, and compresses the hydraulic fluid to increase the pressure. The accumulator 261a stores the hydraulic fluid whose pressure has been increased by the pump 261. The pump 261 and the accumulator 261a are provided outside the master cylinder 100, and serve to pressurize the hydraulic fluid stored in the reservoir 251 with a predetermined power and supply it to the wheel cylinders 12, 13, 14, and 15. And constitutes the “power source” of the present invention.

  The above-described connection path 210, connection path 220, and connection path 260 are all interposed between the wheel cylinders 12, 13, 14, and 15 with pressure increase valves 262, 263, 264, and 265 controlled to be opened and closed by the controller 300. It has a route to do. These pressure increasing valves 262, 263, 264, and 265 are used to increase the pressure of the hydraulic fluid in the wheel cylinders 12, 13, 14, and 15 as necessary. On the other hand, the wheel cylinders 12, 13, 14, and 15 are connected to the pressure reducing path 270 via pressure reducing valves 272, 273, 274, and 275 that are controlled to open and close by the control unit 300. These pressure reducing valves 272, 273, 274, and 275 are used for reducing the pressure of the hydraulic fluid in the wheel cylinders 12, 13, 14, and 15 as necessary.

  According to the brake control device 10 configured as described above, the hydraulic fluid supplied to the stroke simulator 120 is stored in the master housings 101 and 102 separately from the first master cylinder chamber 111 and the second master cylinder chamber 112. By providing the reaction force chamber 110, it is possible to improve the fail-safe property, reduce the cost of the device, and improve the brake feeling. On the other hand, in the case of the brake control device 10, since the first master cut valve 211 and the second master cut valve 221 are both controlled to be closed when the brake is operated, the hydraulic fluid in the master cylinder chambers 111 and 112 is pressurized. Master cylinder pistons 106 and 108 hardly move. Therefore, when the hydraulic pressure in the master cylinder chambers 111 and 112 is reliably detected as the brake operating pressure and used for controlling the power source (pump 261 and accumulator 261a), the wheel cylinders 12, 13, 14, and 15 are supplied from this power source. The hydraulic pressure of the supplied hydraulic fluid cannot be properly controlled.

  Therefore, in the present embodiment, two pressure sensors 232 for detecting the hydraulic pressure of the working fluid in the reaction force chamber 110 are connected to the connection path 230 that connects the reaction force chamber 110 and the introduction port 121 of the stroke simulator 120. 233 is installed. In this case, since the connection path 230 is a path that does not supply hydraulic pressure to the master cylinder chambers 111 and 112, even if the pistons 106 and 108 hardly move during the brake operation of the brake pedal 11, the output from the master cylinder 100 is performed. The hydraulic pressure can be reliably detected using the two pressure sensors 232 and 233. That is, the present embodiment is characterized by a technique in which a pressure sensor related to the detection of the hydraulic pressure is appropriately arranged in order to reliably detect the hydraulic pressure output from the master cylinder 100 during a brake operation. As a result, in accordance with the pressure detection value, the control unit 300 determines a target value of a predetermined braking parameter related to the control of the braking force applied to the wheel (for example, vehicle deceleration, wheel torque or braking force, wheel, The target value such as the hydraulic pressure supplied to the cylinders 12, 13, 14, and 15) can be correctly derived. Further, according to the derived result, the hydraulic pressure of the hydraulic fluid supplied from the power source to the wheel cylinders 12, 13, 14, 15 can be appropriately controlled. In particular, by providing two pressure sensors 232 and 233 in the connection path, one pressure sensor can be used as a backup for the other pressure sensor.

  As a modification of the brake control device 10 having the above configuration, one or a plurality of pressure sensors that perform the same function as the pressure sensors 232 and 233 can be additionally provided in the connection path 230.

  In order to reliably detect the hydraulic pressure output from the master cylinder 100 during the brake operation, a structure other than the brake control device 10 having the above-described configuration may be employed. Hereinafter, a modified example of the brake control device 10 will be described.

  The brake control device 20 shown in FIG. 2 is different from the brake control device 10 in that the connection path 230 is not provided with the pressure sensor 232, but the second master cylinder chamber 112 and the second master cut valve 221 in the connection path 220. There is a difference that a pressure sensor 212 is provided. In this case, the first master cylinder piston 106 is operated in the first direction D1 opposite to the input piston 104 before the input piston 104 that operates in the first direction D1 at the time of the brake operation contacts the first master cylinder piston 106. It is preferable to employ an operating mechanism. This operating mechanism is for operating the first master cylinder piston 106 in the first direction D1 with this hydraulic pressure even when the hydraulic pressure of the hydraulic fluid in the reaction force chamber 110 is relatively low. For example, it can be realized by a structure in which the cross-sectional area of the reaction force chamber 110 is relatively small (a structure in which the diameter is reduced) or a structure in which the separation distance between the input piston 104 and the first master cylinder piston 106 is relatively large. Become. Thus, when the brake pedal 11 is braked, the hydraulic pressure output from the master cylinder 100 can be reliably detected by both the pressure sensor 233 of the connection path 230 and the pressure sensor 212 of the connection path 220.

  Further, in the brake control device 20, when the difference between the hydraulic pressure detected by the pressure sensor 233 and the hydraulic pressure detected by the pressure sensor 212 is large, the brake control device 20 applies these hydraulic pressures to the wheels. It is assumed that the target value of the predetermined braking parameter relating to the control of the braking force cannot be derived correctly. Therefore, in order to cope with this point, it is preferable to correct at least one of the hydraulic pressure obtained by the pressure sensor 233 and the hydraulic pressure obtained by the pressure sensor 212. In this case, the hydraulic pressure detected by the pressure sensor 212 is less likely to increase than the hydraulic pressure detected by the pressure sensor 233 with respect to the depression operation of the brake pedal 11 (the depression operation is reflected in the hydraulic pressure increase). Therefore, it is particularly preferable to correct the hydraulic pressure obtained from the pressure sensor 212. As a specific example, an average value of a hydraulic pressure correction value by the pressure sensor 212 and a hydraulic pressure by the pressure sensor 233 can be calculated, and a target value of a predetermined braking parameter can be derived based on the calculated average value. As another specific example, a target value of a predetermined braking parameter is derived using the hydraulic pressure of the pressure sensor 212, and a correction value (calculated value Pa) of the derived target value is calculated, while the pressure sensor 233 The target value (calculated value Pb) of the braking parameter can be calculated using the hydraulic pressure, and the average value of the calculated value Pa and the calculated value Pb can be set as the final target value of the predetermined braking parameter. Note that it is typically preferable to use an arithmetic expression or a correction map stored in advance in the control unit 300 for the correction process for obtaining the correction value of the hydraulic pressure or the correction value of the target value of the braking parameter.

  As a modification of the brake control device 20 having the above configuration, one or more pressure sensors that perform the same function as the pressure sensor 233 are additionally provided in the connection path 230, or one or more that perform the same function as the pressure sensor 212. A pressure sensor can be additionally provided in the connection path 220. One or more pressure sensors that perform the same function as the pressure sensor 212 may be provided in the connection path 210 instead of or in addition to the pressure sensor 212.

  The brake control device 30 shown in FIG. 3 is different from the brake control device 10 in that one pressure sensor 232 is provided in an upstream region of the on-off valve 231 in the connection path 230. Here, when the brake control device 30 is abnormal, the on-off valve 231 is controlled from the open state to the closed state, and the on-off valve 241 is controlled from the closed state to the open state. In this case, the downstream area of the on-off valve 231 in the connection path 230 is opened to the atmosphere through the connection path 240. When a pressure sensor is installed in this downstream area, the atmospheric pressure is detected by the pressure sensor. The hydraulic pressure output from the reaction force chamber 110 when the brake is operated cannot be reliably detected. On the other hand, the upstream area of the on-off valve 231 in the connection path 230 is an atmosphere non-communication area (atmosphere cutoff area where communication with the atmosphere is blocked) that does not communicate with the atmosphere when the brake pedal is operated. Even if the on-off valve 231 is closed, the hydraulic pressure output from the reaction force chamber 110 is reliably applied to the region when the brake is operated. Therefore, the brake control device 30 employs a configuration in which the pressure sensor 232 is provided in the upstream region. Thus, even when the brake control device 30 is abnormal, the hydraulic pressure output from the reaction force chamber 110 when the brake is operated is reliably detected, for example, the target of the hydraulic fluid supplied to the wheel cylinders 12, 13, 14, and 15, for example. The hydraulic pressure can be set to an appropriate value.

  In the brake control device 30 described above, the pressure sensor 232 and the pressure sensor 233 are installed on both sides of the connection path 230 with the on-off valve 231 interposed therebetween. In this case, the on-off valve 231 acts as a throttle when the hydraulic fluid flows from the reaction force chamber 110 to the stroke simulator 120 through the connection path 230. Therefore, the pressure sensor 232 installed in the upstream region of the on-off valve 231 in the connection path 230 is more susceptible to the depression speed of the brake pedal 11 than the pressure sensor 233 installed in the downstream region of the on-off valve 231. . For example, when the brake pedal 11 is suddenly depressed by the driver, the pressure detection value by the pressure sensor 232 becomes larger than the pressure detection value by the pressure sensor 233. Therefore, for example, when the target deceleration is calculated using this pressure detection value, the target deceleration also increases, so the depression speed of the brake pedal 11 has an influence on the brake feeling. On the other hand, since the pressure sensor 233 is installed in the downstream region of the on-off valve 231, even if the brake pedal 11 is suddenly depressed by the driver, the pressure detection value by the pressure sensor 233 is the pressure sensor 232. Not as affected. Therefore, to calculate the target deceleration, the pressure detection value of the pressure sensor 233 that is not easily influenced by the depression speed of the brake pedal 11 is used, or the pressure detection value of the pressure sensor 232 that is easily influenced by the depression speed of the brake pedal. It is preferable to use the correction value (appropriate brake operating pressure corresponding to the pressure detection value of the pressure sensor 233). For deriving the correction value, a simulator consumption liquid amount diagram showing the characteristics of the stroke simulator 120 can be used. This simulator consumption liquid amount diagram is stored in the controller 300 in advance, and the appropriate fluid pressure is estimated from this pressure detection value by applying the pressure detection value of the pressure sensor 232 to the simulator consumption liquid amount diagram. be able to. Alternatively, by applying a known filtering process to the pressure detection value of the pressure sensor 232, an appropriate hydraulic pressure can be estimated from the pressure detection value. Then, a target value of a predetermined braking parameter (for example, a target value such as vehicle deceleration, wheel torque or braking force, hydraulic pressure supplied to the wheel cylinders 12, 13, 14, 15) from the estimated hydraulic pressure is obtained. Can be accurately derived.

  As a modified example of the brake control device 30 configured as described above, one or more pressure sensors that perform the same function as the pressure sensor 232 are additionally provided in the upstream region of the on-off valve 231 in the connection path 230 or the same as the pressure sensor 233. One or a plurality of pressure sensors that fulfill the above function may be additionally provided in the downstream area of the on-off valve 231 in the connection path 230.

  The brake control device 40 shown in FIG. 4 is different from the brake control device 30 in that both pressure sensors 232 and 233 are provided upstream of the on-off valve 231 in the connection path 230. Thereby, even when the brake control device 40 is abnormal, the hydraulic pressure output from the reaction force chamber 110 when the brake is operated can be reliably detected, and in particular, when one of the pressure sensors is defective, the other pressure sensor is detected. Can be backed up.

  As a modified example of the brake control device 40 having the above-described configuration, one or more pressure sensors that perform the same function as the pressure sensors 232 and 233 can be additionally provided in the upstream region of the on-off valve 231 in the connection path 230.

  The present invention is not limited to the above exemplary embodiment, and various applications and modifications are possible. For example, each of the following embodiments to which the above embodiment is applied can be implemented.

  In the above-described embodiment, the case where the stroke simulator 120 is provided in the master housing 101 of the master cylinder 100 has been described. However, in the present invention, the stroke simulator 120 may be configured as a device separate from the master cylinder 100. .

  10, 20, 30, 40 ... brake control device, 11 ... brake pedal, 12, 13, 14, 15 ... wheel cylinder, 100 ... master cylinder, 101, 102 ... master housing, 101a, 101b ... closing member, 103 ... input Rod, 104 ... Input piston, 105, 107, 109 ... Coil spring, 106 ... First master cylinder piston, 108 ... Second master cylinder piston, 110 ... Reaction force chamber, 111 ... First master cylinder chamber, 112 ... Second Master cylinder chamber, 113 ... pressurizing chamber, 114 ... compartment, 115 ... opening, 116 ... compartment, 120 ... stroke simulator, 121 ... inlet, 122 ... space, 123 ... movable piston, 124 ... movable piston, 125 126 ... Coil spring, 200 ... Hydraulic pressure actuator, 210 ... Contact Path, 211 ... first master cut valve, 212 ... pressure sensor, 220 ... connection path, 221 ... second master cut valve, 230 ... connection path, 231 ... open / close valve, 232, 233 ... pressure sensor, 240 ... connection path, 241 ... Open / close valve, 250 ... Connection path, 251 ... Reservoir, 260 ... Connection path, 261 ... Pump, 261a ... Accumulator, 262, 263, 264, 265 ... Booster valve, 270 ... Pressure reduction path, 272, 273, 274, 275 ... Pressure reducing valve, 300 ... Control unit

Claims (9)

A brake control device mounted on a vehicle,
In the master housing, it is supplied to a master cylinder chamber for storing hydraulic fluid supplied to a wheel cylinder for applying a braking force to the wheels, and a stroke simulator for generating a reaction force corresponding to the brake operation of the brake pedal. And a master cylinder piston provided between the master cylinder chamber and the reaction force chamber so that the hydraulic fluid in the master cylinder chamber can be pressurized by a hydraulic pressure of the reaction force chamber. And a master cylinder having
A first connection for connecting the master cylinder chamber and the wheel cylinder in order to switch between a supply state in which the hydraulic fluid stored in the master cylinder chamber is supplied to the wheel cylinder and a cutoff state in which the supply is shut off. A master cut valve provided in the path to be openable and closable,
A power source provided outside the master cylinder for pressurizing the hydraulic fluid with a predetermined power and supplying the hydraulic fluid to the wheel cylinder;
The hydraulic pressure output during the brake operation of the brake pedal can be detected by the hydraulic fluid stored in the master cylinder, and the reaction force chamber and the stroke simulator can be connected without communicating with the first connection path. A plurality of pressure sensors including at least one pressure sensor provided in a second connection path to be connected;
When the brake pedal is operated in the shut-off state of the master cut valve, the hydraulic fluid supplied from the power source to the wheel cylinder according to the hydraulic pressure detected by the plurality of pressure sensors A control unit for controlling the pressure;
A brake control device. The brake control device according to claim 1,
The brake control device, wherein the plurality of pressure sensors includes at least two pressure sensors provided in the second connection path. The brake control device according to claim 1 or 2,
The brake control device, wherein the plurality of pressure sensors includes at least one pressure sensor provided in the first connection path. The brake control device according to claim 3,
The master cylinder has an input piston that is connected to the brake pedal in a master housing and disposed opposite to the master cylinder piston with the reaction force chamber in between.
When a brake operation of the brake pedal is performed in the shut-off state of the master cut valve, the input piston moves close to the master cylinder piston to pressurize the hydraulic fluid in the reaction force chamber, A brake control device, wherein the master cylinder piston operates in a direction opposite to the input piston before the contact with the input piston to pressurize the hydraulic fluid in the master cylinder chamber. The brake control device according to claim 3 or 4,
The control unit corrects a hydraulic pressure detected by the at least one pressure sensor provided in the first connection path, and derives a braking parameter of the vehicle using the corrected hydraulic pressure. apparatus. The brake control device according to claim 2,
The second connection path includes an atmosphere non-communication area that does not communicate with the atmosphere during a brake operation of the brake pedal, and at least one of the two pressure sensors provided in the second connection path is the atmosphere non-communication area. Brake control device provided in The brake control device according to claim 6,
The brake control device, wherein both of the two pressure sensors provided in the second connection path are provided in the atmosphere non-communication region. The brake control device according to claim 6 or 7,
An open / close valve provided in the second connection path so as to be openable and closable, and the atmosphere non-communication area is configured by an upstream area of the second connection path between the reaction force chamber and the open / close valve;
The said control part is a brake control apparatus which correct | amends the hydraulic pressure detected by the said pressure sensor provided in the said atmosphere non-communication area | region, and derive | leads out the braking parameter of the said vehicle using the said corrected hydraulic pressure. The brake control device according to any one of claims 1 to 8,
The brake control device, wherein the stroke simulator is provided in a master housing of the master cylinder.

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