Hydraulic control unit

Abstract

The present invention is a hydraulic pressure control unit which can accurately estimate the stroke amount of an armature of a solenoid valve. In this hydraulic pressure control unit, a control device includes an estimation unit which estimates the stroke amount (△x) of an armature (312) of a solenoid valve (31). The estimation unit estimates the stroke amount (△x) on the basis of the amount of drop in a current value of current flowing through a winding (314) of the solenoid valve (31) when the current value temporarily drops in a process in which the current value is supposed to rise toward a target current value at the start of the application of current to the winding (314).

Description

Technical Field

[0001] This disclosure relates to a hydraulic control unit that can accurately estimate the stroke amount of the armature of a solenoid valve.

Background Art

[0002] Conventionally, as a behavior control system for controlling the behavior of vehicles such as motorcycles, there is a hydraulic control unit that controls the hydraulic pressure generated in the working fluid. In the hydraulic control unit, the hydraulic pressure generated in the working fluid is controlled by operating a solenoid valve provided in the flow path of the working fluid.

[0003] Here, in order to properly function the solenoid valve that opens and closes the flow path, it is necessary to optimize the stroke amount of the armature, which is a movable part in the solenoid valve. Therefore, in order to optimize the stroke amount of the armature, a technique for estimating the stroke amount of the armature has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional technology related to the hydraulic control unit, it is unclear whether the stroke amount of the armature of the solenoid valve can be accurately estimated. That is, a new proposal regarding the mechanism for estimating the stroke amount of the armature is desired.

[0006] The present invention has been made against the background of the above problems, and aims to obtain a hydraulic control unit that can accurately estimate the stroke amount of the armature of a solenoid valve.

Means for Solving the Problems

[0007] The hydraulic control unit according to the present invention is a hydraulic control unit used in a vehicle behavior control system, and includes a base body, and a component incorporated in the base body and including a solenoid valve for controlling the hydraulic pressure generated in the hydraulic fluid of the behavior control system. The hydraulic control mechanism includes a control device including a control unit for controlling the operation of the component. The solenoid valve includes a winding and an armature that moves as a current is applied to the winding, and is a valve that closes or opens in an energized state where a current is applied to the winding. The control device includes an estimation unit for estimating the stroke amount of the armature. The estimation unit estimates the stroke amount based on the amount of decrease in the current value when the current value temporarily decreases in the process of the current value flowing through the winding rising toward the target current value at the start of application of the current to the winding.

Advantages of the Invention

[0008] In the hydraulic control unit according to the present invention, the control device includes an estimation unit for estimating the stroke amount of the armature of the solenoid valve. The estimation unit estimates the stroke amount based on the amount of decrease in the current value when the current value temporarily decreases in the process of the current value flowing through the winding of the solenoid valve rising toward the target current value at the start of application of the current to the winding. Thereby, paying attention to the phenomenon that a counter electromotive force is generated in the winding as the armature moves, the stroke amount of the armature can be appropriately estimated. Therefore, the stroke amount of the armature of the solenoid valve can be accurately estimated.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the hydraulic control unit according to the present invention will be described with reference to the drawings.

[0011] Note that, hereinafter, a hydraulic control unit used in a braking system of a two-wheeled motorcycle (refer to vehicle 100 in FIG. 1) is described, but the hydraulic control unit according to the present invention may be used in other behavior control systems other than the braking system (for example, a system for controlling the damping force of a suspension, etc.). Further, the hydraulic control unit according to the present invention may be used in a behavior control system of a vehicle other than a two-wheeled motorcycle (for example, other saddle-riding type vehicles such as a buggy, a three-wheeled motorcycle, a bicycle, or a four-wheeled automobile, etc.). Note that a saddle-riding type vehicle means a vehicle on which a rider straddles and includes a scooter, etc.

[0012] Also, hereinafter, a case where there is one front wheel braking mechanism and one rear wheel braking mechanism each is described (refer to the front wheel braking mechanism 12 and the rear wheel braking mechanism 14 in FIG. 2), but at least one of the front wheel braking mechanism and the rear wheel braking mechanism may be plural, and one of the front wheel braking mechanism and the rear wheel braking mechanism may not be provided.

[0013] In addition, the configurations, operations, etc. described below are examples, and the hydraulic control unit according to the present invention is not limited to such configurations, operations, etc.

[0014] In addition, in the following, the same or similar descriptions are appropriately simplified or omitted as appropriate. Also, in each figure, the same or similar members or parts are either not given reference numerals or are given the same reference numerals. Also, the detailed structure is appropriately simplified or omitted in the illustration.

[0015] <Configuration of Vehicle> With reference to FIGS. 1 to 5, the configuration of a vehicle 100 according to an embodiment of the present invention will be described.

[0016] FIG. 1 is a schematic diagram showing a schematic configuration of the vehicle 100. FIG. 2 is a schematic diagram showing a schematic configuration of the brake system 10.

[0017] The vehicle 100 is a two-wheeled motorcycle corresponding to an example of the vehicle according to the present invention. As shown in FIG. 1, the vehicle 100 includes a body 1, a handle 2 rotatably held on the body 1, a front wheel 3 rotatably held on the body 1 together with the handle 2, a rear wheel 4 rotatably held on the body 1, a hydraulic control unit 5, and a notification device 6. The hydraulic control unit 5 is used for the brake system 10 of the vehicle 100. The notification device 6 performs notification to the rider. The notification device 6 has a sound output function and a display function. The sound output function is a function of outputting sound and is realized by, for example, a speaker. The display function is a function of visually displaying information and is realized by, for example, a liquid crystal display or a lamp. Note that the vehicle 100 includes a drive source such as an engine or a motor, and travels using the power output from the drive source.

[0018] As shown in FIGS. 1 and 2, the braking system 10 includes a first brake operation unit 11, a front-wheel braking mechanism 12 that brakes the front wheels 3 in conjunction with at least the first brake operation unit 11, a second brake operation unit 13, and a rear-wheel braking mechanism 14 that brakes the rear wheels 4 in conjunction with at least the second brake operation unit 13. The braking system 10 also includes a hydraulic control unit 5, and a part of the front-wheel braking mechanism 12 and a part of the rear-wheel braking mechanism 14 are included in the hydraulic control unit 5. The hydraulic control unit 5 is a unit that functions to control the braking force applied to the front wheels 3 by the front-wheel braking mechanism 12 and the braking force applied to the rear wheels 4 by the rear-wheel braking mechanism 14.

[0019] The first brake operation unit 11 is provided on the handle 2 and is operated by the rider's hand. The first brake operation unit 11 is, for example, a brake lever. The second brake operation unit 13 is provided at the lower part of the body 1 and is operated by the rider's foot. The second brake operation unit 13 is, for example, a brake pedal. However, both the first brake operation unit 11 and the second brake operation unit 13 may be brake levers that are operated by the rider's hand, such as the brake operation units of a scooter.

[0020] Each of the front-wheel braking mechanism 12 and the rear-wheel braking mechanism 14 includes a master cylinder 21 having a piston (not shown) built therein, a reservoir 22 attached to the master cylinder 21, a brake caliper 23 held by the body 1 and having a brake pad (not shown), a wheel cylinder 24 provided in the brake caliper 23, a main flow path 25 for circulating the brake fluid of the master cylinder 21 to the wheel cylinder 24, a sub-flow path 26 for discharging the brake fluid of the wheel cylinder 24, and a supply flow path 27 for supplying the brake fluid of the master cylinder 21 to the sub-flow path 26.

[0021] Each of the front-wheel braking mechanism 12 and the rear-wheel braking mechanism 14 is provided with a solenoid valve 31 for controlling the hydraulic pressure generated in the brake fluid, which is the working fluid. In the example of FIG. 2, the solenoid valve 31 includes a charging valve (EV) 31a, a releasing valve (AV) 31b, a first valve (USV) 31c, and a second valve (HSV) 31d.

[0022] The charging valve 31a is provided in the main flow path 25. The sub-flow path 26 bypasses between the wheel cylinder 24 side and the master cylinder 21 side of the main flow path 25 with respect to the charging valve 31a. In the sub-flow path 26, a releasing valve 31b, an accumulator 32, and a pump 33 are provided in order from the upstream side. A first valve 31c is provided between the end on the master cylinder 21 side of the main flow path 25 and the connection point of the downstream end of the sub-flow path 26. The supply flow path 27 communicates between the master cylinder 21 and the suction side of the pump 33 in the sub-flow path 26. A second valve 31d is provided in the supply flow path 27.

[0023] The charging valve 31a is, for example, a solenoid valve 31 that opens in a non-energized state and closes in an energized state. The releasing valve 31b is, for example, a solenoid valve 31 that closes in a non-energized state and opens in an energized state. The first valve 31c is, for example, a solenoid valve 31 that opens in a non-energized state and closes in an energized state. The second valve 31d is, for example, a solenoid valve 31 that closes in a non-energized state and opens in an energized state.

[0024] The hydraulic pressure control unit 5 includes a hydraulic pressure control mechanism 51 that includes a part of the front-wheel braking mechanism 12 and a part of the rear-wheel braking mechanism 14 described above, and a control device (ECU) 52 that controls the operation of the hydraulic pressure control mechanism 51.

[0025] The hydraulic pressure control mechanism 51 includes a base body 51a and components including a solenoid valve 31 for controlling the hydraulic pressure generated in the brake fluid, which is the working fluid of the brake system 10, incorporated in the base body 51a. Components mean elements such as parts incorporated in the base body 51a.

[0026] The base body 51a has, for example, a substantially rectangular parallelepiped shape and is formed of a metallic material. Inside the base body 51a of the hydraulic control mechanism 51, a main flow path 25, an auxiliary flow path 26, and a supply flow path 27 are formed, and solenoid valves 31 (specifically, a filling valve 31a, a releasing valve 31b, a first valve 31c, and a second valve 31d), an accumulator 32, and a pump 33 are incorporated as the above components. The operations of these components are controlled by the control device 52 of the hydraulic control unit 5, as will be described later. Note that the base body 51a may be formed of one member or may be formed of a plurality of members. Further, when the base body 51a is formed of a plurality of members, each component may be provided separately for the plurality of members.

[0027] Hereinafter, with reference to FIG. 3, the detailed configuration of the solenoid valve 31 provided in the hydraulic control unit 5 will be described. FIG. 3 is a schematic cross-sectional view showing an example of the solenoid valve 31 of the hydraulic control unit 5. In the following, after mainly describing the case where the solenoid valve 31 in FIG. 3 is a valve that closes in the energized state (specifically, the filling valve 31a and the first valve 31c), the valves that open in the energized state (specifically, the releasing valve 31b and the second valve 31d) will be supplemented.

[0028] As shown in FIG. 3, the solenoid valve 31 includes, for example, a case 311, an armature 312, a tappet 313, a winding 314, a core 315, a spring 316, a first flow path 317, and a second flow path 318.

[0029] The armature 312 corresponds to a movable part that can reciprocate relative to the case 311 inside the case 311. The armature 312 has, for example, a substantially cylindrical shape. The armature 312 is disposed in the internal space formed inside the case 311 and can reciprocate along the axial direction of the armature 312. The tappet 313 is fixed to the armature 312 and can move integrally with the armature 312. For example, the tappet 313 is a solid rod-shaped member having a circular cross-sectional shape and is fitted and fixed to the inner peripheral portion of the armature 312.

[0030] The winding 314 is fixed to the case 311 and generates a magnetic field when a current is applied. For example, the winding 314 is provided so as to surround the inner space of the case 311 along the circumferential direction of the armature 312. The core 315 is an iron core magnetized by the magnetic field generated by the winding 314 and has, for example, a substantially cylindrical shape. The core 315 is arranged coaxially with the armature 312 in the inner space of the case 311, and the tappet 313 is inserted through the inner peripheral portion of the core 315. When the core 315 is magnetized, a magnetic force in the direction approaching the core 315 acts on the armature 312. Thus, the armature 312 moves as the current is applied to the winding 314.

[0031] The spring 316 biases the armature 312 in a direction away from the core 315. For example, the spring 316 is provided sandwiched between the inner peripheral portion of the case 311 and the end face of the armature 312 on the core 315 side in the inner space of the case 311.

[0032] The first flow path 317 and the second flow path 318 are formed inside the case 311 and form part of the main flow path 25, the sub-flow path 26, or the supply flow path 27 in which the solenoid valve 31 is provided. Further, the first flow path 317 and the second flow path 318 are connected to each other via a space in which the tip of the tappet 313 is accommodated in the case 311.

[0033] In the solenoid valve 31 (specifically, the filling valve 31a and the first valve 31c) that closes in the energized state, in a state where no current is applied to the winding 314 (that is, in the non-energized state), the armature 312 is held at a position separated from the core 315 by the biasing force of the spring 316 as shown by the solid line in FIG. 3. Thereby, the first flow path 317 and the second flow path 318 are in a state of being in communication with each other (that is, the solenoid valve 31 is in an open state).

[0034] On one hand, in a state where a current is applied to the winding 314 (i.e., an energized state), the armature 312 is attracted toward the core 315 together with the tappet 313 by the magnetic force generated between the armature 312 and the magnetized core 315, and is held at the position indicated by the dashed - double - dotted line in FIG. 3. Thereby, the opening at the end of the second flow path 318 is blocked by the tip of the tappet 313, and the first flow path 317 and the second flow path 318 are in a state of being blocked from each other (i.e., the state where the solenoid valve 31 is closed).

[0035] Note that in the solenoid valve 31 (specifically, the release valve 31b and the second valve 31d) that opens in the energized state, in the non - energized state, as shown by the dashed - double - dotted line in FIG. 3, the opening at the end of the second flow path 318 is blocked by the tip of the tappet 313, and the first flow path 317 and the second flow path 318 are in a state of being blocked from each other (i.e., the state where the solenoid valve 31 is closed). Then, in the energized state, a magnetic force in a direction away from the opening at the end of the second flow path 318 acts on the armature 312, and as shown by the solid line in FIG. 3, the first flow path 317 and the second flow path 318 are in a state of being communicated with each other (i.e., the state where the solenoid valve 31 is opened).

[0036] As shown in FIG. 2, the hydraulic control unit 5 is provided with a current sensor 41 that detects the current value of the current flowing through the winding 314 of the solenoid valve 31. Note that the current sensor 41 may detect another physical quantity that can be substantially converted into the current value of the current flowing through the winding 314 of the solenoid valve 31. The current sensor 41 is provided for each solenoid valve 31. Specifically, the current sensor 41 includes a current sensor 41a provided for the filling valve 31a, a current sensor 41b provided for the release valve 31b, a current sensor 41c provided for the first valve 31c, and a current sensor 41d provided for the second valve 31d. The detection results of each current sensor 41 are output to the control device 52 and used for the processing performed by the control device 52.

[0037] Hereinafter, with reference to FIG. 4, the detailed configuration of the current sensor 41 provided in the hydraulic control unit 5 will be described. FIG. 4 is a schematic diagram showing an example of the current sensor 41 of the hydraulic control unit 5.

[0038] As shown in FIG. 4, the current sensor 41 includes, for example, a shunt resistor 411 and an operational amplifier 412.

[0039] The shunt resistor 411 is connected in series with the winding 314 of the solenoid valve 31 connected to the power source 7 such as a secondary battery. Electric power is supplied from the power source 7 to the winding 314 of the solenoid valve 31. The operational amplifier 412 is connected in parallel to the shunt resistor 411, and amplifies and outputs the voltage difference across both ends of the shunt resistor 411. The current sensor 41 detects the current value of the current flowing through the winding 314 of the solenoid valve 31 based on the resistance value of the shunt resistor 411 and the output value of the operational amplifier 412.

[0040] Also, as shown in FIG. 2, temperature sensors 42 and 43 for detecting the temperature of the brake fluid are provided in the hydraulic control unit 5. Note that the temperature sensors 42 and 43 may detect other physical quantities that can be substantially converted into the temperature of the brake fluid. The temperature sensor 42 is provided in the front wheel braking mechanism 12 and detects the temperature of the brake fluid in the front wheel braking mechanism 12. The temperature sensor 43 is provided in the rear wheel braking mechanism 14 and detects the temperature of the brake fluid in the rear wheel braking mechanism 14. The temperature sensors 42 and 43 are provided, for example, inside the master cylinder pressure sensor.

[0041] The control device 52 of the hydraulic control unit 5 controls the operations of the above-described components incorporated in the base body 51a of the hydraulic control mechanism 51. For example, part or all of the control device 52 is constituted by a microcomputer, a microprocessor unit, or the like. Also, for example, part or all of the control device 52 may be constituted by something updatable such as firmware, or may be a program module or the like executed according to instructions from a CPU or the like. The control device 52 may be, for example, one, or may be divided into a plurality. Also, the control device 52 may be attached to the base body 51a, or may be attached to other members other than the base body 51a.

[0042] FIG. 5 is a block diagram showing an example of the functional configuration of the control device 52 of the hydraulic control unit 5. As shown in FIG. 5, the control device 52 includes, for example, an acquisition unit 52a, a control unit 52b, and an estimation unit 52c.

[0043] The acquisition unit 52a acquires information from each sensor provided in the hydraulic control unit 5 and outputs it to the control unit 52b and the estimation unit 52c. For example, the acquisition unit 52a acquires information from each current sensor 41 and temperature sensors 42, 43.

[0044] The control unit 52b controls the operations of the above-described components incorporated in the base body 51a of the hydraulic control mechanism 51. Thereby, the control unit 52b can control the braking force applied to the front wheels 3 by the front-wheel braking mechanism 12 and the braking force applied to the rear wheels 4 by the rear-wheel braking mechanism 14. Note that the control unit 52b can also control the operation of the notification device 6, as will be described later.

[0045] The control unit 52b controls the operations of the above components according to, for example, the driving state of the vehicle 100. In normal times (that is, when anti-lock brake control or automatic brake control described later is not executed), the control unit 52b opens the intake valve 31a and closes the release valve 31b. In this state, when the first brake operation unit 11 is operated, in the front-wheel braking mechanism 12, the piston (not shown) of the master cylinder 21 is pushed in, the hydraulic pressure of the brake fluid in the wheel cylinder 24 increases, and the brake pad (not shown) of the brake caliper 23 is pressed against the rotor 3a of the front wheel 3, generating braking force on the front wheel 3. Also, when the second brake operation unit 13 is operated, in the rear-wheel braking mechanism 14, the piston (not shown) of the master cylinder 21 is pushed in, the hydraulic pressure of the brake fluid in the wheel cylinder 24 increases, and the brake pad (not shown) of the brake caliper 23 is pressed against the rotor 4a of the rear wheel 4, generating braking force on the rear wheel 4.

[0046] Anti-lock brake control is executed, for example, when a wheel (specifically, the front wheel 3 or the rear wheel 4) is locked or is likely to be locked, and it is control to reduce the braking force applied to the wheel without depending on the brake operation by the rider. For example, when anti-lock brake control is executed, the control unit 52b closes the intake valve 31a, opens the release valve 31b, opens the first valve 31c, and closes the second valve 31d. In this state, when the control unit 52b drives the pump 33, the hydraulic pressure of the brake fluid in the wheel cylinder 24 decreases, and the braking force applied to the wheel decreases.

[0047] The automatic brake control is executed, for example, when there is a need to stabilize the posture of the vehicle 100 during turning of the vehicle 100 or the like, and is a control that causes a braking force applied to the wheels (specifically, the front wheels 3 or the rear wheels 4) to occur without depending on the brake operation by the rider. For example, when the automatic brake control is executed, the control unit 52b opens the inlet valve 31a, closes the release valve 31b, closes the first valve 31c, and opens the second valve 31d. In this state, when the pump 33 is driven by the control unit 52b, the hydraulic pressure of the brake fluid in the wheel cylinder 24 increases, and a braking force for braking the wheels is generated.

[0048] The estimation unit 52c estimates the stroke amount Δx (see FIG. 3) of the armature 312 of the electromagnetic valve 31. The stroke amount Δx of the armature 312 is the distance from the movement start position to the movement end position of the armature 312 when current is applied to the winding 314 of the electromagnetic valve 31 (that is, the movement amount of the armature 312). As described above, since the tappet 313 is movable integrally with the armature 312, the stroke amount Δx of the armature 312 coincides with the stroke amount of the tappet 313.

[0049] In the example of FIG. 3, when current is applied to the winding 314, the armature 312 moves to the position where the electromagnetic valve 31 is closed as indicated by the two-dot chain line. That is, the stroke amount Δx of the armature 312 is large enough for the electromagnetic valve 31 to function properly. Here, for example, when the viscosity of the brake fluid increases with a decrease in temperature or the like, the stroke amount Δx of the armature 312 may become small, and the blocking or flowing of the brake fluid by the electromagnetic valve 31 may not be realized as expected. In order to optimize the stroke amount Δx in such a case, it is necessary to estimate the stroke amount Δx. When the viscosity of the brake fluid increases, the moving speed of the armature 312 also decreases. This can also be a factor that causes the blocking or flowing of the brake fluid by the electromagnetic valve 31 not to be realized as expected.

[0050] In this embodiment, by devising the process related to the estimation of the stroke amount Δx of the armature 312 performed by the control device 52, it is possible to accurately estimate the stroke amount Δx. Details of such a process related to the estimation of the stroke amount Δx of the armature 312 will be described later.

[0051] <Operation of the hydraulic control unit> With reference to FIGS. 6 and 7, the operation of the hydraulic control unit 5 according to an embodiment of the present invention will be described.

[0052] In this embodiment, the estimation unit 52c estimates the stroke amount Δx of the armature 312 based on the behavior of the current value of the current flowing through the winding 314 of the solenoid valve 31 at the start of applying current to the winding 314. Hereinafter, with reference to FIG. 6, the behavior of the current value of the current flowing through the winding 314 at the start of applying current to the winding 314 will be described.

[0053] FIG. 6 is a schematic diagram showing an example of the transition of the current value of the current flowing through the winding 314 of the solenoid valve 31 of the hydraulic control unit 5 at the start of applying current to the winding 314. In FIG. 6, the horizontal axis represents time t [s], and the vertical axis represents the current value i [A] of the current flowing through the winding 314.

[0054] When the application of current to the winding 314 of the solenoid valve 31 starts, the current value i of the current flowing through the winding 314 begins to rise toward the target current value isw. Then, after the current value i reaches the target current value isw, it is maintained at the target current value isw. In this specification, the start of applying current to the winding 314 of the solenoid valve 31 means the time from when the current value i starts to rise with the application of current to the winding 314 until it reaches the target current value isw.

[0055] In the example shown by the solid line in FIG. 6, at time t1, the application of current to winding 314 starts, and the current value i of the current flowing through winding 314 begins to increase. After that, at time t4, the current value i reaches the target current value isw1. Then, after time t4, the current value i is maintained at the target current value isw1. Note that although the target current value isw in the example of the solid line in FIG. 6 is the target current value isw1, the control unit 52b can change the target current value isw.

[0056] Here, when the application of current to winding 314 starts, the core 315 is magnetized, and a magnetic force in the direction approaching the core 315 acts on the armature 312. The armature 312 is attracted and moves toward the core 315 together with the tappet 313. At this time, the armature 312 moves relative to the magnetic field generated by the winding 314 within the magnetic field generated by the winding 314. Thereby, a back electromotive force is generated in the winding 314 so as to weaken the magnetic flux generated by the winding 314. Therefore, in the process in which the current value i of the current flowing through the winding 314 increases toward the target current value isw, the current value i shows a behavior of temporarily decreasing. For example, in the example of the solid line in FIG. 6, at time t2, the current value i has started to decrease. After that, at time t3, the decrease of the current value i ends, and the current value i starts to increase again toward the target current value isw.

[0057] In this embodiment, the estimation unit 52c estimates the stroke amount Δx of the armature 312 based on the decrease amount Δi of the current value i when the current value i temporarily decreases in the process of the current flowing through the winding 314 rising toward the target current value isw at the start of applying current to the winding 314 of the solenoid valve 31. For example, the decrease amount Δi in the example of the solid line in FIG. 6 is the decrease amount Δi1 corresponding to the difference between the current value i at time point t2 and the current value i at time point t3. Focusing on the phenomenon that a counter electromotive force is generated in the winding 314 as the armature 312 moves, it can be seen that the smaller the stroke amount Δx of the armature 312, the smaller the decrease amount Δi of the current value i. Therefore, the estimation unit 52c estimates a smaller value as the stroke amount Δx, for example, the smaller the decrease amount Δi. In this way, by focusing on the phenomenon that a counter electromotive force is generated in the winding 314 as the armature 312 moves, the stroke amount Δx of the armature 312 can be accurately estimated.

[0058] Here, when the current value i at the time point after the elapse of the reference time from the start point of the decrease of the current value i (for example, time point t2 in the example of the solid line in FIG. 6) is lower than the reference value or more compared to the current value i at the start point of the decrease (that is, when the difference between the current value i at the time point after the elapse of the reference time from the start point of the decrease of the current value i and the current value i at the start point of the decrease is the reference value or more), the estimation unit 52c determines that the current value i has temporarily decreased. The above reference time and reference value are set to values that can distinguish whether the current value i has temporarily decreased due to the generation of a counter electromotive force in the winding 314 or whether the detected value of the current sensor 41 has only temporarily decreased slightly due to noise components. That is, when the difference between the current value i at the time point after the elapse of the reference time from the start point of the decrease of the current value i and the current value i at the start point of the decrease is less than the reference value, the estimation unit 52c determines that the detected value of the current sensor 41 has only temporarily decreased slightly due to noise components, and does not estimate the stroke amount Δx.

[0059] Note that the example shown by the dashed line in FIG. 6 is an example where the temperature of the brake fluid is different compared to the example of the solid line. Also, the example shown by the dashed-dotted line in FIG. 6 is an example where the target current value isw is different compared to the example of the solid line. These examples will be described later.

[0060] FIG. 7 is a flowchart showing an example of the flow of processing related to the estimation of the stroke amount Δx of the armature 312 performed by the control device 52 of the hydraulic control unit 5. The control flow shown in FIG. 7 is repeatedly started at preset time intervals, for example, after completion. Steps S101 and S108 in FIG. 7 correspond to the start and end of the control flow, respectively.

[0061] Note that the control flow shown in FIG. 7 is executed sequentially or in parallel for each solenoid valve 31, for example. Also, the control flow shown in FIG. 7 is executed sequentially or in parallel for each braking mechanism of the front-wheel braking mechanism 12 and the rear-wheel braking mechanism 14, for example. However, the control flow shown in FIG. 7 may be executed only for some of the solenoid valves 31 of the hydraulic control unit 5. In that case, the current sensor 41 may be provided only for the solenoid valve 31 for which the estimation of the stroke amount Δx is performed. The processing related to the estimation of the stroke amount Δx described below is applicable to valves that close in the energized state (specifically, the charging valve 31a and the first valve 31c), and is also applicable to valves that open in the energized state (specifically, the releasing valve 31b and the second valve 31d).

[0062] When the control flow shown in FIG. 7 is started, in step S102, the estimation unit 52c determines whether the application of current to the winding 314 of the solenoid valve 31 has started. If it is determined that the application of current to the winding 314 has started (step S102 / YES), the process proceeds to step S103. On the other hand, if it is determined that the application of current to the winding 314 has not started (step S102 / NO), the control flow shown in FIG. 7 ends.

[0063] For example, the estimation unit 52c determines whether or not the application of current to the winding 314 has started based on the detected value of the current sensor 41. As described above, when the application of current to the winding 314 starts, the current value i of the current flowing through the winding 314 begins to rise toward the target current value isw. Therefore, the estimation unit 52c can determine whether or not the application of current to the winding 314 has started based on the behavior of the current value i of the current flowing through the winding 314 (for example, whether or not the current value i has risen beyond a predetermined value).

[0064] If it is determined YES in step S102, in step S103, the estimation unit 52c determines whether or not the rise of the current value i of the current flowing through the winding 314 of the solenoid valve 31 has ended. If it is determined that the rise of the current value i of the current flowing through the winding 314 has ended (step S103 / YES), the process proceeds to step S104. On the other hand, if it is determined that the rise of the current value i of the current flowing through the winding 314 has not ended (step S103 / NO), the determination process in step S103 is repeated.

[0065] For example, the estimation unit 52c determines whether or not the rise of the current value i of the current flowing through the winding 314 has ended based on the detected value of the current sensor 41. As described above, the current value i of the current flowing through the winding 314 is maintained at the target current value isw after rising to the target current value isw. Therefore, the estimation unit 52c can determine whether or not the rise of the current value i of the current flowing through the winding 314 has ended based on the behavior of the current value i of the current flowing through the winding 314 (for example, whether or not the variation range of the current value i has become equal to or less than a predetermined value).

[0066] If it is determined YES in step S103, in step S104, the estimation unit 52c estimates the stroke amount Δx of the armature 312. Specifically, as described above, the estimation unit 52c estimates the stroke amount Δx of the armature 312 based on the decrease amount Δi of the current value i when the current value i temporarily decreases in the process of the current value i increasing toward the target current value isw at the start of applying current to the winding 314 of the solenoid valve 31. For example, after step S102 and until it is determined YES in step S103, the acquisition unit 52a continuously acquires the current value i at each time point, and the estimation unit 52c can specify the decrease amount Δi based on the history of the obtained current value i.

[0067] Here, from the viewpoint of improving the estimation accuracy of the stroke amount Δx of the armature 312, it is preferable that the estimation unit 52c estimates the stroke amount Δx based on other parameters in addition to the decrease amount Δi of the current value i.

[0068] For example, the estimation unit 52c estimates the stroke amount Δx based on the viscosity index information which is information serving as an index for evaluating the viscosity of the brake fluid as the working fluid, in addition to the decrease amount Δi of the current value i. The viscosity index information includes, for example, the temperature information of the brake fluid (that is, information regarding the temperature of the brake fluid). There is a relationship that the lower the temperature of the brake fluid, the higher the viscosity of the brake fluid. Therefore, the temperature of the brake fluid serves as an index for evaluating the viscosity of the brake fluid. The acquisition unit 52a can acquire the temperature information of the brake fluid from the temperature sensors 42 and 43, for example. Note that the temperature information of the brake fluid may be information directly indicating the temperature of the brake fluid, or may be information indicating another physical quantity that can be substantially converted into the temperature of the brake fluid.

[0069] Here, in the example shown by the dashed line in FIG. 6, compared with the example of the solid line, the temperature of the brake fluid is low and the viscosity of the brake fluid is high. As a result, in the example shown by the dashed line in FIG. 6, compared with the example of the solid line, the decrease amount Δi of the current value i is small. Specifically, the decrease amount Δi in the example of the dashed line in FIG. 6 is a decrease amount Δi2 that is smaller than the decrease amount Δi1.

[0070] As described above, the lower the temperature of the brake fluid, the smaller the tendency for the decrease amount Δi of the current value i. That is, the higher the viscosity of the brake fluid, the smaller the tendency for the decrease amount Δi of the current value i. Thus, the decrease amount Δi of the current value i changes with the change in the viscosity of the brake fluid. Therefore, the estimation unit 52c can improve the estimation accuracy of the stroke amount Δx by estimating the stroke amount Δx in consideration of not only the decrease amount Δi but also the viscosity index information (for example, the lower the temperature of the brake fluid, the smaller the value estimated as the stroke amount Δx).

[0071] In addition, in the above description, an example in which the temperature information of the brake fluid is used as the viscosity index information has been described, but the estimation unit 52c may use viscosity index information other than the temperature information of the brake fluid. For example, the estimation unit 52c may use the number of days elapsed since the brake fluid was last replaced, or information indicating the deceleration generated in the vehicle 100 during the operation of the anti-lock brake control, etc. as the viscosity index information.

[0072] Further, for example, the estimation unit 52c estimates the stroke amount Δx based on the target current value isw in addition to the decrease amount Δi of the current value i.

[0073] Here, in the example shown by the dash-dotted line in FIG. 6, compared with the example of the solid line, the target current value isw is small. Specifically, the target current value isw in the example of the dash-dotted line in FIG. 6 is a target current value isw2 that is smaller than the target current value isw1. As a result, in the example shown by the dash-dotted line in FIG. 6, compared with the example of the solid line, the decrease amount Δi of the current value i is large. Specifically, the decrease amount Δi in the example of the dash-dotted line in FIG. 6 is a decrease amount Δi3 that is larger than the decrease amount Δi1.

[0074] As described above, the smaller the target current value isw, the greater the tendency for the decrease amount Δi of the current value i to increase. Thus, the decrease amount Δi of the current value i changes with the change in the target current value isw. Therefore, the estimation unit 52c estimates the stroke amount Δx in consideration of not only the decrease amount Δi but also the target current value isw (for example, the smaller the target current value isw, the larger the value estimated as the stroke amount Δx), thereby improving the estimation accuracy of the stroke amount Δx.

[0075] In the above, in the estimation of the stroke amount Δx, an example in which viscosity index information of the brake fluid is used in addition to the decrease amount Δi of the current value i and an example in which the target current value isw is used in addition to the decrease amount Δi of the current value i have been described in order. However, from the viewpoint of more effectively improving the estimation accuracy of the stroke amount Δx of the armature 312, it is preferable that the estimation unit 52c estimates the stroke amount Δx based on both the viscosity index information of the brake fluid and the target current value isw in addition to the decrease amount Δi of the current value i. Note that the relationship between the stroke amount Δx and each parameter (for example, the decrease amount Δi, the temperature of the brake fluid, and the target current value isw) and the mathematical formula or map used for the estimation of the stroke amount Δx may be determined based on a theoretical formula or may be determined based on experimental results.

[0076] Next, in step S105, the control unit 52b determines whether the stroke amount Δx is smaller than the reference stroke amount. If it is determined that the stroke amount Δx is smaller than the reference stroke amount (step S105 / YES), the process proceeds to step S106, and the control unit 52b increases the target current value isw to be larger than the current value. Therefore, in the process of repeating the control flow shown in FIG. 7, the target current value isw gradually increases until the stroke amount Δx becomes equal to or greater than the reference stroke amount (that is, until it is determined as NO in step S105). On the other hand, if it is determined that the stroke amount Δx is equal to or greater than the reference stroke amount (step S105 / NO), the process proceeds to step S107.

[0077] The reference stroke amount in step S105 is set to a value that can determine whether the stroke amount Δx is large enough for the solenoid valve 31 to function properly. That is, when it is determined that the stroke amount Δx is equal to or greater than the reference stroke amount (that is, when the determination in step S105 is NO), it can be determined that the stroke amount Δx is large enough for the solenoid valve 31 to function properly.

[0078] On the other hand, when it is determined that the stroke amount Δx is smaller than the reference stroke amount (that is, when the determination in step S105 is YES), it can be determined that the stroke amount Δx is insufficient to the extent that the solenoid valve 31 does not function properly. In such a case, the control unit 52b increases the target current value isw to be larger than the current value. Thereby, since the stroke amount Δx can be increased, the shortage of the stroke amount Δx can be eliminated, and the solenoid valve 31 can be made to function properly.

[0079] As described above, from the viewpoint of avoiding a shortage of the stroke amount Δx, it is preferable that the control unit 52b controls the target current value isw based on the estimation result of the stroke amount Δx. Specifically, in the above example, when the current stroke amount Δx is smaller than the reference stroke amount, the control unit 52b increases the target current value isw. However, the control unit 52b may increase the target current value isw when it is predicted that the stroke amount Δx may fall below the reference stroke amount in the future.

[0080] The control unit 52b can predict, for example, based on the temperature such as the current brake fluid temperature or the outside air temperature, whether the stroke amount Δx may fall below the reference stroke amount in the future. For example, when the current brake fluid temperature is relatively high, it is assumed that the brake fluid temperature will decrease significantly in the future. Therefore, even when the current stroke amount Δx is equal to or greater than the reference stroke amount, the control unit 52b may predict that the stroke amount Δx may fall below the reference stroke amount in the future. In that case, by increasing the target current value isw in advance, a shortage of the stroke amount Δx can be avoided in advance.

[0081] When it is determined as NO in step S105, or, next to step S106, in step S107, the control unit 52b controls the notification operation based on the estimation result of the stroke amount Δx, and the control flow shown in FIG. 7 ends.

[0082] The notification operation is an operation of notifying various information to the rider. For example, the notification operation may be performed by the notification device 6 and may be an operation of displaying information or an operation of outputting sound. Note that the control flow shown in FIG. 7 may end when the notification operation continues for a set time, or the control flow shown in FIG. 7 may end when an input operation for stopping the notification operation is performed by the rider.

[0083] In step S107, for example, when the control unit 52b determines that the stroke amount Δx is smaller than the reference stroke amount (that is, when it is determined as YES in step S105), the control unit 52b causes the notification device 6 to perform a notification operation of notifying that the stroke amount Δx is insufficient to the extent that the solenoid valve 31 does not function properly. On the other hand, when the control unit 52b determines that the stroke amount Δx is equal to or greater than the reference stroke amount (that is, when it is determined as NO in step S105), the control unit 52b stops the notification operation by the notification device 6. However, when it is determined as NO in step S105, the control unit 52b may cause the notification device 6 to perform a notification operation of notifying that the stroke amount Δx is large enough for the solenoid valve 31 to function properly.

[0084] Note that the notification operation may be performed by a device other than the notification device 6. For example, the notification operation may be performed by a display device provided in a helmet worn on the rider's head (for example, a transparent display arranged on the rider's line of sight). Further, for example, the notification operation may be performed by an audio output device provided in a helmet worn on the rider's head. Further, for example, the notification operation may be an operation of generating vibration by a vibration generating device provided in the vehicle 100 or worn on the rider. Further, for example, the notification operation may be an operation of instantaneously decelerating the vehicle 100. Note that the above instantaneous deceleration may be realized by reducing the output of the drive source, may be realized by generating a braking force by the hydraulic control unit 5, or may be realized by changing the gear ratio of the transmission mechanism of the vehicle 100.

[0085] In the above, with reference to FIG. 7, an example of the flow of the process for estimating the stroke amount Δx has been described. However, the flow of the process for estimating the stroke amount Δx is not limited to the example of the flowchart in FIG. 7. For example, additional steps may be added to the flowchart in FIG. 7. Further, for example, some steps (for example, step S107, etc.) in the flowchart in FIG. 7 may be omitted. Further, for example, the order of some steps in the flowchart in FIG. 7 may be changed (for example, step S107 may be performed before step S105).

[0086] <Effect of the hydraulic control unit> The effect of the hydraulic control unit 5 according to the embodiment of the present invention will be described.

[0087] In the hydraulic control unit 5, the estimation unit 52c estimates the stroke amount Δx of the armature 312 based on the amount of decrease Δi of the current value i when the current value i temporarily decreases in the process of the current flowing through the winding 314 rising toward the target current value isw at the start of application of current to the winding 314 of the solenoid valve 31. Thereby, paying attention to the phenomenon that a counter electromotive force is generated in the winding 314 as the armature 312 moves, the stroke amount Δx of the armature 312 can be appropriately estimated. Therefore, the stroke amount Δx of the armature 312 of the solenoid valve 31 can be accurately estimated. Further, the stroke amount Δx can be estimated without using a sensor that directly detects the stroke amount Δx of the armature 312.

[0088] Preferably, in the hydraulic control unit 5, the estimation unit 52c estimates the stroke amount Δx based on the target current value isw in addition to the amount of decrease Δi of the current value i. Thereby, paying attention to the relationship between the target current value isw and the amount of decrease Δi, the stroke amount Δx of the armature 312 can be more appropriately estimated. Therefore, the estimation accuracy of the stroke amount Δx of the armature 312 of the solenoid valve 31 can be improved.

[0089] Preferably, in the hydraulic control unit 5, the estimation unit 52c estimates the stroke amount Δx based on viscosity index information, which is information serving as an index for evaluating the viscosity of the working fluid (brake fluid in the above example), in addition to the amount of decrease Δi of the current value i. Thereby, paying attention to the relationship between the viscosity of the brake fluid and the amount of decrease Δi, the stroke amount Δx of the armature 312 can be more appropriately estimated. Therefore, the estimation accuracy of the stroke amount Δx of the armature 312 of the solenoid valve 31 can be improved.

[0090] Preferably, in the hydraulic control unit 5, the viscosity index information includes temperature information of the working fluid (brake fluid in the above example). Thereby, by focusing on the relationship between the viscosity of the brake fluid and the decrease amount Δi, it is appropriately realized to estimate the stroke amount Δx of the armature 312. Therefore, it is appropriately realized to improve the estimation accuracy of the stroke amount Δx of the armature 312 of the solenoid valve 31.

[0091] Preferably, in the hydraulic control unit 5, the control unit 52b controls the target current value isw based on the estimation result of the stroke amount Δx. Thereby, when the stroke amount Δx is insufficient or may be insufficient in the future to such an extent that the solenoid valve 31 does not function properly, it is possible to avoid the shortage of the stroke amount Δx and make the solenoid valve 31 function properly.

[0092] Preferably, in the hydraulic control unit 5, when the stroke amount Δx is smaller than the reference stroke amount, the control unit 52b increases the target current value isw. Thereby, when the stroke amount Δx is insufficient to such an extent that the solenoid valve 31 does not function properly, it is possible to eliminate the shortage of the stroke amount Δx and make the solenoid valve 31 function properly.

[0093] Preferably, in the hydraulic control unit 5, when the control unit 52b predicts that the stroke amount Δx may be less than the reference stroke amount in the future, the control unit 52b increases the target current value isw. Thereby, when the stroke amount Δx may be insufficient in the future to such an extent that the solenoid valve 31 does not function properly, it is possible to avoid the shortage of the stroke amount Δx in advance and make the solenoid valve 31 function properly.

[0094] Preferably, in the hydraulic control unit 5, the control unit 52b controls the notification operation based on the estimation result of the stroke amount Δx. Thereby, it is possible to notify the lidar of the information indicating the estimation result of the stroke amount Δx. Therefore, the lidar can grasp whether the solenoid valve 31 is in a state where it functions properly. Thus, safety is improved.

[0095] Preferably, in the hydraulic control unit 5, when the current value i at the time after the reference time has elapsed since the start point of the decrease in the current value i is lower than or equal to a reference value as compared with the current value i at the start point of the decrease, the estimation unit 52c determines that the current value i has temporarily decreased. Thereby, it is possible to distinguish whether the current value i has temporarily decreased due to the generation of a counter electromotive force in the winding 314, or whether the detected value of the current sensor 41 has only temporarily decreased slightly due to a noise component. Therefore, it is appropriately realized to estimate the stroke amount Δx by paying attention to the phenomenon in which a counter electromotive force is generated in the winding 314 as the armature 312 moves.

[0096] The present invention is not limited to the description of the embodiments. For example, only a part of the embodiments may be implemented.

Explanation of reference numerals

[0097] 1 Body, 2 Handle, 3 Front wheel, 3a Rotor, 4 Rear wheel, 4a Rotor, 5 Hydraulic control unit, 6 Notification device, 7 Power source, 10 Brake system, 11 First brake operation unit, 12 Front wheel braking mechanism, 13 Second brake operation unit, 14 Rear wheel braking mechanism, 21 Master cylinder, 22 Reservoir, 23 Brake caliper, 24 Wheel cylinder, 25 Main flow path, 26 Sub-flow path, 27 Supply flow path, 31 Solenoid valve, 31a Closing valve, 31b Opening valve, 31c First valve, 31d Second valve, 32 Accumulator, 33 Pump, 41 Current sensor, 41a Current sensor, 41b Current sensor, 41c Current sensor, 41d Current sensor, 42 Temperature sensor, 43 Temperature sensor, 51 Hydraulic control mechanism, 51a Base body, 52 Control device, 52a Acquisition unit, 52b Control unit, 52c Estimation unit, 100 Vehicle, 311 Case, 312 Armature, 313 Tappet, 314 Winding, 315 Core, 316 Spring, 317 First flow path, 318 Second flow path, 411 Shunt resistor, 412 Operational amplifier, i Current value, isw Target current value, isw1 Target current value, isw2 Target current value, Δi Decrease amount, Δi1 Decrease amount, Δi2 Decrease amount, Δi3 Decrease amount, Δx Stroke amount.

Claims

1. A hydraulic control unit (5) used in a behavior control system (10) of a vehicle (100), including a base body (51a) and a component incorporated in the base body (51a) and including a solenoid valve (31) for controlling the hydraulic pressure generated in the working fluid of the behavior control system (10), that is, a hydraulic control mechanism (51), a control device (52) including a control unit (52b) for controlling the operation of the component, comprising, the solenoid valve (31) includes a winding (314) and an armature (312) that moves with the application of current to the winding (314), and is a valve that closes or opens in an energized state where current is applied to the winding (314), the control device (52) includes an estimation unit (52c) for estimating the stroke amount (Δx) of the armature (312), the estimation unit (52c) estimates the stroke amount (Δx) based on the decrease amount (Δi) of the current value (i) when the current value (i) temporarily decreases in the process of the current value (i) flowing through the winding (314) rising toward the target current value (isw) after the start of application of current to the winding (314), the control unit (52b) controls the target current value (isw) based on the estimation result of the stroke amount (Δx), Hydraulic control unit.

2. The estimation unit (52c) estimates the stroke amount (Δx) based on the target current value (isw) in addition to the decrease amount (Δi), The hydraulic control unit according to claim 1.

3. The estimation unit (52c) estimates the stroke amount (Δx) based on viscosity index information, which is information serving as an index for evaluating the viscosity of the working fluid, in addition to the decrease amount (Δi), The hydraulic control unit according to claim 1 or 2.

4. The viscosity index information includes temperature information of the working fluid, The hydraulic control unit according to claim 3.

5. When the stroke amount (Δx) is smaller than a reference stroke amount, the control unit (52b) increases the target current value (isw). The hydraulic control unit according to any one of claims 1 to 4.

6. When the control unit (52b) predicts that the stroke amount (Δx) may be less than the reference stroke amount in the future, the control unit (52b) increases the target current value (isw). The hydraulic control unit according to any one of claims 1 to 5.

7. The control unit (52b) controls a notification operation based on an estimation result of the stroke amount (Δx). The hydraulic control unit according to any one of claims 1 to 6.

8. When the current value (i) at a time point after a reference time has elapsed from the start point of the decrease in the current value (i) is lower than a reference value compared to the current value (i) at the start point of the decrease, the estimation unit (52c) determines that the current value (i) has temporarily decreased. The hydraulic control unit according to any one of claims 1 to 7.

9. The vehicle (100) is a motorcycle. The hydraulic control unit according to any one of claims 1 to 8.

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