Hydraulic pressure controller, straddle-type vehicle brake system, and straddle-type vehicle

A hydraulic pressure controller, cost of which can be cut, a straddle-type vehicle brake system, and a straddle-type vehicle are obtained.A hydraulic pressure controller (110) is used for the straddle-type vehicle brake system which includes a single system of a hydraulic circuit capable of controlling a hydraulic pressure and in which brake fluid in a wheel cylinder is released to a master cylinder without increasing the hydraulic pressure. A first coil (112B), a second coil (113B), and a hydraulic pressure detector (116) are erected on the same surface of a base body (111). An axis of the hydraulic pressure detector (116) is offset from a reference plane including an axis of the first coil (112B) and an axis of the second coil (113B), and is located between a first plane that is orthogonal to the reference plane and includes the axis of the first coil (112B) and a second plane that is orthogonal to the reference plane and includes the axis of the second coil (113B).

BACKGROUND OF THE INVENTION

The invention relates to a hydraulic pressure controller, a straddle-type vehicle brake system including the hydraulic pressure controller, and a straddle-type vehicle including the straddle-type vehicle brake system.

Conventionally, as a brake system that is mounted on a straddle-type vehicle (for example, a pedal-driven vehicle, a two-wheeled motor vehicle, a three-wheeled motor vehicle, an all-terrain vehicle, or the like), a brake system that only includes a single system of a hydraulic circuit capable of controlling a hydraulic pressure has been available. In the hydraulic circuit, a primary channel that communicates between a master cylinder and a wheel cylinder is filled with brake fluid. When an occupant operates a braking operation section such as a lever, a hydraulic pressure of the brake fluid in the primary channel is increased, and a braking force can be generated and applied to a wheel that is provided with the wheel cylinder. In addition, in the hydraulic circuit, the brake fluid in the wheel cylinder can be released to the master cylinder via a secondary channel. That is, the brake system includes a hydraulic pressure controller, and the hydraulic pressure controller controls an operation of a hydraulic pressure regulation valve provided in the primary channel and an operation of a hydraulic pressure regulation valve provided in the secondary channel. In this way, the hydraulic pressure of the brake fluid in the wheel cylinder, that is, the braking force for the wheel is controlled. For example, when lift-off or possible lift-off of a rear wheel is recognized, the hydraulic pressure controller allows a flow of the brake fluid through the secondary channel, so as to lower the hydraulic pressure of the brake fluid in the wheel cylinder (for example, see WO 2016/174533).

SUMMARY OF THE INVENTION

As specifications of the conventional brake system that only includes the single system of the hydraulic circuit capable of controlling the hydraulic pressure, a specification in which the brake fluid in the wheel cylinder is released by driving a pump (that is, by increasing the hydraulic pressure) and a specification in which the brake fluid in the wheel cylinder is released without increasing the hydraulic pressure exist, for example. In the specification in which the brake fluid in the wheel cylinder is released by driving the pump, a motor as a drive source of the pump has to be attached to a base body of the hydraulic pressure controller. In the specification in which the brake fluid in the wheel cylinder is released without increasing the hydraulic pressure, the base body of the hydraulic pressure controller has to be provided with a hydraulic pressure detector that recognizes the lift-off or the possible lift-off of the rear wheel, that is, the hydraulic pressure detector that detects a brake hydraulic pressure of the wheel cylinder. However, in the conventional brake system, shapes, manufacturing processes, and the like of components of the hydraulic pressure controller have to be changed for each of the specifications, and this results in increased part cost (for example, purchase cost, machining cost, maintenance cost, and the like).

The invention has been made with a problem as described above as the background and therefore has a purpose of obtaining a hydraulic pressure controller capable of achieving cost cut, a straddle-type vehicle brake system including such a hydraulic pressure controller, and a straddle-type vehicle including such a straddle-type vehicle brake system.

A hydraulic pressure controller according to the invention is a hydraulic pressure controller for a straddle-type vehicle brake system. A single system of a hydraulic circuit capable of controlling a hydraulic pressure is provided. In the hydraulic circuit, a primary channel communicating between a master cylinder and a wheel cylinder is filled with brake fluid, and the brake fluid in the wheel cylinder is released to the master cylinder via a secondary channel without increasing the hydraulic pressure. The hydraulic pressure controller includes: a base body that is formed with internal channels including a first channel that constitutes at least a portion of the primary channel and a second channel that constitutes at least a portion of the secondary channel; a first coil as a drive source of a first hydraulic pressure regulation valve that opens/closes the first channel; a second coil as a drive source of a second hydraulic pressure regulation valve that opens/closes the second channel; and a hydraulic pressure detector that is provided in the internal channel and detects the hydraulic pressure of the brake fluid in the wheel cylinder. The first coil, the second coil, and the hydraulic pressure detector are erected on the same surface of the base body. An axis of the hydraulic pressure detector is offset from a reference plane that includes an axis of the first coil and an axis of the second coil, and is located between a first plane that is orthogonal to the reference plane and includes the axis of the first coil and a second plane that is orthogonal to the reference plane and includes the axis of the second coil.

A straddle-type vehicle brake system according to the invention includes the above-described hydraulic pressure controller.

A straddle-type vehicle according to the invention includes the above-described straddle-type vehicle brake system.

In the hydraulic pressure controller according to the invention, the first coil, the second coil, and the hydraulic pressure detector are erected on the same surface of the base body. The axis of the hydraulic pressure detector is offset from the reference plane that includes the axis of the first coil and the axis of the second coil, and is located between the first plane that is orthogonal to the reference plane and includes the axis of the first coil and the second plane that is orthogonal to the reference plane and includes the axis of the second coil. In a specification in which the brake fluid in the wheel cylinder is released by driving a pump, it is preferred for a purpose of downsizing to place an axis of a motor at a position that is offset from the reference plane and between the first plane and the second plane. In addition, the hydraulic pressure detector that is required for a specification in which the brake fluid in the wheel cylinder is released without increasing the hydraulic pressure is provided in a similar position to the motor. In this way, shapes of components, a manufacturing process, and the like of the hydraulic pressure controller can be commonalized. Therefore, cost of the hydraulic pressure controller is cut.

DETAILED DESCRIPTION

A description will hereinafter be made on an embodiment of the invention with appropriate reference to the drawings.

Note that the following description will be made on a case where a straddle-type vehicle brake system according to the invention is mounted on a pedal-driven vehicle (for example, a bicycle, a tricycle, or the like); however, the straddle-type vehicle brake system according to the invention may be mounted on a straddle-type vehicle other than the pedal-driven vehicle (for example, a two-wheeled motor vehicle, a three-wheeled motor vehicle, an all-terrain vehicle, or the like). The pedal-driven vehicle means a vehicle in general that can travel forward on a road by a pressing force that is applied to a pedal. The pedal-driven vehicle includes a normal pedal-driven vehicle, an electric-assisted pedal-driven vehicle, an electric pedal-driven vehicle, and the like. The two-wheeled motor vehicle or the three-wheeled motor vehicle means a so-called motorcycle, and the motorcycle includes a bike, a scooter, an electric scooter, and the like.

A configuration, an operation, and the like, which will be described below, constitute merely one example, and a hydraulic pressure controller according to the invention is not limited to a case with such a configuration, such an operation, and the like. For example, the hydraulic pressure controller according to the invention may execute control other than rear wheel lift-off prevention control.

In the drawings, members or portions that are the same or in a corresponding relationship will be denoted by the same reference sign or will not be denoted by the reference sign. In addition, in each of the drawings, detailed portions will appropriately be simplified or will not be depicted.

First Embodiment

A description will hereinafter be made on a straddle-type vehicle brake system according to a first embodiment.

<Mounting of Straddle-Type Vehicle Brake System on Pedal-Driven Vehicle>

A description will be made on mounting of the straddle-type vehicle brake system according to the first embodiment on the pedal-driven vehicle.

FIG. 1is a schematic configuration view of the straddle-type vehicle brake system according to the first embodiment of the invention and the pedal-driven vehicle to which the straddle-type vehicle brake system is applied. Note thatFIG. 1depicts a case where a pedal-driven vehicle1is the bicycle; however, the pedal-driven vehicle1may be another pedal-driven vehicle such as the tricycle.

As depicted inFIG. 1, the pedal-driven vehicle1includes: a straddle section10that an occupant straddles; and a turning section20turnable with respect to the straddle section10.

The straddle section10includes a frame11, a saddle12, pedals13, a rear wheel14, and a rear wheel braking section15. The frame11pivotally supports the turning section20. In addition, the frame11holds the saddle12. Furthermore, the frame11supports the rear wheel14and the rear wheel braking section15.

The turning section20includes a steering column21, a handlebar stem22, a handlebar23, a braking operation section24, a fork25, a front wheel26, and a front wheel braking section27. The handlebar stem22is held by the steering column21that is pivotally supported by the straddle section10. The handlebar23is held by the handlebar stem22. The braking operation section24is attached to the handlebar23. The front wheel26and the front wheel braking section27are supported by the fork25that is coupled to the steering column21.

The braking operation section24includes: a mechanism that is used as an operation section of the rear wheel braking section15; and a mechanism that is used as an operation section of the front wheel braking section27. For example, the mechanism that is used as the operation section of the rear wheel braking section15is disposed on a left end side of the handlebar23, and the mechanism that is used as the operation section of the front wheel braking section27is disposed on a right end side of the handlebar23.

A hydraulic pressure controller110that controls a hydraulic pressure of brake fluid in the front wheel braking section27is coupled to the turning section20of the pedal-driven vehicle1. Meanwhile, the rear wheel braking section15is a type of a braking section incapable of controlling a braking force (that is, the type of the braking section that only generates the braking force corresponding to an operation amount by the occupant received by the braking operation section24and cannot control the braking force). In other words, the hydraulic pressure controller110can only control the braking force that is generated and applied to the front wheel26of the pedal-driven vehicle1. Note that the hydraulic pressure controller110may be coupled to a member other than the turning section20of the pedal-driven vehicle1.

A power supply unit190as a power supply for the hydraulic pressure controller110is attached to the frame11of the pedal-driven vehicle1. The power supply unit190may acquire electric power from a battery cell, a generator, or the like, or may acquire the electric power from a battery that stores the electric power produced by the generator or the like. The power supply unit190may exclusively be used for the hydraulic pressure controller110or may also be used for another device.

More specifically, a straddle-type vehicle brake system100that includes the rear wheel braking section15, the braking operation section24, the front wheel braking section27, the hydraulic pressure controller110, and the power supply unit190is mounted on the pedal-driven vehicle1. The straddle-type vehicle brake system100only controls the hydraulic pressure of the brake fluid in the front wheel braking section27by using the hydraulic pressure controller110.

A description will be made on a configuration of the straddle-type vehicle brake system according to the first embodiment.

FIG. 2is a schematic configuration diagram of the straddle-type vehicle brake system according to the first embodiment of the invention. InFIG. 2, components of the straddle-type vehicle brake system100that are related to braking of the rear wheel14are not depicted.

As depicted inFIG. 2, the straddle-type vehicle brake system100only includes a single system of a hydraulic circuit101capable of controlling the hydraulic pressure.

The hydraulic pressure controller110includes a base body111, which will be described below in detail. The base body111is formed with a master cylinder port111A and a wheel cylinder port111B.

The braking operation section24includes a brake lever24A, a master cylinder24B, a reservoir24C, and a fluid pipe24D. The master cylinder24B includes a piston (not depicted) that moves in an interlocking manner with an operation of the brake lever24A by the occupant. The reservoir24C stores the brake fluid for the master cylinder24B at the atmospheric pressure. One end of the fluid pipe24D is connected to the master cylinder24B, and the other end of the fluid pipe24D is connected to the master cylinder port111A.

The front wheel braking section27includes a wheel cylinder27A, a brake disc27B, and a fluid pipe27C. The wheel cylinder27A is held by the fork25. The wheel cylinder27A includes a piston (not depicted) that moves in an interlocking manner with a change in the hydraulic pressure of the brake fluid in the fluid pipe27C connected to the wheel cylinder port111B. The brake disc27B is attached to the front wheel26and rotates with the front wheel26. When the piston in the wheel cylinder27A moves, a brake pad (not depicted) is pressed against the brake disc27B, and the front wheel26is thereby braked.

The base body111is formed with a first channel111C, a second channel111D, and a third channel111E as internal channels.

In an example depicted inFIG. 2, the first channel111C is formed to communicate between the master cylinder port111A and the wheel cylinder port111B. In other words, a primary channel170is constructed of the fluid pipe24D, the first channel111C, and the fluid pipe27C, and the master cylinder24B and the wheel cylinder27A communicate with each other via the primary channel170. Note that the master cylinder24B and the master cylinder port111A may directly be connected without the fluid pipe24D being interposed therebetween and that the wheel cylinder27A and the wheel cylinder port111B may directly be connected without the fluid pipe27C being interposed therebetween. That is, the first channel111C is a channel that constitutes at least a portion of the primary channel170.

In the example depicted inFIG. 2, the second channel111D is formed to bypass a region of the first channel111C. In other words, a secondary channel180is constructed of the second channel111D. The secondary channel180is a channel through which the brake fluid in the wheel cylinder27A is released to the master cylinder24B. Note that the second channel111D may be connected to the master cylinder24B without the first channel111C being interposed therebetween (that is, via a master cylinder port other than the master cylinder port111A and a fluid channel other than the fluid pipe24D). In addition, the second channel111D may be connected to the wheel cylinder27A without the first channel111C being interposed therebetween (that is, via a wheel cylinder port other than the wheel cylinder port111B and a fluid channel other than the fluid pipe27C). That is, the second channel111D is a channel that constitutes at least a portion of the secondary channel180.

The hydraulic pressure controller110includes a first hydraulic pressure regulation valve112, a second hydraulic pressure regulation valve113, an accumulator114, a check valve115, and a hydraulic pressure detector116. Those components are assembled to the base body111.

The first hydraulic pressure regulation valve112is provided in the region of the first channel111C that is bypassed by the second channel111D. The second hydraulic pressure regulation valve113is provided in an intermediate portion of the second channel111D. The first hydraulic pressure regulation valve112is an electromagnetic valve that is opened during non-energization, and does not block a flow of the brake fluid during the non-energization. When a first coil112B, which will be described below, is brought into an energized state in the first hydraulic pressure regulation valve112, the first hydraulic pressure regulation valve112is brought into a closed state and thereby blocks the flow of the brake fluid. The second hydraulic pressure regulation valve113is an electromagnetic valve that is closed during the non-energization, and blocks the flow of the brake fluid during the non-energization. When a second coil113B, which will be described below, is brought into an energized state in the second hydraulic pressure regulation valve113, the second hydraulic pressure regulation valve113is brought into an opened state and thereby allows the flow of the brake fluid. Each of the first hydraulic pressure regulation valve112and the second hydraulic pressure regulation valve113may not be able to regulate an opening degree thereof in the opened state or may be able to regulate the opening degree thereof in the opened state.

The accumulator114is provided on a downstream side of the second hydraulic pressure regulation valve113in the second channel111D. The accumulator114stores the brake fluid that has flowed through the second hydraulic pressure regulation valve113. An elastic element is installed in the accumulator114, and the elastic element is operated to discharge the brake fluid that has flowed into the accumulator114. Because the check valve115is provided on a downstream side of the accumulator114, backflow of the discharged brake fluid to the accumulator114is prevented. That is, in the hydraulic circuit101, the brake fluid in the wheel cylinder27A is released to the master cylinder24B via the secondary channel180without increasing the hydraulic pressure (that is, in a pumpless method).

In the internal channel formed in the base body111, the hydraulic pressure detector116is provided at a position where the hydraulic pressure is substantially the same as the hydraulic pressure of the brake fluid in the wheel cylinder27A. Note that the example depicted inFIG. 2depicts a case where the third channel111E is formed in a portion of the first channel111C, to which an upstream end of the second channel111D is connected, and the hydraulic pressure detector116is provided in the third channel111E; however, the hydraulic pressure detector116may be connected to another portion of the first channel111C between the first hydraulic pressure regulation valve112and the wheel cylinder port111B with or without the third channel111E being interposed therebetween. Alternatively, the hydraulic pressure detector116may be connected to a portion of the second channel111D on an upstream side of the second hydraulic pressure regulation valve113with or without the third channel111E being interposed therebetween.

The hydraulic pressure controller110includes a control section160. The control section160may be configured by including a microcomputer, a microprocessor unit, or the like, may be configured by including a member in which firmware and the like can be updated, or may be configured by including a program module or the like that is executed by a command from a CPU or the like, for example.

The control section160controls the hydraulic pressure of the brake fluid in the wheel cylinder27A, that is, the braking force for the front wheel26by controlling operations of the first hydraulic pressure regulation valve112and the second hydraulic pressure regulation valve113in the hydraulic pressure controller110, that is, the energization of the first coil112B and the second coil113B, which will be described below.

For example, in the case where locking or possible locking of the rear wheel14is recognized on the basis of output of a front-wheel rotational frequency detector (not depicted) and a rear-wheel rotational frequency detector (not depicted) and overshoot of the hydraulic pressure of the brake fluid in the wheel cylinder27A is recognized on the basis of output of the hydraulic pressure detector116when the braking force is generated and applied to the front wheel26through the operation of the brake lever24A by the occupant, the control section160initiates the rear wheel lift-off prevention control.

Once initiating the rear wheel lift-off prevention control, the control section160brings the first hydraulic pressure regulation valve112into the closed state and blocks the flow of the brake fluid between the master cylinder24B and the wheel cylinder27A, so as to prevent an increase in the hydraulic pressure of the brake fluid in the wheel cylinder27A. Meanwhile, the control section160brings the second hydraulic pressure regulation valve113into the opened state and allows the flow of the brake fluid from the wheel cylinder27A to the accumulator114, so as to lower the hydraulic pressure of the brake fluid in the wheel cylinder27A. In this way, lift-off of the rear wheel14is avoided. When determining that the hydraulic pressure of the brake fluid in the wheel cylinder27A is lowered to a specified value, the control section160brings the second hydraulic pressure regulation valve113into the closed state and brings the first hydraulic pressure regulation valve112into the opened state for a short period, so as to increase the hydraulic pressure of the brake fluid in the wheel cylinder27A. The control section160may increase/lower the hydraulic pressure of the brake fluid in the wheel cylinder27A once or may repeatedly increase/lower the hydraulic pressure of the brake fluid in the wheel cylinder27A for multiple times.

When the rear wheel lift-off prevention control is terminated and the operation of the brake lever24A is canceled, the inside of the master cylinder24B is brought into an atmospheric pressure state, and the brake fluid in the wheel cylinder27A is returned to the master cylinder24B. Due to generation of this atmospheric pressure state, the brake fluid in the accumulator114is also returned to the master cylinder24B.

<Schematic Configuration of Hydraulic Pressure Controller>

A description will be made on a schematic configuration of the hydraulic pressure controller for the straddle-type vehicle brake system according to the first embodiment.FIG. 3andFIG. 4are perspective views of the schematic configuration of the hydraulic pressure controller for the straddle-type vehicle brake system according to the first embodiment of the invention.FIG. 5is an exploded perspective view of the schematic configuration of the hydraulic pressure controller for the straddle-type vehicle brake system according to the first embodiment of the invention.

As depicted inFIG. 3toFIG. 5, the hydraulic pressure controller110is constructed of: the base body111that is formed with the internal channels; the first hydraulic pressure regulation valve112, the second hydraulic pressure regulation valve113, the accumulator114, the check valve115, and the hydraulic pressure detector116that are assembled to the base body111; a casing141that is attached to the base body111; an electronic substrate161that is provided on an opposite side of the casing141from the base body111; a cover142that covers the electronic substrate161; and the like.

The base body111is made of aluminum and is a substantially rectangular parallelepiped block, for example. The base body111has a first surface121, a second surface122, a third surface123, a fourth surface124, a fifth surface125, and a sixth surface126. The first surface121and the second surface122are in an opposing positional relationship. The third surface123and the fourth surface124are in an opposing positional relationship. The fifth surface125and the sixth surface126are in an opposing positional relationship.

The first surface121of the base body111is formed with: a first hydraulic pressure regulation valve attachment hole131to which the first hydraulic pressure regulation valve112is inserted and attached; a second hydraulic pressure regulation valve attachment hole132to which the second hydraulic pressure regulation valve113is inserted and attached; and a hydraulic pressure detector attachment hole133to which the hydraulic pressure detector116is inserted and attached. That is, the first hydraulic pressure regulation valve112, the second hydraulic pressure regulation valve113, and the hydraulic pressure detector116are erected on the same surface (the first surface121) of the base body111. Additionally, each of the first surface121and the other surfaces is capable of including a stepped portion or a curved portion.

The third surface123of the base body111is formed with: the master cylinder port111A to which the fluid pipe24D is connected; and the wheel cylinder port111B to which the fluid pipe27C is connected.

The fourth surface124of the base body111is formed with an accumulator attachment hole134to which the accumulator114and the check valve115are inserted and attached.

The casing141is attached to the first surface121of the base body111. The casing141is formed with an accommodation section141B that is opened in an attachment surface141A to the base body111and will be described below. In a state where the first hydraulic pressure regulation valve112, the second hydraulic pressure regulation valve113, and the hydraulic pressure detector116, which are erected in the base body111, are accommodated in the accommodation section141B, the casing141is attached to the first surface121of the base body111.

The first hydraulic pressure regulation valve112includes: a plunger112A that opens/closes a valve body by linear reciprocal motion; and the first coil112B that drives the plunger112A inserted in a hollow section. The second hydraulic pressure regulation valve113includes: a plunger113A that opens/closes a valve body by linear reciprocal motion; and the second coil113B that drives the plunger113A inserted in a hollow section. Coil terminals are provided at a top of each of the first coil112B and the second coil113B, which are erected.

A hydraulic pressure detection element is provided on an end surface on a base side of the hydraulic pressure detector116, and a signal output terminal is provided on an end surface on a top side of the hydraulic pressure detector116.

Coil terminal through holes152,153and a hydraulic pressure detector through hole154are formed at a bottom151of the accommodation section141B in the casing141. When the casing141is attached to the first surface121of the base body111, the coil terminals of the first coil112B, the coil terminals of the second coil113B, and the signal output terminal of the hydraulic pressure detector116are each brought into a projected state to a back side of the bottom151of the accommodation section141B. The electronic substrate161as a component of the control section160is connected to those terminals, and the cover142is attached to the casing141in a manner to accommodate the electronic substrate161.

At the bottom151of the accommodation section141B in the casing141, motor terminal through holes155,156are formed on both sides of the hydraulic pressure detector through hole154. In a specification in which the brake fluid in the wheel cylinder27A is released by driving a pump, instead of the hydraulic pressure detector116, a motor as a drive source of the pump is erected at the position of the hydraulic pressure detector116, and motor terminals (a positive terminal and a negative terminal) provided at a top of the motor are brought into projected states to the back side of the bottom151of the accommodation section141B through the motor terminal through holes155,156. That is, the casing141is used in a specification in which the brake fluid in the wheel cylinder27A is released without increasing the hydraulic pressure and the specification in which the brake fluid in the wheel cylinder27A is released by driving the pump.

<Configuration of Primary Section of Hydraulic Pressure Controller>

A description will be made on a configuration of a primary section of the hydraulic pressure controller for the straddle-type vehicle brake system according to the first embodiment.

FIG. 6is an exemplary perspective view of the base body of the hydraulic pressure controller for the straddle-type vehicle brake system according to the first embodiment of the invention.FIG. 7is a partial cross-sectional view of the hydraulic pressure controller for the straddle-type vehicle brake system according to the first embodiment of the invention.

As depicted inFIG. 6, on the first surface121of the base body111, the first hydraulic pressure regulation valve attachment hole131, the second hydraulic pressure regulation valve attachment hole132, and the hydraulic pressure detector attachment hole133are formed axially parallel to each other. An axis A3of the hydraulic pressure detector attachment hole133is offset from a reference plane PR that includes an axis A1of the first hydraulic pressure regulation valve attachment hole131and an axis A2of the second hydraulic pressure regulation valve attachment hole132. In addition, the axis A3of the hydraulic pressure detector attachment hole133is located between a first plane P1that is orthogonal to the reference plane PR and includes the axis A1and a second plane P2that is orthogonal to the reference plane PR and includes the axis A2. That is, the axis A3of the hydraulic pressure detector116is offset from the reference plane PR that includes the axis A1of the first coil112B and the axis A2of the second coil113B, and is located between the first plane P1that is orthogonal to the reference plane PR and includes the axis A1of the first coil112B and the second plane P2that is orthogonal to the reference plane PR and includes the axis A2of the second coil113B.

The third surface123of the base body111is formed with the master cylinder port111A and the wheel cylinder port111B. Of two lateral surfaces of the first surface121that are orthogonal to the reference plane PR, the third surface123is the lateral surface that is close to the axis A1. In other words, with the first plane P1being a reference, the master cylinder port111A and the wheel cylinder port111B are formed in a region on a side of the base body111where the second plane P2is absent.

The fourth surface124of the base body111is formed with the accumulator attachment hole134. Of the two lateral surfaces of the first surface121that are orthogonal to the reference plane PR, the fourth surface124is the lateral surface that is close to the axis A2. A check valve attachment hole135is formed at a bottom of the accumulator attachment hole134, and the check valve115is inserted in and attached to the check valve attachment hole135.

Note that the example depicted inFIG. 6depicts a case where the upstream end of the second channel111D is connected to the first channel111C at a position inside the first hydraulic pressure regulation valve attachment hole131and that the third channel111E is connected to a portion of the second channel111D between the second hydraulic pressure regulation valve attachment hole132and the first hydraulic pressure regulation valve attachment hole131; however, the base body111may have a different configuration from such a configuration. For example, the upstream end of the second channel111D may be connected to another portion of the first channel111C. In addition, the third channel111E may be connected to the first channel111C or may be connected to another portion of the second channel111D. Furthermore, the hydraulic pressure detector attachment hole133may directly be connected to the first channel111C or the second channel111D without the third channel111E being interposed therebetween.

As depicted inFIG. 7, a joint section116A and a flange116B are formed at an end on the base side of the hydraulic pressure detector116, that is, the end thereof on a side that is attached to the base body111. The joint section116A is inserted in and joined to the hydraulic pressure detector attachment hole133, and the flange116B is formed on a side where the electronic substrate161is present from the joint section116A. The joint section116A includes: a pressing section116Aa that presses the base body111; and plural grooves116Ab. The base body111, which is deformed by pressing, bites the grooves116Ab. The flange116B is used to abut a jig from the top side of the hydraulic pressure detector116, and the jig is used to press the pressing section116Aa against the base body111. A stepped surface133A is formed around the hydraulic pressure detector attachment hole133in the base body111, and the stepped surface133A is lower than the region of the first surface121where the first coil112B and the second coil113B are erected. The hydraulic pressure detector116is inserted in the hydraulic pressure detector attachment hole133until a tip of the jig abuts the stepped surface133A. By such assembly, a height position of the top of the hydraulic pressure detector116is set.

The end on the top side of the hydraulic pressure detector116, which is assembled just as described, is brought into the projected state to the back side of the bottom151of the accommodation section141B in the casing141through the hydraulic pressure detector through hole154. The electronic substrate161is formed with through holes to which the coil terminals of the first coil112B and the second coil113B are inserted and connected. In a state where the coil terminals are connected to the electronic substrate161, the signal output terminal, which is provided on the end surface on the tip side of the hydraulic pressure detector116, is brought into an abutment state against a contact piece161A provided in the electronic substrate161.

A description will be made on effects of the straddle-type vehicle brake system according to the first embodiment.

In the hydraulic pressure controller110, the first coil112B, the second coil113B, and the hydraulic pressure detector116are erected on the same surface of the base body111. The axis A3of the hydraulic pressure detector116is offset from the reference plane PR that includes the axis A1of the first coil112B and the axis A2of the second coil113B, and is located between the first plane P1that is orthogonal to the reference plane PR and includes the axis A1of the first coil112B and the second plane P2that is orthogonal to the reference plane PR and includes the axis A2of the second coil113B. In the specification in which the brake fluid in the wheel cylinder27A is released by driving the pump, it is preferred for a purpose of downsizing to place an axis of the motor as the drive source of the pump at a position that is offset from the reference plane PR and between the first plane P1and the second plane P2. The hydraulic pressure detector116that is required for the specification in which the brake fluid in the wheel cylinder27A is released without increasing the hydraulic pressure is provided at a similar position to the motor. In this way, the components, the manufacturing process, and the like of the hydraulic pressure controller110can be commonalized. Thus, cost of the hydraulic pressure controller110is cut.

Preferably, in the hydraulic pressure controller110, the master cylinder port111A, to which the fluid pipe24D communicating with the master cylinder24B is connected, and the wheel cylinder port111B, to which the fluid pipe27C communicating with the wheel cylinder27A is connected, are formed in the region on the side of the base body111where the second plane P2is absent with the first plane P1being the reference. That is, the master cylinder port111A is formed not near the second hydraulic pressure regulation valve113but near the first hydraulic pressure regulation valve112. In the specification in which the brake fluid in the wheel cylinder27A is released by driving the pump, from a perspective of preventing transmission of pump pulsations, it is preferred that a discharge port of the pump is not too close to the master cylinder port111A. In addition, in the case where the master cylinder port111A is formed not near the second hydraulic pressure regulation valve113but near the first hydraulic pressure regulation valve112, the first channel111C is formed between the motor, which is erected instead of the hydraulic pressure detector116, and the master cylinder port111A. In this way, the transmission of the pump pulsations can be prevented while enlargement of the base body111is avoided. Thus, the cost of the hydraulic pressure controller110can be cut while performance of the hydraulic pressure controller110is secured.

Preferably, the hydraulic pressure controller110includes: the casing141that is attached to the base body111, has the accommodation section141B opened in the attachment surface141A to the base body111, and accommodates the first coil112B, the second coil113B, and the hydraulic pressure detector116in the accommodation section141B; and the electronic substrate161that is provided on the back side of the bottom151of the accommodation section141B. The hydraulic pressure detector through hole154is formed in the region of the bottom151that crosses the axis A3of the hydraulic pressure detector116, and the top of the hydraulic pressure detector116is projected to the back side of the bottom151through the hydraulic pressure detector through hole154. Thus, complicated connection of the hydraulic pressure detector116to the electronic substrate161is prevented.

In particular, at the bottom151of the accommodation section141B in the casing141, the motor terminal through holes155,156are preferably formed on both of the sides of the hydraulic pressure detector through hole154. With such a configuration, the casing141can have the same shape for the specification in which the brake fluid in the wheel cylinder27A is released without increasing the hydraulic pressure and the specification in which the brake fluid in the wheel cylinder27A is released by driving the pump. Thus, the cost of the hydraulic pressure controller110can further be cut.

In particular, the first coil112B and the second coil113B are preferably connected to the electronic substrate161, to which the hydraulic pressure detector116is connected, and the joint section116, which is inserted in and joined to the hydraulic pressure detector attachment hole133formed in the base body111, and the flange116B, which is formed on the side where the electronic substrate161is present from the joint section116A, are preferably formed at the end of the hydraulic pressure detector116on the side attached to the base body111. With such a configuration, the hydraulic pressure detector116can be assembled to the base body111while the height position of the top of the hydraulic pressure detector116is set with a high degree of accuracy. Thus, the first coil112B, the second coil113B, and the hydraulic pressure detector116can simultaneously be connected to the electronic substrate161.

In particular, the stepped surface133A, which is lower than the region of the base body111where the first coil112B and the second coil113B are erected, is preferably formed around the hydraulic pressure detector attachment hole133of the base body111. With such a configuration, a distance between the surface of the flange116B that the jig abuts and the joint section116A is reduced, and thus the joint section116A can reliably be joined to the base body111.

The first embodiment has been described so far. However, the invention is not limited to a mode of the first embodiment. For example, the first embodiment may only partially be implemented.

REFERENCE SIGNS LIST

14: Rear wheel

20: Turning section

24: Braking operation section

24B: Master cylinder

26: Front wheel

27B: Brake disc

100: Straddle-type vehicle brake system

110: Hydraulic pressure controller

111: Base body

111A: Master cylinder port

111B: Wheel cylinder port

111C: First channel

111D: Second channel

111E: Third channel

112: First hydraulic pressure regulation valve

112B: First coil

113: Second hydraulic pressure regulation valve

113B: Second coil

115: Check valve

116: Hydraulic pressure detector

116A: Joint section

116Aa: Pressing section

121: First surface

122: Second surface

123: Third surface

124: Fourth surface

125: Fifth surface

126: Sixth surface

131: First hydraulic pressure regulation valve attachment hole

132: Second hydraulic pressure regulation valve attachment hole

133: Hydraulic pressure detector attachment hole

134: Accumulator attachment hole

135: Check valve attachment hole

141A: Attachment surface

141B: Accommodation section

152,153: Coil terminal through hole

154: Hydraulic pressure detector through hole

155,156: Motor terminal through hole

160: Control section

161: Electronic substrate

161A: Contact piece

170: Primary channel

180: Secondary channel

190: Power supply unit

PR: Reference plane

P1: First plane

P2: Second plane