Brake system

Abstract

In a brake system (1), a first brake system (50) has a first main hydraulic passage (51) and a switching valve (56) provided in the first main hydraulic passage (51). The second brake system (60) has a third main hydraulic passage (61). The connection hydraulic passage (71) leads from the first main hydraulic passage (51) to the third main hydraulic passage (61). When energized, the switching valve (56) is in a state in which the first main hydraulic passage (51) and the connection hydraulic passage (71) do not communicate with each other. The switching valve (56) is in a state in which the first main hydraulic passage (51) and the connection hydraulic passage (71) communicate with each other when the current is not supplied. In this configuration, even when the first brake unit (10) is not operating, brake hydraulic pressure can be applied to the wheel brakes of the first brake unit (10).

Description

Technical Field

[0001] This invention relates to a braking system. Background Technology

[0002] There exists a braking system having a hydraulic generator and two braking systems connected to the hydraulic generator, wherein the hydraulic generator drives an electric motor to generate braking hydraulic pressure according to the amount of travel of the brake pedal, and braking hydraulic pressure is applied from one hydraulic generator to the two braking systems (for example, see Patent Document 1).

[0003] [Existing technical documents] [Patent Literature]

[0004] Patent Document 1: Japanese Patent Publication No. 2012-210879 Summary of the Invention

[0005] [The technical problem to be solved by this invention]

[0006] From the perspective of failure protection, such as Figure 6 As shown, a braking system 100 is required, having two braking units 10 and 20. Each braking unit 10 and 20 has a hydraulic generating device 12 and 22, a braking system 50 and 60, and electronic control devices 14 and 24, respectively. This braking system 100 is used to independently control the two braking units 10 and 20. In this braking system 100, the two wheel brakes B1 and B2 on the front wheels FR and FL sides are connected to one braking unit 10, and the two wheel brakes B3 and B4 on the rear wheels RR and RL sides are connected to the other braking unit 20.

[0007] In the braking system 100, when the electronic control device 14 or hydraulic generator 12 of the braking unit 10 is not working, braking force is obtained only by the two wheel brakes B3 and B4 connected to the other braking unit 20.

[0008] The present invention addresses the aforementioned problem by providing a braking system that can apply braking hydraulic pressure to the two wheel brakes of the first braking unit even when the electronic control device or hydraulic generator of the first braking unit is not working.

[0009] [Technical solutions used to solve technical problems]

[0010] To solve the aforementioned technical problem, the present invention provides a braking system comprising a first braking unit, a second braking unit, and a connecting hydraulic passage connecting the first braking unit and the second braking unit. The first braking unit comprises a first hydraulic generating device, a first braking system, and a first electronic control device, wherein the first hydraulic generating device generates braking hydraulic pressure according to the operation amount of a braking actuator; the first electronic control device controls the first hydraulic generating device and the first braking system. The first braking system comprises a first main hydraulic passage, a second main hydraulic passage, and a switching valve, wherein the first main hydraulic passage leads from the first hydraulic generating device to a first wheel brake; the second main hydraulic passage leads from the first main hydraulic passage to a second wheel brake; the switching valve is disposed in the first main hydraulic passage. The second main hydraulic passage communicates with the first main hydraulic passage on the side closer to the first wheel brake than the switching valve. The second braking unit comprises a second hydraulic generating device, a second braking system, and a second electronic control device, wherein the second hydraulic generating device generates braking hydraulic pressure according to the operation amount of the braking actuator; the second electronic control device controls the second hydraulic generating device and the second braking system. The second braking system has a third main hydraulic passage and a fourth main hydraulic passage. The third main hydraulic passage leads from the second hydraulic generator to the third wheel brake; the fourth main hydraulic passage leads from the third main hydraulic passage to the fourth wheel brake; and the connecting hydraulic passage leads from the first main hydraulic passage to the third main hydraulic passage. When energized, the switching valve is in a state where the first hydraulic generator side of the first main hydraulic passage is connected to the first wheel brake side, and the first main hydraulic passage is not connected to the connecting hydraulic passage. When de-energized, the switching valve is in a state where the first hydraulic generator side of the first main hydraulic passage is not connected to the first wheel brake side, and the first main hydraulic passage is connected to the connecting hydraulic passage.

[0011] In the braking system of the present invention, when the switching valve is not energized, the braking hydraulic pressure generated by the second hydraulic generator is transmitted to the third main hydraulic passage, and is transmitted from the connecting hydraulic passage to the first main hydraulic passage through the switching valve.

[0012] In the braking system described above, preferably, the first wheel brake and the second wheel brake are respectively disposed on the left and right front wheels, and the third wheel brake and the fourth wheel brake are respectively disposed on the left and right rear wheels.

[0013] In this structure, even if the first electronic control device or the first hydraulic generator of the first braking unit is not working, the vehicle can still be braked stably because the wheel brakes of the left and right front wheels generate a large braking force.

[0014] In the braking system, preferably, the first braking system has a first inlet valve, a second inlet valve, a return fluid passage, and an outlet valve, wherein the first inlet valve is used to open and close the first main hydraulic passage; the second inlet valve is used to open and close the second main hydraulic passage; the return fluid passage leads from the first main hydraulic passage and the second main hydraulic passage to the reservoir; and the outlet valve is used to open and close the return fluid passage.

[0015] In this structure, by opening the inlet valve and closing the outlet valve, the brake hydraulic pressure generated by the hydraulic generator is transmitted to the wheel brakes (during normal braking operation or during anti-lock braking control pressure boosting). Conversely, when the inlet valve is closed and the outlet valve is opened, the brake hydraulic pressure transmitted to the wheel brakes is reduced (during anti-lock braking control pressure reduction). Finally, when both the inlet and outlet valves are closed, the brake hydraulic pressure transmitted to the wheel brakes is maintained (during anti-lock braking control maintenance).

[0016] In the braking system described above, it is preferable that the driving amount of the second hydraulic generator is set to be greater when the switching valve is de-energized compared to when the switching valve is energized. Furthermore, it is preferable that the second hydraulic generator is set to increase the driving amount based on the required fluid volume when the switching valve is de-energized.

[0017] In this structure, even if the electronic control device or hydraulic generator of the first braking unit is not working, the same braking hydraulic pressure as under normal conditions can be applied to the two wheel brakes of the first braking unit solely through the second hydraulic generator of the second braking unit.

[0018] In the braking system, a third wheel brake and a first electric brake are installed on the first rear wheel, and a fourth wheel brake and a second electric brake are installed on the second rear wheel. Additionally, a third inlet valve and a fourth inlet valve are installed on the second braking system, wherein the third inlet valve is used to open and close the third main hydraulic passage, and the fourth inlet valve is used to open and close the fourth main hydraulic passage. Furthermore, when the switching valve is de-energized, the third inlet valve and the fourth inlet valve are closed, and the first electric brake and the second electric brake are activated.

[0019] In this way, when the first electronic control device or the first hydraulic generator of the first braking unit is not working and the switching unit is in a de-energized state, the braking hydraulic pressure generated by the second hydraulic generator is not transmitted to the third main hydraulic passage but is entirely transmitted to the first main hydraulic passage. This increases the braking force of the wheel brakes installed on the two front wheels. Furthermore, the two rear wheels can be braked by the first electric brake and the second electric brake.

[0020] In the aforementioned braking system, when the switching valve is composed of a three-way valve, it is possible to connect two braking systems while suppressing the number of solenoid valves.

[0021] In the braking system described above, the first hydraulic generator and the second hydraulic generator are configured to generate braking hydraulic pressure by moving a piston within a cylinder via an electric motor. Furthermore, the first main hydraulic passage is connected to the cylinder of the first hydraulic generator, and the third main hydraulic passage is connected to the cylinder of the second hydraulic generator. Moreover, during normal braking operation, braking hydraulic pressure is applied from the first hydraulic generator to the first and second wheel brakes, and from the second hydraulic generator to the third and fourth wheel brakes.

[0022] In the braking system described above, the second electronic control device may be configured to switch the energized and de-energized states of the switching valve.

[0023] Furthermore, the second electronic control device can be configured to switch the energized and de-energized state of the switching valve based on the action detection of the first braking unit.

[0024] In this structure, for example, if the second electronic control device detects a malfunction in the first braking unit, the second electronic control device de-energizes the switching valve, thereby enabling the application of braking hydraulic pressure from the second hydraulic generator to the two wheel brakes of the first braking unit.

[0025] [Invention Effects]

[0026] In the braking system of the present invention, even when the electronic control device or hydraulic generator of the first braking unit is not working, braking hydraulic pressure can still be applied to the two wheel brakes of the first braking unit to brake the vehicle. Attached Figure Description

[0027] Figure 1 This is a structural diagram illustrating the braking system according to an embodiment of the present invention.

[0028] Figure 2 This is a structural diagram of the braking system during conventional braking operation according to the embodiments of the present invention.

[0029] Figure 3 This is a structural diagram of the braking system according to an embodiment of the present invention, under the condition that the first electronic control device or the first hydraulic generating device of the first braking unit is not working.

[0030] Figure 4It is a graph showing the change in braking hydraulic pressure generated by the hydraulic generating device in the braking system according to the embodiments of the present invention.

[0031] Figure 5 This is a structural diagram of the braking system according to an embodiment of the present invention, in which braking hydraulic pressure is applied only to the wheel brakes of the first braking unit when the first electronic control device or the first hydraulic generator of the first braking unit is not working.

[0032] Figure 6 It is a structural diagram representing the reference configuration of the braking system. Detailed Implementation

[0033] While referring to the appendix appropriately Figure 1 The embodiments of the present invention will be described in detail below.

[0034] In this embodiment, the application of the braking system of the present invention to a four-wheeled vehicle will be used as an example for explanation.

[0035] like Figure 1 As shown, braking system 1 is a by-wire braking system that operates when the prime mover (engine, motor, etc.) starts.

[0036] Braking system 1 can be installed in hybrid electric vehicles that use electric motors in combination, electric vehicles / fuel cell vehicles that use electric motors as the power source only, and vehicles that use engines (internal combustion engines) as the power source only.

[0037] The braking system 1 has a first braking unit 10, a second braking unit 20 and a hydraulic passage 71, wherein the first braking unit 10 is connected to a first wheel brake B1 and a second wheel brake B2; and the second braking unit 20 is connected to a third wheel brake B3 and a fourth wheel brake B4.

[0038] In this embodiment, the first wheel brake B1 is used to brake the left front wheel FL, and the second wheel brake B2 is used to brake the right front wheel FR. Additionally, the third wheel brake B3 is used to brake the left rear wheel RL, and the fourth wheel brake B4 is used to brake the right rear wheel RR. Thus, the braking system 1 of this embodiment has an H-pipe brake structure.

[0039] In addition, in this embodiment, a first electric brake EB1 that functions as a parking brake is provided on the left rear wheel RL, and a second electric brake EB2 that functions as a parking brake is provided on the right rear wheel RR.

[0040] The first braking unit 10 includes a first base 11, a first hydraulic generating device 12, a first braking system 50, a first reservoir 13, and a first electronic control device 14.

[0041] The first substrate 11 is a metal block mounted on a vehicle. Multiple flow paths are formed inside the first substrate 11.

[0042] The first hydraulic generating device 12 is an electric actuator that generates brake hydraulic fluid based on the stroke (operation amount) of the brake pedal P (brake operating element). The first hydraulic generating device 12 is mounted on the first base 11. The first hydraulic generating device 12 generates brake hydraulic fluid by moving the piston 12b within the cylinder 12c, driven by an electric motor 12a.

[0043] The first reservoir 13 is a container used to replenish brake fluid to the first hydraulic generator 12, and is installed on the first base 11. Brake fluid is replenished from the first reservoir 13 to the cylinder 12c of the first hydraulic generator 12 through the flow path within the first base 11.

[0044] The first braking system 50 has a first main hydraulic passage 51, a second main hydraulic passage 52 and a first return fluid passage 53 formed in the first base 11.

[0045] The first main hydraulic passage 51 is the flow path from the first hydraulic generator 12 to the wheel cylinder of the first wheel brake B1. The second main hydraulic passage 52 is the flow path from the first main hydraulic passage 51 to the wheel cylinder of the second wheel brake B2.

[0046] The first main hydraulic passage 51 is connected to the cylinder 12c of the first hydraulic generator 12, and braking hydraulic pressure is applied from the first hydraulic generator 12 to the first main hydraulic passage 51 and the second main hydraulic passage 52.

[0047] The first return fluid passage 53 is a flow path from the first main hydraulic passage 51 and the second main hydraulic passage 52 to the first storage tank 13.

[0048] The first return fluid passage 53 has a first branch fluid passage 54 and a second branch fluid passage 55, wherein the first branch fluid passage 54 is a passage branching off from the first main hydraulic passage 51; and the second branch fluid passage 55 is a passage branching off from the second main hydraulic passage 52. The first branch fluid passage 54 and the second branch fluid passage 55 merge to form a single fluid passage. That is, the first return fluid passage 53 has a first branch fluid passage 54 and a second branch fluid passage 55 respectively connected to the first main hydraulic passage 51 and the second main hydraulic passage 52, and a fluid passage leading from the merging point of the first branch fluid passage 54 and the second branch fluid passage 55 to the first storage tank 13.

[0049] Brake fluid discharged from the first wheel brake B1 and the second wheel brake B2 flows into the first return fluid passage 53. The brake fluid discharged into the first return fluid passage 53 returns to the first reservoir 13 through the first return fluid passage 53.

[0050] On the first main hydraulic passage 51, a switching valve 56 is provided at the branch point of the first branch hydraulic passage 54, closer to the first hydraulic generator 12. In this embodiment, the switching valve 56 is a solenoid valve that is a 2-position 3-way valve.

[0051] The first hydraulic generator 12 side of the first main hydraulic passage 51, the first wheel brake B1 side of the first main hydraulic passage 51, and the connecting hydraulic passage 71 (described later) are respectively connected to each interface of the switching valve 56.

[0052] In addition, the second main hydraulic passage 52 is connected to the first main hydraulic passage 51 of the ratio switching valve 56 on the side of the first wheel brake B1.

[0053] like Figure 2 As shown, when energized, the switching valve 56 is in a state where the first hydraulic generator 12 side of the first main hydraulic passage 51 is connected to the first wheel brake B1 side, and the first main hydraulic passage 51 is not connected to the connecting hydraulic passage 71. In the normally operating braking system 1, when performing conventional braking control and anti-lock braking control, the switching valve 56 is energized.

[0054] like Figure 1 As shown, when not energized, the switching valve 56 is in a state where the first hydraulic generator 12 side of the first main hydraulic passage 51 is not connected to the first wheel brake B1 side, and the first main hydraulic passage 51 is connected to the connecting hydraulic passage 71. Except when the power to the braking system 1 is disconnected, the power to the switching valve 56 is stopped when the first hydraulic generator 12 or the first electronic control device 14 is not working properly.

[0055] A first inlet valve 51a is provided on the first main hydraulic passage 51 between the branch point of the second main hydraulic passage 52 and the branch point of the first branch hydraulic passage 54. The first inlet valve 51a is a normally open solenoid valve used to open and close the first main hydraulic passage 51.

[0056] A first outlet valve 54a is provided on the first branch liquid passage 54. The first outlet valve 54a is a normally closed solenoid valve used to open and close the first branch liquid passage 54.

[0057] On the second main hydraulic passage 52, a second inlet valve 52a is provided on the side of the first hydraulic generator 12 at the branch point relative to the second branch hydraulic passage 55. The second inlet valve 52a is a normally open solenoid valve used to open and close the second main hydraulic passage 52.

[0058] A second outlet valve 55a is provided on the second branch liquid passage 55. The second outlet valve 55a is a normally closed solenoid valve used to open and close the second branch liquid passage 55.

[0059] The first electronic control device 14 has a housing for accommodating the control board and is mounted on the first base 11. The first electronic control device 14 controls the operation of the first hydraulic generator 12 or the opening and closing of each valve of the first braking system 50 based on information obtained from various sensors such as pressure sensors or stroke sensors or pre-stored programs.

[0060] The first braking unit 10 is capable of performing anti-lock braking control. During the execution of anti-lock braking control, the switching valve 56 is energized, and the first hydraulic generator 12 side of the first main hydraulic passage 51 is connected to the first wheel brake B1 side.

[0061] like Figure 2 As shown, during normal braking operation and during the pressurization of anti-lock braking control, the first inlet valve 51a and the second inlet valve 52a are opened, and the first outlet valve 54a and the second outlet valve 55a are closed. Thus, the braking hydraulic pressure generated by the first hydraulic generator 12 is transmitted to the two wheel brakes B1 and B2.

[0062] During the decompression of the anti-lock braking system, the first inlet valve 51a and the second inlet valve 52a are energized and closed, while the first outlet valve 54a and the second outlet valve 55a are energized and opened. As a result, brake fluid is discharged from the two wheel brakes B1 and B2 into the first return fluid passage 53, and the brake fluid pressure transmitted to the two wheel brakes B1 and B2 is decompressed.

[0063] When the anti-lock braking control is maintained, the first inlet valve 51a and the second inlet valve 52a are energized and closed, and the first outlet valve 54a and the second outlet valve 55a are closed. As a result, the brake hydraulic pressure transmitted to the two wheel brakes B1 and B2 is maintained.

[0064] The second braking unit 20 has the same structure as the first braking unit 10, and includes a second base 21, a second hydraulic generating device 22, a second braking system 60, a second reservoir 23, and a second electronic control device 24.

[0065] The second hydraulic generator 22 generates brake hydraulic pressure corresponding to the stroke of the brake pedal P by moving the piston 22b within the cylinder 22c via an electric motor 22a.

[0066] The second braking system 60 has a third main hydraulic passage 61 and a fourth main hydraulic passage 62, wherein the third main hydraulic passage 61 leads from the second hydraulic generator 22 to the third wheel brake B3; and the fourth main hydraulic passage 62 leads from the third main hydraulic passage 61 to the fourth wheel brake B4. No switching valve is provided in the second braking system 60.

[0067] In addition, the second braking system 60 has a second return fluid passage 63 leading from the third main hydraulic passage 61 and the fourth main hydraulic passage 62 to the second reservoir 23.

[0068] The second return fluid passage 63 has a third branch fluid passage 64 branching from the third main hydraulic passage 61 and a fourth branch fluid passage 65 branching from the fourth main hydraulic passage 62. The third branch fluid passage 64 and the fourth branch fluid passage 65 merge to form a single fluid passage. That is, the second return fluid passage 63 has a third branch fluid passage 64 and a fourth branch fluid passage 65 respectively connected to the third main hydraulic passage 61 and the fourth main hydraulic passage 62, and a fluid passage leading from the junction of the third branch fluid passage 64 and the fourth branch fluid passage 65 to the second storage tank 23.

[0069] A third inlet valve 61a is provided on the third main hydraulic passage 61, and a third outlet valve 64a is provided on the third branch hydraulic passage 64 of the second return hydraulic passage 63. In addition, a fourth inlet valve 62a is provided on the fourth main hydraulic passage 62, and a fourth outlet valve 65a is provided on the fourth branch hydraulic passage 65.

[0070] Similar to the first braking unit 10, the second braking unit 20 controls the operation of the second hydraulic generator 22 or the opening and closing of each valve of the second braking system 60 through the second electronic control device 24, and can perform anti-lock braking control.

[0071] The braking system 1 of this embodiment has a connecting hydraulic passage 71 that leads from the first main hydraulic passage 51 to the third main hydraulic passage 61.

[0072] The hydraulic passage 71 is composed of flow paths within the first base 11 and the second base 21, and piping disposed between the first base 11 and the second base 21.

[0073] One end of the hydraulic passage 71 is connected to the switching valve 56. The other end of the hydraulic passage 71 is connected to the third main hydraulic passage 61 on the side closer to the second hydraulic generator 22 than the third inlet valve 61a.

[0074] In the braking system 1 of this embodiment, the driving amount of the second hydraulic generator 22 is set to be greater when the switching valve 56 is de-energized compared to when the switching valve 56 is energized (see reference). Figure 4Specifically, the driving amount of the second hydraulic generator 22 is controlled to supply the required amount of fluid (required fluid) from the second hydraulic generator 22. The required amount of fluid refers to the amount of fluid that makes the brake hydraulic fluid (requested brake hydraulic fluid) applied to the two wheel brakes respectively when the switching valve 56 is energized and the brake hydraulic fluid (requested brake hydraulic fluid) applied to the four wheel brakes respectively when the switching valve 56 is de-energized.

[0075] Next, the braking control of the braking system 1 in this embodiment will be explained.

[0076] like Figure 2 As shown, during normal braking operation, the switching valve 56 of the first braking unit 10 is energized.

[0077] Thus, the first hydraulic generator 12 side of the first main hydraulic passage 51 is connected to the first wheel brake B1 side. Then, the braking hydraulic pressure generated by the first hydraulic generator 12 is transmitted to the first wheel brake B1, and also transmitted to the second wheel brake B2 through the second main hydraulic passage 52.

[0078] In addition, the braking hydraulic pressure generated by the second hydraulic generator 22 is transmitted to the third wheel brake B3 through the third main hydraulic passage 61, and to the fourth wheel brake B4 through the fourth main hydraulic passage 62.

[0079] Thus, during normal braking operation, braking force is generated on the two wheel brakes B1 and B2 on the front wheel FR and FL sides by the first hydraulic generating device 12, and braking force is generated on the two wheel brakes B3 and B4 on the rear wheel RR and RL sides by the second hydraulic generating device 22.

[0080] like Figure 3 As shown, during normal braking operation, sometimes a malfunction occurs in the first braking unit 10, and at least one of the first electronic control device 14 and the first hydraulic generator 12 fails to operate, causing the switching valve 56 to be de-energized. In this case, since the valve position of the switching valve 56 returns to the initial state (de-energized state), the first hydraulic generator 12 side of the first main hydraulic passage 51 is not connected to the first wheel brake B1 side, and the first main hydraulic passage 51 is connected to the connecting hydraulic passage 71.

[0081] In this state, the braking hydraulic pressure generated by the second hydraulic generator 22 is transmitted to the two wheel brakes B3 and B4 on the rear wheel RR and RL sides. Moreover, the braking hydraulic pressure generated by the second hydraulic generator 22 is also transmitted from the third main hydraulic passage 61 through the connecting hydraulic passage 71, the switching valve 56, the first main hydraulic passage 51 and the second main hydraulic passage 52 to the two wheel brakes B1 and B2 on the front wheel FR and FL sides.

[0082] Thus, even when the first electronic control device 14 or the first hydraulic generator 12 of the first braking unit 10 is not working, braking force is still generated by the second hydraulic generator 22 of the second braking unit 20 on the two wheel brakes B1 and B2 on the front wheel FR and FL sides and the two wheel brakes B3 and B4 on the rear wheel RR and RL sides.

[0083] Furthermore, the driving amount of the second hydraulic generator 22 is set to be greater than that of the switching valve 56 when it is de-energized (when the first electronic control device 14 or the first hydraulic generator 12 is not operating) compared to the case where the switching valve 56 is energized (during normal braking operation). Figure 4 Therefore, even when the second hydraulic generator 22 applies braking hydraulic pressure to the four wheel brakes, the same braking hydraulic pressure is applied to each wheel brake as in normal operation.

[0084] The above-described braking system 1, during normal braking operation, such as... Figure 2 As shown, the first hydraulic generator 12 applies braking hydraulic pressure to the first wheel brake B1 and the second wheel brake B2, and the second hydraulic generator 22 applies braking hydraulic pressure to the third wheel brake B3 and the fourth wheel brake B4. Thus, in the braking system 1, two braking units 10 and 20 can be controlled independently.

[0085] In the braking system 1 of this embodiment, as Figure 3 As shown, even when the first electronic control device 14 or the first hydraulic generator 12 of the first braking unit 10 is not working, braking hydraulic pressure can be applied to the two wheel brakes B1 and B2 on the front wheel FR and FL sides, in addition to the two wheel brakes B3 and B4 on the rear wheel RR and RL sides, which are connected to the first braking unit 10.

[0086] Therefore, even when the first electronic control device 14 or the first hydraulic generator 12 of the first braking unit 10 is not working, the vehicle can still be braked stably because the wheel brakes B1 and B2 located on the left and right front wheels FR and FL generate a large braking force.

[0087] The above describes the embodiments of the present invention, but the present invention is not limited to the embodiments described, and can be appropriately modified within the scope of its spirit.

[0088] For example, such as Figure 5 As shown, it can be configured such that when the first electronic control device 14 or the first hydraulic generator 12 of the first braking unit 10 is not working and the switching valve 56 is in a non-energized state, the third inlet valve 61a and the fourth inlet valve 62a are closed.

[0089] In this way, the braking hydraulic pressure generated by the second hydraulic generator 22 is not transmitted to the third main hydraulic passage 61 but is entirely transmitted to the first main hydraulic passage 51. As a result, the braking force of the two wheel brakes B1 and B2 on the front wheel FR and FL sides can be increased.

[0090] Furthermore, in the aforementioned braking control, the first electric brake EB1 is activated to brake the left rear wheel RL, and the second electric brake EB2 is activated to brake the right rear wheel RR.

[0091] In the braking system 1 of this embodiment, it can be configured such that: Figure 1 The second electronic control device 24 shown can detect the operating state of the first braking unit 10, and the second electronic control device 24 can switch the energized and de-energized state of the switching valve 56.

[0092] In this structure, the switching valve 56 is not de-energized during normal braking operation. However, if the second electronic control device 24 detects a malfunction in the operation of the first braking unit 10, the switching valve 56 is de-energized by the second electronic control device 24, thereby enabling the application of braking hydraulic pressure from the second hydraulic generating device 22 to the two wheel brakes B1 and B2 of the first braking unit 10.

[0093] In the braking system 1 of this embodiment, the switching valve 56 is a three-way valve, but it can also be configured into a switching valve by combining multiple solenoid valves.

[0094] In this embodiment, the first wheel brake B1 brakes the front wheel FL, the second wheel brake B2 brakes the front wheel FR, and the third wheel brake B3 brakes the rear wheel RL and the fourth wheel brake B4 brakes the rear wheel RR, but the wheels braked by each wheel brake are not limited.

[0095] [Explanation of reference numerals in the attached figures]

[0096] 1: Braking system; 10: First braking unit; 11: First base; 12: First hydraulic generator; 12a: Electric motor; 12b: Piston; 12c: Cylinder; 13: First reservoir; 14: First electronic control device; 20: Second braking unit; 21: Second base; 22: Second hydraulic generator; 22a: Electric motor; 22b: Piston; 22c: Cylinder; 23: Second reservoir; 24: Second electronic control device; 50: First braking system; 51: First main hydraulic passage; 51a: First inlet valve; 52: Second main hydraulic passage; 52a: Second inlet valve; 53: First return fluid passage; 54: First branch fluid passage; 54a: First outlet valve; 55: Second branch fluid passage 55a: Second outlet valve; 56: Switching valve; 60: Second braking system; 61: Third main hydraulic passage; 61a: Third inlet valve; 62: Fourth main hydraulic passage; 62a: Fourth inlet valve; 63: Second return fluid passage; 64: Third branch fluid passage; 64a: Third outlet valve; 65: Fourth branch fluid passage; 65a: Fourth outlet valve; 71: Connecting hydraulic passage; B1: First wheel brake; B2: Second wheel brake; B3: Third wheel brake; B4: Fourth wheel brake; EB1: First electric brake; EB2: Second electric brake; FL: Left front wheel; FR: Right front wheel; RL: Left rear wheel; RR: Right rear wheel; P: Brake pedal.

Claims

1. A braking system comprising a first braking unit, a second braking unit, and a connecting hydraulic passage connecting the first braking unit and the second braking unit, characterized in that, The first braking unit includes a first hydraulic generating device, a first braking system, and a first electronic control device, wherein, The first hydraulic generating device generates brake hydraulic pressure according to the amount of operation of the brake operating component; The first electronic control device is used to control the first hydraulic generator and the first braking system. The first braking system has a first main hydraulic passage, a second main hydraulic passage, and a switching valve, wherein, The first main hydraulic passage leads from the first hydraulic generator to the first wheel brake; The second main hydraulic passage leads from the first main hydraulic passage to the second wheel brake; The switching valve is located in the first main hydraulic passage. The second main hydraulic passage connects to the first main hydraulic passage on the side closer to the first wheel brake than the switching valve. The second braking unit includes a second hydraulic generating device, a second braking system, and a second electronic control device, wherein, The second hydraulic generating device generates brake hydraulic pressure according to the amount of operation of the brake operating component; The second electronic control device is used to control the second hydraulic generator and the second braking system. The second braking system has a third main hydraulic passage and a fourth main hydraulic passage, wherein, The third main hydraulic passage leads from the second hydraulic generator to the third wheel brake; The fourth main hydraulic passage leads from the third main hydraulic passage to the fourth wheel brake. The connecting hydraulic passage extends from the first main hydraulic passage to the third main hydraulic passage. When energized, the switching valve is in a state where the first hydraulic generator side of the first main hydraulic passage is connected to the first wheel brake side, and the first main hydraulic passage is not connected to the connecting hydraulic passage. When not energized, the switching valve is in a state where the first hydraulic generator side of the first main hydraulic passage is not connected to the first wheel brake side, and the first main hydraulic passage is connected to the connecting hydraulic passage.

2. The braking system according to claim 1, characterized in that, The first wheel brake and the second wheel brake are respectively located on the left and right front wheels. The third wheel brake and the fourth wheel brake are respectively located on the left and right rear wheels.

3. The braking system according to claim 1, characterized in that, The first braking system has a first inlet valve, a second inlet valve, a return fluid passage, and an outlet valve, wherein, The first inlet valve is used to open and close the first main hydraulic passage; The second inlet valve is used to open and close the second main hydraulic passage; The return fluid passage leads from the first main hydraulic passage and the second main hydraulic passage to the storage tank; The outlet valve is used to open and close the return fluid passage.

4. The braking system according to claim 1, characterized in that, The driving amount of the second hydraulic generator is set to be greater when the switching valve is not energized, compared to when the switching valve is energized.

5. The braking system according to claim 4, characterized in that, The second hydraulic generator is configured to increase the driving force according to the required hydraulic volume when the switching valve is in a non-energized state.

6. The braking system according to claim 2, characterized in that, The third wheel brake and the first electric brake are installed on the first rear wheel. The fourth wheel brake and the second electric brake are installed on the second rear wheel. The second braking system has a third inlet valve and a fourth inlet valve, wherein, The third inlet valve is used to open and close the third main hydraulic passage; The fourth inlet valve is used to open and close the fourth main hydraulic passage. When the switching valve is in a non-energized state Close the third inlet valve and the fourth inlet valve, and To activate the first electric brake and the second electric brake.

7. The braking system according to claim 1, characterized in that, The switching valve is a three-way valve.

8. The braking system according to claim 1, characterized in that, The first hydraulic generator and the second hydraulic generator are configured to generate braking hydraulic pressure by moving a piston within a cylinder via an electric motor. The first main hydraulic passage is connected to the cylinder of the first hydraulic generator. The third main hydraulic passage is connected to the cylinder of the second hydraulic generator.

9. The braking system according to claim 1, characterized in that, The second electronic control device can switch the energized and de-energized states of the switching valve.

10. The braking system according to claim 9, characterized in that, The second electronic control device switches the energized and de-energized state of the switching valve based on the action detection of the first braking unit.

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