Exhaust method of vehicle brake system

Abstract

The invention provides an exhaust method for a vehicle brake system, which can exhaust air more efficiently in a vehicle brake system using a switching valve to shorten a flow path and reduce the size of the system, and using a bypass flow path and a check valve to ensure the flow rate of brake fluid. The exhaust method of a vehicle brake system includes: a first step of actuating a slave cylinder on a pressurization side in a state in which a switching valve communicates with the slave cylinder and a brake hydraulic pressure control device, and discharging air remaining in a flow path section from the slave cylinder to the brake hydraulic pressure control device from an exhaust hole; and a second step in which, after the first step, the slave cylinder is actuated on the pressure reduction side in a state in which the exhaust hole is closed, and the air remaining in the bypass flow path is moved into the flow path section, and after the second step, the first step is performed again, and the air moved from the bypass flow path into the flow path section is discharged from the exhaust hole.

Description

Technical Field

[0001] The invention relates to an exhaust method for a vehicle brake system. Background Art

[0002] In the prior art, a vehicle brake system includes a master cylinder that generates brake fluid pressure by operating a brake operator (e.g., a brake pedal), and a slave cylinder that generates brake fluid pressure by using a driving force of an actuator (e.g., an electric motor) based on an electrical signal, so as to supply the brake fluid pressure generated by the master cylinder or the slave cylinder through pressurizing the brake fluid to the wheel cylinder, thereby applying necessary braking force to the wheel. In the flow path on the downstream side of the slave cylinder, a vehicle behavior stabilizer is provided as a brake fluid pressure control device for controlling the brake fluid pressure transmitted to the wheel cylinder. In addition, the vehicle brake system may be provided with a switching valve (e.g., Patent Document 1) to switch the connection state of the master cylinder and the slave cylinder (whether to supply brake fluid to the brake fluid pressure control device), thereby shortening the flow path and miniaturizing the vehicle brake system.

[0003] In general, when the vehicle brake system performs a braking action that does not rely on the driver's operation, the switching valve is switched to connect the slave cylinder with the brake hydraulic control device, but when an abnormality occurs in the slave cylinder, the switching valve is switched to connect the master cylinder with the brake hydraulic control device. At this time, since the throttle hole (cross-sectional area) of the flow path connecting the switching valve and the master cylinder is smaller than the throttle hole (cross-sectional area) of the flow path connecting the switching valve and the slave cylinder, the fluidity of the brake fluid deteriorates at low temperatures. In response to this, a bypass flow path (bypass passage) and a check valve (check valve) that connect the flow path from the reservoir of the master cylinder or the slave cylinder to the downstream side of the switching valve have been developed in the vehicle brake system (e.g., Patent Document 2), thereby ensuring the flow of brake fluid required for the pressure control of the brake hydraulic control device. However, when this structure is adopted, air is easily retained in the flow path on the downstream side of the check valve. When air is trapped on the downstream side of the check valve, it is not possible to manually exhaust the air through a foot pedal or the like, and a dedicated exhaust device must be used to exhaust the air, which increases additional costs and operating procedures.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-147644

[0007] [Patent Document 2] Japanese Patent Publication No. 2016-078753 Summary of the invention

[0008] The present invention provides an exhaust method for a vehicle brake system, which can exhaust air more efficiently in a vehicle brake system that uses a switching valve to shorten a flow path and miniaturize the system, and uses a bypass flow path and a one-way valve to ensure the flow of brake fluid.

[0009] The present invention provides an exhaust method for a vehicle brake system, which is used to exhaust air from the vehicle brake system. The vehicle brake system includes a master cylinder, a slave cylinder, a flow path, a wheel cylinder, a switching valve, a brake hydraulic control device, a bypass flow path, and a one-way valve. The master cylinder generates brake hydraulic pressure by operating a brake operator, and the slave cylinder generates brake hydraulic pressure based on an electrical signal using the driving force of an actuator. The flow path connects the master cylinder and the slave cylinder to the wheel cylinder. The switching valve switches the communication state between the master cylinder and the slave cylinder. The brake hydraulic control device is arranged in the flow path on the downstream side of the switching valve, and controls the pressure transmitted to the wheel cylinder. Braking hydraulics, the bypass flow path is connected from a reservoir installed on the master cylinder or the slave cylinder to a portion of the flow path that is more downstream than the switching valve and more upstream than the brake hydraulic control device, the one-way valve is arranged in the bypass flow path, when the brake hydraulic control device controls the brake fluid pressure, the one-way valve allows the brake fluid to flow from the side close to the reservoir to the side close to the brake hydraulic control device, and prevents the brake fluid from flowing from the side close to the brake hydraulic control device to the side close to the reservoir, and the wheel cylinder has a switchable exhaust hole. Among them, the exhaust method of the vehicle brake system includes: a first step, in a state where the switching valve connects the slave cylinder and the brake hydraulic control device, the slave cylinder is actuated on the pressurization side, and the air retained in the flow path section from the slave cylinder to the brake hydraulic control device is discharged from the exhaust hole; and a second step, after the first step, in a state where the exhaust hole is closed, the slave cylinder is actuated on the decompression side, and the air retained in the bypass flow path is moved to the flow path section, and after the second step, the first step is performed again, and the air moved from the bypass flow path to the flow path section is discharged from the exhaust hole.

[0010] Based on the above, in the exhaust method of the vehicle brake system of the present invention, for a vehicle brake system that uses a switching valve to switch the communication state of the master cylinder and the slave cylinder connected to the wheel cylinder as a hydraulic supply source, and uses a bypass flow path and a one-way valve connected from a reservoir installed on the master cylinder or the slave cylinder to a portion of the flow path that is more downstream than the switching valve and more upstream than the brake hydraulic control device, the slave cylinder is operated on the pressurization side and the decompression side in sequence, and the exhaust hole of the wheel cylinder is opened and closed, so that the air retained in the bypass flow path is moved from the bypass flow path to the flow path section and discharged from the exhaust hole. In this way, the present invention does not need to use an external exhaust device, and can exhaust air through simple operations such as the operation of the slave cylinder and / or the opening and closing operation of the exhaust hole, thereby saving additional cost and operation procedures. Accordingly, the exhaust method of the vehicle brake system of the present invention can more efficiently exhaust air in a vehicle brake system that uses a switching valve to shorten the flow path and miniaturize the system, and uses a bypass flow path and a one-way valve to ensure the flow of brake fluid.

[0011] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of the structure of a vehicle braking system according to an embodiment of the present invention;

[0013] Figure 2 yes Figure 1 A partial enlarged schematic diagram of a vehicle braking system is shown;

[0014] Figure 3 yes Figure 1 A flow chart of a method for bleeding a vehicle brake system is shown.

[0015] Description of Reference Numerals

[0016] 50: pedal device;

[0017] 52, 62: liquid reservoir;

[0018] 54: Pedal force simulator;

[0019] 56: Safety valve;

[0020] 58: Piping;

[0021] 60: booster device;

[0022] 64: gear set;

[0023] 64a: input gear;

[0024] 64b: Idle gear;

[0025] 64c: output gear;

[0026] 100: Vehicle braking system;

[0027] 110: master cylinder;

[0028] 120: slave cylinder;

[0029] 130: Flow path;

[0030] 130a, 130b, 130c: flow path sections;

[0031] 140: wheel cylinder;

[0032] 142: Exhaust hole;

[0033] 150: switching valve;

[0034] 160: Brake hydraulic control device;

[0035] 170: bypass flow path;

[0036] 180: one-way valve;

[0037] B: brake pedal;

[0038] M: motor;

[0039] S: liquid supply source;

[0040] S1: first step;

[0041] S2: second step;

[0042] W: Wheel. DETAILED DESCRIPTION

[0043] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Figure 1 is a schematic diagram of the structure of a vehicle braking system according to an embodiment of the present invention, Figure 2 yes Figure 1 The partially enlarged schematic diagram of the vehicle braking system shown in FIG. Figure 3 yes Figure 1 The following is a flow chart of the exhaust method of the vehicle brake system. Figures 1 to 3 The specific structure of the vehicle brake system 100 and the operation flow of the exhaust method of the vehicle brake system 100 of this embodiment are described, but this is only one example of the present invention, and the present invention is not limited thereto and can be adjusted according to needs.

[0044] Please refer to Figure 1In this embodiment, the vehicle brake system 100 has two types of brake systems: a by-wire brake system that transmits an electrical signal to operate the brake, and a hydraulic brake system that transmits hydraulic pressure to operate the brake. The vehicle brake system 100 includes a master cylinder 110, a slave cylinder 120, a flow path 130, a wheel cylinder 140, a switching valve 150, a brake hydraulic control device 160, a bypass flow path 170, and a check valve 180. The implementation of each component will be described in order below.

[0045] In this embodiment, the master cylinder 110 generates brake fluid pressure by operating a brake operator (e.g., brake pedal B). The slave cylinder 120 generates brake fluid pressure by using the driving force of an actuator (e.g., motor M) based on an electrical signal. The master cylinder 110 is configured as a part of a pedal device 50 (i.e., brake input device), for example. The pedal device 50 further includes a brake pedal B as a brake operator, a reservoir 52 for storing brake fluid, a pedal force simulator 54, and a safety valve 56, and these components are connected to each other via a pipe 58 in the pedal device 50. Correspondingly, the slave cylinder 120 is configured as a part of a booster device 60 (i.e., electric cylinder device), for example. The booster device 60 further includes a motor M as an actuator, a reservoir 62 for storing brake fluid, and a gear set 64 including an input gear 64a, an idle gear 64b, and an output gear 64c, and these components are connected to each other. The pedal device 50 including the master cylinder 110 and the booster device 60 including the slave cylinder 120 may be installed in the engine room of the vehicle, and the pedal device 50 and the booster device 60 may be electrically connected via a wiring harness (not shown) or the like. In addition, the reservoir 52 connected to the master cylinder 110 and the reservoir 62 connected to the slave cylinder 120 may be supplied with brake fluid from the same fluid supply source S. However, the present invention is not limited thereto and may be adjusted according to requirements.

[0046] Furthermore, in this embodiment, if Figure 1As shown, the flow path 130 connects the master cylinder 110 and the slave cylinder 120 to the wheel cylinder 140, so that the brake fluid pressure generated by pressurizing the brake fluid in the master cylinder 110 or the slave cylinder 120 is supplied to the wheel cylinder 140, thereby applying necessary braking force to the wheel W. The switching valve 150 is provided on the flow path 130 at a position further downstream than the master cylinder 110 and the slave cylinder 120, and connects the master cylinder 110, the slave cylinder 120, and the wheel cylinder 140 through the flow path 130. The switching valve 150 switches the communication state between the master cylinder 110 and the slave cylinder 120. Among them, the flow path 130 includes a flow path section 130a from the master cylinder 110 to the switching valve 150, a flow path section 130b from the slave cylinder 120 to the switching valve 150, and a flow path section 130c from the switching valve 150 to the wheel cylinder 140. Therefore, the switching valve 150 is, for example, a three-way valve connecting the master cylinder 110, the slave cylinder 120, and the wheel cylinder 140, but is not limited thereto. In addition, the wheel cylinders 140 are respectively connected to each wheel W of the vehicle (not shown). That is, the wheel cylinders 140 can be set one by one corresponding to the number of wheels W (for example, four wheels W and four wheel cylinders 140 are provided). As a result, it is possible to provide a braking force to each wheel W via the brake hydraulic pressure generated by at least one of the master cylinder 110 and the slave cylinder 120, thereby performing brake control on the vehicle.

[0047] More specifically, the master cylinder 110 and the slave cylinder 120 are, for example, tandem cylinders each having two cylinder barrels. Therefore, the two cylinder barrels of the master cylinder 110 and the slave cylinder 120 can be connected to the wheel cylinders 140 via two groups of flow paths 130. The first group of flow paths 130 connects a portion of the wheel cylinders 140 (for example, connects two of the wheel cylinders 140) to the downstream side from one of the cylinder barrels of the master cylinder 110 and one of the cylinder barrels of the slave cylinder 120 through the first switching valve 150. Correspondingly, the second group of flow paths 130 connects another portion of the wheel cylinders 140 (for example, connects another two of the wheel cylinders 140) to the downstream side from the other cylinder barrel of the master cylinder 110 and the other cylinder barrel of the slave cylinder 120 through the second switching valve 150. The set of flow paths 130 refers to the general term for the pipes extending between the master cylinder 110, the slave cylinder 120, and the wheel cylinder 140 to connect these cylinders (i.e., including flow path sections 130a, 130b, 130c). The vehicle brake system 100 is also provided with two switching valves 150 when using a master cylinder 110 and a slave cylinder 120 having two cylinder barrels and having two flow paths 130. The two sets of flow paths 130 and the two switching valves 150 can be controlled separately or simultaneously, and one can be controlled as a main flow path and the other as a backup flow path. However, the master cylinder 110 and the slave cylinder 120 can each have a single cylinder barrel, and the vehicle brake system 100 can also be provided with only one set of flow paths 130 and one switching valve 150. The present invention is not limited to this and can be adjusted according to needs.

[0048] Furthermore, in this embodiment, if Figure 1As shown, the brake hydraulic pressure control device 160 is provided in the flow path 130 on the downstream side of the switching valve 150 (i.e., the flow path section 130c), and controls the brake hydraulic pressure transmitted to the wheel cylinder 140, thereby supporting the stabilization of the vehicle behavior. More specifically, the brake hydraulic pressure control device 160 connects the master cylinder 110 and the slave cylinder 120 via the aforementioned flow path 130 (the switching valve 150 is provided in the flow path 130). For example, the flow path section 130c is connected from the switching valve 150 to the brake hydraulic pressure control device 160 provided on the upstream side of the wheel cylinder 140. Furthermore, the brake hydraulic pressure control device 160 is connected to the wheel cylinder 140 via the internal piping thereof, and the internal piping may also be provided with a control valve or the like for controlling whether the piping is connected to the wheel cylinder 140, but the present invention is not limited thereto. The wheel cylinder 140 is, for example, a part of a disc brake mechanism (not shown). The brake hydraulic pressure from the master cylinder 110 or the slave cylinder 120 and controlled (pressurized or depressurized) by the brake hydraulic pressure control device 160 can be transmitted to the wheel cylinder 140, thereby driving the disc brake mechanism to provide braking force to each wheel W. Among them, the two groups of flow paths 130 connecting the master cylinder 110 and the slave cylinder 120 are respectively connected to different groups of wheel cylinders 140 through the switching valve 150 and the brake hydraulic pressure control device 160, so that the wheel cylinders 140 can brake the wheels W independently of each other. However, the present invention is not limited to this, and it can be adjusted according to needs.

[0049] As an example, the brake hydraulic control device 160 is implemented by a vehicle behavior stabilization device such as the registered trademark Vehicle Stability Assist (VBA), but is not limited to this. The brake hydraulic control device 160 has, for example, an anti-lock braking system (ABS) function to prevent wheel locking during braking, a traction control system (TCS) function to prevent wheel slip during acceleration, and a function to prevent side slip during cornering. The brake hydraulic control device 160 can be installed in the engine compartment of the vehicle, wherein the pedal device 50, the boost device 60, and the brake hydraulic control device 160 can be separately arranged in the engine compartment, or part or all of these devices can be integrated. However, the present invention is not limited to this, and it can be adjusted according to needs.

[0050] In addition, in this embodiment, Figure 1 As shown, the bypass flow path 170 is connected from the reservoir installed in the master cylinder 110 or the slave cylinder 120 (in this example, from the reservoir 52 installed in the master cylinder 110) to a portion of the flow path 130 that is downstream of the switching valve 150 and upstream of the brake fluid pressure control device 160 (i.e., Figure 1 130c in the flow path section 130c). That is, the bypass flow path 170 bypasses the master cylinder 110 and the switching valve 150 from the reservoir 52 and is connected to the flow path section 130c between the switching valve 150 and the brake hydraulic control device 160. In addition, the one-way valve 180 is provided in the bypass flow path 170. When the brake hydraulic control device 160 controls the pressure of the brake fluid, the one-way valve 180 allows the brake fluid to flow from the side close to the reservoir 52 to the side close to the brake hydraulic control device 160, and prevents the brake fluid from flowing from the side close to the brake hydraulic control device 160 to the side close to the reservoir 52. In the present example in which two sets of flow paths 130 are provided as described above, two bypass flow paths 170 and two one-way valves 180 may also be provided, but the present invention is not limited thereto.

[0051] Through the above arrangement, when the brake fluid control device 160 performs pressure control on the brake fluid, the one-way valve 180 provided in the bypass flow path 170 allows the brake fluid to flow from the side close to the reservoir 52 to the side close to the brake fluid control device 160. Therefore, the brake fluid for pressurization can be directly sucked from the reservoir 52 on the upstream side of the brake fluid control device 160 through the bypass flow path 170, thereby providing sufficient brake fluid to the brake fluid control device 160 that performs pressure control from the reservoir 52 installed in the master cylinder 110 through the bypass flow path 170. That is, during the pressure control of the brake fluid control device 160, it is not necessary to supply the brake fluid through the master cylinder 110 or the slave cylinder 120, so that compared with the prior art, the resistance when the brake fluid is sucked is smaller and the flow rate is larger. As a result, the flow rate of the brake fluid required for the pressure control of the brake fluid control device 160 can be smoothly ensured. Furthermore, the check valve 180 prevents the brake fluid from flowing from the side close to the brake fluid pressure control device 160 to the side close to the reservoir 52 .

[0052] In other embodiments not shown, the bypass flow path 170 may also be connected from the reservoir 62 installed in the slave cylinder 120 to a portion of the flow path 130 that is downstream of the switching valve 150 and upstream of the brake hydraulic pressure control device 160 (i.e., the flow path section 130c). That is, the bypass flow path 170 bypasses the slave cylinder 120 and the switching valve 150 from the reservoir 62 and is connected to the flow path section 130c between the switching valve 150 and the brake hydraulic pressure control device 160. In addition, the bypass flow path 170 may also be provided with a one-way valve 180 to perform control similar to the above. That is, when the brake hydraulic control device 160 performs pressure control on the brake fluid, the one-way valve 180 allows the brake fluid to flow from the side close to the reservoir 62 to the side close to the brake hydraulic control device 160, so that the brake fluid for pressurization can be directly sucked from the reservoir 62 on the upstream side of the brake hydraulic control device 160 through the bypass flow path 170, thereby providing sufficient brake fluid from the reservoir 62 installed in the slave cylinder 120 to the brake hydraulic control device 160 performing pressure control via the bypass flow path 170. In this way, the flow rate of the brake fluid required for the pressure control of the brake hydraulic control device 160 can also be smoothly ensured. However, the present invention does not limit the specific connection position of the bypass flow path 170, which can be adjusted according to needs.

[0053] Please refer to Figure 2 In this embodiment, when the vehicle brake system 100 adopts this structure, air is easily retained in the flow path on the downstream side of the one-way valve 180, that is, the area R between the one-way valve 180 and the flow path section 130c (the end of the bypass flow path 170). In this regard, this embodiment proposes the following Figure 3 The exhaust method of the vehicle brake system 100 shown in the figure is to exhaust air from the vehicle brake system 100 by operating the components of the vehicle brake system 100 itself without using a dedicated exhaust device. Figure 1 ), so that when no brake control is performed, the components of the vehicle brake system 100 itself are operated, and air is discharged from the exhaust hole 142 of the wheel cylinder 140.

[0054] Specifically, in this embodiment, if Figure 1 and Figure 3As shown, the exhaust method of the vehicle brake system 100 is used to exhaust air from the vehicle brake system 100. The exhaust method of the vehicle brake system 100 includes a first step S1 and a second step S2. In the first step S1, when the switching valve 150 is connected to the slave cylinder 120 and the brake hydraulic control device 160, the slave cylinder 120 is actuated on the pressurizing side, and the air retained in the flow path sections 130b and 130c from the slave cylinder 120 to the brake hydraulic control device 160 is exhausted from the exhaust hole 142 (as shown in FIG. Figure 1 In the second step S2, after the first step S1, the exhaust hole 142 is closed, and the slave cylinder 120 is operated on the pressure reducing side, so that the air retained in the bypass flow path 170 moves to the flow path sections 130b and 130c (as shown in FIG. Figure 1 Furthermore, after the second step S2, the first step S1 is performed again, and the air moving from the bypass flow path 170 to the flow path sections 130b and 130c is discharged from the exhaust hole 142 (as shown in FIG. Figure 1 The exhaust path is shown by the solid arrow in FIG.

[0055] Specifically, in this embodiment, the first step S1 is performed first, and the slave cylinder 120 operating on the pressurizing side supplies brake fluid to the wheel cylinder 140 through the connected switching valve 150 and the brake hydraulic control device 160. At this time, the air retained in the flow path sections 130b and 130c from the slave cylinder 120 to the brake hydraulic control device 160 also moves to the wheel cylinder 140 along with the brake fluid (e.g., Figure 1 Then, the second step S2 is performed, the slave cylinder 120 actuated on the pressure reducing side reversely extracts the brake fluid flowing to the wheel cylinder 140 through the connected switching valve 150 and the brake fluid control device 160, so that the air retained in the bypass flow path 170 moves to the flow path sections 130b and 130c (as shown in FIG. Figure 1 At this time, since the air in the flow path sections 130b and 130c has been largely exhausted and the exhaust hole 142 is closed, it is possible to prevent the air from flowing back from the side close to the exhaust hole 142 to the flow path sections 130b and 130c. Finally, the first step S1 is performed again, and the air moved from the bypass flow path 170 to the flow path sections 130b and 130c in the second step S2 is exhausted from the exhaust hole 142 (as shown in FIG. Figure 1 The exhaust path is shown by the solid arrow in FIG.

[0056] It can be seen from this that in the exhaust method of the vehicle brake system 100 of the present embodiment, for the vehicle brake system 100 that uses the switching valve 150 to switch the connection state between the master cylinder 110 and the slave cylinder 120 connected to the wheel cylinder 140 as a hydraulic supply source, and uses the bypass flow path 170 and the one-way valve 180 connected from the reservoir 52 installed on the master cylinder 110 or the reservoir 62 of the slave cylinder 120 to the part of the flow path 130 that is more downstream than the switching valve 150 and more upstream than the brake hydraulic control device 160 (that is, the flow path section 130c), the slave cylinder 120 is actuated on the pressurization side and the decompression side in sequence, and the exhaust hole 142 of the wheel cylinder 140 is opened and closed, so that the air retained in the bypass flow path 170 is moved from the bypass flow path 170 to the flow path sections 130b and 130c and discharged from the exhaust hole 142. Thus, the present embodiment does not need to use an external exhaust device, and can exhaust air through simple operations such as operating the slave cylinder 120 and / or opening and closing the exhaust hole 142, thereby saving additional cost and operation procedures. Accordingly, the exhaust method of the vehicle brake system 100 can exhaust air more efficiently in the vehicle brake system 100 that uses the switching valve 150 to shorten the flow path 130 and miniaturize the system, and uses the bypass flow path 170 and the check valve 180 to ensure the flow rate of the brake fluid.

[0057] Although the above content takes the vehicle brake system 100 as an example to explain the implementation of the exhaust method of the vehicle brake system 100, the exhaust method of the vehicle brake system is not limited to the situation of exhausting the vehicle brake system 100 having the above structure, as long as the exhaust method of the vehicle brake system is used for the vehicle brake system having the master cylinder 110, the slave cylinder 120, the flow path 130, the wheel cylinder 140, the switching valve 150, the brake hydraulic pressure control device 160, the bypass flow path 170, and the check valve 180 that meet the above description. In particular, the vehicle brake system needs to have the slave cylinder 120, the flow path 130, the wheel cylinder 140 having the exhaust hole 142, the switching valve 150, the brake hydraulic pressure control device 160, the bypass flow path 170, and the check valve 180, so as to implement the first step S1 and the second step S2 in the exhaust method of the vehicle brake system. Furthermore, the exhaust method of the vehicle brake system is not limited to having only the first step S1 and the second step S2, and may also have other unillustrated operating steps to assist in exhausting the air. The exhaust method of the vehicle brake system only lists the minimum necessary steps. Furthermore, the present invention is not limited to only performing the first step S1 again after performing the first step S1 and the second step S2. For example, in an unillustrated embodiment, the first step S1 and the second step S2 may also be repeatedly performed to facilitate exhausting the air trapped in the bypass flow path 170 (especially trapped on the downstream side of the one-way valve 180) from the exhaust hole 142. The present invention is not limited to this, and it can be adjusted according to needs.

[0058] In summary, in the exhaust method of the vehicle brake system of the present invention, for a vehicle brake system that uses a switching valve to switch the connection state of the master cylinder and the slave cylinder connected to the wheel cylinder as a hydraulic supply source, and uses a bypass flow path and a one-way valve connected from a reservoir installed on the master cylinder or the slave cylinder to a portion of the flow path that is more downstream than the switching valve and more upstream than the brake hydraulic control device, the slave cylinder is operated on the pressurization side and the decompression side in sequence, and the exhaust hole of the wheel cylinder is opened and closed, so that the air retained in the bypass flow path is moved from the bypass flow path to the flow path section and discharged from the exhaust hole. Preferably, the switching valve is a three-way valve connecting the master cylinder, the slave cylinder, and the wheel cylinder. In this way, the present invention does not need to use an external exhaust device, but can exhaust air through simple operations such as the operation of the slave cylinder and / or the opening and closing operation of the exhaust hole, thereby saving additional cost and operating procedures. Accordingly, the exhaust method of the vehicle brake system of the present invention can exhaust air more efficiently in a vehicle brake system that uses a switching valve to shorten the flow path and miniaturize the system, and uses a bypass flow path and a check valve to ensure the flow rate of the brake fluid.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for exhausting air from a vehicle brake system, the method being used to exhaust air from the vehicle brake system, the vehicle brake system comprising a master cylinder, a slave cylinder, a flow path, a wheel cylinder, a switching valve, a brake hydraulic pressure control device, a bypass flow path, and a one-way valve, the master cylinder generating brake hydraulic pressure by operating a brake operator, the slave cylinder generating brake hydraulic pressure based on an electrical signal using a driving force of an actuator, the flow path connecting the master cylinder and the slave cylinder to the wheel cylinder, the switching valve switching the communication state between the master cylinder and the slave cylinder, and the brake hydraulic pressure control device being arranged in the flow path on the downstream side of the switching valve and controls the brake fluid pressure transmitted to the wheel cylinder, the bypass flow path is connected from a reservoir installed in the master cylinder or the slave cylinder to a portion of the flow path that is more downstream than the switching valve and more upstream than the brake fluid pressure control device, the one-way valve is arranged in the bypass flow path, when the brake fluid pressure control device controls the brake fluid pressure, the one-way valve allows the brake fluid to flow from the side close to the reservoir to the side close to the brake fluid pressure control device, and prevents the brake fluid from flowing from the side close to the brake fluid pressure control device to the side close to the reservoir, the wheel cylinder has a switchable exhaust hole, wherein The exhaust method of the vehicle brake system is characterized by comprising: In a first step, in a state where the switching valve is connected to the slave cylinder and the brake hydraulic control device, the slave cylinder is actuated on the pressurizing side, so that air retained in a flow path section from the slave cylinder to the brake hydraulic control device is discharged from the exhaust hole; as well as In the second step, after the first step, the slave cylinder is operated on the pressure reducing side while the exhaust hole is closed, so that the air retained in the bypass flow path moves to the flow path section, and After the second step, the first step is performed again, and the air moved from the bypass flow path to the flow path section is discharged from the exhaust hole.

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