Control device for a vehicle brake system, vehicle, and method for controlling a vehicle brake system

Abstract

To achieve a control device of a brake system for a vehicle which is capable of restraining more discomfort than ever before when a driver operates a brake operation part.SOLUTION: A control device of a brake system for a vehicle executes a first control of bringing normally-open type two-position valves and second selector valves into an open state, as well as, bringing normally-closed type two-position valves and first selector valves into a closed state, and driving a motor so as to increase hydraulic pressure of wheel cylinders. The first selector valve is configured, when controlled to be in the closed state and when hydraulic pressure acting from the wheel cylinder side is higher than a specified pressure, to release a brake liquid from a wheel cylinder side to a master cylinder side. Then, when a brake operation part is operated during the first control with the hydraulic pressure of the wheel cylinder being at the specified pressure, the control device executes a second control of bringing the normally-closed type two-position valves into the open state from the first control state so as to cause the brake liquid to flow into accumulators, respectively.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a control device for a vehicle braking system, a vehicle equipped with the control device, and a method for controlling a vehicle braking system.

Background Art

[0002] Among conventional vehicle braking systems mounted on vehicles, there are those capable of executing automatic pressure boosting control (see, for example, Patent Document 1). Specifically, a braking system capable of executing automatic pressure boosting control includes a hydraulic circuit having a main flow path, a supply flow path, and a sub-flow path. The main flow path is a flow path that connects the master cylinder and the wheel cylinder. The supply flow path is a flow path that supplies brake fluid to a first intermediate portion that is an intermediate portion of the main flow path. One end of the supply flow path, i.e., the first end, communicates with the master cylinder, and the other end, i.e., the second end, is connected to the first intermediate portion of the main flow path. The sub-flow path is a flow path that discharges the brake fluid in the main flow path. One end of the sub-flow path, i.e., the third end, is connected to a second intermediate portion that is an intermediate portion located on the wheel cylinder side with respect to the first intermediate portion in the main flow path.

[0003] Further, a braking system capable of executing automatic pressure boosting control includes a filling valve, an accumulator, a releasing valve, a first switching valve, a second switching valve, a pump, and a motor. The filling valve is provided in a region between the first intermediate portion and the second intermediate portion in the main flow path. The accumulator is provided in the sub-flow path and stores the brake fluid that has flowed from the second intermediate portion of the main flow path into the sub-flow path. The releasing valve is provided in a region on the third end side with respect to the accumulator in the sub-flow path. The first switching valve is provided in a region on the master cylinder side with respect to the first intermediate portion in the main flow path. The second switching valve is provided in the supply flow path. The pump is provided in a region on the second end side with respect to the second switching valve in the supply flow path, with the suction side communicating with the second switching valve and the discharge side communicating with the second end. The motor serves as a driving source for the pump.

[0004] Furthermore, the control device of the brake system capable of performing automatic pressure boosting control opens the fill valve, closes the release valve, closes the first switching valve, opens the second switching valve, and drives the motor to increase the hydraulic pressure of the wheel cylinder when performing automatic pressure boosting control. As a result, braking force can be generated in the wheel, which generates braking force according to the hydraulic pressure of the wheel cylinder, even when the brake operation unit (brake lever and brake pedal, etc.) that receives brake operation by the driver is not operated. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-24470 [Overview of the project] [Problems that the invention aims to solve]

[0006] The first switching valve of the brake system, which is capable of automatic pressure boosting control, is configured to release brake fluid from the wheel cylinder side to the master cylinder side when the hydraulic pressure acting from the wheel cylinder side exceeds a specified pressure, while being controlled to a closed state by the control device. Therefore, in automatic pressure boosting control, after the hydraulic pressure in the wheel cylinder reaches the specified pressure, even if brake fluid is supplied to the main flow path from the first intermediate section by the pump, the same amount of brake fluid as that supplied will be released from the wheel cylinder side to the master cylinder side through the first switching valve. As a result, automatic pressure boosting control that sets the hydraulic pressure in the wheel cylinder to the specified pressure will continue.

[0007] Here, when the brake control unit is operated during automatic pressure boosting control, and the piston of the master cylinder is pressed by the brake control unit, the brake fluid from the master cylinder flows into the main passage from the first intermediate section through the second switching valve and the pump. At this time, if the hydraulic pressure of the wheel cylinder is at the specified pressure, the same amount of brake fluid that flowed into the main passage from the first intermediate section will be returned from the wheel cylinder side to the master cylinder side through the first switching valve. As a result, the amount of brake fluid on the master cylinder side will not change, making it difficult to move the brake control unit. Hereinafter, the feeling of operating the brake control unit when it is difficult to move will be referred to as a hard brake feeling.

[0008] Thus, in conventional brake systems capable of automatic pressure boosting control, when the driver operates the brake lever during automatic pressure boosting control, the feel of operating the brake lever becomes a hard braking feeling. Therefore, conventional brake systems capable of automatic pressure boosting control have the problem that they can cause the driver to feel uncomfortable when operating the brake lever.

[0009] The present invention was made against the backdrop of the above-mentioned problems, and its first objective is to provide a control device for a vehicle brake system that can suppress, to a greater extent than conventional methods, the discomfort experienced by the driver when operating the brake control unit. The second objective of the present invention is to provide a vehicle equipped with such a control device for a vehicle brake system. The third objective of the present invention is to provide a control method for a vehicle brake system that can suppress, to a greater extent than conventional methods, the discomfort experienced by the driver when operating the brake control unit. [Means for solving the problem]

[0010] The control device according to the present invention is a control device for a vehicle brake system, the brake system includes a hydraulic circuit having a main passage that connects a master cylinder and a wheel cylinder, a supply passage that supplies brake fluid to a first intermediate section which is an intermediate part of the main passage, and a sub-passage that releases the brake fluid from the main passage, the supply passage having one end, the first end, that communicates with the master cylinder and the other end, the second end, that is connected to the first intermediate section, and the sub-passage, the third end, that is one end, that connects to the wheel cylinder with respect to the first intermediate section of the main passage It is connected to a second intermediate section which is an intermediate section located in the region on the master cylinder side, and further, the brake system includes a filling valve provided in the region of the main flow path between the first intermediate section and the second intermediate section, an accumulator provided in the sub-flow path which stores brake fluid that has flowed into the sub-flow path from the second intermediate section, a release valve provided in the region of the sub-flow path which is on the third end side with respect to the accumulator, and a first switching valve provided in the region of the main flow path which is on the master cylinder side with respect to the first intermediate section, and The system comprises a second switching valve provided in the supply passage, a pump provided in the region of the supply passage that is on the second end side with respect to the second switching valve, the suction side communicating with the second switching valve and the discharge side communicating with the second end, and a motor which is the driving source for the pump, wherein the first switching valve is configured to release brake fluid from the wheel cylinder side to the master cylinder side when the hydraulic pressure acting from the wheel cylinder side is greater than a specified pressure while being controlled to a closed state by the control device, and the control device controls the condensation The system is configured to perform a first control, which involves opening the valve, closing the release valve, closing the first switching valve, opening the second switching valve, and driving the motor to increase the hydraulic pressure of the wheel cylinder. Furthermore, during the first control, when the hydraulic pressure of the wheel cylinder reaches the specified pressure, and the brake operation unit, which receives brake operation from the vehicle driver, is operated, the system is configured to perform a second control, which involves opening the release valve from the state of the first control and allowing brake fluid to flow into the accumulator through the release valve.

[0011] Furthermore, the vehicle according to the present invention is equipped with a control device for the vehicle brake system according to the present invention.

[0012] Furthermore, the control method according to the present invention is a control method for a vehicle brake system, wherein the brake system includes a hydraulic circuit having a main passage that connects a master cylinder and a wheel cylinder, a supply passage that supplies brake fluid to a first intermediate section which is an intermediate part of the main passage, and a sub-passage that releases the brake fluid from the main passage, wherein one end of the supply passage, the first end, is in communication with the master cylinder, and the other end, the second end, is connected to the first intermediate section, and one end of the sub-passage, the third end, is located in front of the first intermediate section of the main passage. The brake system is connected to a second intermediate section which is an intermediate section located in the region on the wheel cylinder side, and further comprises a suction valve provided in the region between the first intermediate section and the second intermediate section of the main flow path, an accumulator provided in the sub-flow path which stores brake fluid that has flowed into the sub-flow path from the second intermediate section, a release valve provided in the region of the sub-flow path which is on the third end side with respect to the accumulator, and a first switching valve provided in the region of the main flow path which is on the master cylinder side with respect to the first intermediate section The system comprises a second switching valve provided in the supply passage, a pump provided in the region of the supply passage that is on the second end side with respect to the second switching valve, the suction side communicating with the second switching valve and the discharge side communicating with the second end, and a motor which is the driving source for the pump, wherein the first switching valve, when controlled to be in a closed state, releases brake fluid from the wheel cylinder side to the master cylinder side when the hydraulic pressure acting from the wheel cylinder side is greater than a specified pressure, and the control method is to open the filling valve The system includes a first control step of closing the release valve, closing the first switching valve, opening the second switching valve, and driving the motor to increase the hydraulic pressure of the wheel cylinder, and a second control step of opening the release valve from the state of the first control when the hydraulic pressure of the wheel cylinder is at the specified pressure during the first control and a brake operation unit that receives brake operation by the driver of the vehicle is operated, thereby allowing brake fluid to flow into the accumulator through the release valve. [Effects of the Invention]

[0013] The present invention executes a second control when the driver operates the brake control unit while a first control, similar to conventional automatic pressure boosting control, is being performed and the hydraulic pressure in the wheel cylinder is at a specified pressure. In this second control, the release valve is opened from the state of the first control, and brake fluid is allowed to flow into the accumulator via the release valve. As a result, when brake fluid flows out of the master cylinder due to the operation of the brake control unit and flows into the main flow path from the first intermediate section through the second switching valve and pump, approximately the same amount of brake fluid is stored in the accumulator. Therefore, even when the driver operates the brake control unit while the hydraulic pressure in the wheel cylinder is at the specified pressure, fluctuations in the hydraulic pressure in the wheel cylinder can be suppressed, and the return of brake fluid from the wheel cylinder side to the master cylinder side via the first switching valve can be suppressed. Thus, the present invention can perform automatic pressure boosting control while suppressing a hard braking feeling when operating the brake control unit. Therefore, the present invention can suppress the driver from feeling any discomfort when operating the brake control unit compared to conventional methods. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows the configuration of a vehicle equipped with a brake system according to an embodiment of the present invention. [Figure 2] This figure shows the configuration of a brake system according to an embodiment of the present invention. [Figure 3] A block diagram showing a control device according to an embodiment of the present invention. [Figure 4] This figure illustrates an example of the control operation of the wheel cylinder's hydraulic pressure by the control unit of a control device according to an embodiment of the present invention. [Figure 5] This figure illustrates an example of the control operation of the wheel cylinder's hydraulic pressure by the control unit of a control device according to an embodiment of the present invention. [Figure 6]This figure illustrates an example of the control operation of the wheel cylinder's hydraulic pressure by the control unit of a control device according to an embodiment of the present invention. [Figure 7] This figure illustrates the second control performed by the control unit of the control device according to an embodiment of the present invention. [Figure 8] This is a control flow diagram showing the control operation when the control device according to an embodiment of the present invention performs automatic pressure boosting control. [Modes for carrying out the invention]

[0015] The control device for a vehicle brake system according to the present invention, a vehicle equipped with the control device, and a control method for the vehicle brake system will be described below with reference to the drawings. In the following description, the present invention will be explained in the context of its application to motorcycles, but it may also be applied to other vehicles. Other vehicles include, for example, bicycles, three-wheeled and four-wheeled vehicles powered by at least one of an engine and an electric motor. A bicycle is defined as any vehicle capable of propelling itself on the road by the force applied to the pedals. In other words, bicycles include ordinary bicycles, electric assist bicycles, electric bicycles, etc. Motorcycles and three-wheeled vehicles refer to so-called motorcycles, and motorcycles include motorcycles, scooters, electric scooters, etc. In the following description, an example of the present invention being applied to a vehicle brake system equipped with two hydraulic circuits is explained, but the number of hydraulic circuits in a vehicle brake system to which the present invention is applied is not limited to two. A vehicle brake system to which the present invention is applied may be equipped with only one hydraulic circuit, or it may be equipped with three or more hydraulic circuits.

[0016] Furthermore, the configurations and operations described below are merely examples, and the present invention is not limited to such configurations and operations. In addition, in each figure, the same or similar components or parts may be denoted by the same reference numeral, or the reference numeral may be omitted. Also, detailed structures have been simplified or omitted from the illustrations as appropriate.

[0017] Embodiment A braking system for a vehicle equipped with a control device according to the present embodiment will be described below.

[0018] <Configuration and Operation of Vehicle Braking System> The configuration and operation of a braking system equipped with a control device according to the present embodiment will be described. FIG. 1 is a diagram showing the configuration of a vehicle on which a braking system according to an embodiment of the present invention is mounted. FIG. 2 is a diagram showing the configuration of a braking system according to an embodiment of the present invention.

[0019] As shown in FIGS. 1 and 2, the braking system 10 is mounted on a vehicle 100, which is, for example, a motorcycle. The vehicle 100 includes a body 1, a handle 2 rotatably held by the body 1, a front wheel 3 rotatably held by the body 1 together with the handle 2, and a rear wheel 4 rotatably held by the body 1.

[0020] The braking system 10 includes a brake lever 11, a first hydraulic circuit 12 filled with brake fluid, a brake pedal 13, and a second hydraulic circuit 14 filled with brake fluid. The brake lever 11 is provided on the handle 2 and is operated by the driver's hand. The first hydraulic circuit 12 generates a braking force corresponding to the operation amount of the brake lever 11 on a rotor 3a that rotates with the front wheel 3. That is, the first hydraulic circuit 12 generates a braking force corresponding to the operation amount of the brake lever 11 on the front wheel 3. The brake pedal 13 is provided at the lower part of the body 1 and is operated by the driver's foot. The second hydraulic circuit 14 generates a braking force corresponding to the operation amount of the brake pedal 13 on a rotor 4a that rotates with the rear wheel 4. That is, the second hydraulic circuit 14 generates a braking force corresponding to the operation amount of the brake pedal 13 on the rear wheel 4.

[0021] Note that the brake lever 11 and brake pedal 13 are examples of brake operating parts. For example, a brake pedal other than the brake pedal 13 provided on the body 1 may be used as a brake operating part instead of the brake lever 11. Alternatively, a brake lever other than the brake lever 11 provided on the handle 2 may be used as a brake operating part instead of the brake pedal 13. Furthermore, the first hydraulic circuit 12 may generate a braking force on the rotor 4a that rotates with the rear wheel 4 according to the amount of operation of the brake lever 11 or the amount of operation of the brake pedal other than the brake pedal 13 provided on the body 1. Furthermore, the second hydraulic circuit 14 may generate a braking force on the rotor 3a that rotates with the front wheel 3 according to the amount of operation of the brake pedal 13 or the amount of operation of the brake lever other than the brake lever 11 provided on the handle 2.

[0022] The first hydraulic circuit 12 and the second hydraulic circuit 14 of the brake system 10 have the same configuration. Therefore, the configuration of the first hydraulic circuit 12 will be described below as a representative example. The first hydraulic circuit 12 includes a master cylinder 21 having a piston (not shown), a reservoir 22 attached to the master cylinder 21, a brake caliper 23 held by the body 1 and having brake pads (not shown), and a wheel cylinder 24 that operates the brake pads (not shown) of the brake caliper 23.

[0023] Furthermore, the first hydraulic circuit 12 includes a main flow path 25, a supply flow path 27, and a sub-flow path 26. In this embodiment, the main flow path 25, the supply flow path 27, and the sub-flow path 26 are provided on the base 51 of the hydraulic control unit 50.

[0024] The main passage 25 is a passage that connects the master cylinder 21 and the wheel cylinder 24. In this embodiment, the master cylinder port MP formed at one end of the main passage 25 is connected to the master cylinder 21 by a liquid pipe. Also, the wheel cylinder port WP formed at the other end of the main passage 25 is connected to the wheel cylinder 24 by a liquid pipe. In this way, the main passage 25 connects the master cylinder 21 and the wheel cylinder 24. The main passage 25 may also be directly connected to the master cylinder 21 and the wheel cylinder 24.

[0025] The supply passage 27 is a passage that supplies brake fluid to the intermediate section 25a of the main passage 25. Specifically, brake fluid from the master cylinder 21 is supplied to the intermediate section 25a of the main passage 25 via the supply passage 27. One end of the supply passage 27, end 27a, is in communication with the master cylinder 21, and the other end, end 27b, is connected to the intermediate section 25a of the main passage 25. Specifically, in this embodiment, end 27a of the supply passage 27 is connected to the main passage 25 (more specifically, the region on the master cylinder 21 side with respect to the first switching valve 32, which will be described later). End 27a of the supply passage 27 is in communication with the master cylinder 21 via the fluid pipe connecting the master cylinder 21 and the master cylinder port MP, and via the main passage 25. Note that end 27a of the supply passage 27 may be connected to the master cylinder port MP or directly to the master cylinder 21. Here, the intermediate portion 25a of the main flow path 25 corresponds to the first intermediate portion of the present invention. The end portion 27a of the supply flow path 27 corresponds to the first end portion of the present invention. The end portion 27b of the supply flow path 27 corresponds to the second end portion of the present invention.

[0026] The sub-channel 26 is a channel for venting brake fluid from the main channel 25. Specifically, brake fluid that flows from the wheel cylinder 24 into the main channel 25 is vented into the sub-channel 26. One end of the sub-channel 26, end 26a, is connected to an intermediate section 25b of the main channel 25. The intermediate section 25b is located in the region of the main channel 25 that is on the wheel cylinder 24 side, relative to the intermediate section 25a. The end 26b of the sub-channel 26, opposite to end 26a, is connected to an intermediate section 27c of the supply channel 27. The intermediate section 27c is located in the region of the supply channel 27 between the second switching valve 33 (described later) and the pump 31. Here, the intermediate section 25b of the main channel 25 corresponds to the second intermediate section of the present invention. The end section 26a of the sub-channel 26 corresponds to the third end section of the present invention. The end section 26b of the sub-channel 26 corresponds to the fourth end section of the present invention. The intermediate section 27c of the supply channel 27 corresponds to the third intermediate section of the present invention.

[0027] Furthermore, the brake system 10 includes a first hydraulic circuit 12, a fill valve 28, a release valve 29, an accumulator 30, a first switching valve 32, a second switching valve 33, a pump 31, and a motor 40.

[0028] The saturation valve 28 is located in the region between intermediate sections 25a and 25b of the main flow path 25. The opening and closing operation of the saturation valve 28 controls the flow rate of brake fluid circulating in this region. The accumulator 30 is located in the sub-flow path 26 and stores the brake fluid that flows into the sub-flow path 26 from intermediate section 25b. The release valve 29 is located in the region of the sub-flow path 26 that is on the end 26a side with respect to the accumulator 30. The opening and closing operation of the release valve 29 controls the flow rate of brake fluid circulating in this region. The first switching valve 32 is located in the region of the main flow path 25 that is on the master cylinder 21 side with respect to intermediate section 25a. The opening and closing operation of the first switching valve 32 controls the flow rate of brake fluid circulating in this region. The second switching valve 33 is located in the supply flow path 27. The flow rate of brake fluid circulating in the supply passage 27 is controlled by the opening and closing operation of the second switching valve 33. The pump 31 is installed in the region of the supply passage 27 that is on the end 27b side with respect to the second switching valve 33. The suction side of the pump 31 is in communication with the second switching valve 33, and the discharge side is in communication with the end 27b. The motor 40 is the driving source for the pump 31. In other words, the pump 31 is driven by the motor 40. In this embodiment, the pump 31 of the first hydraulic circuit 12 and the pump 31 of the second hydraulic circuit 14 are driven by a common motor 40.

[0029] Furthermore, the brake system 10 includes a master cylinder-side pressure sensor 34 for detecting the hydraulic pressure of the master cylinder 21 and a wheel cylinder-side pressure sensor 35 for detecting the hydraulic pressure of the wheel cylinder 24 in the first hydraulic circuit 12. Hydraulic pressure refers to the pressure of the brake fluid. The master cylinder-side pressure sensor 34 is located in the area of ​​the main flow path 25 closer to the master cylinder 21 than the first switching valve 32. The wheel cylinder-side pressure sensor 35 is located in the area of ​​the main flow path 25 closer to the wheel cylinder 24 than the filling valve 28.

[0030] The suction valve 28 is a solenoid valve that, for example, changes from an open state to a closed state when the coil of the suction valve 29 changes from a non-energized state to an energized state, switching the flow of brake fluid at its installation location from open to closed. The release valve 29 is a solenoid valve that, for example, changes from a closed state to an open state when the coil of the release valve 29 changes from a non-energized state to an energized state, switching the flow of brake fluid toward the accumulator 30 via its installation location from closed to open. The first switching valve 32 is a solenoid valve that, for example, changes from an open state to a closed state when the coil of the first switching valve 32 changes from a non-energized state to an energized state, switching the flow of brake fluid at its installation location from open to closed. The second switching valve 33 is a solenoid valve that, for example, changes from a closed state to an open state when the coil of the second switching valve 33 changes from a non-energized state to an energized state, switching the flow of brake fluid toward the pump 31 via its installation location from closed to open.

[0031] The open / closed states of the suction valve 28, the release valve 29, the first switching valve 32, and the second switching valve 33 are controlled by the control device 60. The drive state of the motor 40 is also controlled by the control device 60. In other words, the brake system 10 is equipped with a control device 60. The control device 60 may be a single unit or may be divided into multiple units. The control device 60 may be attached to the base 51 or to other components other than the base 51. Furthermore, part or all of the control device 60 may be composed of, for example, a microcontroller, a microprocessor unit, etc., or may be composed of updatable firmware, etc., or may be a program module executed by commands from a CPU, etc. Details of the control device 60 will be described later.

[0032] In this embodiment, the hydraulic pressure control unit 50 is composed of a base body 51, various components provided on the base body 51 (such as a suction valve 28, a release valve 29, an accumulator 30, a pump 31, a first switching valve 32, a second switching valve 33, a master cylinder side pressure sensor 34, a wheel cylinder side pressure sensor 35, a motor 40, etc.), and a control device 60. Note that the suction valve 28, the release valve 29, the accumulator 30, the pump 31, the first switching valve 32, the second switching valve 33, the master cylinder side pressure sensor 34, the wheel cylinder side pressure sensor 35, the motor 40, etc. may be provided on multiple base bodies 51.

[0033] Here, the first switching valve 32 is configured to release brake fluid from the wheel cylinder 24 to the master cylinder 21 when the hydraulic pressure acting from the wheel cylinder 24 side is greater than the specified pressure while the first switching valve 32 is controlled to a closed state by the control device 60. Specifically, in this embodiment, the first switching valve 32 closes by using the magnetic force generated in the coil when the coil of the first switching valve 32 is energized, to press the valve body against the valve seat. At this time, the hydraulic pressure acting from the wheel cylinder 24 side acts on the valve body of the first switching valve 32 in the direction that the valve body moves away from the valve seat. When the hydraulic pressure acting from the wheel cylinder 24 side is greater than the specified pressure, the hydraulic pressure acting from the wheel cylinder 24 side causes the valve body to move away from the valve seat. As a result, when the first switching valve 32 is controlled to be in the closed state by the control device 60, if the hydraulic pressure acting from the wheel cylinder 24 side is greater than the specified pressure, brake fluid will be released from the wheel cylinder 24 side to the master cylinder 21 side.

[0034] The force pressing the valve body against the valve seat is proportional to the magnetic force generated in the coil. Furthermore, the magnetic force generated in the coil is proportional to the magnitude of the current flowing through the coil. Therefore, the specified pressure can be changed by controlling the current flowing through the coil. In this embodiment, the control device 60 is configured to control the magnitude of the current flowing through the coil of the first switching valve 32, thereby changing the specified pressure.

[0035] Furthermore, in this embodiment, the brake system 10 includes a check valve 36 in the first hydraulic circuit 12 as part of the configuration of the hydraulic control unit 50. The check valve 36 is connected in parallel with the first switching valve 32 to the main passage 25 and allows the flow of brake fluid from the master cylinder 21 side to the wheel cylinder 24 side.

[0036] Figure 3 is a block diagram showing a control device according to an embodiment of the present invention. In this embodiment, the control device 60 receives the outputs of the master cylinder-side pressure sensor 34 and the wheel cylinder-side pressure sensor 35. The control device 60 may also receive the outputs of sensors not shown, such as a wheel speed sensor and an acceleration sensor. The control device 60 includes a control unit 61 as a functional unit. The control unit 61 is a functional unit that controls the opening and closing states of the loading valve 28, the release valve 29, the first switching valve 32, and the second switching valve 33, as well as the driving state of the motor 40, in accordance with the outputs of sensors etc. input to the control device 60, and controls the hydraulic pressure of the wheel cylinder 24. For example, the control unit 61 controls the hydraulic pressure of the wheel cylinder 24 in the first hydraulic circuit 12 and controls the braking force generated on the front wheel 3. Also, for example, the control unit 61 controls the hydraulic pressure of the wheel cylinder 24 in the second hydraulic circuit 14 and controls the braking force generated on the rear wheel 4. An example of the hydraulic pressure control operation of the wheel cylinder 24 performed by the control unit 61 will be described below with reference to Figures 4 to 7. Furthermore, Figures 4 to 7 below illustrate an example in which the control unit 61 controls the hydraulic pressure of the wheel cylinder 24 of the first hydraulic circuit 12.

[0037] Figure 4 is a diagram illustrating an example of the control operation of the wheel cylinder hydraulic pressure performed by the control unit of the control device according to an embodiment of the present invention. In the first hydraulic circuit 12 shown in Figure 4, the main flow of brake fluid in the control operation example described in Figure 4 is shown by a solid line.

[0038] For example, in the normal state, as shown in Figure 4, the control unit 61 opens the loading valve 28, closes the release valve 29, opens the first switching valve 32, closes the second switching valve 33, and stops the motor 40. In this state, when the brake lever 11 is operated, the piston (not shown) of the master cylinder 21 is pressed by the brake lever 11, and an amount of brake fluid corresponding to the amount of operation of the brake lever 11 is pushed out of the master cylinder 21. The brake fluid pushed out of the master cylinder 21 then flows into the wheel cylinder 24 through the first switching valve 32 and the loading valve 28, and the hydraulic pressure of the wheel cylinder 24 increases. As a result, the brake pads (not shown) of the brake caliper 23 are pressed against the rotor 3a of the front wheel 3, and a braking force corresponding to the amount of operation of the brake lever 11 is generated on the front wheel 3. In addition, the control unit 61 performs similar control in the second hydraulic circuit 14, so that a braking force corresponding to the amount of operation of the brake pedal 13 is generated on the rear wheel 4.

[0039] Figure 5 is a diagram illustrating an example of the control operation of the wheel cylinder hydraulic pressure performed by the control unit of the control device according to an embodiment of the present invention. In the first hydraulic circuit 12 shown in Figure 5, the main flow of brake fluid in the control operation example described in Figure 5 is shown by a solid line.

[0040] For example, if the hydraulic pressure in the wheel cylinder 24 becomes excessive or potentially excessive, the control unit 61 performs automatic pressure reduction control to discharge brake fluid from the wheel cylinder 24 and reduce the hydraulic pressure in the wheel cylinder 24. In automatic pressure reduction control, as shown in Figure 5, the control unit 61 closes the fill valve 28, opens the release valve 29, opens the first switching valve 32, and closes the second switching valve 33. Then, the control unit 61 drives the motor 40. As a result, the brake fluid from the wheel cylinder 24 flows from the intermediate section 25b into the sub-channel 26 due to the suction force of the pump 31 driven by the motor 40. The brake fluid that flows into the sub-channel 26 then passes through the release valve 29 and is stored in the accumulator 30. This reduces the pressing force of the brake pad (not shown) of the brake caliper 23 against the rotor 3a, and a braking force smaller than the braking force corresponding to the amount of operation of the brake lever 11 is generated on the front wheel 3. Furthermore, by having the control unit 61 perform similar control in the second hydraulic circuit 14, a braking force smaller than the braking force corresponding to the amount of operation of the brake pedal 13 will be generated on the rear wheel 4.

[0041] Incidentally, brake systems that perform automatic pressure reduction control without using a pump are known. Hereinafter, brake systems that perform automatic pressure reduction control without using a pump will be referred to as pumpless brake systems. In pumpless brake systems, for example, the pressure difference before and after a release valve when the release valve is opened is used to cause brake fluid in the wheel cylinder to flow into the accumulator. The brake system 10 according to this embodiment may be configured to perform automatic pressure reduction control without using a pump 31, similar to conventional pumpless brake systems. In this case, the end 26b of the sub-flow channel 26 does not need to be connected to the middle part 27c of the supply flow channel 27. Here, in the case of a configuration that performs automatic pressure reduction control using a pump 31, the hydraulic pressure in the wheel cylinder 24 can be reduced more quickly by the amount of the suction force of the pump 31 compared to the case of a configuration that performs automatic pressure reduction control without using a pump 31. Furthermore, as will be described later, the brake system 10 according to this embodiment is configured to perform automatic pressure boosting control. A pump 31 is an essential component for performing this automatic pressure boosting control. Therefore, in a brake system 10 capable of automatic pressure boosting control, it is preferable that the pump 31 is used to perform automatic pressure reduction control. In other words, in a brake system 10 capable of automatic pressure boosting control, it is preferable that the end portion 26b of the sub-flow channel 26 is connected to the middle portion 27c of the supply flow channel 27.

[0042] Figure 6 is a diagram illustrating an example of the control operation of the wheel cylinder hydraulic pressure performed by the control unit of the control device according to an embodiment of the present invention. In the first hydraulic circuit 12 shown in Figure 6, the main flow of brake fluid in the control operation example described in Figure 6 is shown by a solid line.

[0043] For example, if the hydraulic pressure of the wheel cylinder 24 is insufficient or potentially insufficient, the control unit 61 performs automatic pressure boosting control to supply brake fluid to the wheel cylinder 24 and increase the hydraulic pressure of the wheel cylinder 24. In automatic pressure boosting control, as shown in Figure 6, the control unit 61 opens the fill valve 28, closes the release valve 29, closes the first switching valve 32, and opens the second switching valve 33. Then, the control unit 61 drives the motor 40. As a result, the brake fluid from the master cylinder 21 flows into the supply passage 27 due to the suction force of the pump 31 driven by the motor 40. The brake fluid that has flowed into the supply passage 27 flows from the end 27b through the second switching valve 33 and the pump 31 to the middle section 25a of the main passage 25. The brake fluid that has flowed into the main passage 25 from the middle section 25a flows into the wheel cylinder 24 through the fill valve 28, and the hydraulic pressure of the wheel cylinder 24 increases. As a result, the pressing force of the brake pads (not shown) of the brake caliper 23 against the rotor 3a increases, and a braking force greater than that corresponding to the amount of operation of the brake lever 11 is generated on the front wheel 3.

[0044] As described above, the first switching valve 32 is configured to release brake fluid from the wheel cylinder 24 to the master cylinder 21 when the hydraulic pressure acting from the wheel cylinder 24 side is greater than the specified pressure while the first switching valve 32 is controlled to be closed by the control device 60. Therefore, after the hydraulic pressure of the wheel cylinder 24 increases to the specified pressure in the automatic pressure boosting control, even if brake fluid is supplied to the main flow path 25 from the intermediate section 25a by the pump 31, the same amount of brake fluid as the supplied brake fluid is released from the wheel cylinder 24 side to the master cylinder 21 side through the first switching valve 32. Therefore, after the hydraulic pressure of the wheel cylinder 24 increases to the specified pressure, the automatic pressure boosting control that sets the hydraulic pressure of the wheel cylinder 24 to the specified pressure continues.

[0045] In the following, the automatic pressure boosting control shown in Figure 6 will be referred to as the first control. Specifically, the first control is a control that opens the loading valve 28, closes the release valve 29, closes the first switching valve 32, opens the second switching valve 33, and drives the motor 40 to increase the hydraulic pressure of the wheel cylinder 24. In other words, the control unit 61 is configured to execute the first control. Furthermore, the control unit 61 executes the first control even when the brake lever 11 is not being operated if there is a shortage or possibility of a shortage of hydraulic pressure in the wheel cylinder 24. In addition, in this embodiment, the control unit 61 is configured to execute the first control in the second hydraulic circuit 14 as well.

[0046] Incidentally, in conventional vehicle brake systems, if the brake control unit is operated during automatic pressure boosting control similar to the first control, it may become difficult to move the brake control unit. Below, we will explain an example in which it becomes difficult to move the brake lever 11, which is an example of a brake control unit, when it is operated during the first control shown in Figure 6. In the following, the feeling of operating the brake control unit when it becomes difficult to move will be referred to as a hard brake feeling.

[0047] As described above, when the brake lever 11 is operated, the piston of the master cylinder 21 is pressed by the brake lever 11, and brake fluid is pushed out of the master cylinder 21. At this time, the brake fluid that flows out of the master cylinder 21 flows into the supply passage 27 and flows into the pump 31 through the second switching valve 33. This brake fluid is then discharged from the pump 31 and flows into the passage on the wheel cylinder 24 side. At this time, for example, in the first control, the hydraulic pressure of the wheel cylinder 24 has not yet increased to the specified pressure. In this state, the brake fluid in the passage on the wheel cylinder 24 side does not flow into the passage on the master cylinder 21 side through the first switching valve 32. The flow path on the wheel cylinder 24 side includes the portion of the main flow path 25 that is on the wheel cylinder 24 side with respect to the first switching valve 32, the portion of the supply flow path 27 that is on the wheel cylinder 24 side with respect to the pump 31, the portion of the sub-flow path 26 that is on the wheel cylinder 24 side with respect to the release valve 29, and the liquid pipe connecting the wheel cylinder port WP and the wheel cylinder 24. The flow path on the master cylinder 21 side includes the portion of the main flow path 25 that is on the master cylinder 21 side with respect to the first switching valve 32, the portion of the supply flow path 27 that is on the master cylinder 21 side with respect to the pump 31, and the liquid pipe connecting the master cylinder port MP and the master cylinder 21.

[0048] Therefore, in the first control, when the hydraulic pressure of the wheel cylinder 24 has not yet increased to the specified pressure, even if the brake lever 11 is operated, it is possible to suppress the feeling of the brake lever 11 being hard to brake.

[0049] Furthermore, since the brake system 10 according to this embodiment is equipped with a check valve 36, it is possible to further suppress the hard braking feeling that occurs when operating the brake lever 11. Specifically, if the flow rate of brake fluid discharged from the pump 31 is too low compared to the flow rate of brake fluid flowing out from the master cylinder 21 when the brake lever 11 is operated, the fluid pressure in the flow path on the master cylinder 21 side will increase. In such a case, even if the fluid pressure in the wheel cylinder 24 has not yet increased to the specified pressure in the first control, the brake lever 11 may feel like it is being hard braked. However, if the brake system 10 is equipped with a check valve 36, when the fluid pressure in the flow path on the master cylinder 21 side becomes higher than the fluid pressure in the flow path on the wheel cylinder 24 side, brake fluid can flow from the flow path on the master cylinder 21 side to the flow path on the wheel cylinder 24 side through the check valve 36. For this reason, by equipping the brake system 10 with a check valve 36, it is possible to further suppress the hard braking feeling that occurs when operating the brake lever 11.

[0050] On the other hand, in the first control, the hydraulic pressure in the wheel cylinder 24 is assumed to have already increased to the specified pressure. When the brake lever 11 is operated in this state, the following occurs. Specifically, as described above, when the brake lever 11 is operated and brake fluid is pushed out from the master cylinder 21, the brake fluid that has flowed out of the master cylinder 21 flows into the supply passage 27 and flows into the pump 31 through the second switching valve 33. This brake fluid is then discharged from the pump 31 and flows into the passage on the wheel cylinder 24 side. At this time, if the hydraulic pressure in the wheel cylinder 24 has already increased to the specified pressure, the hydraulic pressure in the passage on the wheel cylinder 24 side has also already increased to the specified pressure. Therefore, the same amount of brake fluid that has flowed into the passage on the wheel cylinder 24 side is returned to the passage on the master cylinder 21 side through the first switching valve 32. As a result, even if the brake lever 11 is operated, the amount of brake fluid in the passage on the master cylinder side does not change. Therefore, in the first control, if the brake lever 11 is operated when the hydraulic pressure of the wheel cylinder 24 has already increased to the specified pressure, the operation of the brake lever 11 will feel like a hard brake. The same is true if the brake pedal 13 is operated in the second hydraulic circuit 14 during the first control. In this embodiment, in order to suppress the operation of the brake control unit from feeling like a hard brake, the control device 60 is configured as follows.

[0051] Specifically, as shown in Figure 3, the control device 60 according to this embodiment includes a determination unit 62 as a functional unit. During the first control, the determination unit 62 is a functional unit that determines whether or not the brake lever 11 has been operated when the hydraulic pressure of the wheel cylinder 24 is at a specified pressure. When the determination unit 62 determines that the brake lever 11 has been operated when the hydraulic pressure of the wheel cylinder 24 is at a specified pressure, the control unit 61 executes the second control. In the second control, the control unit 61 controls the release valve 29 from the state of the first control as follows. The method of the second control will be explained in detail below using Figure 7. Figure 7 shows an example in which the control unit 61 executes the second control in the first hydraulic circuit 12.

[0052] Figure 7 is a diagram illustrating the second control performed by the control unit of the control device according to an embodiment of the present invention. In Figure 7, the main flow of brake fluid when the brake lever 11 is operated during the second control is shown by a solid line. In the second control, as shown in Figure 7, the control unit 61 opens the release valve 29 from the state of the first control. As a result, when brake fluid flows out of the master cylinder 21 due to the operation of the brake lever 11, and flows into the main passage 25 from the intermediate section 25a after passing through the second switching valve 33 and the pump 31, approximately the same amount of brake fluid is stored in the accumulator 30. Therefore, even when the driver operates the brake lever 11 while the hydraulic pressure of the wheel cylinder 24 is at the specified pressure, fluctuations in the hydraulic pressure of the wheel cylinder 24 can be suppressed, and the return of brake fluid from the passage on the wheel cylinder 24 side to the passage on the master cylinder 21 side can be suppressed.

[0053] Therefore, by executing the second control, automatic pressure boosting control can be performed while suppressing the feeling of hard braking when operating the brake lever 11. For this reason, the control device 60 according to this embodiment can suppress the driver from feeling any discomfort when operating the brake lever 11 more than conventional devices. In addition, the control device 60 according to this embodiment is configured to perform the second control in the second hydraulic circuit 14 as well.

[0054] Here, as described above, during the first control, the determination unit 62 determines whether the brake operating unit has been operated when the hydraulic pressure of the wheel cylinder 24 is at a specified pressure. That is, during the first control, the determination unit 62 determines whether the hydraulic pressure of the wheel cylinder 24 is at a specified pressure. The determination unit 62 also determines whether the brake operating unit has been operated during the first control. In this case, various methods can be used to determine whether the hydraulic pressure of the wheel cylinder 24 is at a specified pressure. Also, various methods can be used to determine whether the brake operating unit has been operated.

[0055] For example, the hydraulic pressure of the wheel cylinder 24 can be estimated from the discharge rate of the pump 31. For example, the determination unit 62 may use this estimated hydraulic pressure to determine whether the hydraulic pressure of the wheel cylinder 24 is at the specified pressure during the first control. Alternatively, for example, the determination unit 62 may use the hydraulic pressure of the wheel cylinder 24 detected by the wheel cylinder-side pressure sensor 35 to determine whether the hydraulic pressure of the wheel cylinder 24 is at the specified pressure during the first control. In this embodiment, the determination unit 62 uses the hydraulic pressure of the wheel cylinder 24 detected by the wheel cylinder-side pressure sensor 35 to determine whether the hydraulic pressure of the wheel cylinder 24 is at the specified pressure. This is because the wheel cylinder-side pressure sensor 35 can directly detect the hydraulic pressure of the wheel cylinder 24, making it possible to accurately determine whether the hydraulic pressure of the wheel cylinder 24 is at the specified pressure. As a result, the switching timing from the first control to the second control can be set to a more favorable timing.

[0056] For example, the vehicle 100 or brake system 10 may be configured with a switch that is pressed when the brake operating part is operated. When this switch is pressed during the first control, the determination unit 62 may determine that the brake operating part has been operated. Alternatively, the vehicle 100 or brake system 10 may be configured with a detection device that detects the amount of operation (stroke) of the brake operating part. Based on the detection result of this detection device, the determination unit 62 may determine whether or not the brake operating part has been operated during the first control. Furthermore, when the brake operating part is operated during the first control, the hydraulic pressure of the master cylinder 21 changes. For this reason, the determination unit 62 may determine whether or not the brake operating part has been operated during the first control based on the hydraulic pressure information of the master cylinder 21.

[0057] Furthermore, if the control device 60 can acquire hydraulic pressure information of the master cylinder 21, it is preferable for the control unit 61 to vary the rotational speed of the motor 40 according to the hydraulic pressure information of the master cylinder 21. Specifically, as described above, when the brake operating unit is operated in the first control, if the flow rate of brake fluid discharged from the pump 31 is too low compared to the flow rate of brake fluid flowing out of the master cylinder 21 when the brake lever 11 is operated, the hydraulic pressure in the flow path on the master cylinder 21 side will increase. In such a case, the operation of the brake lever 11 may feel like a hard brake. For this reason, if the control device 60 can acquire hydraulic pressure information of the master cylinder 21, it is preferable for the control unit 61 to vary the rotational speed of the motor 40, which is the drive source for the pump 31, according to the hydraulic pressure information of the master cylinder 21. Note that the control to vary the rotational speed of the motor 40 according to the hydraulic pressure information of the master cylinder 21 may be performed during the second control, or during both the first and second control.

[0058] For example, if the rotational speed of the motor 40, which is the drive source for the pump 31, is constant, the larger the amount of operation of the brake operating unit, the greater the increase in the hydraulic pressure of the master cylinder 21 per unit time. For this reason, the control unit 61 may increase the rotational speed of the motor 40 as the increase in the hydraulic pressure of the master cylinder 21 per unit time increases. In this case, the control unit 61 may increase the rotational speed of the motor 40 linearly, curvely, or in steps as the increase in the hydraulic pressure of the master cylinder 21 per unit time increases. That is, when comparing two states with different increases in the hydraulic pressure of the master cylinder 21 per unit time, the control unit 61 increases the rotational speed of the motor 40 when the increase in the hydraulic pressure of the master cylinder 21 per unit time is large compared to when the increase in the hydraulic pressure of the master cylinder 21 per unit time is small.

[0059] Furthermore, for example, if the rotational speed of the motor 40, which is the drive source for the pump 31, is constant, the greater the amount of operation of the brake operating unit, the greater the hydraulic pressure in the master cylinder 21. For this reason, the control unit 61 may increase the rotational speed of the motor 40 as the hydraulic pressure in the master cylinder 21 increases. In this case, the control unit 61 may increase the rotational speed of the motor 40 linearly, curvely, or in steps as the hydraulic pressure in the master cylinder 21 increases. In other words, when comparing two states with different hydraulic pressures in the master cylinder 21, the control unit 61 increases the rotational speed of the motor 40 when the hydraulic pressure in the master cylinder 21 is higher compared to when the hydraulic pressure in the master cylinder 21 is lower.

[0060] Furthermore, if the control device 60 can acquire hydraulic pressure information from the master cylinder 21, it is preferable for the control unit 61 to vary the opening time of the release valve 29 in the second control according to the rotational speed of the motor 40. For example, the control unit 61 increases the opening time of the release valve 29 in the second control as the rotational speed of the motor 40 increases. In this case, the control unit 61 may increase the opening time of the release valve 29 in the second control linearly, curvely, or in a stepwise manner as the rotational speed of the motor 40 increases. That is, when comparing two states with different rotational speeds of the motor 40, the control unit 61 increases the opening time of the release valve 29 in the second control when the motor 40 is rotating at a higher speed compared to when the motor 40 is rotating at a lower speed.

[0061] As the rotational speed of the motor 40 increases, the flow rate of brake fluid discharged from the pump 31 and flowing into the main passage 25 increases. Therefore, by varying the opening time of the release valve 29 in the second control according to the rotational speed of the motor 40, the amount of brake fluid stored in the accumulator 30 can be adjusted according to the flow rate of brake fluid discharged from the pump 31 and flowing into the main passage 25. This further suppresses fluctuations in the hydraulic pressure of the wheel cylinder 24 when the second control is executed.

[0062] The hydraulic pressure information of the master cylinder 21 can be obtained by various methods. For example, the vehicle 100 or brake system 10 can be configured with a detection device that detects the amount of operation (stroke) of the brake operating part. The hydraulic pressure of the master cylinder 21 estimated from the amount of operation of the brake operating part can then be used as the hydraulic pressure information of the master cylinder 21. Alternatively, for example, the hydraulic pressure of the master cylinder 21 detected by the master cylinder side pressure sensor 34 can be used as the hydraulic pressure information of the master cylinder 21. In this embodiment, the hydraulic pressure of the master cylinder 21 detected by the master cylinder side pressure sensor 34 is used as the hydraulic pressure information of the master cylinder 21. Since the hydraulic pressure of the master cylinder 21 can be directly detected, the rotational speed of the motor 40 can be set to a more suitable rotational speed when the rotational speed of the motor 40 is varied, and the opening time of the release valve 29 in the second control can be set to a more suitable opening time when the opening time of the release valve 29 is varied.

[0063] Next, the control operation (control method) when the control device 60 according to this embodiment performs automatic pressure boosting control will be described.

[0064] Figure 8 is a control flow diagram showing the control operation when the control device according to an embodiment of the present invention performs automatic pressure boosting control. When the conditions for executing automatic pressure boosting control are met, in step S1, the control device 60 starts the control shown in Figure 8. Step S2 is the first control step. In step S2, the control unit 61 of the control device 60 executes the first control. That is, the control unit 61 opens the loading valve 28, closes the release valve 29, closes the first switching valve 32, opens the second switching valve 33, and drives the motor 40 to increase the hydraulic pressure of the wheel cylinder 24. This first control is also executed when the brake lever 11 is not operated.

[0065] Step S3, following step S2, is a decision step to determine whether or not to execute the second control. In step S3, the determination unit 62 of the control device 60 determines whether or not the brake operating unit has been operated when the hydraulic pressure of the wheel cylinder 24 is at the specified pressure. If the determination unit 62 determines that the brake operating unit has been operated when the hydraulic pressure of the wheel cylinder 24 is at the specified pressure, the control unit 61 decides in step S3 to execute the second control. Note that in the normal state shown in Figure 4, if the amount of operation of the brake operating unit becomes large enough, it becomes difficult to move the brake operating unit. For this reason, if the amount of operation of the brake operating unit is large enough, the control unit 61 may decide not to execute the second control. Also, for example, if each step shown in Figure 8 is repeated and the second control has been performed a specified number of times in one automatic pressure boosting control, the control unit 61 may decide not to execute the second control.

[0066] If it is decided in step S3 to execute the second control, the control device 60 proceeds to step S4. Step S4 is the second control step. In step S4, the control unit 61 executes the second control. That is, when the brake operating unit is operated while the hydraulic pressure of the wheel cylinder 24 is at a specified pressure during the first control, the control unit 61 opens the release valve 29 from the state of the first control and allows brake fluid to flow into the accumulator 30 through the release valve 29. Step S5, following step S4, is the termination determination step. In step S5, the control device 60 determines whether the conditions for terminating the automatic pressure boosting control have been met. If the conditions for terminating the automatic pressure boosting control have been met, the control device 60 proceeds to step S7 and terminates the control shown in Figure 8. If the conditions for terminating the automatic pressure boosting control have not been met, the control device 60 returns to step S3.

[0067] On the other hand, if it is determined in step S3 that the second control should not be executed, the control device 60 proceeds to step S6. Step S6 is the termination determination step. In step S6, the control device 60 determines whether or not the conditions for terminating the automatic pressure boosting control have been met. If the conditions for terminating the automatic pressure boosting control have been met, the control device 60 proceeds to step S7 and terminates the control shown in Figure 8. If the conditions for terminating the automatic pressure boosting control have not been met, the control device 60 returns to step S2. Then, in step S2, the control unit 61 executes the first control. Here, step S3 can be reached either from step S2 or from step S5. For this reason, if the process proceeds from step S2 to step S3, and then from step S6 to step S2, the control unit 61 will continue the first control. Also, if the process proceeds from step S5 to step S3, and then from step S6 to step S2, the control unit 61 will switch from the second control to the first control.

[0068] <Effects of the control device> The control device 60 according to this embodiment is a control device for a brake system 10 for a vehicle 100. The brake system 10 includes a hydraulic circuit. The hydraulic circuit has a main passage 25 that connects a master cylinder 21 and a wheel cylinder 24, a supply passage 27 that supplies brake fluid to an intermediate section 25a of the main passage 25, and a sub-passage 26 that releases the brake fluid from the main passage 25. One end of the supply passage 27, end 27a, is connected to the master cylinder 21, and the other end, end 27b, is connected to the intermediate section 25a. One end of the sub-passage 26, end 26a, is connected to an intermediate section 25b of the main passage 25, which is located in the region on the wheel cylinder 24 side with respect to the intermediate section 25a. Furthermore, the brake system 10 includes a suction valve 28, an accumulator 30, a release valve 29, a first switching valve 32, a second switching valve 33, a pump 31, and a motor 40. The suction valve 28 is located in the region between intermediate sections 25a and 25b of the main flow path 25. The accumulator 30 is located in the sub-flow path 26 and stores brake fluid that flows into the sub-flow path 26 from intermediate section 25b. The release valve 29 is located in the region of the sub-flow path 26 that is on the end 26a side with respect to the accumulator 30. The first switching valve 32 is located in the region of the main flow path 25 that is on the master cylinder 21 side with respect to intermediate section 25a. The second switching valve 33 is located in the supply flow path 27. The pump 31 is located in the region of the supply flow path 27 that is on the end 27b side with respect to the second switching valve 33, with its suction side communicating with the second switching valve 33 and its discharge side communicating with the end 27b. The motor 40 is the driving source for the pump 31. Furthermore, the first switching valve 32 is configured to release brake fluid from the wheel cylinder 24 to the master cylinder 21 when the hydraulic pressure acting from the wheel cylinder 24 side is greater than the specified pressure while the first switching valve 32 is controlled to be closed by the control device 60. The control device 60 is configured to perform the first control. The first control is to open the fill valve 28, close the release valve 29, close the first switching valve 32, open the second switching valve 33, and drive the motor 40 to increase the hydraulic pressure of the wheel cylinder 24.Furthermore, the control device 60 is configured to execute a second control when, during the first control, the hydraulic pressure of the wheel cylinder 24 is at a specified pressure and the brake operation unit, which accepts brake operation by the driver of the vehicle 100, is operated. The second control is to open the release valve 29 from the state of the first control and allow brake fluid to flow into the accumulator 30 through the release valve 29.

[0069] In the control device 60 configured in this way, as described above, by executing the second control, it is possible to perform automatic pressure boosting control while suppressing the feeling of hard braking when operating the brake unit. Therefore, the control device 60 configured in this way can suppress the feeling of discomfort that the driver experiences when operating the brake unit more effectively than in conventional systems.

[0070] Preferably, the vehicle 100 equipped with the control device 60 according to this embodiment is a motorcycle. The control device 60 according to this embodiment can suppress the feeling of discomfort when operating the brake operation part more than conventional systems without adding any new mechanical components such as valves. Here, compared to four-wheeled vehicles, motorcycles have less space for mounting the brake system. For this reason, it is preferable to install the control device 60 according to this embodiment on a motorcycle, which has limited space for mounting the brake system.

[0071] Preferably, if the vehicle 100 is a motorcycle, the brake operating part of the brake system in which the control device 60 performs the second control is the brake lever provided on the vehicle 100. The brake lever is operated by the driver's hand. The hand is more sensitive to differences in the feel of operating the brake operating part than the foot. Therefore, by using the brake lever as the brake operating part of the brake system in which the control device 60 performs the second control, the effect of the control device 60 can be more easily recognized.

[0072] Although the control device 60 according to this embodiment has been described above, the control device according to the present invention is not limited to the description of this embodiment, and only a part of this embodiment may be implemented. For example, the control device 60 according to this embodiment performs the second control on all of the hydraulic circuits (first hydraulic circuit 12 and second hydraulic circuit 14) of the brake system 10. However, the control device according to the present invention may perform the second control on only some of the hydraulic circuits of the brake system. [Explanation of Symbols]

[0073] 1 Body, 2 Handle, 3 Front wheel, 3a Rotor, 4 Rear wheel, 4a Rotor, 10 Brake system, 11 Brake lever, 12 First hydraulic circuit, 13 Brake pedal, 14 Second hydraulic circuit, 21 Master cylinder, 22 Reservoir, 23 Brake caliper, 24 Wheel cylinder, 25 Main flow path, 25a Intermediate section, 25b Intermediate section, 26 Secondary flow path, 26a End section, 26b End section, 27 Supply flow path, 27a End section, 27b End section, 27c Intermediate section, 28 Fill valve, 29 Release valve, 30 Accumulator, 31 Pump, 32 First switching valve, 33 Second switching valve, 34 Master cylinder side pressure sensor, 35 Wheel cylinder side pressure sensor, 36 Check valve, 40 Motor, 50 Hydraulic control unit, 51 Base, 60 Control device, 61 control unit, 62 determination unit, 100 vehicle, MP master cylinder port, WP wheel cylinder port.

Claims

1. A control device (60) for a vehicle (100) brake system (10), The aforementioned brake system (10) The hydraulic circuit (12, 14) includes a main passage (25) that connects the master cylinder (21) and the wheel cylinder (24), a supply passage (27) that supplies brake fluid to a first intermediate section (25a) which is an intermediate section of the main passage (25), and a sub-passage (26) that releases the brake fluid from the main passage (25). The supply channel (27) has one end, the first end (27a), which is connected to the master cylinder (21), and the other end, the second end (27b), which is connected to the first intermediate section (25a). The third end (26a), which is one end of the sub-flow channel (26), is connected to the second intermediate section (25b), which is an intermediate section located in the region of the main flow channel (25) that is on the wheel cylinder (24) side, with reference to the first intermediate section (25a). Furthermore, the brake system (10) A sealing valve (28) is provided in the region between the first intermediate section (25a) and the second intermediate section (25b) of the main flow path (25), An accumulator (30) is provided in the aforementioned sub-channel (26) and stores the brake fluid that flows into the sub-channel (26) from the second intermediate section (25b), A release valve (29) is provided in the region of the subflow channel (26) that is on the third end (26a) side with respect to the accumulator (30), A first switching valve (32) is provided in the region of the main flow path (25) that is on the master cylinder (21) side, with reference to the first intermediate portion (25a), The second switching valve (33) is provided in the supply channel (27), A pump (31) is provided in the region of the supply channel (27) that is on the second end (27b) side with respect to the second switching valve (33), with the suction side communicating with the second switching valve (33) and the discharge side communicating with the second end (27b), The motor (40) is the driving source for the pump (31), It is equipped with, The first switching valve (32), when controlled to a closed state by the control device (60), is configured to release brake fluid from the wheel cylinder (24) side to the master cylinder (21) side when the hydraulic pressure acting from the wheel cylinder (24) side is greater than a specified pressure. The control device (60) is The system is configured to perform a first control that increases the hydraulic pressure of the wheel cylinder (24) by opening the filling valve (28), closing the release valve (29), closing the first switching valve (32), opening the second switching valve (33), and driving the motor (40). Furthermore, during the first control, when the hydraulic pressure of the wheel cylinder (24) is at the specified pressure, and the brake operation unit that receives brake operation by the driver of the vehicle (100) is operated, the system is configured to execute a second control that opens the release valve (29) from the state of the first control and allows brake fluid to flow into the accumulator (30) through the release valve (29). A control device (60) for a vehicle (100) brake system (10).

2. The brake system (10) includes a check valve (36) connected in parallel with the first switching valve (32) to the main flow path (25), which allows the flow of brake fluid from the master cylinder (21) side to the wheel cylinder (24) side. A control device (60) for a brake system (10) for a vehicle (100) according to claim 1.

3. The configuration is such that the rotational speed of the motor (40) is varied according to the hydraulic pressure information of the master cylinder (21). A control device (60) for a vehicle (100) brake system (10) according to claim 1 or claim 2.

4. The configuration is such that the opening time of the release valve (29) in the second control differs depending on the rotational speed of the motor (40). A control device (60) for a brake system (10) for a vehicle (100) according to any one of claims 1 to 3.

5. Furthermore, the brake system (10) includes a master cylinder-side pressure sensor (34) that detects the hydraulic pressure of the master cylinder (21), The hydraulic pressure information of the master cylinder (21) is the hydraulic pressure of the master cylinder (21) detected by the master cylinder-side pressure sensor (34). A control device (60) for a vehicle (100) brake system (10) according to claim 3 or claim 4.

6. Furthermore, the brake system (10) includes a wheel cylinder-side pressure sensor (35) for detecting the hydraulic pressure of the wheel cylinder (24). A control device (60) for a brake system (10) for a vehicle (100) according to any one of claims 1 to 5.

7. The fourth end (26b) of the sub-flow channel (26), which is the end opposite to the third end (26a), is connected to the third intermediate section (27c), which is an intermediate section located in the region between the second switching valve (33) and the pump (31) of the supply flow channel (27). A control device (60) for a vehicle (100) brake system (10) according to any one of claims 1 to 6.

8. The vehicle (100) brake system (10) is equipped with a control device (60) according to any one of claims 1 to 7. Vehicle (100).

9. The vehicle (100) is a motorcycle. The vehicle (100) according to claim 8.

10. The aforementioned motorcycle is equipped with a brake lever (11), The brake operating part is the brake lever (11). The vehicle (100) according to claim 9.

11. A control method for a brake system (10) for a vehicle (100), The aforementioned brake system (10) The hydraulic circuit (12, 14) includes a main passage (25) that connects the master cylinder (21) and the wheel cylinder (24), a supply passage (27) that supplies brake fluid to a first intermediate section (25a) which is an intermediate section of the main passage (25), and a sub-passage (26) that releases the brake fluid from the main passage (25). The supply channel (27) has one end, the first end (27a), which is connected to the master cylinder (21), and the other end, the second end (27b), which is connected to the first intermediate section (25a). The third end (26a), which is one end of the sub-flow channel (26), is connected to the second intermediate section (25b), which is an intermediate section located in the region of the main flow channel (25) that is on the wheel cylinder (24) side, with reference to the first intermediate section (25a). Furthermore, the brake system (10) A sealing valve (28) is provided in the region between the first intermediate section (25a) and the second intermediate section (25b) of the main flow path (25), An accumulator (30) is provided in the aforementioned sub-channel (26) and stores the brake fluid that flows into the sub-channel (26) from the second intermediate section (25b), A release valve (29) is provided in the region of the subflow channel (26) that is on the third end (26a) side with respect to the accumulator (30), A first switching valve (32) is provided in the region of the main flow path (25) that is on the master cylinder (21) side, with reference to the first intermediate portion (25a), The second switching valve (33) is provided in the supply channel (27), A pump (31) is provided in the region of the supply channel (27) that is on the second end (27b) side with respect to the second switching valve (33), with the suction side communicating with the second switching valve (33) and the discharge side communicating with the second end (27b), The motor (40) is the driving source for the pump (31), It is equipped with, The first switching valve (32), when controlled to be in the closed state, is configured to release brake fluid from the wheel cylinder (24) side to the master cylinder (21) side when the hydraulic pressure acting from the wheel cylinder (24) side is greater than a specified pressure. The control method described above is A first control step (S2) is performed to open the filling valve (28), close the release valve (29), close the first switching valve (32), open the second switching valve (33), and drive the motor (40) to increase the hydraulic pressure of the wheel cylinder (24). During the first control, when the hydraulic pressure of the wheel cylinder (24) is at the specified pressure, and the brake operating unit that receives brake operation by the driver of the vehicle (100) is operated, a second control step (S4) is performed to open the release valve (29) from the state of the first control and to allow brake fluid to flow into the accumulator (30) through the release valve (29), A method for controlling a brake system (10) for a vehicle (100) equipped with the following.

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