Hydraulic system for vehicles

Abstract

A hydraulic system (40) for vehicles comprises: a front wheel brake which is a first hydraulic drive device (60) driven by hydraulic pressure generated by a first hydraulic pump (80); a single front wheel motor (130) which serves as a power source for the first hydraulic pump; a front wheel first control unit (143) which controls the front wheel brake; a rear wheel brake which is a first hydraulic drive device (260) driven by hydraulic pressure generated by a first hydraulic pump (280); a rear wheel jack which is a second hydraulic drive device (300) driven by hydraulic pressure generated by a second hydraulic pump (320); a single rear wheel motor (330) which serves as a common power source for the first hydraulic pump (280) and the second hydraulic pump (320); and rear wheel control devices (340, 343, 344) which control the rear wheel hydraulic brake and the rear wheel hydraulic jack. The front wheel first control unit (143) is capable of communicating with the rear wheel control devices (340, 343, 344).

Description

Vehicle Hydraulic Systems

[0001] The present invention relates to a vehicle hydraulic system suitable for installation in various vehicles such as saddle-ride vehicles.

[0002] Some types of vehicles, such as saddle-ride vehicles such as motorcycles and three-wheeled vehicles, are equipped with a vehicle hydraulic system equipped with multiple hydraulic drive units. The multiple hydraulic drive units are driven by hydraulic pressure generated by respective hydraulic pumps. Each hydraulic pump is driven by its own motor. Such a vehicle hydraulic system equipped with multiple hydraulic drive units is known, for example, from Patent Document 1.

[0003] The vehicle hydraulic system disclosed in Patent Document 1 includes both an antilock braking system (ABS) that controls the hydraulic pressure applied to the hydraulic brakes of the motorcycle, and a vehicle height adjustment mechanism that adjusts the vehicle height of the motorcycle. The ABS and the vehicle height adjustment mechanism are types of hydraulic drive devices that function differently from each other.

[0004] The vehicle hydraulic system known from Patent Document 1 has duplicated equipment, such as hydraulic pumps and motors, for the ABS and the height-adjustable suspension mechanism, which function differently from each other. This is also true for vehicle hydraulic systems installed in other vehicles. In recent years, there has been a trend toward an increase in the number of devices installed in vehicles. For this reason, it is necessary to fully consider various design factors, such as the space and weight distribution for arranging the duplicated equipment on the vehicle.

[0005] For example, as disclosed in Patent Document 1, a vehicle hydraulic system has two hydraulic drive devices that function differently from each other. A vehicle hydraulic system that uses a single motor as a common power source by continuously rotating the single motor is known, for example, from Patent Document 2.

[0006] Patent No. 6021561 Patent No. 7308249

[0007] The vehicle hydraulic system known from Patent Document 2 can be configured to have two hydraulic channels for hydraulic brakes for front and rear wheels, similar to Patent Document 1. That is, for example, as disclosed in Patent Document 1, in order to drive the front and rear wheel hydraulic brakes with a single motor, the piping of the hydraulic circuit from the front wheel hydraulic brake to the single motor and the piping of the hydraulic circuit from the single motor to the rear wheel hydraulic brake must extend from the front wheel hydraulic brake to the rear wheel hydraulic brake via the single motor, which results in a long total length of the paths for both piping.

[0008] An object of the present invention is to provide a vehicle hydraulic system that can reduce the installation space required for the vehicle.

[0009] The present inventor has newly discovered that in a vehicle hydraulic system that drives hydraulic brakes for the front wheels and hydraulic brakes for the rear wheels, as disclosed in Patent Document 1, for example, rather than using a single motor as a common power source, the motor for the hydraulic brakes for the front wheels and the motor for the hydraulic brakes for the rear wheels can each be used as a power source depending on their location; in other words, the hydraulic circuits for the hydraulic brakes for the front wheels and the hydraulic circuits for the hydraulic brakes for the rear wheels can be separated.

[0010] However, it was newly discovered that by continuously rotating a single motor, it is possible to use the single motor as a common power source for the hydraulic drive unit for the separated rear wheel hydraulic brake and the hydraulic drive unit for the rear wheel height adjustment mechanism. As a result, it has been discovered that it is possible to provide a vehicle hydraulic system that can reduce the installation space on the vehicle. The present invention was completed based on these discoveries.

[0011] According to the present disclosure, there is provided a front wheel first hydraulic drive device driven by hydraulic pressure generated by a front wheel first hydraulic pump, the front wheel first hydraulic drive device constituting a front wheel hydraulic brake, a single front wheel motor serving as a power source for the front wheel first hydraulic pump, a front wheel first control unit controlling the front wheel hydraulic brake, the front wheel first control unit being capable of communicating with at least one of the rear wheel first control unit and the rear wheel second control unit, and a rear wheel first hydraulic drive device driven by hydraulic pressure generated by the rear wheel first hydraulic pump. A vehicle hydraulic system is provided that includes: a first rear wheel hydraulic drive unit that constitutes a rear wheel hydraulic brake; a second rear wheel hydraulic drive unit that is driven by hydraulic pressure generated by a second rear wheel hydraulic pump and that constitutes a rear wheel hydraulic jack; a single rear wheel motor that serves as a common power source for the first rear wheel hydraulic pump and the second rear wheel hydraulic pump; the first rear wheel control unit that controls the rear wheel hydraulic brake; and the second rear wheel control unit that controls the rear wheel hydraulic jack.

[0012] The present invention can provide a vehicle hydraulic system that can reduce the installation space required for the vehicle.

[0013] It is a side view of a motorcycle equipped with a vehicle hydraulic system according to an embodiment.It is a hydraulic circuit diagram of a front wheel side of a vehicle hydraulic system according to an embodiment.It is a hydraulic circuit diagram of a rear wheel side of a vehicle hydraulic system according to an embodiment.It is a hydraulic circuit diagram of a vehicle hydraulic system according to a second embodiment.

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. Note that the embodiments shown in the accompanying drawings are merely examples of the present invention, and the present invention is not limited to these embodiments.

[0015] First Embodiment A vehicle hydraulic system 40 according to a first embodiment and a motorcycle 10 (saddle-ride type vehicle 10) equipped with the vehicle hydraulic system 40 will be described with reference to FIGS. 1 to 3. FIG.

[0016] The vehicle hydraulic system 40 is mounted on various types of vehicles such as saddle-ride vehicles. For example, the vehicle hydraulic system 40 is mounted on a motorcycle 10, which is a type of saddle-ride vehicle on which a rider straddles.

[0017] 1, a motorcycle 10 includes a body 11, an engine 12 supported at the lower center of the body 11, front forks 13 (only one side is shown) provided at the front of the body 11, a front wheel 14 supported by the front forks 13, a steering wheel 15 connected to the front forks 13, and a rider seat 16 provided at the upper center of the body 11. The motorcycle 10 also includes a wheel support mechanism 17, typically a link mechanism or swing arm, that extends rearward from the rear of the body 11 and is capable of swinging up and down, a rear wheel 18 supported by the wheel support mechanism 17, and a rear cushion 20 that spans between the body 11 and the wheel support mechanism 17.

[0018] The front fork 13 is also referred to as a front wheel hydraulic shock absorber 13. The rear cushion 20 is also referred to as a rear wheel hydraulic shock absorber 20.

[0019] As shown in FIG. 2, the front wheel hydraulic shock absorber 13 is equipped with a jack unit 30 that adjusts the suspension spring 13a in the extension / retraction direction. The jack unit 30 includes a jack housing 31 and a plunger 32. The plunger 32 is held in an interior 33 (jack chamber 33) of the jack housing 31 so as to be able to move back and forth, and presses the suspension spring 13a. The jack chamber 33 is filled with oil that can push the plunger 32 in the extension direction. The plunger 32 moves back and forth by adjusting the hydraulic pressure of the oil in the jack chamber 33. As a result, the suspension spring 13a can be adjusted in the extension / retraction direction by the plunger 32.

[0020] The first hydraulic drive unit 60 for the front wheels, the second hydraulic drive unit 100 for the front wheels excluding the jack unit 30 (hydraulic control unit 110), and the single front wheel motor 130 are provided in the front wheel housing 1, and a control unit 140 is provided outside the front wheel housing 1, but the control unit 140 may also be provided inside the front wheel housing 1.

[0021] The front wheel housing 1 is attached to the front wheel first piping 57 leading to the front wheel braking section (brake caliper 55) by the front wheel first hydraulic coupler 56, and the front wheel housing 1 is attached to the front wheel second piping 37 leading to the front wheel jack section 30 by the front wheel second hydraulic coupler 36.

[0022] Similarly, as shown in Figure 3, the rear wheel hydraulic shock absorber 20 is equipped with a jack unit 230 that adjusts the suspension spring 24 in the extension / retraction direction. The jack unit 230 includes a jack housing 231 and a plunger 232. The plunger 232 is held in an interior 233 (jack chamber 233) of the jack housing 231 so as to be able to move back and forth, and presses the suspension spring 24. The jack chamber 233 is filled with oil that can push the plunger 232 in the extension direction. The plunger 232 moves back and forth by adjusting the hydraulic pressure of the oil in the jack chamber 233. As a result, the suspension spring 24 can be adjusted in the extension / retraction direction by the plunger 232.

[0023] The first hydraulic drive unit 260 for the rear wheels, the second hydraulic drive unit 300 for the rear wheels excluding the jack unit 230 (hydraulic control unit 310), and the single rear wheel motor 330 are provided in the rear wheel housing 201, and a control unit 340 is provided outside the rear wheel housing 201, but the control unit 340 may also be provided inside the rear wheel housing 201.

[0024] The rear wheel housing 201 is attached to the first rear wheel piping 257 leading to the rear wheel braking section (brake caliper 255) by the first rear wheel hydraulic coupler 256, and the rear wheel housing 201 is attached to the second rear wheel piping 237 leading to the rear wheel jack section 230 by the second rear wheel hydraulic coupler 236.

[0025] The first hydraulic circuit 50 and the second hydraulic circuit 90 of the front-wheel vehicle hydraulic system 40 in Fig. 2 will be described in detail later. Similarly, the first hydraulic circuit 250 and the second hydraulic circuit 290 of the rear-wheel vehicle hydraulic system 40 in Fig. 3 will be described in detail later.

[0026] The front-wheel vehicle hydraulic system 40 may omit the second hydraulic circuit 90. In other words, the vehicle height adjustment mechanism may be provided only on the rear-wheel side.

[0027] Next, the control system of the vehicle hydraulic system 40 will be described.

[0028] 2, the vehicle hydraulic system 40 on the front wheel side includes a control device 140 (front wheel control device 140) that controls the first hydraulic drive unit 60, the second hydraulic drive unit 100, and the motor 130. This control device 140 receives signals from various input members, such as a vehicle speed sensor 151, a wheel speed sensor 152 (front wheel speed sensor 152), a vehicle height adjustment input unit 153, and a movement amount sensor 154 (front wheel movement amount sensor 154), and executes various types of preset control and displays the control status on a display unit 155.

[0029] The front-wheel side vehicle hydraulic system 40 in FIG. 2 and the rear-wheel side vehicle hydraulic system 40 in FIG. 3 also include a first hydraulic circuit 250 and a second hydraulic circuit 290 of the rear-wheel side vehicle hydraulic system 40 in FIG.

[0030] As shown in Figure 3, the rear-wheel vehicle hydraulic system 40 includes a control device 340 (rear-wheel control device 340) that controls the first hydraulic drive device 260, the second hydraulic drive device 300, and the motor 330. This control device 340 receives signals from various input members, such as a wheel speed sensor 352 (rear-wheel speed sensor 352) and a movement amount sensor 354 (rear-wheel movement amount sensor 354), and executes various types of preset control. The control device 340 in Figure 3 can receive signals from the vehicle speed sensor 151 and the vehicle height adjustment input unit 153 in Figure 2, and can display the control status on the display unit 155 in Figure 2.

[0031] Because the first hydraulic circuit 50 and the second hydraulic circuit 90 on the front wheel side in FIG. 2 are separated from the first hydraulic circuit 250 and the second hydraulic circuit 290 on the rear wheel side in FIG. 3 , there is no need to connect the front wheel side vehicle hydraulic system 40 and the rear wheel side vehicle hydraulic system 40 with hydraulic piping. In other words, the motor 130 in FIG. 2 and the motor 330 in FIG. 3 can be arranged on the front wheel side and the rear wheel side, respectively, and the two motors 130, 330 can be separated. This makes it possible to shorten the total path length of the piping for the first hydraulic circuit 50 on the front wheel side and the first hydraulic circuit 250 on the rear wheel side. This also improves the degree of freedom in the layout of the front wheel side vehicle hydraulic system 40 in FIG. 2 and the rear wheel side in FIG. 3 .

[0032] However, in order to perform coordinated control of the front and rear wheels, the communication unit 346 of the control device 340 can communicate various data with the communication unit 146 of the control device 140, preferably bidirectionally, typically via an in-vehicle network 500 (e.g., CAN: Controller Area Network).

[0033] The control devices 140 and 340 may communicate all or some of the signals from the various sensors 151, 152, 154, 352, and 354 and the vehicle height adjustment input unit 153, as well as the signal to the display unit 155, with other control devices or ECUs (Electronic Control Units) via CAN.

[0034] (Vehicle Height Adjustment Amount) The vehicle height adjustment input unit 153 is used to input the amount of adjustment of the vehicle height of the motorcycle 10, and is configured, for example, by a user interface such as a touch panel that can be operated by the driver. As an example, the vehicle height adjustment input unit 153 is configured to display three target vehicle height levels, high, medium, and low, on a display portion, allowing the driver to select the target vehicle height, and a signal indicating the selection is sent to the second control unit 142, 342. The second control unit 142, 342 controls (feedback control) the hydraulic jack 100, 300 so as to adjust the suspension springs 13a, 24 in the extension / contraction direction by the target movement amount corresponding to the target vehicle height.

[0035] The movement amount sensors 154, 354 are detection units (vehicle height sensors) that detect the amount of movement of the plungers 32, 232 relative to the jack housings 31, 231, that is, the amount of expansion and contraction of the jack units 30, 230 (the amount of adjustment of the suspension springs 13a, 24).

[0036] The movement amount sensor 154, 354 or the detection unit may further include a stroke sensor that detects the amount of expansion and contraction of the suspension springs 13a, 24 (suspension springs) in order to detect the overall length of the hydraulic shock absorbers 13, 20.

[0037] Since the motorcycle 10 is equipped with a front-wheel height adjustment mechanism and a rear-wheel height adjustment mechanism, in other words, to execute coordinated control of the front and rear wheels, as disclosed in, for example, Japanese Patent No. 6266870, the front-wheel first control unit 142 can communicate with the rear-wheel second control unit 342. Specifically, the rear-wheel second control unit 342 can receive the amount of movement of the front-wheel jack unit 30 from the front-wheel first control unit 142 and balance the amount of movement of the rear-wheel jack unit 230 with the amount of movement of the front-wheel jack unit 30.

[0038] In addition, the second control unit 342 for the rear wheels may transmit the amount of movement of the rear wheel jack unit 230 to the first control unit 142 for the front wheels, and the second control unit 342 for the rear wheels may instruct the first control unit 142 for the front wheels to balance the amount of movement of the rear wheel jack unit 230 with the amount of movement of the front wheel jack unit 30.

[0039] (Raising and lowering vehicle height) In addition to the above-mentioned vehicle height holding mode (three target vehicle height levels: high, medium, and low), or instead of the vehicle height holding mode, the vehicle height adjustment input unit 153 may input whether a vehicle height lowering control mode and / or a vehicle height raising control mode is serviceable or unserviceable, as disclosed in, for example, Japanese Patent No. 6266870.

[0040] Specifically, when the vehicle speed V of the vehicle becomes equal to or lowers the vehicle height lowering speed Vd (V≦Vd), the system enters a vehicle height lowering control mode, and the second control units 142, 342 can control the hydraulic jacks 100, 300 to lower. Preferably, the rear wheel second control unit 342 lowers the rear wheel hydraulic jack 300 before the front wheel hydraulic jack 100, thereby lowering the vehicle height on the rear wheel side first and improving the ease of foot reach when the vehicle is stopped.

[0041] In addition, since Japanese Patent No. 6266870 uses a so-called self-pumping mechanism, i.e., a hydraulic pump that discharges hydraulic oil by pumping with the extension and contraction of a piston rod, the vehicle height raising and lowering speed is relatively slow. In contrast, the hydraulic jacks 100 and 300 are driven by motors 130 and 330, and can raise and lower the vehicle height faster.

[0042] The vehicle speed sensor 151 is capable of detecting the traveling speed (vehicle speed V) of the motorcycle 10. The front wheel speed sensor 152 and the rear wheel speed sensor 352 are capable of detecting the rotational speeds of the front wheel 14 and the rear wheel 18, respectively. The second control units 142, 342 may calculate the vehicle speed V using the rotational speeds detected by the wheel speed sensors 152, 352 instead of or in addition to the traveling speed detected by the vehicle speed sensor 151.

[0043] The control device 140 (front wheel control device 140) includes a first control unit 141 that controls the first hydraulic drive device 60 and the motor 130, and a second control unit 142 that controls the second hydraulic drive device 100 and the motor 130. Similarly, the control device 340 (rear wheel control device 340) includes a first control unit 341 that controls the first hydraulic drive device 260 and the motor 330, and a second control unit 342 that controls the second hydraulic drive device 300 and the motor 330.

[0044] The first control unit 141 and the second control unit 142 are configured to simultaneously execute their respective controls. When the first control unit 141 controls the first hydraulic drive unit 60 (ABS 60), the second control unit 142 simultaneously controls the second hydraulic drive unit 100 (hydraulic jack 100), i.e., performs parallel control, and they communicate related signals with each other. Similarly, the first control unit 341 and the second control unit 342 are configured to simultaneously execute their respective controls. When the first control unit 341 controls the first hydraulic drive unit 260 (ABS 260), the second control unit 342 simultaneously controls the second hydraulic drive unit 300 (hydraulic jack 300), i.e., performs parallel control, and they communicate related signals with each other.

[0045] Furthermore, the control device 140 includes a first valve drive unit 143 that drives the first inlet control valve 62 and the first outlet control valve 63 in response to a control signal from the first control unit 141, a second valve drive unit 144 that drives the second inlet control valve 115 and the second outlet control valve 116 in response to a control signal from the second control unit 142, and a motor drive unit 145 that drives the motor 130 in response to control signals from the first control unit 141 and the second control unit 142. Similarly, the control device 340 includes the first valve drive unit 143 that drives the first inlet control valve 62 and the first outlet control valve 63 in response to a control signal from the first control unit 341, a second valve drive unit 344 that drives the second inlet control valve 315 and the second outlet control valve 316 in response to a control signal from the second control unit 342, and a motor drive unit 345 that drives the motor 330 in response to control signals from the first control unit 341 and the second control unit 342.

[0046] (ABS) The front wheel first control unit 141 calculates the slip ratio of the front wheels 14 based on, for example, the traveling speed (vehicle speed V) detected by the vehicle speed sensor 151 and the rotation speed of the front wheels 14 detected by the front wheel speed sensor 152. Similarly, the rear wheel first control unit 341 calculates the slip ratio of the rear wheels 18 based on, for example, the traveling speed (vehicle speed V) detected by the vehicle speed sensor 151 and the rotation speed of the rear wheels 18 detected by the rear wheel speed sensor 352.

[0047] When the traveling speed (vehicle speed V: vehicle speed) = wheel speed, i.e., when the wheels (tires) are rolling on the road surface without locking, the slip ratio is 0%. When the wheels (tires) are completely locked, the slip ratio is 100%. The front wheel first control unit 141 can control the first hydraulic drive unit 60 and the motor 130 so that the slip ratio of the front wheels 14 falls within a range of 10% to 20%. Similarly, the rear wheel first control unit 341 can control the first hydraulic drive unit 260 and the motor 330 so that the slip ratio of the rear wheels 18 falls within a range of 10% to 20%.

[0048] As disclosed in Patent Document 2, the first control unit 141 for the front wheels can determine whether or not lowering of the vehicle height is necessary, and when it determines that lowering of the vehicle height is necessary, it can send a jack-down request signal to the second control unit 342 for the rear wheels, and in response, the hydraulic jack 300 for the rear wheels can lower the vehicle height of the motorcycle 10.

[0049] In addition, the first control unit for front wheels 141 may transmit data such as the rotation speed of the front wheels 14 and the slip ratio of the front wheels 14 to the second control unit for rear wheels 342 .

[0050] (Hydraulic Circuits) Referring again to FIGS. 2 and 3, the first hydraulic circuit 50, the second hydraulic circuit 90, the first hydraulic circuit 250 and the second hydraulic circuit 290 will be described.

[0051] First, we will explain the first hydraulic circuit 50. The first hydraulic circuit 250 operates in the same manner as the first hydraulic circuit 50, and detailed explanation of the operation of the first hydraulic circuit 250 will be omitted. Also, the same reference numerals as those in FIG. 2 are used in FIG. 3.

[0052] The first hydraulic circuit 50 is a brake circuit for braking, for example, the front wheels 14 (see FIG. 1 ), and includes a brake operating member 51 such as a brake lever provided on the steering wheel 15, a master cylinder 52 that generates oil hydraulic pressure (hydraulic fluid pressure) in response to operation of the brake operating member 51, and a wheel brake 53 that applies braking pressure to the front wheels 14 by the hydraulic pressure generated by the master cylinder 52. The wheel brake 53 is made up of a brake disc 54 provided on the front wheel 14 and a brake caliper 55 that applies braking pressure to the brake disc 54. The hydraulic pressure (brake hydraulic pressure) generated from the master cylinder 52 in response to operation of the brake operating member 51 is applied to the brake caliper 55, thereby applying braking pressure to the brake disc 54.

[0053] Furthermore, the first hydraulic circuit 50 includes a first hydraulic drive unit 60, i.e., an antilock brake system 60 (ABS 60), that can adjust the brake pressure of the wheel brakes 53. The ABS 60 controls the brake pressure applied to the brake calipers 55 so that the slip ratio is a desired slip ratio when braking the front wheels 14, in order to prevent the front wheels 14 from slipping (locking up). As a result, the ABS 60 can adjust the brake pressure to decrease or maintain the brake pressure (preventing excessive increase in brake pressure). The ABS 60 can also adjust the brake pressure to increase.

[0054] The first hydraulic drive system 60 is controlled by a first control unit 141, which will be described later. The first hydraulic drive system 60 includes a reservoir 61 (first reservoir 61) that temporarily stores oil, an inlet control valve 62 (first inlet control valve 62) provided between the master cylinder 52 and the brake caliper 55, an outlet control valve 63 (first outlet control valve 63) provided between the brake caliper 55 and the first reservoir 61, and a check valve 64 connected in parallel to the first inlet control valve 62. The first reservoir 61 is formed of, for example, a sealed container.

[0055] The first inlet control valve 62 is configured as a normally-open solenoid valve that is open under normal circumstances when no control signal is received from the first control unit 141, and is located in the first brake hydraulic line 71 from the master cylinder 52 to the brake caliper 55. Under normal circumstances, the first inlet control valve 62 allows brake hydraulic pressure to be applied from the master cylinder 52 to the brake caliper 55. When the front wheels 14 are about to lock, the first inlet control valve 62 receives a control signal from the first control unit 141 and changes from an open state to a closed state, thereby cutting off the brake hydraulic pressure applied to the brake caliper 55.

[0056] The first outlet control valve 63 is configured as a normally closed electromagnetic valve that is normally closed when no control signal is received from the first control unit 141, and is located in the second brake hydraulic line 72 from the brake caliper 55 to the first reservoir 61. When the front wheels 14 are about to lock, the first outlet control valve 63 receives a control signal from the first control unit 141 and changes from a closed state to an open state, thereby releasing the brake hydraulic pressure applied to the brake caliper 55 to the first reservoir 61.

[0057] The check valve 64 is connected in parallel to the first inlet control valve 62 with respect to the first brake hydraulic line 71, and allows the flow of brake hydraulic pressure only in the direction from the brake caliper 55 to the master cylinder 52. Therefore, even if the first inlet control valve 62 is in a closed state, when the operating force of the brake operating member 51 is released, oil can be allowed to flow from the brake caliper 55 to the master cylinder 52.

[0058] The first hydraulic pump 80 provided in the first hydraulic circuit 50 is interposed in the third brake hydraulic line 73 from the first reservoir 61 to the master cylinder 52. This first hydraulic pump 80 draws oil temporarily stored in the first reservoir 61 and discharges it to the master cylinder 52 side, thereby discharging it to the brake caliper 55 via the third brake hydraulic line 73 and the first brake hydraulic line 71.

[0059] The first hydraulic pump 80 has a suction valve 81 (first suction valve 81) at its suction port and a discharge valve 82 (first discharge valve 82) at its discharge port. The first suction valve 81 is configured as a check valve that only allows oil to flow from the first reservoir 61 to the first hydraulic pump 80. The first discharge valve 82 is configured as a check valve that only allows oil to flow from the first hydraulic pump 80 to the master cylinder 52. The first suction valve 81 and the first discharge valve 82 may be configured as either an integral part of the first hydraulic pump 80 or as separate parts.

[0060] Next, the second hydraulic circuit 90 will be described. The second hydraulic circuit 290 operates in the same manner as the first hydraulic circuit 90, and detailed description of the operation of the second hydraulic circuit 290 will be omitted. Also, the same reference numerals as those in FIG. 2 are used in FIG. 3.

[0061] The second hydraulic circuit 90 is a jack circuit that adjusts the vehicle height of the motorcycle 10, and includes the second hydraulic drive unit 100 as described above. The second hydraulic drive unit 100 is configured as a hydraulic jack that adjusts the vehicle height of the motorcycle 10. The second hydraulic drive unit 100 can adjust the height of the passenger seat 16 relative to the center of the rear wheel 18. The second hydraulic drive unit 100 (hydraulic jack 100) includes the jack unit 30 described above, which is attached to the hydraulic shock absorber 20, and a hydraulic control unit 110 that controls the hydraulic pressure of the jack unit 30.

[0062] The hydraulic control unit 110 is controlled by a second control unit 142, which will be described later. The hydraulic control unit 110 includes a reservoir 111 (second reservoir 111) that stores oil, and three jack hydraulic lines 112 to 114 that are connected in parallel between the second reservoir 111 and the jack chamber 33.

[0063] The second reservoir 111 is formed, for example, by an open container that is open to the atmosphere. The first jack hydraulic line 112 is formed as an oil supply line that supplies oil from the second reservoir 111 to the jack chamber 33, and has a second hydraulic pump 120 interposed therebetween. The second jack hydraulic line 113 is formed as an oil return line that returns oil from the jack chamber 33 to the second reservoir 111. The third jack hydraulic line 114 is formed as an oil pressure relief line that releases excessive oil pressure to the second reservoir 111.

[0064] Furthermore, the hydraulic control unit 110 includes an inlet control valve 115 (second inlet control valve 115) provided in the first jack hydraulic path 112, an outlet control valve 116 (second outlet control valve 116) provided in the second jack hydraulic path 113, and a pressure valve 117 provided in the third jack hydraulic path 114.

[0065] The second inlet control valve 115 is configured as a normally closed electromagnetic valve that is normally closed when no control signal is received from the second control unit 142, and is interposed in the first jack hydraulic line 112 between the second reservoir 111 and the suction port of the second hydraulic pump 120. When the vehicle height of the motorcycle 10 is raised, the second inlet control valve 115 receives a control signal from the second control unit 142 and changes from a closed state to an open state, allowing the application of jack hydraulic pressure from the second reservoir 111 to the jack chamber 33.

[0066] The second outlet control valve 116 is configured as a normally closed solenoid valve that is normally closed when no control signal is received from the second control unit 142, and is interposed in the second jack hydraulic line 113. When the vehicle height of the motorcycle 10 is lowered, the second outlet control valve 116 receives a control signal from the second control unit 142 and changes from a closed state to an open state, returning the jack hydraulic pressure in the jack chamber 33 to the second reservoir 111.

[0067] The pressure valve 117 releases excessive hydraulic pressure generated in the jack chamber 33 and the third jack hydraulic line 114. The pressure valve 117 releases excessive hydraulic pressure applied to the discharge side of the second hydraulic pump 120 to the second reservoir 111, thereby protecting the second hydraulic pump 120.

[0068] The second hydraulic pump 120 is capable of sucking in oil stored in the second reservoir 111 and discharging it to the jack chamber 33. The second hydraulic pump 120 has a suction valve 121 (second suction valve 121) at its suction port and a discharge valve 122 (second discharge valve 122) at its discharge port. The second suction valve 121 is configured as a check valve that only allows oil to flow from the second reservoir 111 to the second hydraulic pump 120. The second discharge valve 122 is configured as a check valve that only allows oil to flow from the second hydraulic pump 120 to the jack chamber 33. The second suction valve 121 and the second discharge valve 122 may be configured as either an integral part of the second hydraulic pump 120 or as separate valves.

[0069] The first hydraulic pump 80 and the second hydraulic pump 120 are configured, for example, by plunger pumps. Negative suction pressure is intermittently generated at the suction ports of the plunger pumps 80 and 120. However, the hydraulic brake 60 and the hydraulic jack 100 have different operating modes. Therefore, the hydraulic jack 100 may be stopped while the hydraulic brake 60 is operating.

[0070] In contrast, the motor 130 is a common power source for the first hydraulic pump 80 and the second hydraulic pump 120, and therefore rotates continuously in one direction so as to be able to drive both pumps 80, 120 simultaneously. When only one of these pumps 80, 120 (the second hydraulic pump 120) is driving a load, the other pump 80 (the first hydraulic pump 80) is in a so-called idling state, with no load. As a result, a negative suction pressure (pump suction negative pressure) is generated at the suction port of the idling pump 80.

[0071] The first reservoir 61 of the hydraulic brake 60 is a sealed container. When the pump suction negative pressure of the first hydraulic pump 80 increases, the first reference negative pressure Sp1 of the first suction valve 81 is set to a large value so that this pump suction negative pressure does not affect the brake hydraulic pressure of the first hydraulic circuit 50. Therefore, stable braking action by the first hydraulic circuit 50 can be sufficiently maintained.

[0072] On the other hand, the second reservoir 111 of the hydraulic jack 100 is an open container that is open to the atmosphere. The second reference negative pressure Sp2 of the second suction valve 121 is set small so that oil can be easily sucked from the open second reservoir 111 by the pump suction negative pressure of the second hydraulic pump 120. This makes it possible to sufficiently maintain a stable jacking action by the second hydraulic circuit 90.

[0073] The relationship between the first reference negative pressure Sp1 and the second reference negative pressure Sp2 can be summarized as follows: The hydraulic brake 60 includes a first reservoir 61 that is connected to the brake caliper 55 and stores oil. A first suction valve 81 that only allows oil to flow from the first reservoir 61 to the first hydraulic pump 80 is provided in an oil passage 73 (third brake hydraulic passage 73) through which oil is sucked from the first reservoir 61 by the first hydraulic pump 80.

[0074] The hydraulic jack 100 includes a second reservoir 111 that stores oil. A second suction valve 121 that only allows oil to flow from the second reservoir 111 to the second hydraulic pump 120 is provided in an oil passage 112 (first jack hydraulic passage 112) through which oil flows from the second reservoir 111 to the suction port of the second hydraulic pump 120.

[0075] The reference negative pressure Sp1 (first reference negative pressure Sp1) at which the first suction valve 81 opens due to suction by the first hydraulic pump 80 is set to be greater than the reference negative pressure Sp2 (second reference negative pressure Sp2) at which the second suction valve 121 opens due to suction by the second hydraulic pump 120. Therefore, it is possible to sufficiently maintain both a stable braking action by the first hydraulic circuit 50 and a stable jacking action by the second hydraulic circuit 90.

[0076] Here, the set value of the reference pressure P1 (valve opening pressure P1) at which the pressure valve 117 opens will be explained. The second hydraulic circuit 90 is equipped with a pressure valve 117 that protects the second hydraulic pump 120. The hydraulic pressure P2 in the jack chamber 33 required to raise the vehicle height of the motorcycle 10 to its maximum value using the hydraulic jack 100 is referred to as the "maximum hydraulic pressure P2." This maximum hydraulic pressure P2 corresponds to the maximum jack pressure P2 for driving the hydraulic jack 100. The maximum value of the discharge pressure generated by the second hydraulic pump 120 is referred to as the "maximum discharge pressure P3."

[0077] The valve opening pressure P1 of the pressure valve 117 is set to be greater than the maximum jack pressure P2 for driving the hydraulic jack 100 and less than the maximum discharge pressure P3 of the second hydraulic pump 120 (P2<P1<P3). Therefore, when the jack oil pressure in the third jack hydraulic line 114 or the jack chamber 33 exceeds the maximum jack pressure P2 and becomes excessive, the excessive jack oil pressure can be released to the second reservoir 111. As a result, an excessive load is not applied to the second hydraulic pump 120, and the second hydraulic pump 120 can be protected. More specifically, the maximum discharge pressure P3 of the second hydraulic pump 120 is the outlet pressure of the second discharge valve 122.

[0078] Second Embodiment Next, a vehicle hydraulic system 240 according to a second embodiment will be described with reference to FIG.

[0079] 4 is a hydraulic circuit diagram of a vehicle hydraulic system 40 according to a second embodiment, which has basically the same configuration as the vehicle hydraulic system 40 according to the first embodiment. Differences between the first and second embodiments will be described below.

[0080] 2 or 3 may be replaced with an IMU sensor 151a. The IMU (Inertial Measurement Unit) sensor 151a can detect three-dimensional inertial motion (translational motion and rotational motion in three orthogonal axial directions) and can detect vehicle behavior other than the forward vehicle speed V. In order to stabilize the vehicle behavior, the vehicle hydraulic system 40 (control devices 140, 340) of the second embodiment can utilize the detection results of the IMU.

[0081] The vehicle hydraulic system 40 of the second embodiment may be combined with a front-rear wheel interlocking brake that automatically and appropriately distributes braking force between the front and rear wheels, as disclosed in, for example, 2006-176086. The front wheel control device 140 (specifically, the first control unit 141 of FIG. 2) and the rear wheel control device 340 (specifically, the first control unit 341 of FIG. 3) of FIG. 4 can control the braking force of the front and rear wheels in accordance with the operation amount of the brake operating member 51, 251. In other words, the first control unit 141 of FIG. 2 can transmit the adjustment amount of the braking force of the front wheels to the first control unit 341 of FIG. 3, and the first control unit 341 can transmit the adjustment amount of the braking force of the rear wheels to the first control unit 141. In this way, the vehicle hydraulic system 40 of the second embodiment may perform coordinated control of the front and rear wheels.

[0082] The vehicle hydraulic system 40 of the present invention is suitable for installation in a saddle-ride type vehicle.

[0083] 10 Vehicle (saddle-ride type vehicle, motorcycle) 40 Vehicle hydraulic system 50, 250 First hydraulic circuit 55, 255 Brake caliper 60, 260 First hydraulic drive device (hydraulic brake, ABS) 61, 261 First reservoir 62, 262 First inlet control valve 63, 263 First outlet control valve 80, 280 First hydraulic pump 81, 281 First suction valve 90, 290 Second hydraulic circuit 100, 300 Second hydraulic drive device (hydraulic jack) 110, 310 Hydraulic control unit 112, 312 First jack hydraulic path 113, 313 Second jack hydraulic path 115, 315 Second inlet control valve 116, 316 Second outlet control valve 117, 317 Pressure valve 120, 320 Second hydraulic pump 121, 321 Second suction valve 130, 330 Motor 140, 340 Control device 141, 341 First control unit 142, 342 Second control unit P1, P11 Opening pressure of pressure valve P2, P12 Maximum jack pressure for driving hydraulic jack (maximum hydraulic pressure in the jack chamber) P3, P13 Maximum discharge pressure of second hydraulic pump Sp1, Sp11 Reference negative pressure at which the first suction valve opens Sp2, Sp12 Reference negative pressure at which the second suction valve opens

Claims

1. A front wheel first hydraulic drive unit driven by hydraulic pressure generated by a front wheel first hydraulic pump, said front wheel first hydraulic drive unit constituting a front wheel hydraulic brake; a single front wheel motor serving as a power source for said front wheel first hydraulic pump; a front wheel first control unit controlling said front wheel hydraulic brake; a rear wheel first hydraulic drive unit driven by hydraulic pressure generated by a rear wheel first hydraulic pump, said rear wheel first hydraulic drive unit constituting a rear wheel hydraulic brake; a rear wheel second hydraulic drive unit driven by hydraulic pressure generated by a rear wheel second hydraulic pump, said rear wheel second hydraulic drive unit constituting a rear wheel hydraulic jack; a single rear wheel motor serving as a common power source for said rear wheel first hydraulic pump and said rear wheel second hydraulic pump; a rear wheel first control unit controlling said rear wheel hydraulic brake; and a rear wheel second control unit controlling said rear wheel hydraulic jack. A vehicle hydraulic system, wherein the first control unit for front wheels is capable of communicating with at least one of the first control unit for rear wheels and the second control unit for rear wheels.

2. A hydraulic system for a vehicle as described in claim 1, further comprising: a second front wheel hydraulic drive device driven by hydraulic pressure generated by a second front wheel hydraulic pump, the second front wheel hydraulic drive device constituting a front wheel hydraulic jack; and a second front wheel control unit that controls the front wheel hydraulic jack, wherein the single front wheel motor serves as a common power source for the first front wheel hydraulic pump and the second front wheel hydraulic pump.

3. A vehicle hydraulic system as described in claim 1, wherein the rear wheel hydraulic jack comprises a rear wheel jack section, and the second rear wheel control section feedback controls the single rear wheel motor based on the amount of movement of the rear wheel jack section.

4. A hydraulic system for a vehicle as described in claim 2, wherein the rear wheel hydraulic jack comprises a rear wheel jack section that adjusts the rear wheel suspension springs in the direction of extension and contraction, the rear wheel second control section feedback controls the single rear wheel motor based on the amount of extension and contraction of the rear wheel jack section and the amount of extension and contraction of the rear wheel suspension springs, the front wheel hydraulic jack comprises a front wheel jack section that adjusts the front wheel suspension springs in the direction of extension and contraction, the front wheel second control section feedback controls the single front wheel motor based on the amount of extension and contraction of the front wheel jack section and the amount of extension and contraction of the front wheel suspension springs, and the rear wheel second control section balances the amount of movement of the rear wheel jack section with the amount of movement of the front wheel jack section.

5. A hydraulic system for a vehicle as described in claim 4, wherein when the rear wheel hydraulic jack and the front wheel hydraulic jack are lowered, the second rear wheel control unit lowers the rear wheel hydraulic jack before lowering the front wheel hydraulic jack.

6. A hydraulic system for a vehicle as set forth in claim 1, wherein the first front wheel hydraulic drive device and the single front wheel motor are provided in a front wheel housing, and the front wheel housing is assembled by a first front wheel hydraulic coupler to a first front wheel piping leading to a front wheel braking section; the first rear wheel hydraulic drive device, the second rear wheel hydraulic drive device and the single rear wheel motor are provided in a rear wheel housing, and the rear wheel housing is assembled by a first rear wheel hydraulic coupler to a first rear wheel piping leading to a rear wheel braking section; and the rear wheel housing is assembled by a second rear wheel hydraulic coupler to a second rear wheel piping leading to a rear wheel jack section.

7. A vehicle hydraulic system as described in claim 2, wherein the first front wheel hydraulic drive unit, the second front wheel hydraulic drive unit, and the single front wheel motor are provided in a front wheel housing, and the front wheel hydraulic jack includes a front wheel jack portion, and the front wheel jack portion is provided on a front fork.

8. A vehicle hydraulic system as described in claim 1, wherein the first control unit for the front wheels is connected to a CAN (Controller Area Network), which is an in-vehicle network, and at least one of the first control unit for the rear wheels and the second control unit for the rear wheels is connected to the CAN.

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