Saddle-type vehicle

Abstract

To provide a saddle-riding type vehicle which can optimize brake force distribution of front-rear wheels when decelerating during straight travel and in front of corner or the like.SOLUTION: In a saddle-riding type vehicle (1) which includes a front wheel brake part (32) which provides a front wheel (WF) with brake force and a rear wheel brake part (34) which provides a rear wheel (WR) with brake force and operates by interlocking the front wheel brake part (32) and the rear wheel brake part (34) according to operation of unit operator (5), first of all, the front wheel brake part (32) starts the operation according to the operation of the operator (5) and then, the rear wheel brake part (34) starts the operation when brake condition of the front wheel brake part (32) satisfies a first condition. The saddle-riding type vehicle is configured so as to increase the brake force of the rear wheel brake part (34) while keeping the brake force of the front wheel brake part (32) to a first front wheel brake force (P1) if the first condition is satisfied.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a saddle-ride type vehicle, and more particularly to a saddle-ride type vehicle employing a front and rear linked brake that operates a front wheel brake and a rear wheel brake in a linked manner by operating a single operating element. [Background technology]

[0002] 2. Description of the Related Art Vehicles equipped with brake systems that can improve vehicle body behavior during braking by adjusting the distribution of braking force between front and rear wheels have been known.

[0003] Patent Document 1 discloses a technology for adjusting the distribution of braking force between the front and rear wheels in a brake system of a four-wheeled vehicle in order to suppress pitch behavior of the vehicle body when the vehicle is stopped due to braking operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-112950 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology in Patent Document 1 is intended to suppress pitch behavior when stopping a four-wheeled vehicle, and does not consider the distribution of braking force between the front and rear wheels appropriate for deceleration when traveling in a straight line or before a corner in saddle-type vehicles such as two-wheeled vehicles, which are prone to large changes in vehicle body posture when braking.

[0006] SUMMARY OF THE PRESENT INVETION The object of the present invention is to provide a saddle-type vehicle which overcomes the problems of the prior art and is capable of optimizing the distribution of braking force between the front and rear wheels when decelerating while traveling in a straight line or before a corner. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a saddle-type vehicle (1) having a front wheel braking unit (32) that applies a braking force to a front wheel (WF) and a rear wheel braking unit (34) that applies a braking force to a rear wheel (WR), and in which the front wheel braking unit (32) and the rear wheel braking unit (34) are operated in conjunction with each other in response to the operation of a single operating element (5), wherein a first feature of the present invention is that in response to the operation of the operating element (5), first the front wheel braking unit (32) starts operating, and then the rear wheel control unit (34) starts operating when the braking condition of the front wheel braking unit (32) satisfies a first condition.

[0008] A second feature of the present invention is that when the first condition is satisfied, the braking force of the front wheel braking portion (32) is maintained at the first front wheel braking force (P1) while the braking force of the rear wheel braking portion (34) is increased.

[0009] A third feature is that when the increasing braking force of the rear wheel braking portion (34) reaches the first rear wheel braking force (P2), the braking force of the rear wheel braking portion (34) is maintained at the first rear wheel braking force (P2).

[0010] A fourth feature is that the first rear wheel braking force (P2) varies in response to the amount of operation of the operation element (5).

[0011] A fifth feature is that when a predetermined time (T1) has elapsed since the first condition is satisfied, the braking force of the front wheel braking unit (32) starts to transition to a second front wheel braking force (P4), and the braking force of the rear wheel braking unit (34) starts to transition to a second rear wheel braking force (P3) which is smaller than the second front wheel braking force (P4).

[0012] A sixth feature is that the second front wheel braking force (P4) and the second rear wheel braking force (P3) vary in response to the amount of operation of the operation element (5).

[0013] A seventh feature is that the vehicle is provided with an operating force generating means (40) for operating the front wheel braking section (32) in response to operation of the operating element (5), and the first condition is that the operating force generated by the operating force generating means (40) is equal to or greater than a predetermined value.

[0014] An eighth feature is that the operating force generating means (40) is a front wheel master cylinder that generates hydraulic pressure in response to the operation of the operating element (5), and the operating force is hydraulic pressure detected by a hydraulic pressure sensor (50).

[0015] Furthermore, a ninth feature is that when the roll angular velocity of the vehicle body becomes maximum after the first condition is satisfied, the braking force of the front wheel braking unit (32) starts to transition to a second front wheel braking force (P4), and the braking force of the rear wheel braking unit (34) starts to transition to a second rear wheel braking force (P3) which is smaller than the second front wheel braking force (P4). Effect of the Invention

[0016] According to the first feature, in a saddle-type vehicle (1) having a front wheel braking unit (32) that applies braking force to a front wheel (WF) and a rear wheel braking unit (34) that applies braking force to a rear wheel (WR), the front wheel braking unit (32) and the rear wheel braking unit (34) are operated in conjunction with each other in response to the operation of a single operating element (5), the front wheel braking unit (32) first starts operating in response to the operation of the operating element (5), and then the rear wheel control unit (34) starts operating when the braking condition of the front wheel braking unit (32) satisfies a first condition. Therefore, in a saddle-type vehicle having a front and rear linked brake system, by first applying braking force to the front wheels and then applying braking force to the rear wheels, nose dive of the vehicle body is suppressed when decelerating while traveling straight, and it is also possible to operate the linked brakes while making the vehicle behavior easier to bank when decelerating before entering a corner by operating a single operating element. In addition, because braking force is applied only to the front wheels until the first condition is met, it can also meet the needs of drivers who want to apply braking force only to the front wheels in saddle-type vehicles equipped with a front and rear linked brake system.

[0017] According to the second feature, when the first condition is satisfied, the braking force of the front wheel braking unit (32) is maintained at the first front wheel braking force (P1) while the braking force of the rear wheel braking unit (34) is increased. Therefore, by applying a constant braking force to the front wheels while increasing the braking force of the rear wheels, it is possible to gradually transfer the load on the front wheels to the rear wheels, and to apply braking forces to the front and rear wheels more stably.

[0018] According to the third feature, when the increasing braking force of the rear wheel braking unit (34) reaches the first rear wheel braking force (P2), the braking force of the rear wheel braking unit (34) is maintained at the first rear wheel braking force (P2). Therefore, by maintaining the braking force of the rear wheel braking unit at the first rear wheel braking force, it is possible to suppress nose dive of the vehicle body.

[0019] According to the fourth feature, the first rear wheel braking force (P2) varies in accordance with the amount of operation of the operation element (5), so that a first rear wheel braking force that is in line with the driver's braking intention can be obtained.

[0020] According to the fifth feature, when a predetermined time (T1) has elapsed since the first condition is satisfied, the braking force of the front wheel braking unit (32) starts to transition to the second front wheel braking force (P4), and the braking force of the rear wheel braking unit (34) starts to transition to the second rear wheel braking force (P3) which is smaller than the second front wheel braking force (P4). Therefore, when a predetermined time has elapsed since the first condition is satisfied, the braking force of the front wheels starts to transition higher than the braking force of the rear wheels, so that it is possible to naturally guide the riding posture of the driver to a forward leaning posture while suppressing nose dive of the vehicle body.

[0021] According to the sixth feature, the second front wheel braking force (P4) and the second rear wheel braking force (P3) vary according to the amount of operation of the operating element (5), so that a second front wheel braking force and a second rear wheel braking force in accordance with the driver's braking intention can be obtained.

[0022] According to the seventh feature, there is provided an actuation force generating means (40) for actuating the front wheel braking section (32) in response to operation of the operating element (5), and the first condition is that the actuation force generated by the actuation force generating means (40) is equal to or greater than a predetermined value. Therefore, by setting the first condition to a predetermined value of the actuation force that changes directly in response to operation of the operating element, it is possible to detect the driver's intention to brake more quickly.

[0023] According to the eighth feature, the operating force generating means (40) is a front wheel master cylinder that generates hydraulic pressure in response to operation of the operating element (5), and the operating force is hydraulic pressure detected by a hydraulic pressure sensor (50). Therefore, by using the hydraulic pressure generated by the front wheel master cylinder as an operation start condition for the rear wheel braking section, it is possible to detect the driver's intention to brake more quickly.

[0024] According to the ninth feature, when the roll angular velocity of the vehicle body reaches a maximum after the first condition is satisfied, the braking force of the front wheel braking unit (32) starts to transition to the second front wheel braking force (P4), and the braking force of the rear wheel braking unit (34) starts to transition to the second rear wheel braking force (P3) which is smaller than the second front wheel braking force (P4). Therefore, when the roll angular velocity of the vehicle body reaches a maximum during cornering, the force raising the vehicle body in the upright direction becomes stronger, making the transition to the next operation smoother. [Brief description of the drawings]

[0025] [Figure 1] 1 is a right side view of a motorcycle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram showing a configuration of a front and rear linked brake system provided in the motorcycle. [Diagram 3] 4 is a conceptual diagram showing the distribution of braking force between the front and rear wheels when braking is performed by operating the brake lever. FIG. [Figure 4] 5 is a graph showing the progress of output signals from a first hydraulic pressure sensor and a second hydraulic pressure sensor accompanying operation of a brake lever. [Diagram 5] FIG. 13 is a conceptual diagram showing a configuration of a braking operation during straight-line traveling. [Figure 6]6 is a graph showing the progress of each parameter corresponding to FIG. 5. [Figure 7] FIG. 1 is a conceptual diagram showing a configuration of a braking operation before entering a corner or during an evasive maneuver. [Figure 8] 8 is a graph showing the progress of each parameter corresponding to FIG. 7. [Figure 9] 4 is a flowchart showing a procedure of brake control according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] A preferred embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a right side view of a motorcycle 1 according to one embodiment of the present invention. The motorcycle 1 is a saddle-ride type vehicle that transmits the driving force of a power unit P to a rear wheel WR via a drive chain 14. A steering stem (not shown) is pivotally supported on a head pipe F1 located at the front end of a body frame F. A bottom bridge 23 and a top bridge 24 that support a pair of left and right front forks 10 are fixed above and below the steering stem.

[0027] A steering handle 2 supporting a rearview mirror 4 is attached to the upper part of the top bridge 24, and a brake lever 5 is attached to the steering handle 2 on the right side in the vehicle width direction as an operator to be operated by the right hand of the rider. A front wheel brake caliper 32 is attached to the front fork 10 as a front wheel braking part that applies a braking force to a front wheel brake disc 31 that rotates synchronously with the front wheel WF. A front fender 11 that covers the upper part of the front wheel WF is fixed to the front fork 10.

[0028] A pair of left and right main frames F2 extending diagonally rearward and downward, and an under frame F5 extending downward to support the underside of the power unit P are attached to the rear of the head pipe F1. A pivot frame F3 having a pivot 22 that pivotally supports the swing arm 15 so that it can swing freely is connected to the rear end of the main frame F2, and the rear end of the under frame F5 is connected to the lower end of the pivot frame F3. A pair of left and right foot steps 51 on which the driver places his / her feet are attached to the pivot frame F3.

[0029] The driving force of the power unit P, which is surrounded and supported by the main frame F2 and the underframe F5, is transmitted to the rear wheel WR via a drive chain 14. An underguard 12 is attached to the bottom part near the front of the power unit P. Combustion gas from the power unit P is sent to the muffler 16 at the rear of the vehicle body via an exhaust pipe 37 that passes inside the underguard 12.

[0030] The rear wheel WR is rotatably supported at the rear end of the swing arm 15, which is journalled by the pivot 22 and suspended from the vehicle body by a rear cushion 36. A rear wheel brake caliper 34 serving as a rear wheel braking unit that applies braking force to a rear wheel brake disc 33 that rotates synchronously with the rear wheel WR is supported on the swing arm 15. A brake pedal 39, which is operated by the right foot of the driver standing on the foot step 51, is pivotally supported for free swinging on the pivot frame F3 on the right side in the vehicle width direction.

[0031] A front cowl 7 supporting a headlight 9, a windscreen 6, and a pair of left and right front flashers 8 is disposed in front of the head pipe F1. A fuel tank 3 is disposed behind the front cowl 7 and above the main frame F2. A rear frame F4 supporting a front seat 21 on which a driver sits and a rear seat 20 on which a passenger sits is fixed to the rear of the pivot frame F3. The left and right sides of the rear frame F4 in the vehicle width direction are covered with a rear cowl 19, and a rear fender 38 supporting a taillight device 18 and a pair of left and right rear flashers 17 is attached to the rear end of the rear cowl 19.

[0032] 2 is a block diagram showing the configuration of a front and rear linked brake system provided in the motorcycle 1. The motorcycle 1 according to this embodiment is equipped with a front and rear linked brake system that operates the front wheel braking unit 32 and the rear wheel braking unit 34 in a linked manner in response to the operation of a brake lever 5 serving as a single operating element.

[0033] The brake lever 5 is connected to a front wheel master cylinder 40 as an operating force generating means for generating hydraulic pressure for generating a braking force, and the operating force (hydraulic pressure) of the front wheel master cylinder 40 is detected by a first hydraulic pressure sensor 50. On the other hand, the brake pedal 39 is connected to a rear wheel master cylinder 41, and the operating force (hydraulic pressure) of the rear wheel master cylinder 41 is detected by a second hydraulic pressure sensor 51. The present invention is characterized by the mode of braking force distribution between the front and rear wheels when the front and rear linked brakes are operated in response to the operation of the brake lever 5.

[0034] The control unit 60 controls a front wheel brake modulator 70 and a rear wheel brake modulator 71 that generate hydraulic pressure by actuators based on output signals from the first hydraulic pressure sensor 50 and the second hydraulic pressure sensor 51, etc. The hydraulic pressure generated by the front wheel brake modulator 70 is supplied to a front wheel braking unit 32 that brakes the front wheels WF. The hydraulic pressure generated by the rear wheel brake modulator 71 is supplied to a rear wheel braking unit 34 that brakes the rear wheels WR. The hydraulic pressures generated in the front wheel braking unit 32 and the rear wheel braking unit 34 are detected by a third hydraulic pressure sensor 80 and a fourth hydraulic pressure sensor 81.

[0035] The control unit 60 includes a memory section 61 and a calculation section 62 for controlling the front wheel brake modulator 70 and the rear wheel brake modulator 71. The control unit 60 controls the front wheel braking section 32 and the rear wheel braking section 34 to operate in an interlocking manner while adjusting the braking force distribution between the front and rear wheels in accordance with the operation mode of the brake lever 5 and the driving conditions of the motorcycle 1. The braking force distribution between the front and rear wheels is calculated by the calculation section 62 consisting of a microcomputer, and the memory section 61 stores an arithmetic formula for calculating the braking force distribution, etc.

[0036] 3 is a conceptual diagram showing the distribution of braking force between the front and rear wheels when braking is performed by operating the brake lever 5. In this diagram, the target braking force of the entire vehicle when the brake lever 5 is operated is shown by a trapezoid, and the overall picture of the braking force distribution is shown by dividing the distribution into the front wheel brake and the rear wheel brake.

[0037] In this embodiment, the front wheel brake is first applied, followed by the rear wheel brake, in response to the operation of the brake lever 5. The rear wheel brake is distributed more heavily in the early stage of the braking operation, and the front and rear braking force distributions are switched in the middle stage of the braking operation, with the front wheel brake being distributed more heavily in the later stage of the braking operation. This makes it possible to suppress nose diving of the vehicle when decelerating while traveling straight ahead, and to make it easier for the vehicle to bank when decelerating before entering a corner.

[0038] 4 is a graph showing the progress of output signals of the first hydraulic sensor 50 and the second hydraulic sensor 51 accompanying the operation of the brake lever 5. The braking forces of the front wheel braking unit 32 and the rear wheel braking unit 34 are generated by a front wheel brake modulator 70 and a rear wheel brake modulator 71. The output signals of the third hydraulic sensor 80 and the fourth hydraulic sensor 81 correspond to the braking forces generated by the front wheel braking unit 32 and the rear wheel braking unit 34, respectively.

[0039] At time t1, operation of the brake lever 5 is started, and the output of the first hydraulic sensor 50 rises accordingly. At time t2, the output of the first hydraulic sensor 50 reaches the hydraulic pressure P1 corresponding to the first front wheel braking force, and the first condition as a braking condition is satisfied. In this embodiment, the front wheel braking unit 32 first starts operating in response to operation of the brake lever 5, and then the rear wheel control unit 34 starts operating when the braking condition of the front wheel braking unit 32 satisfies the first condition. That is, when the first condition is satisfied at time t2, the rear wheel brake modulator 71 starts operating, and the output of the fourth hydraulic sensor 81 that detects the hydraulic pressure generated in the rear wheel braking unit 34 rises.

[0040] In this embodiment, when the braking conditions of the front wheel braking unit 32 satisfy a first condition, the braking force of the front wheel braking unit 32 is maintained at the first front wheel braking force, while the braking force of the rear wheel braking unit 34 is increased. That is, when the first condition is satisfied at time t2, the hydraulic pressure of the front wheel braking unit 32 detected by the third hydraulic pressure sensor 80 is maintained at the hydraulic pressure P1 corresponding to the first front wheel braking force, and the hydraulic pressure of the rear wheel braking unit 34 starts to increase.

[0041] Next, at time t3, the hydraulic pressure of the rear wheel braking unit 34, which started to increase from time t2, reaches hydraulic pressure P2 corresponding to the first rear wheel braking force. In this embodiment, when the hydraulic pressure of the rear wheel braking unit 34 reaches hydraulic pressure P2 corresponding to the first rear wheel braking force, the braking force of the rear wheel braking unit 34 is configured to be maintained at the first rear wheel braking force. In other words, when the hydraulic pressure of the rear wheel braking unit 34 reaches hydraulic pressure P2 corresponding to the first rear wheel braking force at time t3, the hydraulic pressures of the front wheel braking unit 32 and the rear wheel braking unit 34 are each controlled to be maintained constant.

[0042] At time t4, the braking forces of the front wheel braking unit 32 and the rear wheel braking unit 34 each begin to transition, triggered by the passage of a predetermined time T1 from time t2 when the first condition is satisfied. More specifically, the hydraulic pressure of the front wheel braking unit 32 begins to increase toward a hydraulic pressure P4 corresponding to the second front wheel braking force, and the hydraulic pressure of the rear wheel braking unit 34 begins to decrease toward a hydraulic pressure P3 corresponding to the second rear wheel braking force. In this embodiment, the hydraulic pressure P3 is set lower than the hydraulic pressure P4, and after the transition begins at time t4, the magnitude relationship between the braking force of the front wheel braking unit 32 and the braking force of the rear wheel braking unit 34 is reversed.

[0043] Next, at time t5 when the second predetermined time T2 has elapsed from time t4, the hydraulic pressure of the front wheel braking unit 32 reaches the hydraulic pressure P4 corresponding to the second front wheel braking force, and the hydraulic pressure of the rear wheel braking unit 34 reaches the hydraulic pressure P3 corresponding to the second rear wheel braking force. In this embodiment, the hydraulic pressure P4 of the front wheel braking unit 32 and the hydraulic pressure P3 of the rear wheel braking unit 34 are each kept constant from time t5 when the second predetermined time T2 as the transition period ends.

[0044] Then, at time t6, the operation of the brake lever 5 starts to be released. Accordingly, the hydraulic pressures of the front wheel braking unit 32 and the rear wheel braking unit 34 each start to decrease so as to reach zero at time t7.

[0045] Figure 5 is a conceptual diagram showing the configuration of braking operation while traveling in a straight line. Figure 6 is a graph showing the progress of each parameter corresponding to Figure 5. In both Figures 5 and 6, the circled numbers (1) indicate the early stage of braking mainly using the rear wheel brake, (2) the transition start timing, (3) the middle stage of braking as a transition period, and (4) the later stage of braking mainly using the front wheel brake.

[0046] The graph in Fig. 6 shows, from the top, the brake lever operation, the front wheel brake braking force, the rear wheel brake braking force, the front fork stroke, the rear cushion stroke, the vehicle body pitch angle, and the pitch angular velocity. In the graph, the case of the present invention control is shown with a solid line, and the case of the conventional control is shown with a two-dot chain line. Also, each indication of time t corresponds to the graph in Fig. 4.

[0047] The braking operation according to the present invention is roughly divided into three periods: an initial period (1) in which the rear wheel brake is the main force, a middle period (3) in which the magnitude relationship of the braking forces of the front wheel brake and the rear wheel brake is switched, and a later period (4) in which the front wheel brake is the main force. In the present invention, the braking force distribution to the rear wheel brake is increased in the initial period of braking, and the front wheel braking force is gradually increased in the middle period of braking, thereby reducing the rate of change of the front fork stroke and the rear cushion stroke, and as a result, it is possible to reduce the pitch behavior (nose dive) of the vehicle body.

[0048] More specifically, when braking the motorcycle 1, the front fork 10 contracts and the rear cushion 36 expands, causing nose dive; however, in the present invention, the timing of expansion and contraction of the front and rear suspensions is divided into an initial braking phase (1) and a middle braking phase (3), making it possible to suppress sudden nose dive.

[0049] Fig. 7 is a conceptual diagram showing the configuration of braking operations before entering a corner or during evasive maneuvers. Fig. 8 is a graph showing the progress of each parameter corresponding to Fig. 7. In both Figs. 7 and 8, the circled numbers (1) indicate the early stage of braking where the rear wheel brake is the main force, (2) the transition start timing, (3) the middle stage of braking as a transition period, and (4) the later stage of braking where the front wheel brake is the main force.

[0050] The graph in Fig. 8 shows, from the top, the brake lever operation, the front wheel brake braking force, the rear wheel brake braking force, the roll angle, and the roll angular velocity. In the graph, the solid line shows the case of the present invention control, and the two-dot chain line shows the case of the conventional control, and each indication of time t corresponds to the graph in Fig. 4.

[0051] The braking operation according to the present invention is roughly divided into three periods: an initial period (1) in which the rear wheel brake is the main brake, a middle period (3) in which the magnitude relationship of the braking forces of the front wheel brake and the rear wheel brake is switched, and a later period (4) in which the front wheel brake is the main brake. In the present invention, the vehicle body is easily banked by increasing the braking force distribution of the rear wheel brake in the initial period, and the force to make the vehicle body upright is strengthened by gradually increasing the front wheel braking force in the middle period, so that it is possible to obtain good vehicle body behavior during cornering and evasive action. In the vehicle body characteristics and driving state shown in this embodiment, the timing at which the roll angular velocity of the vehicle body reaches its maximum and the transition start timing (2) are almost the same, so that the effect of making the vehicle body easily banked when entering a corner, etc., and easily standing up when exiting a corner, etc. while preventing excessive banking, is enhanced.

[0052] 9 is a flowchart showing the procedure of brake control according to this embodiment. In step S1, braking by the front wheel braking unit 32 is started by operating the brake lever 5 (time t1 in FIG. 4). In the following step S2, it is determined whether the front wheel braking force has reached a first front wheel braking force P1.

[0053] If the determination in step S2 is affirmative, it is determined that the braking conditions of the front wheel braking unit 32 satisfy the first condition, and the process proceeds to step S3, where braking force control for operating the rear wheel control unit 34 is started (time t2 in FIG. 4). If the determination in step S2 is negative, the process returns to the determination in step S2.

[0054] In step S4, it is determined whether the rear wheel braking force has reached the first rear wheel braking force P2. If the determination in step S4 is affirmative, the process proceeds to step S5, where the rear wheel braking force is maintained at the first rear wheel braking force P2 as a predetermined braking force (time t3 in FIG. 4). If the determination in step S4 is negative, the process returns to the determination in step S4.

[0055] In the next step S6, it is determined whether a predetermined time T1 has elapsed since the first condition was satisfied, and if the determination is affirmative, the process proceeds to step S7. In step S7, control is started to gradually shift the front wheel braking force and the rear wheel braking force to the second braking force (the second front wheel braking force P4 and the second rear wheel braking force P3), respectively (time t4 in FIG. 4). If the determination is negative in step S6, the process returns to the determination in step S6.

[0056] In step S8, it is determined whether the front wheel braking force and the rear wheel braking force have reached the second braking force, and if the determination is affirmative, the process proceeds to step S9, where the second braking forces (the second front wheel braking force P4 and the second rear wheel braking force P3) are maintained (time t5 in FIG. 4). If the determination is negative in step S8, the process returns to the determination in step S8.

[0057] In the next step S10, it is determined whether the brake lever 5 has been released, and if the determination is affirmative, the process proceeds to step S11. If the determination is negative in step S10, the process returns to the determination in step S9. Then, in step S11, control is started to gradually shift the front wheel braking force and the rear wheel braking force to zero (time t6 in FIG. 4), and when the front wheel braking force and the rear wheel braking force become zero, the series of controls ends (time t7 in FIG. 4).

[0058] Of the above-mentioned first front wheel braking force P1, first rear wheel braking force P2, second rear wheel braking force P3, and second front wheel braking force P4, the values ​​of the first rear wheel braking force P2, the second rear wheel braking force P3, and the second front wheel braking force P4 may vary depending on the amount of operation of the brake lever 5 (the operating force generated by the front wheel master cylinder 40).

[0059] As described above, according to the front and rear interlocking brake system of the saddle riding type vehicle of this embodiment, the front wheel braking unit 32 starts to operate first in response to the operation of the brake lever 5, and then the rear wheel control unit 34 starts to operate when the braking force of the front wheel braking unit 32 reaches the first front wheel braking force P1, so that by first applying braking force to the front wheel WF and then to the rear wheel WR, nose diving of the vehicle body during deceleration while traveling straight ahead is suppressed, and it is possible to operate the interlocking brake while making the vehicle body behave in a way that makes it easier to bank the vehicle body when decelerating before entering a corner by operating a single operator. In addition, since braking force is applied only to the front wheels until the first condition is satisfied, the need of the driver who wants to apply braking force only to the front wheels can be met in a saddle riding type vehicle equipped with a front and rear interlocking brake system.

[0060] In addition, when the braking force of the front wheel braking unit 32 reaches the first front wheel braking force P1, the braking force of the rear wheel braking unit 34 is increased while maintaining the braking force of the front wheel braking unit 32 at the first front wheel braking force P1. Therefore, by increasing the braking force of the rear wheel WR while applying a constant braking force to the front wheel WF, it is possible to gradually transfer the load on the front wheel WF to the rear wheel, and apply braking forces to the front and rear wheels more stably.

[0061] Furthermore, when the braking force of the rear wheel braking portion 34 reaches the first rear wheel braking force P2, the braking force of the rear wheel braking portion 34 is maintained at the first rear wheel braking force P2, making it possible to suppress nose dive of the vehicle body.

[0062] Furthermore, when a predetermined time T1 has elapsed since the braking force of the front wheel braking unit 32 reaches the first front wheel braking force P1, the braking force of the front wheel braking unit 32 begins to transition to the second front wheel braking force P4, and the braking force of the rear wheel braking unit 34 begins to transition to the second rear wheel braking force P3 which is smaller than the second front wheel braking force P4.Therefore, when a predetermined time T1 has elapsed since the braking force of the front wheel braking unit 32 reaches the first front wheel braking force P1, the braking force of the front wheel WF begins to transition higher than the braking force of the rear wheel WR, making it possible to naturally guide the driver's riding posture into a forward leaning posture while suppressing nose dive of the vehicle body.

[0063] The configuration of the motorcycle, the structures of the front wheel braking unit and the rear wheel braking unit, the structures of the master cylinder and the brake modulator, the structure of the control unit, the structure of the hydraulic sensor, the settings of the predetermined time and the second predetermined time, the settings of the first front wheel braking force, the first rear wheel braking force, the second front wheel braking force, and the second rear wheel braking force, etc. are not limited to the above embodiment and can be modified in various ways. The brake system according to the present invention can be applied to various two-wheeled vehicles, three-wheeled vehicles, etc. [Explanation of symbols]

[0064] Reference Signs List 1...motorcycle (saddle-ride type vehicle), 5...brake lever (operator), 32...front wheel brake caliper (front wheel braking portion), 34...rear wheel brake caliper (rear wheel braking portion), 40...front wheel master cylinder (operating force generating means), 50...first hydraulic sensor (hydraulic sensor), WF...front wheel, WR...rear wheel, P1...first front wheel braking force, P2...first rear wheel braking force, P4...second front wheel braking force, P3...second rear wheel braking force, T1...predetermined time

Claims

1. A saddle-type vehicle (1) having a front wheel braking section (32) that applies a braking force from a front wheel brake modulator (70) to a front wheel (WF) in response to operation of an operator (5, 39), and a rear wheel braking section (34) that applies a braking force from a rear wheel brake modulator (71) to a rear wheel (WR), the front wheel braking section (32) and the rear wheel braking section (34) being operated in conjunction with each other in response to operation of a single operator (5, 39), When the braking force of the front wheels (WF) reaches a predetermined value, only the rear wheel braking force is increased according to the amount of operation of the operation element (5, 39), A straddle-type vehicle, characterized in that after a predetermined time (T1) has elapsed since the braking force of the front wheels (WF) reached a predetermined value, the distribution of the front wheel braking force is increased within a range of a target braking force.

2. The first condition is that the braking force of the front wheels (WF) reaches a predetermined value; 2. The saddle-type vehicle according to claim 1, characterized in that, when the first condition is satisfied, the braking force of the front wheel braking unit (32) is maintained at a first front wheel braking force (P1) while the braking force of the rear wheel braking unit (34) is increased toward a target braking force.

3. 3. The saddle-type vehicle according to claim 2, characterized in that when the increasing braking force of the rear wheel braking unit (34) reaches a first rear wheel braking force (P2), the braking force of the rear wheel braking unit (34) is maintained at the first rear wheel braking force (P2).

4. 4. The saddle-type vehicle according to claim 3, wherein the first rear wheel braking force (P2) varies in accordance with an amount of operation of the operating element (5).

5. 4. The saddle-type vehicle according to claim 3, characterized in that when a predetermined time (T1) has elapsed since the first condition is satisfied, the braking force of the front wheel braking unit (32) begins to transition to a second front wheel braking force (P4), and the braking force of the rear wheel braking unit (34) begins to transition to a second rear wheel braking force (P3) which is smaller than the second front wheel braking force (P4).

6. 6. The saddle-type vehicle according to claim 5, wherein the second front wheel braking force (P4) and the second rear wheel braking force (P3) vary in accordance with an amount of operation of the operation element (5).

7. an operating force generating means (40) for operating the front wheel braking portion (32) in response to an operation of the operating element (5); 6. The straddle-type vehicle according to claim 5, wherein the first condition is that the operating force generated by the operating force generating means (40) is equal to or greater than a predetermined value.

8. The operating force generating means (40) is a front wheel master cylinder that generates hydraulic pressure in response to the operation of the operating element (5), 8. The straddle-type vehicle according to claim 7, wherein the actuating force is a hydraulic pressure detected by a hydraulic pressure sensor (50).

9. 4. The saddle-type vehicle according to claim 3, characterized in that, when the roll angular velocity of the vehicle body becomes maximum after the first condition is satisfied, the braking force of the front wheel braking unit (32) starts to transition to a second front wheel braking force (P4), and the braking force of the rear wheel braking unit (34) starts to transition to a second rear wheel braking force (P3) which is smaller than the second front wheel braking force (P4).

10. A saddle-type vehicle as described in claim 1 or 2, characterized in that the specified time (T1) is an initial braking period from when the front wheel braking force reaches a specified value (t2) to the start of a middle braking phase when the distribution of the front wheel braking force begins to be increased within the range of a target braking force.

Images