Braking system

Abstract

The present application has an object to detect operation of an emergency brake lever with a simple structure. A brake system includes a handle brake lever, a stroke sensor that measures an operation amount of the handle brake lever, an emergency brake lever, a brake lamp switch, a hydraulic pressure generating device that generates working hydraulic pressure that causes a brake to operate, and a control section, wherein the hydraulic pressure generating device includes a hydraulic pressure sensor, the control section performs failure determination of the hydraulic pressure generating device, in the case where failure is not determined in the failure determination, in the case where the brake lamp switch is on, and the operation amount of the handle brake lever detected by the stroke sensor is equal to or less than a prescribed value and the hydraulic pressure detected by the hydraulic pressure sensor is equal to or more than a prescribed value, it is determined that the emergency brake lever is operated.

Description

Technical Field

[0001] The present invention relates to a structure of a braking system having a handle brake lever mounted on the steering wheel and an emergency brake lever disposed outside the steering wheel. Background Technology

[0002] Patent document 1 discloses a braking device in which a brake lever is mounted on the steering wheel and the driver operates the brake lever by hand to activate the brake.

[0003] Patent Document 1: Japanese Patent Application Publication No. 11-342849 Summary of the Invention However, in addition to the lever brake commonly operated by the driver as described in Patent Document 1, the braking device also includes an emergency brake lever that is operated in situations such as insufficient deceleration or an abnormality occurring in the braking device. In such a braking device, it is required to detect the operation of the emergency brake lever. However, since both the lever brake and the emergency brake lever are connected to the same master cylinder, in the prior art, new sensors are required to detect the operation of the emergency brake lever, resulting in a complex structure.

[0004] Therefore, the object of the present invention is to detect the operation of the emergency brake lever in a braking system having a handle brake lever and an emergency brake lever with a simple structure.

[0005] A braking system according to the present invention comprises: a handbrake lever mounted on a steering wheel; a stroke sensor that measures the amount of operation of the handbrake lever; an emergency brake lever disposed outside the steering wheel; a brake light switch that is turned on when the handbrake lever or the emergency brake lever is operated; a hydraulic generating device that generates working hydraulic pressure to actuate the brakes; and a control unit that adjusts the working hydraulic pressure based on an electrical signal from the stroke sensor. The hydraulic generating device includes a hydraulic sensor that detects changes in hydraulic pressure caused by the operation of the handbrake lever or the emergency brake lever. The control unit performs a fault determination of the hydraulic generating device. If no fault is determined in the fault determination, and the emergency brake lever is operated when the brake light switch is turned on, the amount of operation of the handbrake lever detected by the stroke sensor is below a predetermined value, and the hydraulic pressure detected by the hydraulic sensor is above a predetermined value, the control unit determines that the emergency brake lever has been operated.

[0006] Therefore, in a braking system equipped with a handle brake lever and an emergency brake lever, the operation of the emergency brake lever can be detected with a simple structure.

[0007] In the braking system of the present invention, the hydraulic generating device may include: an input piston connected to the emergency brake lever; a master cylinder having a separation chamber for accommodating the input piston; a stroke simulator connected to the separation chamber, which allows working oil flowing out of the separation chamber to flow in when the input piston advances in the separation chamber; and a separation chamber shut-off valve that opens and closes the oil passage between the separation chamber and the stroke simulator, wherein the hydraulic pressure detected by the hydraulic sensor is the hydraulic pressure of the stroke simulator, and the control unit sets the separation chamber shut-off valve to closed when it determines that the emergency brake lever has been operated but the fault determination is not determined to be the fault, and then sets the separation chamber shut-off valve to open when it determines that the operation of the emergency brake lever has been released.

[0008] Therefore, when the emergency brake lever is operated, the working oil is prevented from flowing out of the separator chamber to the stroke simulator. Thus, by operating the emergency brake lever, the input piston can be moved forward rapidly, thereby enabling the brake to act quickly.

[0009] In the braking system of the present invention, the control unit may adjust the working hydraulic pressure by adjusting the servo hydraulic pressure supplied to the master cylinder to the target servo hydraulic pressure. If the fault determination does not identify the fault but determines that the emergency brake lever has been operated, the target servo hydraulic pressure is increased by a predetermined value. Then, if it is determined that the operation of the emergency brake lever has been released, the increase of the target servo hydraulic pressure is released.

[0010] Therefore, when operating the emergency brake lever, the brake can be activated effectively.

[0011] Invention Effects This invention enables the detection of emergency brake lever operation in a braking system equipped with a handle brake lever and an emergency brake lever with a simple structure. Attached Figure Description

[0012] Figure 1 This is a system diagram showing the structure of the braking system in the implementation method.

[0013] Figure 2 It means Figure 1 The diagram shows the structure of the hydraulic generating device of the braking system.

[0014] Figure 3 It means Figure 1 The diagram shows the control system structure of the braking system's control unit.

[0015] Figure 4 This is an explanatory diagram showing the operation of the hydraulic generating device when the handle brake lever or emergency brake lever is operated under normal system conditions.

[0016] Figure 5 This is an explanatory diagram showing the operation of the hydraulic generating device when the emergency brake lever is activated in the event of a system malfunction.

[0017] Figure 6 This is a flowchart for detecting the action of operating the emergency brake lever when the braking system is functioning normally.

[0018] Figure 7 This is a flowchart illustrating the normal operation of the braking system.

[0019] Figure 8 It means through Figure 7 The diagram illustrates the flow of working oil when the separation chamber shut-off valve is closed due to the action shown.

[0020] Figure 9 This is a flowchart representing other actions of the braking system when it is functioning normally. Detailed Implementation

[0021] Hereinafter, the braking system 100 of the embodiment will be described with reference to the accompanying drawings. In the drawings, FR, UP, and RH represent the front, upper, and right sides of the vehicle 200 equipped with the braking system 100, respectively. Furthermore, the opposite directions of FR, UP, and RH represent the rear, lower, and left sides, respectively. Hereinafter, when only the front-back, left-right, and up-down directions are used in the description, unless otherwise specified, they represent the front-back, left-right, and up-down directions of the vehicle 200.

[0022] like Figure 1 As shown, the braking system 100 includes a handle brake lever 20, an emergency brake lever 30, a simulated brake pedal device 40, a handle brake cable 28, an emergency brake cable 34, a stroke sensor 29, a brake light switch 49, a hydraulic generating device 50, and a control unit 77.

[0023] The handbrake lever 20 is mounted on the steering wheel 15 and is a braking device operated by the driver's hand. For example... Figure 1 As shown, the steering wheel 15 is located behind the instrument panel 12 in the cabin 10.

[0024] The handbrake lever 20 consists of a base 21, a lever body 22, connecting rod bases 23 and 24, and connecting rods 25 and 26. The base 21 is a base mounted on the steering wheel 15. The upper end of the lever body 22 is rotatably mounted on the base 21. The connecting rod base 23 is a plate component mounted on the steering wheel 15 and extending downwards. The connecting rod base 24 is a plate component connected to the connecting rod base 23. The connecting rod 25 is an L-shaped plate component rotatably connected to the connecting rod base 24. The connecting rod 26 is a rod-shaped component connecting the upper part of the lever body 22 to one end of the connecting rod 25. The handbrake cable 28 is connected to the other end of the connecting rod 25.

[0025] like Figure 1 As indicated by the arrow, if the driver pulls the lever body 22 toward the steering wheel 15, the connecting rod 26 moves downward, causing the connecting rod 25 to rotate counterclockwise. This causes the handbrake cable 28 to move toward the steering wheel 15.

[0026] The emergency brake lever 30 is located outside the steering wheel 15 and is a braking device operated by the driver's hand. Figure 1 As shown, the emergency brake lever 30 consists of a linkage device 31, a lever 32, and an operating end 33. The linkage device 31 is mounted on the front bulkhead 13 of the vehicle compartment 10. The lever 32 and the emergency brake cable 34 are connected to the linkage device 31. The linkage device 31 converts the movement of the lever 32 into the forward and backward movement of the emergency brake cable 34 via a linkage mechanism located inside. An operating end 33, operated by the driver, is provided at the end of the lever 32 on the vehicle compartment side. If the driver operates the operating end 33 downward as indicated by the arrow, the emergency brake cable 34 moves rearward toward the vehicle.

[0027] The simulated brake pedal device 40 consists of a bracket 41, a simulated brake pedal 43, and an operating lever 46.

[0028] The bracket 41 is mounted to the base 52 of the housing 51 of the hydraulic generating device 50 by bolts 42. Here, the hydraulic generating device 50 is installed inside the front compartment 18 in front of the vehicle compartment 10. The bracket 41 is a generally L-shaped plate component, with the front end extending towards the vehicle compartment 10. The simulated brake pedal 43 is mounted to the bracket 41 in such a way that it has a rotation axis 44 between one end 43A and the other end 43B and is rotatable about the rotation axis 44. An operating lever 46 is rotatably connected to the connection point 45 at one end 43A. The operating lever 46 is connected to the input piston 62 of the brake master cylinder 60. Thus, the simulated brake pedal 43 rotates about the rotation axis 44 at the other end 43B, while one end 43A presses the input piston 62 into the brake master cylinder 60.

[0029] An emergency brake cable 34 is connected to the first connection point 47 at the other end 43B. The emergency brake cable 34, based on the emergency operation amount of the operating end 33 of the emergency brake lever 30, presses the input piston 62 into the brake master cylinder 60 via the simulated brake pedal 43. Furthermore, a handle brake cable 28 is connected to the second connection point 48 at the other end 43B. The handle brake cable 28, based on the operation amount of the lever body 22 of the handle brake lever 20, presses the input piston 62 into the brake master cylinder 60 via the simulated brake pedal 43. Here, the second connection point 48 is positioned further towards the front end of the other end 43B than the first connection point 47, or further away from the rotation axis 44 than the first connection point 47.

[0030] Brake light switch 49 is mounted on bracket 41. It is activated when lever 46 is moved forward and deactivated when lever 46 returns to its original position. As previously described, lever 46 is connected to handle brake lever 20 and emergency brake lever 30 via simulated brake pedal 43. Therefore, if handle brake lever 20 or emergency brake lever 30 is operated, brake light switch 49 is activated; if handle brake lever 20 or emergency brake lever 30 is deactivated and both return to their original positions, brake light switch 49 is deactivated. Brake light switch 49 is connected to control unit 77.

[0031] Next, refer to Figure 2 The structure of the hydraulic generating device 50 is described below. The hydraulic generating device 50 includes a reservoir 53, an accumulator 54, a pump 55, a pump motor 56, a master brake cylinder 60, a regulator 70, a booster linear solenoid valve 81, a depressurization linear solenoid valve 82, a servo hydraulic sensor 83, a stroke simulator 84, a stroke simulator shut-off valve 85, a stroke simulator pressure sensor 86, a separation chamber shut-off valve 87, an accumulator hydraulic sensor 88, a pressure relief valve 89, and multiple equipment status sensors 80 (for reference). Figure 3 ).

[0032] The reservoir 53 is a tank for storing working oil. The pressure of the reservoir 53 is approximately atmospheric pressure. The pump 55, driven by the pump motor 56, pressurizes the working oil supplied from the reservoir 53 and supplies it to the accumulator 54. The accumulator 54 stores the high-pressure working oil pressurized by the pump 55. The high-pressure working oil stored in the accumulator 54 is supplied to the regulator 70 through an oil circuit. An accumulator hydraulic pressure sensor 88, which detects the accumulator hydraulic pressure Pacc, is installed in the oil circuit between the accumulator 54 and the regulator 70. Furthermore, the accumulator 54 is connected to the reservoir 53 via a pressure relief valve 89.

[0033] The brake master cylinder 60 includes a housing 61, an input piston 62, a first pressurizing piston 64, and a second pressurizing piston 68. Furthermore, in the following description, as indicated by the arrows in the figures, the direction in which the input piston 62 moves towards the first pressurizing piston 64 and the second pressurizing piston 68 will be described as forward, and the opposite direction will be described as rearward.

[0034] The input piston 62 is hydraulically fitted into the opening 61A at the rear end of the housing 61 and is slidable in the front-rear direction. An operating lever 46 is connected to the rear of the input piston 62. The first pressurizing piston 64 and the second pressurizing piston 68 are hydraulically fitted into the interior of the housing 61 and are slidable in the front-rear direction. The first pressurizing chamber 67 and the second pressurizing chamber 69 are located in front of the first pressurizing piston 64 and the second pressurizing piston 68. The first pressurizing chamber 67 and the second pressurizing chamber 69 are connected via oil passages to the left and right brakes 93 and 94 of the front wheels and the left and right brakes 91 and 92 of the rear wheels. By supplying pressurized working oil from the first pressurizing chamber 67 and the second pressurizing chamber 69 to the brake cylinders of each brake 91, 92, 93, and 94, each brake 91 to 94 is activated.

[0035] The first pressurizing piston 64 includes a front piston portion 64A located at the front, an intermediate piston portion 64B located in the middle and protruding radially, and a rear small-diameter portion 64C located at the rear and having a diameter smaller than that of the intermediate piston portion 64B. The front piston portion 64A and the intermediate piston portion 64B are respectively fitted into the housing 61 in a liquid-tight and slidable manner. The area in front of the front piston portion 64A forms a first pressurizing chamber 67. The area in front of the intermediate piston portion 64B forms an annular chamber 65.

[0036] A circular inner circumferential protrusion 61B is provided on the housing 61, and the rear small diameter portion 64C is fitted in a liquid-tight manner and can slide in the front-rear direction. Then, a back chamber 66 is formed between the rear of the intermediate piston portion 64B and the inner circumferential protrusion 61B. The rear small diameter portion 64C and the input piston 62 form a separation chamber 63.

[0037] The annular chamber 65 and the separation chamber 63 are connected via an oil circuit through a separation chamber shut-off valve 87. The separation chamber shut-off valve 87 is a solenoid-operated valve. The annular chamber 65 is connected to the stroke simulator 84 via an oil circuit. The separation chamber 63 is also connected to the stroke simulator 84 via the separation chamber shut-off valve 87. Furthermore, the annular chamber 65 is connected to the reservoir 53 via the stroke simulator shut-off valve 85. The separation chamber 63 is connected to the reservoir 53 via both the separation chamber shut-off valve 87 and the stroke simulator shut-off valve 85. A stroke simulator pressure sensor 86 is installed on the oil circuit directly in front of the stroke simulator 84. The stroke simulator pressure sensor 86 detects the stroke simulator hydraulic pressure Prct. Additionally, when the stroke simulator shut-off valve 85 is closed and the separation chamber shut-off valve 87 is open, the stroke simulator hydraulic pressure Prct becomes the same as the hydraulic pressure of the annular chamber 65 and the separation chamber 63. The hydraulic pressure of the annular chamber 65 and the separation chamber 63 corresponds to the magnitude of the input force of the input piston 62 based on the simulated brake pedal 43.

[0038] The regulator 70 includes a control chamber 71, a high-pressure chamber 72, a servo chamber 73, a pilot chamber 74, a control piston 75, and a high-pressure supply valve 76. High-pressure working oil is supplied from the accumulator 54 to the control chamber 71 via a booster linear solenoid valve 81. The control piston 75 is disposed in the control chamber 71. The high-pressure supply valve 76 is disposed in the high-pressure chamber 72. The control chamber 71 is connected to the reservoir 53 via a depressurization linear solenoid valve 82. The servo chamber 73 is connected to the back chamber 66 of the brake master cylinder 60. A servo hydraulic sensor 83, which detects the working oil supplied to the back chamber 66, is disposed between the servo chamber 73 and the back chamber 66.

[0039] The regulator 70 controls the servo hydraulic pressure Psrv at a predetermined target value via the boosting linear solenoid valve 81 and the depressurizing linear solenoid valve 82. Here, the servo hydraulic pressure Psrv is the working hydraulic pressure that actuates the first pressurizing piston 64 and the second pressurizing piston 68. Then, the predetermined servo hydraulic pressure Psrv is applied to the back chamber 66, the first pressurizing piston 64 and the second pressurizing piston 68 advance, and working oil is supplied from the first pressurizing chamber 67 and the second pressurizing chamber 69 to the brakes 91 to 94.

[0040] Figure 3 The equipment status sensor 80 shown is a sensor that detects the status quantities of each piece of equipment included in the hydraulic generating device 50. The equipment status sensor 80 includes a current sensor that detects the current supplied to the pump motor 56, a speed sensor that detects the speed of the pump motor 56, and opening sensors for the booster linear solenoid valve 81 and the depressurization linear solenoid valve 82. However, the equipment status sensor 80 does not include the stroke simulator pressure sensor 86, the separation chamber shut-off valve 87, or the accumulator hydraulic sensor 88. The equipment status sensor 80, the stroke simulator pressure sensor 86, the separation chamber shut-off valve 87, and the accumulator hydraulic sensor 88 constitute all the equipment status sensors 80A.

[0041] Next, refer to Figure 3 The structure of the control unit 77 will be described. The control unit 77 is a computer that includes a processor, i.e., a CPU 78, which performs information processing internally, and a memory 79 that stores control programs or control data.

[0042] The operating stroke of the lever body 22 is input from the stroke sensor 29 to the control unit 77. Furthermore, the control unit 77 receives stroke simulator hydraulic pressure (Prct), servo hydraulic pressure (Psrv), and accumulator hydraulic pressure (Pacc) signals from the stroke simulator pressure sensor 86, servo hydraulic pressure sensor 83, and accumulator hydraulic pressure sensor 88, respectively. The control unit 77 also receives an on / off signal from the brake light switch 49. In addition, data detected by multiple equipment status sensors 80 is input to the control unit 77. Based on these inputs, the control unit 77 adjusts the operation of the booster linear solenoid valve 81, the depressurizing linear solenoid valve 82, the stroke simulator shut-off valve 85, the separation chamber shut-off valve 87, and the pump motor 56. Furthermore, the control unit 77 performs fault diagnosis of the hydraulic generating device 50 based on these inputs.

[0043] Next, refer to Figure 4 , Figure 5 An example of the operation of the braking system 100 will be explained. First, refer to... Figure 4 This section explains the actions taken when the driver operates the handbrake lever 20 while the braking system 100 is functioning normally. For example... Figure 4 As shown, when the braking system 100 is operating normally, the control unit 77 opens the separation chamber shut-off valve 87 and closes the stroke simulator shut-off valve 85. Here, "operating normally" means that the control unit 77's fault determination does not identify a fault. For information on fault determination, please refer to [link / reference]. Figure 6 Please provide an explanation.

[0044] like Figure 1 As indicated by the arrow, if the driver pulls the lever body 22 of the handbrake lever 20 towards the steering wheel 15, the handbrake cable 28 moves towards the steering wheel 15. This causes the simulated brake pedal 43 to rotate counter-clockwise, and the operating lever 46 to advance. Then, the input piston 62 is pushed into the release chamber 63 of the brake master cylinder 60. Furthermore, the brake light switch 49 is turned on, and the brake light (not shown) illuminates.

[0045] If the input piston 62 is pushed into the separator chamber 63, the working oil in the separator chamber 63 flows into the stroke simulator 84 via the separator chamber shut-off valve 87 and pushes into the piston of the stroke simulator 84. As a result, the stroke simulator hydraulic pressure Prct rises. Furthermore, the hydraulic pressure in the separator chamber 63 and the annular chamber 65 also rises to the same pressure as the stroke simulator hydraulic pressure Prct. The rise in hydraulic pressure in the separator chamber 63, as a reaction force from the input piston 62, becomes an operational reaction force via the simulated brake pedal 43 and the lever body 22 of the brake cable 28. This operational reaction force is the operating force required when the driver operates the lever body 22.

[0046] If the driver pulls the lever body 22, the stroke sensor 29 detects the stroke of the lever body 22. Then, the detected electrical signal from the stroke sensor 29 is input to the control unit 77. The control unit 77 calculates the stroke amount and the rate of change of the stroke amount of the lever body 22 based on the input electrical signal from the stroke sensor 29. Then, the control unit 77 calculates the target servo hydraulic pressure based on the calculated stroke amount and rate of change. Then, the control unit 77 adjusts the operation of the boosting linear solenoid valve 81, the depressurizing linear solenoid valve 82, and the pump motor 56 so that the servo hydraulic pressure Psrv detected by the servo hydraulic pressure sensor 83 becomes the target servo hydraulic pressure. Thus, the servo hydraulic pressure Psrv corresponding to the operation of the lever body 22 is applied to the back chamber 66. Then, the first pressurizing piston 64 and the second pressurizing piston 68 advance, and the working oil in the first pressurizing chamber 67 and the second pressurizing chamber 69 is sent to the brakes 91-94, causing the brakes 91-94 to operate. As the first pressurizing piston 64 and the second pressurizing piston 68 advance, the working oil in the annular chamber 65 flows into the stroke simulator 84.

[0047] Thus, when the braking system 100 is functioning normally, the adjustment of the hydraulic pressure of the working fluid to brakes 91-94 is not performed by adjusting the input piston 62, but rather by the control unit 77 adjusting the operation of the booster linear solenoid valve 81, the depressurization linear solenoid valve 82, and the pump motor 56 based on the electrical signal from the stroke sensor 29. Therefore, when the braking system 100 is functioning normally, the driver can operate brakes 91-94 with minimal force by operating the lever body 22.

[0048] Next, refer to Figure 4 This section explains the actions of the driver when operating the emergency brake lever 30, assuming the braking system is functioning normally (100%).

[0049] Similar to the previously described case of the operating handle brake lever 20, if the driver moves the operating end 33 of the emergency brake lever 30 as follows... Figure 1 Pressing the brake lever 43 downwards as indicated by the arrow moves the emergency brake cable 34 toward the vehicle compartment 10. This causes the simulated brake pedal 43 to rotate counter-clockwise, and the operating lever 46 to advance. The input piston 62 is then pushed into the release chamber 63 of the master brake cylinder 60. The brake light switch 49 is activated, and the brake light (not shown) illuminates. The hydraulic fluid in the release chamber 63 then flows into the stroke simulator 84 via the release chamber shut-off valve 87, causing the stroke simulator hydraulic pressure Prct to rise. The stroke simulator pressure sensor 86 detects the stroke simulator hydraulic pressure Prct and inputs it to the control unit 77.

[0050] The control unit 77 calculates the target servo hydraulic pressure based on the electrical signal from the input stroke simulator pressure sensor 86. Then, the control unit 77 adjusts the operation of the booster linear solenoid valve 81, the depressurization linear solenoid valve 82, and the pump motor 56 to make the servo hydraulic pressure Psrv the target servo hydraulic pressure. As a result, the servo hydraulic pressure Psrv corresponding to the operation of the emergency brake lever 30 is applied to the back chamber 66, the first pressurizing piston 64 and the second pressurizing piston 68 advance, and the working oil in the first pressurizing chamber 67 and the second pressurizing chamber 69 is sent to the brakes 91 to 94, causing the brakes 91 to 94 to actuate.

[0051] Next, refer to Figure 5 This section explains the operation of the handbrake lever 20 when the braking system 100 is in an abnormal state. Here, "abnormal state" refers to the result of a fault determination performed by the control unit 77. A fault determination occurs when the control unit 77 cannot adjust the operation of the booster linear solenoid valve 81, the depressurization linear solenoid valve 82, or the pump motor 56. Figure 5 As shown, if the control unit 77 determines that a fault has occurred through fault determination, it closes the separation chamber shut-off valve 87 and opens the stroke simulator shut-off valve 85.

[0052] If the driver Figure 1 Pulling the lever body 22 of the brake lever 20 towards the steering wheel 15, as indicated by the arrow, causes the simulated brake pedal 43 to rotate counterclockwise, and the operating lever 46 to advance. Then, the input piston 62 is pushed into the release chamber 63 of the master cylinder 60. Simultaneously, the brake light switch 49 is turned on, and a brake light (not shown) illuminates.

[0053] If the input piston 62 advances, it causes the first pressurizing piston 64 and the second pressurizing piston 68 to advance as well. This sends the working oil from the first pressurizing chamber 67 and the second pressurizing chamber 69 to the brakes 91-94, actuating the brakes. At this time, the stroke simulator shut-off valve 85 is open, so when the first pressurizing piston 64 and the second pressurizing piston 68 advance, the working oil in the annular chamber 65 flows into the reservoir 53 through the stroke simulator shut-off valve 85, but not into the stroke simulator 84. Furthermore, the separation chamber shut-off valve 87 is closed, so the working oil in the separation chamber 63 does not flow into the stroke simulator 84. Therefore, the stroke simulator hydraulic pressure Prct will not rise.

[0054] In abnormal situations, such as Figure 1 The action of pressing the operating end 33 of the emergency brake lever 30 as shown by the arrow is the same as the action of operating the handle brake lever 20 when the braking system 100 is in an abnormal state.

[0055] As explained above, when the braking system 100 is functioning normally, the separation chamber cut-off valve 87 is open, and the stroke simulator cut-off valve 85 is closed. Furthermore, if either the operating lever brake 20 or the emergency brake lever 30 is operated, the simulated brake pedal 43 rotates counterclockwise, the operating lever 46 advances, and the brake light switch 49 is activated. Additionally, if the operating lever 46 advances and the input piston 62 is pushed into the separation chamber 63 of the master cylinder 60, the working oil in the separation chamber 63 flows into the stroke simulator 84 via the separation chamber cut-off valve 87, causing the stroke simulator hydraulic pressure Prct to rise.

[0056] Therefore, the control unit 77 detects that the emergency brake lever 30 has been activated in the braking system 100, which includes the handle brake lever 20 and the emergency brake lever 30, through the operation described below. (Refer to the following...) Figure 6 The operation of detecting the emergency brake lever 30 when the braking system 100 is normal is explained.

[0057] like Figure 6 As shown in step S101, the control unit 77 performs a fault determination on the braking system 100. The control unit 77 determines a fault if the electrical signals input from all equipment status sensors 80A, including the equipment status sensor 80, the stroke simulator pressure sensor 86, the separation chamber shut-off valve 87, and the accumulator hydraulic sensor 88, are outside the specified range. Furthermore, the control unit 77 determines a fault if the electrical signals input from all equipment status sensors 80A do not match the operation commands for each piece of equipment. For example, if the duty cycle command value of the pump motor 56 is 50% and the detection value of the pump motor 56 speed sensor is zero, it is determined that the electrical signals input from all equipment status sensors 80A do not match the operation commands for each piece of equipment, and a fault is determined.

[0058] Control Unit 77 Figure 6 In step S102, it is determined whether the result of the fault determination is a fault. If it is not determined to be a fault, the control unit 77... Figure 6 In step S102, the result is "No", and then proceeds to... Figure 6 In step S103, the normal status flag is turned on. Then, the control unit 77 proceeds to step S104.

[0059] On the other hand, Figure 6 If the determination in step S102 is "yes", that is, if the fault is determined in the fault determination, the control unit 77 ends the operation of detecting the emergency brake lever 30.

[0060] Control Unit 77 Figure 6In step S104, it is determined whether the brake light switch 49 is turned on and whether the detection value detected by the travel sensor 29 is less than a predetermined threshold. Here, turning on the brake light switch 49 indicates that either the lever brake 20 or the emergency brake 30 has been operated. Furthermore, the detection value detected by the travel sensor 29 being less than the predetermined threshold indicates that the lever brake 20 has not been operated. Then, the control unit 77... Figure 6 If the determination in step S104 is "yes", it is determined that there is a possibility that the handle brake lever 20 has not been operated and the emergency brake lever 30 has been operated, and then proceeds to... Figure 6 Step S105.

[0061] Control Unit 77 Figure 6 In step S105, it is determined whether the stroke simulator hydraulic pressure Prct is above a predetermined hydraulic threshold. As described above, when the braking system 100 is functioning normally, if the emergency brake lever 30 is operated, the stroke simulator hydraulic pressure Prct increases. Therefore, if the stroke simulator hydraulic pressure Prct is above the predetermined hydraulic threshold, it indicates that the operation amount of the emergency brake lever 30 has been operated to a greater than predetermined operation amount.

[0062] Then, control unit 77 in Figure 6 If the condition in step S105 is "yes", it is determined that the operation of the emergency brake lever 30 has been detected, and the process proceeds to... Figure 6 In step S106, the emergency braking operation sign is activated, and the operation of detecting the emergency brake lever 30 is terminated.

[0063] Furthermore, the control unit 77 in Figure 6 If the determination in steps S104 and S105 is "no", skip this step. Figure 6 In step S106, the emergency braking operation sign is not activated, and the operation of detecting the emergency brake lever 30 is terminated.

[0064] Thus, in the braking system 100 equipped with the handle brake lever 20 and the emergency brake lever 30, the control unit 77 can detect the operation of the emergency brake lever 30 with a simple structure.

[0065] Next, refer to Figure 7 The operation of the braking system 100 will be explained. (Refer to the reference...) Figure 6 The same actions are labeled with the same symbols and explained simply.

[0066] Control Unit 77 Figure 7 In steps S101 to S103, if the braking system 100 is determined to be in a normal state, then proceed to... Figure 7 Step S201, by first referring to Figure 6The operation of the emergency brake lever 30 is detected, and it is determined whether the emergency brake operation indicator is activated. The control unit 77... Figure 7 If the determination in step S201 is "no", then standby until... Figure 7 In step S201, the judgment is "yes".

[0067] Control Unit 77 Figure 7 If the condition in step S201 is "yes", proceed to... Figure 7 Step S202 and close the separation chamber shut-off valve 87.

[0068] As referenced above Figure 4 As explained above, when the braking system 100 is in normal operation, the control unit 77 opens the separation chamber cut-off valve 87 and closes the stroke simulator cut-off valve 85, as previously described. If the emergency brake lever 30 is operated, the input piston 62 is pushed into the separation chamber 63 of the master cylinder 60, and the working oil in the separation chamber 63 flows into the stroke simulator 84 via the separation chamber cut-off valve 87. As a result, the stroke simulator hydraulic pressure Prct rises. The control unit 77 adjusts the servo hydraulic pressure Psrv according to the stroke simulator hydraulic pressure Prct and actuates the brakes 91 to 94.

[0069] Here, as Figure 7 As shown in step S202, if the separation chamber shut-off valve 87 is closed, then as follows: Figure 8 As shown, the oil passage between the separator chamber 63 and the stroke simulator 84 is closed, and the working oil in the separator chamber 63 does not flow out to the stroke simulator 84. In this state, if the emergency brake lever 30 is operated again, the input piston 62 is pushed into the separator chamber 63, thereby advancing the first pressurizing piston 64 and the second pressurizing piston 68. At this time, the working oil in the annular chamber 65 continues to flow into the stroke simulator 84, thus maintaining the hydraulic pressure Prct of the stroke simulator.

[0070] Thus, if the separation chamber shut-off valve 87 is closed, the working oil in the separation chamber 63 will not flow out to the stroke simulator 84. Therefore, the input piston 62 is quickly pressed into the separation chamber 63, and the first pressurizing piston 64 and the second pressurizing piston 68 move forward, thereby enabling the brakes 91 to 94 to operate.

[0071] If in Figure 7 In step S202, the separation chamber shut-off valve 87 is closed, and then the control unit 77 enters... Figure 7 Step S203. The control unit 77 releases the emergency brake lever 30 and waits until... Figure 7 In step S203, the emergency braking operation indicator is deactivated. Then, the control unit 77... Figure 7 If the determination in step S203 is "yes", proceed to... Figure 7 Step S204: Open the separation chamber shut-off valve 87 and return to Figure 4 The normal state is shown, and the action ends.

[0072] As explained above, when the emergency brake lever 30 is operated under normal braking system 100 conditions, this action closes the separation chamber shut-off valve 87 and stops the flow of working oil from the separation chamber 63, thus enabling the input piston 62 to be quickly pressed into the separation chamber 63 and causing the brakes 91 to 94 to operate.

[0073] Next, refer to Figure 9 Other operations of the braking system 100 are described. (Regarding references...) Figure 6 , 7 Use the same symbols to describe the same actions and provide a brief explanation.

[0074] Figure 9 The action shown is to refer to Figure 7 The steps S202 and S204 of the described actions are defined as step S302, which raises the target servo hydraulic pressure by a predetermined value ΔP, and step S304, which releases the rise of the target servo hydraulic pressure and returns it to its original value. Other actions are similar to... Figure 7 The actions shown are identical, so explanations are omitted.

[0075] For reference Figure 4 As explained, the control unit 77 adjusts the operation of the boosting linear solenoid valve 81, the depressurizing linear solenoid valve 82, and the pump motor 56 to make the servo hydraulic Psrv the target servo hydraulic, causing the first pressurizing piston 64 and the second pressurizing piston 68 to advance and actuate the brakes 91 to 94.

[0076] Here, with the emergency brake lever 30 activated, in Figure 9 In step S302, if the target servo hydraulic pressure is increased by a predetermined value ΔP, the control unit 77 activates the hydraulic pressure generating device 50 to increase the servo hydraulic pressure Psrv by the predetermined value ΔP. Therefore, compared to the case where the target servo hydraulic pressure is not increased, higher hydraulic pressure can be supplied from each brake 91 to 94, and a larger braking force can be generated.

[0077] Furthermore, the control unit 77 calculates the target servo hydraulic pressure based on the electrical signal from the stroke sensor 29 of the handle brake lever 20. Therefore, when the operation amount of the handle brake lever 20 is small, the target servo hydraulic pressure is also set to a lower value. In this state, if the emergency brake lever 30 is operated, the servo hydraulic pressure Psrv may sometimes decrease to a lower target servo hydraulic pressure before the stroke simulator hydraulic pressure Prct rises and sets the target servo hydraulic pressure to a higher value.

[0078] Therefore, as in normal operation, when the operation of the emergency brake lever 30 is detected, by increasing the target servo hydraulic pressure by a predetermined value ΔP, the temporary decrease of the servo hydraulic pressure Psrv can be suppressed, and the brakes 91 to 94 can be activated quickly.

[0079] As explained above, in the braking system 100 equipped with a handle brake lever 20 and an emergency brake lever 30, the control unit 77 can detect the operation of the emergency brake lever 30 with a simple structure, and can effectively activate the brakes 91 to 94 when the emergency brake lever 30 is operated.

[0080] In the above explanation, Figure 6 In step S104, the example given is detecting that the handle brake lever 20 has not been operated when the detection value of the stroke sensor 29 is less than a predetermined threshold, but this is not a limitation. For example, the stroke amount can be calculated based on the detection value detected by the stroke sensor 29, and if the change in the stroke amount per unit time is less than a predetermined value, it can be detected that the handle brake lever 20 has not been operated.

[0081] Symbol Explanation 10-Vehicle compartment, 12-Instrument panel, 13-Front bulkhead, 15-Steering wheel, 18-Front compartment, 20-Handle brake lever, 21-Base, 22-Lever body, 23, 24-Linkage base, 25, 26-Linkage, 28-Handle brake cable, 29-Stroke sensor, 30-Emergency brake lever, 31-Linkage device, 32-Lever, 33-Operating end, 34-Emergency brake cable, 40-Simulated brake pedal device, 41-Bracket, 4 2- Bolt, 43- Simulated brake pedal, 43A- One end, 43B- The other end, 44- Rotating shaft, 45- Connection point, 46- Operating lever, 47- First connection point, 48- Second connection point, 49- Brake light switch, 50- Hydraulic generating device, 51- Housing, 52- Base, 53- Reservoir, 54- Accumulator, 55- Pump, 56- Pump motor, 60- Master brake cylinder, 61- Housing, 61A- Opening, 61B- 62-Input piston, 63-Separation chamber, 64-First pressurizing piston, 64A-Front piston section, 64B-Intermediate piston section, 64C-Rear small diameter section, 65-Annular chamber, 66-Rear chamber, 68-Second pressurizing piston, 70-Regulator, 71-Control chamber, 72-High pressure chamber, 73-Servo chamber, 74-Pilot chamber, 75-Control piston, 76-High pressure supply valve, 77-Control unit, 78-CPU, 79-Memory, 80-Equipment status sensor, 80A-All equipment status sensors, 81-Boosting linear solenoid valve, 82-Depressurizing linear solenoid valve, 83-Servo hydraulic sensor, 84-Stroke simulator, 85-Stroke simulator shut-off valve, 86-Stroke simulator pressure sensor, 87-Separation chamber shut-off valve, 88-Accumulator hydraulic sensor, 89-Relief valve, 91-94-Brake, 100-Brake system, 200-Vehicle.

Claims

1. A braking system comprising: The handbrake lever is mounted on the steering wheel; A stroke sensor that measures the amount of operation of the handle brake lever; An emergency brake lever is located outside the steering wheel; A brake light switch that is turned on when the handle brake lever or the emergency brake lever is operated; A hydraulic generating device that generates working hydraulic pressure to actuate the brake. and The control unit adjusts the working hydraulic pressure based on the electrical signal from the stroke sensor. The braking system is characterized in that, The hydraulic generating device includes a hydraulic sensor that detects changes in hydraulic pressure caused by the operation of the handle brake lever or the emergency brake lever. The control unit performs fault determination on the hydraulic generating device. If no fault is determined in the fault determination, and the brake light switch is turned on, and the amount of operation of the handle brake lever detected by the stroke sensor is below a specified value and the hydraulic pressure detected by the hydraulic sensor is above a specified value, then the emergency brake lever is determined to be operated.

2. The braking system according to claim 1, characterized in that, The hydraulic generating device includes: An input piston, which is connected to the emergency brake lever; The master cylinder has a separation chamber that accommodates the input piston; A stroke simulator, connected to the separation chamber, causes working oil flowing out of the separation chamber to flow in as the input piston advances within the separation chamber; and The separation chamber shut-off valve opens and closes the oil passage between the separation chamber and the stroke simulator. The hydraulic pressure detected by the hydraulic sensor is the hydraulic pressure of the stroke simulator. If the control unit determines that the emergency brake lever has been operated but the fault determination does not identify it as a fault, it will close the separation chamber shut-off valve. Subsequently, if it is determined that the operation of the emergency brake lever has been released, the separation chamber shut-off valve is set to open.

3. The braking system according to claim 2, characterized in that, The control unit adjusts the working hydraulic pressure by adjusting the servo hydraulic pressure supplied to the master cylinder to the target servo hydraulic pressure. If the fault determination process does not identify the fault as described above, but instead determines that the emergency brake lever has been activated, the target servo hydraulic pressure is increased by a predetermined value. Subsequently, if it is determined that the operation of the emergency brake lever has been released, the rise of the target servo hydraulic pressure is released.

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