JP7526325B2 - Brake system - Google Patents

Description

The present invention relates to a brake device.

Brake devices for vehicles are known in the art. For example, the brake device (input device for a vehicle brake system) described in Patent Document 1 includes a master cylinder and a stroke simulator.

JP 2012-106638 A

In conventional brake devices, no consideration was given to the mounting structure of the master cylinder housing and the stroke simulator housing when they are separate components.

In the brake device according to an embodiment of the present invention, the piston and the reaction piston are not arranged side by side in the axial direction of the master cylinder housing part, and when a straight line extending in the direction in which the reservoir tank and the master cylinder housing part overlap is defined as a first axis, and a straight line perpendicular to the first axis and perpendicular to the axial direction of the cylinder formed in the master cylinder housing part is defined as a second axis, the stroke simulator housing part and the master cylinder housing part are arranged so that they have overlapping portions when viewed from the direction of the first axis, and the overlapping portions overlap in the order of the stroke simulator housing part and the master cylinder housing part when viewed from the surface where the reservoir tank is attached, and the master cylinder housing part and the stroke simulator housing part are arranged so that they have overlapping portions when viewed from the direction of the second axis.

This improves vehicle mountability.

1 is a perspective view of a brake device 1 according to a first embodiment. 1 is a perspective view of a brake device 1 according to a first embodiment. FIG. 2 is a top view of the brake device 1 of the first embodiment. FIG. 2 is a bottom view of the brake device 1 of the first embodiment. FIG. 1 is a side view of a brake device 1 according to a first embodiment. FIG. 1 is a side view of a brake device 1 according to a first embodiment. FIG. 1 is a front view of a brake device 1 according to a first embodiment. FIG. 2 is a rear view of the brake device 1 of the first embodiment. 8 is a cross-sectional view taken along line AA in FIG. 7. FIG. 2 is a perspective view of the actuator 8 of the first embodiment.

Below, the form in which the brake device of the present invention is realized will be explained with reference to the drawings.

[Example 1]
The vehicle to which the brake device of the present embodiment is applied is an electric vehicle capable of generating regenerative braking force by an electric motor, such as a hybrid vehicle equipped with an electric motor (generator) in addition to an engine (internal combustion engine) as a prime mover for driving the wheels, or an electric vehicle equipped with only a motor (generator). The brake system (brake system) of the present embodiment is a hydraulic brake system that applies brake fluid pressure to each wheel of the vehicle to generate braking force. Wheel cylinders (calipers) provided on each wheel of the vehicle generate brake operating fluid pressure (wheel cylinder fluid pressure) by receiving a brake operation fluid pressure or a control fluid pressure. The brake system includes a brake device 1 as an input device to which the driver's brake operation is input, and an electric brake actuator (hereinafter referred to as actuator 8) capable of generating brake fluid pressure based on an electric signal corresponding to the driver's brake operation. The brake device 1 operates in response to the driver's brake operation and generates a master cylinder fluid pressure as the brake operation fluid pressure. The actuator 8 is provided separately from the brake device 1, and controls the wheel cylinder fluid pressure (brake fluid pressure) in response to the brake operation state or the vehicle state.

1 to 9 show the entire brake device 1 of this embodiment from each direction. For the sake of convenience, an orthogonal coordinate system is provided below. With the brake device 1 installed on the vehicle, the x-axis is set in the front-rear direction of the vehicle (the axial direction in which the master cylinder 4 operates). When the brake device 1 is installed on the vehicle, the axial direction of the master cylinder 4 is approximately parallel to the front-rear direction of the vehicle, so the x-axis direction is the front-rear direction of the vehicle. The front of the vehicle (the direction in which the piston 41 of the master cylinder 4 strokes in response to the brake pedal being depressed) is the positive x-axis direction. The y-axis is set in the width direction (left-right or lateral direction) of the vehicle, and the left side as viewed from the rear of the vehicle (the negative x-axis side) is the positive y-axis direction. The z-axis is set in the up-down direction (vertical direction) of the vehicle, and the upper side of the vehicle (the side where the reservoir tank 3 is installed relative to the master cylinder 4) is the positive z-axis direction. FIG. 1 is a perspective view of the brake device 1 as viewed from the negative x-axis side, the positive y-axis side, and the positive z-axis side. FIG. 2 is a perspective view of the brake device 1 as viewed from the positive x-axis, negative y-axis, and positive z-axis sides. FIG. 3 is a top view of the brake device 1 as viewed from the positive z-axis side. FIG. 4 is a bottom view of the brake device 1 as viewed from the negative z-axis side. FIG. 5 is a side view of the brake device 1 as viewed from the positive y-axis side. FIG. 6 is a side view of the brake device 1 as viewed from the negative y-axis side. FIG. 7 is a front view of the brake device 1 as viewed from the positive x-axis side. FIG. 8 is a rear view of the brake device 1 as viewed from the negative x-axis side. FIG. 9 is a cross-sectional view of the brake device 1 cut along a plane passing through the axis of the master cylinder 4, showing the A-A cross section of FIG. 7.

The brake device 1 includes a push rod 2, a reservoir tank 3, a master cylinder 4, a stroke simulator 5, and a stroke simulator valve 6. That is, the brake device 1 is a master cylinder unit with a built-in master cylinder 4. The brake system has two brake piping systems (primary P system and secondary S system). Hereinafter, the members and structures provided corresponding to each system are distinguished by adding the suffixes P and S to the end of their reference numerals. The push rod 2 is connected to the brake pedal via a clevis 20. The brake pedal is an input member (brake operation member) that receives the input of the driver's brake operation. The push rod 2 operates in the x-axis direction in conjunction with the brake pedal. For example, the push rod 2 strokes in the x-axis positive direction in response to the brake pedal depression operation. The x-axis positive end of the push rod 2 abuts against the piston 41P of the master cylinder 4 (see FIG. 9). The push rod 2 receives the driver's operating force input to the brake pedal and transmits it to the master cylinder 4 as a thrust in the x-axis direction. A flange portion 21 is provided on the outer periphery of the push rod 2 on the x-axis positive side. An abutment member 22, the tip of which on the x-axis positive side is formed into a convex spherical shape, is fixed to the x-axis positive end of the push rod 2. The brake device 1 of this embodiment does not include a type of booster (brake booster) that is interposed between the brake pedal and the master cylinder and operates using the intake pressure (negative pressure) generated by the vehicle's engine (master back) to reduce the driver's brake operation force.

The reservoir tank 3 is a brake fluid source that stores brake fluid and supplies brake fluid to the master cylinder 4 and the actuator 8. The reservoir tank 3 has a supply port 30, supply ports 31P and 31S, and supply ports 32a and 32b. The supply port 30 protrudes and opens on the positive z-axis side of the reservoir tank 3 on the positive x-axis side, and is provided so as to be freely opened and closed by a lid 3a. The supply ports 31P and 31S are provided to be aligned in the x-axis direction, and protrude and open on the negative z-axis side of the reservoir tank 3. The supply port 31P is provided on the negative x-axis side of the supply port 31S. The supply ports 32a and 32b are provided on the negative x-axis side of the supply port 31P, and open on both sides of the reservoir tank 3 in the y-axis direction. A fastening portion 35 is provided on the negative z-axis side of the reservoir tank 3 between the supply ports 31P and 31S. The fastening portion 35 has a hole extending in the y-axis direction for inserting a pin to fasten the reservoir tank 3. The reservoir tank 3 is divided into three regions by two partition plates 33a and 33b that are installed so as to extend from the bottom surface on the negative side of the z-axis to the positive direction of the z-axis. The region on the positive side of the x-axis has a supply port 31S, the region on the negative side of the x-axis has supply ports 32a and 32b, and the region between these two regions has a supply port 31P. The partition plate 33 stores brake fluid in each region even when the vehicle tilts or accelerates or decelerates, for example, and thus enables the brake fluid to be replenished from each supply port. The supply port 32a is connected to a pipe mounting portion 320a (see FIG. 1). One end of a brake pipe 71 is attached to the pipe mounting portion 320a. The pipe mounting portion 320a protrudes from the outer surface of the reservoir tank 3 on the negative x-axis, positive y-axis, and negative z-axis sides toward the positive y-axis direction, and is bent toward the positive x-axis direction midway. The tip of the pipe mounting portion 320a to which the brake pipe 71 is attached opens toward the positive x-axis direction. The pipe mounting portion 320b is connected to the supply port 32b (see FIG. 2). One end of another brake pipe is attached to the pipe mounting portion 320b. The pipe mounting portion 320b protrudes from the outer surface of the reservoir tank 3 on the negative x-axis, negative y-axis, and negative z-axis sides toward the negative y-axis direction, and is bent toward the positive x-axis direction midway. The tip of the pipe mounting portion 320b to which the brake pipe is attached opens toward the positive x-axis direction.

The master cylinder 4 is a first brake fluid pressure generating source that generates fluid pressure (master cylinder fluid pressure) in response to the driver's operation of the brake pedal (brake operation). The master cylinder 4 is connected to the wheel cylinders via an oil passage (brake piping) not shown in the figure. The master cylinder fluid pressure is supplied to the wheel cylinders via the oil passage to generate wheel cylinder fluid pressure (brake fluid pressure). The master cylinder 4 has a master cylinder housing (cylinder) 40, a piston 41, and a coil spring 42. The master cylinder housing 40 has a main body portion 40a, a flange portion 40b, and a fitting portion 40c. The main body portion 40a is formed in a cylindrical shape with a bottom that is closed at one end side (x-axis positive direction side) and extends in the x-axis direction. The flange portion 40b is provided on the outer periphery of the main body portion 40a on the x-axis negative direction side. Fastening portions 40d and 40e in which bolt holes extending in the x-axis direction are formed are provided on both sides of the flange portion 40b in the y-axis direction. The fastening portions 40d and 40e are provided at approximately symmetrical positions across the axis of the main body portion 40a. The fitting portion 40c is provided adjacent to the negative x-axis side of the flange portion 40b and is approximately cylindrical and extends in the x-axis direction. A seal member 402 is installed in a seal groove 401 provided to surround the outer periphery of the fitting portion 40c.

Inside the master cylinder housing 40, an axial hole 400 is formed extending in the x-axis direction. The hole 400 opens on the negative x-axis side of the master cylinder housing 40. The master cylinder 4 is a so-called tandem type, and two pistons 41P, 41S are provided in the hole 400 so as to be operable (reciprocating) in the x-axis direction. A concave spherical receiving portion 410 is formed on the negative x-axis side of the piston 41P of the P system. The positive x-axis end of the push rod 2 (contact member 22) formed in a convex spherical shape abuts against the receiving portion 410 and is fitted and installed so as to be rotatable. The piston 41S of the S system is a free piston and is installed on the positive x-axis side of the piston 41P. Each piston 41 is provided with a recess 411 extending in the x-axis direction and opening on the positive x-axis side. Each piston 41 has a radially extending communication hole 412 that connects the inner peripheral surface of the recess 411 to the outer peripheral surface of each piston 41.

The master cylinder housing 40 is formed with a discharge port 44 and a refill port 45, which open on the inner circumferential surface of the hole 400. The discharge port 44 extends in the y-axis direction and opens on the side surface of the master cylinder housing 40 on the negative side of the y-axis, and is connected to the actuator 8 via a brake pipe and is provided so as to be able to communicate with the wheel cylinder. There are two discharge ports 44P of the P system, and the other discharge port 44P extends in the y-axis direction and opens on the side surface of the master cylinder housing 40 on the positive side of the y-axis. The discharge port 44P opening on the positive side of the y-axis is connected to the stroke simulator 5 via the brake pipe 70 and is provided so as to be able to communicate with the stroke simulator 5 (main chamber 54). The refill port 45 extends in the z-axis direction and opens on the upper surface of the master cylinder housing 40 on the positive side of the z-axis, and is connected to the reservoir tank 3 and communicates with it. The refill ports 31P and 31S of the reservoir tank 3 are fitted into the recess 48 (where the refill port 45 opens) on the upper surface of the master cylinder housing 40 via the seal member 34, and are connected to the refill ports 45P and 45S, respectively. That is, the reservoir tank 3 is provided integrally with the master cylinder 4. The master cylinder 4 is refilled with brake fluid from the reservoir tank 3 through the refill ports 31P and 31S and the refill ports 45P and 45S. When viewed from the y-axis direction, a fastening portion 49 is provided between the recesses 48P and 48S at the z-axis positive end of the master cylinder housing 40. The fastening portion 49 has a hole for inserting a pin to fasten the reservoir tank 3, which hole extends in the y-axis direction. The pin is inserted into the fastening portion 49 and the fastening portion 35 of the reservoir tank 3 and fastened, so that the reservoir tank 3 is fixed to the master cylinder housing 40.

Sealing members 46 and 47 with a cup-shaped cross section are fixedly installed on the inner peripheral surface of the hole 400. The sealing members 46 and 47 are arranged to sandwich the opening of the supply port 45 in the x-axis direction. The inner peripheral side (lip portion) of the sealing members 46 and 47 abuts the outer peripheral surface of each piston 41. The sealing members 46 and 47 restrict the flow of brake fluid through the gap between the inner peripheral surface of the hole 400 and the outer peripheral surface of the piston 41 in one direction. The sealing member 46P of the P system restricts the flow of brake fluid from the supply port 45P toward the negative x-axis direction (outside the master cylinder housing 40). The sealing member 46S of the S system allows only the flow of brake fluid from the supply port 45S toward the negative x-axis direction. The sealing member 47 allows only the flow of brake fluid from the supply port 45 toward the positive x-axis direction.

A hydraulic chamber 43 is defined inside the master cylinder housing 40 (hole 400). A hydraulic chamber 43P of the P system is defined between the pistons 41P and 41S (area sealed by the seal members 47P and 46S). A hydraulic chamber 43S of the S system is defined between the piston 41S and the bottom of the master cylinder housing 40 (area sealed by the seal member 47S). A coil spring 42 serving as a return spring for the piston 41 is installed in a compressed state in each hydraulic chamber 43. A discharge port 44 opens in each hydraulic chamber 43. As shown in FIG. 9, when the brake pedal is not depressed (when the flange portion 21 of the push rod 2 is in contact with the stopper portion 507 of the stroke simulator housing 50), each piston 41 is located at the most negative side of the x-axis, and the communication hole 412 of each piston 41 is located on the negative side of the x-axis from the seal member 47. Therefore, the supply port 45 communicates with the inner periphery of the recess 411 of each piston 41, i.e., the hydraulic chamber 43, through the communication hole 412. Brake hydraulic pressure is generated when the piston 41 operates in the x-axis direction within the hole 400. Specifically, the thrust of the push rod 2 in the x-axis positive direction is transmitted to the piston 41P by the driver's brake operation. When each piston 41 strokes toward the x-axis positive direction, the volume of each hydraulic chamber 43 decreases. When the communication hole 412 is positioned on the x-axis positive side of the seal member 47, communication between each hydraulic chamber 43 and the supply port 45 (reservoir tank 3) is blocked, and hydraulic pressure (master cylinder hydraulic pressure) corresponding to the brake operation is generated in each hydraulic chamber 43. Note that approximately the same hydraulic pressure is generated in both hydraulic chambers 43. Brake fluid (master cylinder hydraulic pressure) is supplied from each hydraulic chamber 43 to the actuator 8 (wheel cylinder) through the discharge port 44.

The stroke simulator 5 is provided so that the brake fluid flowing out from the master cylinder 4 can flow in, and is a source of reaction force that generates a simulated reaction force for the brake pedal. The stroke simulator 5 is connected to the master cylinder 4 via an oil passage (brake piping 70) and to the reservoir tank 3 via an oil passage (brake piping 71). The stroke simulator 5 has a stroke simulator housing 50, a reaction piston 51, and a coil spring 52. The stroke simulator housing 50 has a main body portion 50a, a connection portion 50b, and a flange portion 50c, which are integral with each other.

The main body 50a is a stepped cylindrical body with a bottom, and has a large diameter cylindrical portion 50d, a small diameter cylindrical portion 50e, and a flange portion 50f integrally therewith. The small diameter cylindrical portion 50e is provided on the x-axis positive side of the large diameter cylindrical portion 50d, and is approximately coaxial with the cylindrical portion 50d. The flange portion 50f is provided on the x-axis positive side of the small diameter cylindrical portion 50e, and is approximately coaxial with the cylindrical portion 50e. The cylindrical portion 50e is provided with an air bleeder 57 for bleeding air from the stroke simulator 5. The air bleeder 57 is provided so as to protrude from the outer peripheral surface of the cylindrical portion 50e on the x-axis positive side and the z-axis positive side to the y-axis negative side. The outer diameter of the flange portion 50f (main body excluding the fastening portions 50g and 50h described below) is larger than the outer diameter of the cylindrical portion 50e and smaller than the outer diameter of the cylindrical portion 50d. A fastening portion 50g having a bolt hole extending in the x-axis direction is provided on the y-axis positive side and z-axis negative side of the flange portion 50f. A fastening portion 50h having a bolt hole extending in the x-axis direction is provided on the y-axis negative side and z-axis positive side of the flange portion 50f. The fastening portions 50g and 50h are provided at approximately symmetrical positions across the axis of the main body portion 50a. A first axial hole 501, a second axial hole 502, a valve mounting hole 503, an oil passage 55, and the like are formed inside the main body portion 50a. The first axial hole 501 is formed to extend in the x-axis direction on the inner periphery side of the large-diameter cylindrical portion 50d. The second axial hole 502 has a smaller diameter than the first axial hole 501 and is formed on the inner periphery side of the small-diameter cylindrical portion 50e so as to extend in the x-axis direction continuously with the first axial hole 501, and opens at the bottom of the cylindrical portion 50d on the x-axis positive side. An oil passage for the air bleeding bleeder 57 opens at the positive x-axis end and positive z-axis end of the second axial hole 502. One end of the main body 50a (the positive x-axis end of the second axial hole 502) is closed, and the other end (the negative x-axis end of the first axial hole 501) is open.

The valve mounting hole 503 is formed on the inner periphery of the flange portion 50f and the cylindrical portion 50e so as to extend in the x-axis direction, and opens on the positive x-axis side of the flange portion 50f. The valve mounting hole 503 has a stepped shape in which the diameter decreases from the positive x-axis side to the negative x-axis side. The negative x-axis end of the valve mounting hole 503 and the positive x-axis end of the second axial hole 502 are connected via an oil passage 55 extending in the x-axis direction. The axial holes 501, 502, the valve mounting hole 503, and the oil passage 55 are formed approximately coaxially. A connection port 58 communicating with the first axial hole 501 is provided on the positive z-axis side and the positive y-axis side of the cylindrical portion 50d. A pipe mounting portion 580 is connected to the connection port 58. The other end of the brake pipe 71 is attached to the pipe mounting portion 580. Pipe mounting portion 580 protrudes toward the positive y-axis direction from the outer surface of cylindrical portion 50d slightly toward the positive x-axis direction, the positive y-axis direction, and the positive z-axis direction, and is bent toward the positive x-axis direction midway. The tip of pipe mounting portion 580 to which brake pipe 71 is attached opens toward the positive x-axis direction.

The brake pipe 71 is not a steel pipe, but is made of a flexible pipe made of rubber or other material. As shown in FIG. 5, the brake pipe 71 is installed in a U-shape when viewed from the y-axis positive side. The brake pipe 71 extends from the pipe mounting portion 320a of the reservoir tank 3 toward the x-axis positive side, bends toward the z-axis negative side so as to enclose the discharge port 44P (which protrudes and opens toward the y-axis positive side) on the inner periphery, then turns back toward the x-axis negative side and is attached to the pipe mounting portion 580. The first axial hole 501 is connected to the supply port 32a of the reservoir tank 3 through the brake pipe 71 and communicates with the reservoir tank 3. A connection port 59 is provided on the y-axis positive side of the boundary between the cylindrical portion 50e and the flange portion 50f. The connection port 59 communicates with the valve mounting hole 503, and is connected to the discharge port 44P that opens on the y-axis positive side of the master cylinder 4 via the brake pipe 70, and communicates with the master cylinder 4 (hydraulic chamber 43P). The brake pipe 70 is configured as a pipe (e.g., a steel pipe) that is smaller in diameter and has higher rigidity than the brake pipe 71. As shown in FIG. 7, the brake pipe 70 is installed in a U-shape when viewed from the x-axis direction. The brake pipe 70 extends from the discharge port 44P that opens on the y-axis positive side of the master cylinder 4, bending toward the y-axis positive side and the z-axis negative side, then turns back toward the y-axis negative side so as to wrap the brake pipe 71 on the inner periphery, and is connected to the connection port 59.

The connection portion 50b is provided on the z-axis positive side of the main body portion 50a (cylindrical portion 50d). The connection portion 50b is cylindrical with a bottom extending in the x-axis direction. On both sides of the connection portion 50b in the y-axis direction, fastening portions 50i, 50j are provided with bolt holes extending in the x-axis direction. The outer peripheral surface of the connection portion 50b (including fastening portions 50i, 50j) is provided with approximately the same shape and dimensions as the outer peripheral surface of the flange portion 40b (including fastening portions 40d, 40e) of the master cylinder housing 40 when viewed from the x-axis direction. The pipe mounting portion 320a of the reservoir tank 3 is located on the y-axis negative side of the y-axis positive end edge of the connection portion 50b (fastening portion 50i) (it does not protrude further in the y-axis positive direction than the fastening portion 50i). The pipe mounting portion 320b of the reservoir tank 3 is located on the positive y-axis side of the negative y-axis edge of the connection portion 50b (fastening portion 50j) (it does not protrude further in the negative y-axis direction than the fastening portion 50j). The tip of the negative y-axis side of the air bleeding bleeder 57 is located on the positive y-axis side of the negative y-axis edge of the connection portion 50b (fastening portion 50j) (it does not protrude further in the negative y-axis direction than the fastening portion 50j).

As shown in FIG. 9, a first axial hole 504, a second axial hole 505, and a third axial hole 506 are formed inside the connection part 50b. The first axial hole 504 is formed in a substantially cylindrical shape extending in the x-axis direction and opens on the positive x-axis side of the connection part 50b. The diameter of the first axial hole 504 is slightly larger than the diameter of the fitting part 40c of the master cylinder housing 40. The second axial hole 505 has a smaller diameter than the first axial hole 504 and is formed so as to extend in the x-axis direction in continuation of the first axial hole 504. The third axial hole 506 has a smaller diameter than the second axial hole 505 and is formed so as to extend in the x-axis direction in continuation of the second axial hole 505 and opens on the negative x-axis side of the stroke simulator housing 50 (the side of the vehicle mounting surface 508). The axial holes 504 to 506 are formed substantially coaxially. Fastening portions 50i and 50j are provided at positions approximately symmetrical with respect to the axis of holes 504 to 506. A stopper portion 507 is formed at the bottom of the negative x-axis side of connection portion 50b so as to surround third axial hole 506. The surface of stopper portion 507 on the positive x-axis side is tapered and approximately parallel to the surface of flange portion 21 of push rod 2 on the negative x-axis side, and is provided so as to be able to abut against the surface of flange portion 21 on the negative x-axis side.

The flange portion 50c is provided on the negative x-axis side of the stroke simulator housing 50 in the form of a plate extending approximately parallel to the yz plane. The flange portion 50c is a fixing flange for fixing the stroke simulator housing 50 to the vehicle. When viewed from the x-axis direction, the flange portion 50c is approximately rectangular having a side extending in the y-axis direction and a side extending in the z-axis direction, and a stud shaft (a stud bolt as a fixing device) 509 is fixed to each of the four corners so as to protrude in the negative x-axis direction. The axis of the main body portion 50a (axial hole 501, etc.) and the axis of the connection portion 50b (axial hole 504, etc.) are located approximately in the center of the flange portion 50c in the y-axis direction. The axis of the connection portion 50b is located approximately in the center of the flange portion 50c in the z-axis direction. The axis of the main body portion 50a is located slightly below (negative z-axis side) the edge of the negative z-axis side of the flange portion 50c. The width (y-axis dimension) of the flange portion 50c is larger than the width (y-axis dimension) of the main body portion 50a, larger than the width (y-axis dimension) of the main body portion 40a of the master cylinder housing 40, and larger than the width (y-axis dimension) of the reservoir tank 3. The width (y-axis dimension) of the flange portion 50c is approximately the same as the width (y-axis dimension) of the connection portion 50b or the flange portion 40b of the master cylinder housing 40. Specifically, as shown in Figures 3 and 7, the outer periphery of the fastening portions 50i, 50j or the fastening portions 40d, 40e constituting both ends in the y-axis direction of the connection portion 50b or the flange portion 40b is approximately aligned with both ends in the y-axis direction of the flange portion 50c (is at approximately the same y-axis position). The height (z-axis dimension) of the flange portion 50c is larger than the height (z-axis dimension) of the connection portion 50b or the master cylinder housing 40 (flange portion 40b).

As shown in FIG. 9, the reaction piston 51 is installed in the second axial hole 502 of the main body 50a of the stroke simulator housing 50 so as to be operable in the x-axis direction. The reaction piston 51 is installed so as to protrude from the x-axis negative end of the second axial hole 502 into the first axial hole 501. A spring retainer 512 is provided at the x-axis negative end of the reaction piston 51 protruding into the first axial hole 501. The spring retainer 512 is provided so as to be able to move integrally with the reaction piston 51 within the first axial hole 501. A seal groove 510 is provided on the outer periphery of the reaction piston 51, and a seal member 511 is installed in the seal groove 510. The seal member 511 abuts against the inner circumferential surface of the second axial hole 502. A plate-shaped spring retainer 53 is fixedly installed at the opening on the x-axis negative side of the first axial hole 501 to close this opening. A seal member 532 is installed on the outer periphery of the spring retainer 53. The seal member 532 comes into contact with the inner circumferential surface of the first axial hole 501, thereby sealing the opening of the first axial hole 501 liquid-tight. Inside the stroke simulator housing 50, a main chamber 54 and an auxiliary chamber 56 are defined by the reaction piston 51. The main chamber 54 is defined in the second axial hole 502 and on the x-axis positive side of the reaction piston 51. The auxiliary chamber 56 is defined in the first axial hole 501 and on the x-axis negative side of the reaction piston 51. The communication between the main chamber 54 and the auxiliary chamber 56 is suppressed by the seal member 511. In the main chamber 54, an oil passage 55 and an oil passage for an air bleeder 57 are always open.

In the auxiliary chamber 56, a coil spring 52 is installed in a compressed state as a return spring for the reaction piston 51. The coil spring 52 is an elastic member that constantly urges the reaction piston 51 toward the main chamber 54 (in a direction that reduces the volume of the main chamber 54 and increases the volume of the auxiliary chamber 56). The positive x-axis end of the coil spring 52 is held in contact with the outer periphery of the spring retainer 512, and the negative x-axis end of the coil spring 52 is held in contact with the outer periphery of the spring retainer 53. A recess 530 that opens toward the positive x-axis side is formed in a portion of the spring retainer 53 that is more inward than the coil spring 52. An elastic member 531 is installed in the recess 530. The elastic member 531 protrudes toward the positive x-axis side from the spring retainer 53. The elastic member 531 faces the portion of the spring retainer 512 that is more inward than the coil spring 52 in the x-axis direction. When the amount of movement of the reaction piston 51 (spring retainer 512) in the negative x-axis direction exceeds a predetermined amount, the elastic member 531 comes into contact with the inner peripheral portion of the spring retainer 512 and elastically deforms. This restricts the movement of the reaction piston 51 in the negative x-axis direction and also functions as a damper that absorbs the impact caused by the restriction.

The brake device 1 as a master cylinder unit is also a valve unit incorporating a stroke simulator valve 6. The stroke simulator valve 6 is a normally closed (closed in a non-energized state) simulator shutoff valve that is provided to limit the inflow of brake fluid into the stroke simulator 5. The stroke simulator valve 6 is mounted in a valve mounting hole 503 formed in the stroke simulator housing 50 (main body portion 50a). The surface of the main body portion 50a (flange portion 50f) on the x-axis positive side where the valve mounting hole 503 opens constitutes the valve mounting surface. The main chamber 54 of the stroke simulator 5 is connected to the stroke simulator valve 6 via an oil passage 55. The stroke simulator valve 6 is connected to the hydraulic chamber 43P of the master cylinder 4 via an oil passage (brake piping 70).

9, the stroke simulator valve 6 has a solenoid 61, a valve body 62, an armature 63, a plunger 64, a coil spring 65, a valve seat member 66, and a number of oil passage components. The solenoid 61 is fastened with bolts to a flange portion 50f (fastening portions 50g, 50h) at the x-axis positive end of the main body portion 50a of the stroke simulator housing 50. The armature 63 is fixedly installed on the inner periphery of the solenoid 61, and generates an electromagnetic force (magnetic attraction force) when electricity is applied to the solenoid 61. A connector portion 610 that opens toward the x-axis positive end of the solenoid 61 is provided at the x-axis positive end. A wiring (harness) that supplies a drive current to the solenoid 61 is connected to the connector portion 610. The valve body 62 is a hollow cylinder made of a non-magnetic material, and is fixedly installed so as to fit onto the outer periphery of the armature 63, and extends in the negative x-axis direction of the armature 63. The plunger 64 is accommodated in the valve body 62 so as to be movable back and forth in the x-axis direction. A spherical valve body 640 is provided at the tip of the plunger 64 on the negative x-axis direction side. The valve body 640 operates in the x-axis direction. The coil spring 65 is installed in a compressed state between the armature 63 and the plunger 64, and constantly biases the plunger 64 in the negative x-axis direction. The valve seat member 66 is installed on the inner periphery of the valve mounting hole 503 of the main body 50a. The valve seat member 66 is a cylinder with a bottom, and a valve seat is provided at the bottom on the positive x-axis side. An orifice 660 extending in the x-axis direction is provided through the bottom, and opens at the center of the valve seat. The plunger 64 is driven by the electromagnetic force of the armature 63 (attraction force in the positive x-axis direction), and the valve body 640 opens and closes the orifice 660, controlling the communication state of the oil passage (simulator oil passage described below) that includes the orifice 660.

The oil passage component includes a first member 67 as a body, second and third members 68 and 69 as filters, and a seal member 60. The first member 67 is a hollow member fixed by a flange to the opening of the valve mounting hole 503 on the positive x-axis side. A valve seat member 66 is fixed to the inner periphery of the first member 67, and an oil passage is formed between the inner periphery of the first member 67 and the outer periphery of the valve seat member 66. The second member 68 is a ring-shaped filter member fixed to the negative x-axis side of the first member 67. The valve seat member 66 is installed on the inner periphery of the second member 68, and an oil passage is formed between the inner periphery of the second member 68 and the outer periphery of the valve seat member 66. The third member 69 is a disk-shaped filter member (retainer of the seal member 60) installed at the bottom of the negative x-axis side of the valve mounting hole 503, and the valve seat member 66 is installed on its inner periphery. The seal member 60 is a seal member with a cup-shaped cross section similar to the seal member 46, and is installed between the second member 68 and the third member 69. The valve seat member 66 is fixedly installed on the inner periphery of the seal member 60. No oil passage is formed between the inner periphery of the seal member 60 and the outer periphery of the valve seat member 66. The lip portion on the outer periphery of the seal member 60 contacts the inner periphery of the valve mounting hole 503 so as to open toward the positive x-axis direction. The flow of brake fluid between the seal member 60 (lip portion) and the inner periphery of the valve mounting hole 503 is permitted only from the negative x-axis direction side to the positive x-axis direction side, and flow in the opposite direction is suppressed.

A connection port 59 is opened between the second member 68 and the seal member 60 on the inner circumference of the valve mounting hole 503. An oil passage 55 that communicates with the main chamber 54 of the stroke simulator 5 is opened at the bottom of the valve mounting hole 503 on the negative x-axis side. The connection port 59 communicates with the orifice 660 through the oil passage between the outer circumference of the valve seat member 66 and the inner circumference of the first and second members 67, 68, and the recess provided at the positive x-axis end of the first member 67. The orifice 660 communicates with the oil passage 55 through an oil passage 661 provided on the inner circumference side of the valve seat member 66. The above-mentioned paths form a simulator oil passage that connects the hydraulic chamber 43P and the main chamber 54 and can be switched between communication and blocking by the stroke simulator valve 6.

That is, the main chamber 54 of the stroke simulator 5 communicates with the hydraulic chamber 43P via the oil passage 55, the stroke simulator valve 6, and the brake pipe 70. The auxiliary chamber 56 of the stroke simulator 5 is connected to the reservoir tank 3 via the brake pipe 71. The auxiliary chamber 56 is always in communication with the reservoir tank 3 and is open to low pressure (atmospheric pressure), forming a back pressure chamber of the stroke simulator 5. The auxiliary chamber 56 may not be connected to the reservoir tank 3 and may be directly open to low pressure (atmospheric pressure). When the stroke simulator valve 6 is open, the brake fluid flowing out of the master cylinder 4 (hydraulic chamber 43P) due to the driver's brake operation flows into the inside of the stroke simulator housing 50 (main chamber 54) through the simulator oil passage. This brake fluid operates the reaction force piston 51 in the axial direction within the hole 502. This generates a pseudo reaction force to the operation of the brake pedal, which is applied to the brake pedal. Specifically, the stroke simulator valve 6 opens when energized and communicates with the simulator oil passage. The master cylinder hydraulic pressure acts on the main chamber 54 of the stroke simulator 5 through the simulator hydraulic line. When a predetermined hydraulic pressure (master cylinder hydraulic pressure) or more acts on the pressure-receiving surface of the reaction piston 51 in the main chamber 54, this pressure causes the reaction piston 51 to move axially toward the auxiliary chamber 56 while compressing the coil spring 52. The volume of the main chamber 54 expands, and brake fluid flows from the master cylinder 5 (hydraulic pressure chamber 43P) into the main chamber 54 through the simulator hydraulic line. Brake fluid is also discharged from the auxiliary chamber 56 to the reservoir tank 3 through the brake piping 71.

In this way, when the driver applies the brakes (depresses the brake pedal), the stroke simulator 5 creates a pedal stroke by drawing in brake fluid from the master cylinder 5, simulating the fluid stiffness of the wheel cylinder and reproducing the feeling of pressing the brake pedal. Here, while only the coil spring 52 is compressed in the early stage of pressing the brake pedal, the spring constant is low and the increase gradient of the pedal reaction force is low. While the elastic member 531 is compressed in addition to the coil spring 52 in the later stage of pressing the brake pedal, the spring constant is high and the increase gradient of the pedal reaction force is high. By adjusting these spring constants, the pedal depression feeling is set to be similar to that of an existing master cylinder, for example. Note that when the driver finishes the brake operation (depresses the brake pedal back) and the pressure in the main chamber 54 decreases below a predetermined level, the reaction piston 51 returns to its initial position due to the biasing force (elastic force) of the coil spring 52.

In addition, an oil passage that connects the inner circumference of the third member 69 with the end face in the positive x-axis direction may be formed, and the oil passage 55 may be connected to the negative x-axis side of the seal member 60 through this oil passage. In this case, a bypass oil passage is formed that is provided in parallel with the simulator oil passage and the flow direction is regulated by the seal member 60. The seal member 60 allows only the flow of brake fluid from the main chamber 54 of the stroke simulator 5 to the hydraulic chamber 43P of the master cylinder 4 in the bypass oil passage. The bypass oil passage allows the brake fluid to be returned from the main chamber 54 to the master cylinder 4 side through the bypass oil passage even if the stroke simulator valve 6 has a closed failure (stuck in a closed state) with brake fluid flowing into the main chamber 54.

The mounting structure of the brake device 1 will be described below. The master cylinder housing 40 is fixed to the stroke simulator housing 50. The housings 40, 50 are fixed integrally to each other. The housings 40, 50 have joint surfaces for fixing them integrally to each other. The outer peripheral surface of the fitting portion 40c of the master cylinder housing 40 and the x-axis negative end surface of the flange portion 40b, as well as the inner peripheral surface of the first axial hole 504 of the connection portion 50b of the stroke simulator housing 50 and the x-axis positive end surface of the connection portion 50b (where the first axial hole 504 opens) constitute the above joint surface. This joint surface has a spigot portion (the outer peripheral surface of the fitting portion 40c and the inner peripheral surface of the first axial hole 504) that functions as a spigot joint. In other words, a part of the stroke simulator housing 50 (connection portion 50b) is recessed and the protruding portion of the master cylinder housing 40 is fitted into this to join the two housings 40, 50. Specifically, the fitting portion 40c of the master cylinder housing 40 is inserted into the first axial hole 504 of the stroke simulator housing 50, and the two are fitted together. By sliding the two relative to each other in the x-axis direction, the x-axis negative end face of the flange portion 40b of the master cylinder housing 40 abuts against the x-axis positive end face of the connection portion 50b. The master cylinder housing 40 and the stroke simulator housing 50 are fastened together by inserting and fastening the fastening portions 40d, 40e of the master cylinder housing 40 (flange portion 40b) and the fastening portions 50i, 50j of the stroke simulator housing 50 (connection portion 50b) with bolts 10. Note that the seal member 402 installed on the fitting portion 40c abuts against the inner peripheral surface of the first axial hole 504, thereby sealing the opening of the first axial hole 504 liquid-tightly. The portion of the master cylinder housing 40 that protrudes in the negative x-axis direction beyond the mating portion 40c on the inner periphery of the mating portion 40c is housed in the first axial hole 504. The piston 41P that protrudes in the negative x-axis direction from the hole 400 of the master cylinder housing 40 is housed in the second axial hole 505.

On the other hand, the surface of the stroke simulator housing 50 on the negative x-axis direction, including the surface of the flange portion 50c on the negative x-axis direction, constitutes a vehicle mounting surface 508 for mounting the stroke simulator housing 50 (brake device 1) to the vehicle. The stroke simulator housing 50 is fastened and fixed to the lower part of the dash panel (floor panel) of the vehicle body on the positive x-axis direction side by a stud shaft 509. The dash panel is a partition member on the vehicle body side that separates the engine room (or the motor room in which a power unit such as a driving motor is installed; hereinafter, simply referred to as the engine room) from the passenger compartment. The stroke simulator housing 50 is fixed to the dash panel at four fastening points while a slight gap in the x-axis direction is formed between the flange portion 50c and the dash panel by the spacer of the stud shaft 509. The size of the flange portion 50c (thickness in the x-axis direction, width in the y-axis direction, height in the z-axis direction) is set to a level that can sufficiently secure the mounting strength of the brake device 1 to the vehicle, but is not unnecessarily large.

As described above, the master cylinder housing 40 is fixed to the stroke simulator housing 50, and the master cylinder housing 40 is fixed to the vehicle via the stroke simulator housing 50. With the brake device 1 fixed to the dash panel, the negative x-axis side of the push rod 2 penetrates the dash panel and protrudes into the vehicle interior (negative x-axis side). The master cylinder 4, the reservoir tank 3, the stroke simulator 5, etc. are installed in the engine room (positive x-axis side). Note that a part of the stopper portion 507 of the stroke simulator housing 50 protrudes further than the vehicle mounting surface 508 in the negative x-axis direction to form a locking portion. A boot 2a is attached to this locking portion to cover the push rod 2. As described above, the stroke simulator housing 50 is rigidly (without an elastic body) fixed to the dash panel by the stud shaft 509. This creates an excellent reaction force against the driver's braking force (pressure) input to the brake pedal (push rod 2), and the braking force is appropriately transmitted to the piston 41 of the master cylinder 4, generating master cylinder hydraulic pressure according to the braking force.

Next, the arrangement of the brake device 1 will be described. When viewed in the z-axis direction, the master cylinder 4 and the stroke simulator 5 are arranged so that they are in upper and lower positions when mounted on the vehicle. That is, the master cylinder 4 and the stroke simulator 5 are integrally arranged so that they overlap each other when viewed vertically (vertically) when mounted on the vehicle. When mounted on the vehicle, they are arranged in the order of the reservoir tank 3, the master cylinder 4, and the stroke simulator 5 from the top. That is, the reservoir tank 3 is arranged above the master cylinder 4, and the stroke simulator 5 is arranged below the master cylinder 4. In addition, the master cylinder 4 and the stroke simulator 5 are arranged in parallel to each other. In other words, they are arranged so that the axial direction of the master cylinder 4 and the axial direction of the stroke simulator 5 are approximately the same direction. As a result, when mounted on the vehicle, the master cylinder 4 and the stroke simulator 5 are in upper and lower positions with their axial directions aligned.

7, when mounted on a vehicle, the center of the reservoir tank 3 in the y-axis direction, the axis of the master cylinder 4, and the axis of the stroke simulator 5 are arranged so as to be aligned on approximately the same straight line parallel to the z-axis, as viewed from the x-axis direction. Therefore, when mounted on a vehicle, the range in which the reservoir tank 3, the master cylinder 4, and the stroke simulator 5 overlap each other when viewed from the vertical direction is maximized. This minimizes the area of the reservoir tank 3, the master cylinder 4, and the stroke simulator 5 projected vertically. As shown in FIGS. 3 and 4, the master cylinder 4 (main body 40a of the master cylinder housing 40) and the stroke simulator 5 (main body 50a of the stroke simulator housing 50) are arranged to fit within the width (y-axis dimension) of the reservoir tank 3. In addition, the brake pipes 70 and 71 are arranged to fit within the overall height (z-axis dimension) of the reservoir tank 3, the master cylinder housing 40, and the stroke simulator housing 50, as shown in FIG. 5. For example, the brake pipe 71 does not protrude further in the positive direction of the z-axis than the reservoir tank 3. The brake pipe 70 does not protrude further in the negative direction of the z-axis than the stroke simulator housing 50.

When viewed in the y-axis direction, each member and structure of the brake device 1 is arranged to fit within the width of the flange portion 50c of the stroke simulator housing 50. For example, as shown in Figures 3 and 4, the master cylinder 4 (such as the flange portion 40b including the fastening portions 40d and 40e of the master cylinder housing 40) and the stroke simulator 5 (such as the connection portion 50b including the fastening portions 50i and 50j of the stroke simulator housing 50) are configured to fit within the width (dimension in the y-axis direction) of the flange portion 50c. Also, as shown in Figures 3 and 7, the brake pipe 71 is arranged to fit within the width (dimension in the y-axis direction) of the flange portion 50c. That is, the brake pipe 71 is disposed approximately parallel to the xz plane, and the brake pipe 71 (the y-axis positive end) is located on the y-axis negative side of the y-axis positive end edge of the flange portion 50c (it does not protrude further in the y-axis positive side than the flange portion 50c).

The stroke simulator valve 6 is disposed in the axial direction of the stroke simulator 5. That is, as shown in FIG. 7, the stroke simulator valve 6 is disposed on one axial side (x-axis positive side) of the stroke simulator 5 so as to overlap each other when viewed from the axial direction (x-axis direction) of the stroke simulator 5. Also, the stroke simulator valve 6 is disposed so that the operating direction of the valve body 640 (plunger 64) of the stroke simulator valve 6 and the operating direction of the reaction piston 51 of the stroke simulator 5 are substantially the same direction. More specifically, the stroke simulator valve 6 is disposed substantially coaxially with the stroke simulator 5. The central axis of the stroke simulator valve 6 (valve mounting hole 503) is provided substantially on the same line as the central axis of the stroke simulator 5 (axial holes 501, 502). Therefore, the range in which the stroke simulator 5 and the stroke simulator valve 6 overlap each other in the axial direction is maximized. As a result, the area of the stroke simulator 5 and the stroke simulator valve 6 projected in the x-axis direction is minimized. As shown in FIG. 7, the stroke simulator valve 6 (such as the flange portion 50f including the fastening portions 50g and 50h of the stroke simulator housing 50, and the solenoid 61) is arranged to fit within the width (y-axis dimension) and height (z-axis dimension) of the stroke simulator 5 (the main body portion 50a of the stroke simulator housing 50).

The stroke simulator valve 6 is arranged below the master cylinder 4 so as to overlap with the master cylinder 4 when mounted on the vehicle in the vertical direction. The master cylinder 4 and the stroke simulator valve 6 are arranged in parallel (so that their axial directions are approximately the same). As a result, the master cylinder 4 and the stroke simulator valve 6 are in upper and lower positions with their axial directions aligned. When mounted on the vehicle, the axis of the master cylinder 4 and the axis of the stroke simulator valve 6 are arranged so as to be aligned on approximately the same straight line parallel to the z axis when viewed from the x axis direction. Therefore, the range in which the master cylinder 4 and the stroke simulator valve 6 overlap with each other when viewed from the vertical direction is maximized. As shown in Figures 4 and 7, the stroke simulator valve 6 (the flange portion 50f including the fastening portions 50g and 50h of the stroke simulator housing 50, the solenoid 61, etc.) is arranged to fit within the width (y axis dimension) of the master cylinder 4 (the main body portion 40a of the master cylinder housing 40).

When viewed in the x-axis direction, as shown in Figures 3 and 4, the negative x-axis end of the stroke simulator 5, specifically the negative x-axis end of the main body 50a of the stroke simulator housing 50, is provided up to the flange 50c. The positive x-axis end of the stroke simulator valve 6, specifically the positive x-axis end of the solenoid 61 excluding the connector 610, is located on the negative x-axis side of the positive x-axis end face of the master cylinder housing 40 (does not protrude further in the positive x-axis direction than the master cylinder housing 40). As shown in Figures 3 to 6, the positive x-axis end of the reservoir tank 3, the positive x-axis end of the master cylinder 4, and the positive x-axis end of the stroke simulator valve 6 (connector 610) are located at approximately the same x-axis position. As shown in Figures 4 and 5, the brake pipe 71 is provided so as to fit within the length (x-axis dimension) of the master cylinder housing 40 and the stroke simulator housing 50. For example, the brake pipe 71 (its x-axis positive end) is located on the x-axis negative side of the x-axis positive end face of the master cylinder housing 40 (it does not protrude further in the x-axis positive direction than the master cylinder housing 40).

As shown in FIG. 8, when the brake device 1 is viewed from the negative x-axis side, the master cylinder 4, the stroke simulator 5, and the brake pipe 71 (most of the brake pipe on the negative z-axis side) are hidden by the flange 50c. As shown in FIG. 3, when the brake device 1 is viewed from the positive z-axis side, the master cylinder 4 (excluding part of the flange 40b of the master cylinder housing 40) and the stroke simulator 5 (excluding part of the connection part 50b of the stroke simulator housing 50 and the flange 50c, etc.) are hidden by the reservoir 3. Also, as shown in FIG. 6, when the brake device 1 is viewed from the negative y-axis side, the brake pipes 70 and 71 are hidden by the reservoir 3, the master cylinder 4, and the stroke simulator 5 (except for part of the brake pipe 71 on the negative z-axis side and part of the brake pipe 70 that can be seen through the gap between the master cylinder housing 40 and the stroke simulator housing 50).

Next, the actuator 8 will be described. FIG. 10 is a perspective view of the actuator 8 as seen from the negative x-axis, negative y-axis, and positive z-axis direction. The actuator 8 is a second brake fluid pressure generating source that receives brake fluid from the master cylinder 4 and the reservoir tank 3 and can generate brake fluid pressure independent of the driver's brake operation. The actuator 8 is provided between the wheel cylinders of each wheel and the master cylinder 4, and is a hydraulic control unit that can individually supply the master cylinder hydraulic pressure or a control hydraulic pressure generated by the actuator 8 to each wheel cylinder. The actuator 8 includes a hydraulic unit 8a and a controller (electronic control unit ECU) 8b that controls the operation of the hydraulic unit 8a. The hydraulic unit 8a and the controller 8b are configured as an integrated unit.

The hydraulic unit 8a has hydraulic devices for generating the controlled hydraulic pressure, such as a pump that is a hydraulic pressure generating source, and multiple control valves (solenoid valves) that switch the communication state of the oil passages formed in the housing 80. A motor 8c that drives the pump is integrally attached to the hydraulic unit 8a (housing 80). The specific hydraulic circuit configuration of the hydraulic unit 8a is similar to that of known hydraulic units, so a description is omitted. The hydraulic unit 8a is provided with a hydraulic pressure sensor that detects the hydraulic pressure (master cylinder hydraulic pressure, etc.) at a specified part of the oil passage, and the detected value is input to the controller 8b. The controller 8b is configured to be able to control the hydraulic pressure of each wheel cylinder independently of the driver's brake operation by controlling the operation of each device of the hydraulic unit 8a based on various input information.

The hydraulic unit 8a is connected to the brake device 1 via brake piping. The hydraulic unit 8a is arranged, for example, below the brake device 1 so that the direction of the x-axis in FIG. 10 coincides with the direction of the x-axis in FIG. 1. This reduces the projected area of the entire brake system in the vertical direction (vehicle up-down direction), improving vehicle mountability. The housing 80 of the hydraulic unit 8a is fixed to the vehicle body (engine room floor) via a damper 8d and a bracket 8e. On the upper side of the housing 80, the master cylinder ports 81 of the P system and the S system and four wheel cylinder ports 82 are provided as openings of the oil passages formed in the housing 80. The master cylinder port 81P of the P system is connected to the discharge port 44P (on the negative y-axis side) of the P system of the master cylinder 4 via the brake piping, and communicates with the hydraulic chamber 43P. The master cylinder port 81S of the S system is connected to the discharge port 44S of the S system of the master cylinder 4 via another brake pipe, and communicates with the hydraulic chamber 43S. Each wheel cylinder port 82 is connected to each wheel cylinder via a brake pipe. In addition, the other port of the housing 80 is connected to the supply port 32b of the reservoir tank 3 via a brake pipe, and communicates with the reservoir tank 3.

The controller 8b is configured separately from the master cylinder 4, in other words, separately from the brake device 1 (master cylinder unit including the stroke simulator valve 6). The controller 8b is provided with a connector 83 to which a harness is connected. The stroke simulator valve 6 and the controller 8b are connected via a harness. The controller 8b receives detection values sent from a pedal stroke sensor that detects the amount of brake pedal operation, and a hydraulic pressure sensor that detects the pump discharge pressure and master cylinder hydraulic pressure, as well as information on the driving state sent from the vehicle. Based on these detection values and information, the controller 8b controls the opening and closing of each solenoid valve of the hydraulic unit 8a and the motor rotation speed (pump discharge volume) according to a built-in program. By controlling the wheel cylinder hydraulic pressure in this way, it is possible to realize boost control to reduce the brake operation force, antilock brake control (ABS) to suppress wheel slippage due to braking (alleviating the tendency to lock), brake control (vehicle behavior control such as VDC and ESC) to stabilize the vehicle behavior by suppressing the vehicle's skidding, automatic brake control such as preceding vehicle following control, and regenerative cooperative brake control to achieve a target deceleration (target braking force) in cooperation with the regenerative brake. For example, in boost control, the assist hydraulic pressure formed by driving the hydraulic unit 8a (using the pump discharge pressure) is applied to the master cylinder hydraulic pressure generated in response to the brake operation, thereby creating a wheel cylinder hydraulic pressure higher than the master cylinder hydraulic pressure.

When the hydraulic unit 8a is inactive, the hydraulic chamber 43 of the master cylinder 4 and the wheel cylinder of each wheel are in communication. At this time, the master cylinder hydraulic pressure generated by the driver's brake pedal operation force (pressure brake) generates the wheel cylinder hydraulic pressure. In response to the brake pedal depression operation, brake fluid is supplied from the hydraulic chamber 43 of each system of the master cylinder 4 (via the oil passage in the hydraulic unit 8a) to each wheel cylinder (when pressure is increased). In other words, the master cylinder hydraulic pressure generated in response to the brake pedal depression operation is supplied directly to the wheel cylinder. Also, when the brake pedal is released, brake fluid is returned from each wheel cylinder (via the oil passage in the hydraulic unit 8a) to the master cylinder 4 (when pressure is reduced). At this time, the stroke simulator valve 6 provided on the simulator oil passage is de-energized and closed. Therefore, communication between the master cylinder 4 (hydraulic chamber 43P) and the stroke simulator 5 (main chamber 54) is cut off.

On the other hand, when the hydraulic unit 8a is in operation, it is possible to generate wheel cylinder hydraulic pressure by hydraulic pressure generated by the pump while blocking communication between the hydraulic chamber 43 of the master cylinder 4 and each wheel cylinder. This constitutes a so-called brake-by-wire system, and it is possible to realize boost control, regenerative brake coordination control, and the like. At this time, the stroke simulator valve 6 is energized and opens. Therefore, the master cylinder 4 (hydraulic chamber 43P) and the stroke simulator 5 (main chamber 54) are in communication. When the driver performs a brake operation (depresses or releases the brake pedal), the stroke simulator 5 draws and discharges brake fluid from the master cylinder 4 to generate a pedal stroke. The controller 8b controls the operation (energized state) of the stroke simulator valve 6. That is, the controller 8b is an integration of a hydraulic controller for controlling the wheel cylinder hydraulic pressure and a controller for controlling the stroke simulator valve 6. In other words, the former hydraulic controller includes the latter controller.

[Function of Example 1]
Next, the operation will be described. In the brake system of this embodiment, the brake device 1 and the actuator 8 are provided separately (separately). Therefore, each device (brake device 1, actuator 8) has high versatility, and the brake system can be easily applied to different vehicle models. In addition, the brake device 1 can be made smaller than when the brake device 1 and the actuator 8 are provided integrally. Generally, the installation space in a vehicle for the brake device as an input device for inputting brake operation is limited, so by making the brake device 1 smaller, the layout freedom of the brake device 1 can be improved.

In the brake system of this embodiment, the actuator 8 is provided to be capable of executing boost control that generates a wheel cylinder hydraulic pressure higher than the master cylinder hydraulic pressure to reduce the brake operation force. In other words, the actuator 8 as a wheel cylinder hydraulic pressure control means provided separately from the brake device 1 can also function as a booster. Therefore, it is possible to omit a conventional booster, for example, a master back that boosts the brake operation force using the intake pressure (negative pressure) generated by the engine of the vehicle. In addition, the brake device 1 as an input device does not need to be provided with a booster that boosts the brake operation force using an accumulator means (accumulator) or an electric motor, etc. Therefore, the entire brake system can be simplified and is highly applicable to vehicles. In addition, the brake device 1 can be made smaller and the vehicle space can be saved. For example, the brake device 1 can be installed in the space that was previously required for installing the master back. In addition, instead of making the actuator 8 function as a booster, a link type booster using a link mechanism or an electric (hydraulic) booster using an electric motor, etc. may be provided. In addition, the brake device 1 (brake system) of this embodiment is suitable for vehicles capable of generating regenerative braking force, but can also be applied to other vehicles (non-electric vehicles that are driven only by an engine).

In the brake device 1, the reservoir tank 3, the master cylinder 4, and the stroke simulator 5 are provided integrally (as one master cylinder unit). This allows the oil passage connecting the reservoir tank 3, the master cylinder 4, and the stroke simulator 5 to be shortened. In addition, the brake device 1, which is an input device composed of the reservoir tank 3, the master cylinder 4, and the stroke simulator 5, can be made compact. By making the brake device 1 compact, it can be easily installed in different vehicle models, making it highly versatile. This allows the manufacturing costs to be reduced.

Here, the master cylinder generally has variations according to the class of the vehicle on which it is installed. If the master cylinder and the stroke simulator are formed using a common housing, it is necessary to set the common housing for each variation of the master cylinder. Therefore, in this case, it is difficult to apply the brake device to different vehicle models (vehicle classes), and it is difficult to reuse it, and there is a risk that it will lack versatility. In contrast, in the brake device 1, the master cylinder housing 40 is fixed to the stroke simulator housing 50. That is, before the brake device 1 is assembled, the master cylinder 4 and the stroke simulator 5 are separate (each has its own housing 40, 50) and are in a separated state from each other. The brake device 1 is completed by fixing the housings 40, 50 together during assembly. Therefore, it is not necessary to newly provide a housing for the entire brake device 1 for each variation of the master cylinder 4. Therefore, since the existing master cylinder 4 can be used, it is highly versatile for different vehicle models (vehicle classes). In other words, the master cylinder 4 and the stroke simulator 5 are modularized, and it is possible to appropriately combine each module 4, 5 according to the vehicle model (vehicle class) on which it is installed. Therefore, it is easy to reuse existing products. Specifically, by appropriately combining a given stroke simulator 5 (stroke simulator housing 50) with an existing master cylinder 4 (master cylinder housing 40) that corresponds to the class of the vehicle on which it is installed, it is possible to obtain a brake device 1 that is suitable for the vehicle.

The master cylinder housing 40 and the stroke simulator housing 50 are joined (spigot joint) by a joint surface (such as the outer surface of the fitting portion 40c) that has a spigot portion, and are fixed together as a unit. This makes it easier to reuse an existing (general-purpose) master cylinder. For example, if the stroke simulator housing 50 is provided with a recess (in this embodiment, the first axial hole 504) that can fit into some protrusion (in this embodiment, the fitting portion 40c on the negative x-axis side) that is originally provided on the housing of the existing master cylinder, and the two are spigot-jointed, the existing master cylinder 4 can be used as is.

The stroke simulator housing 50 has a vehicle mounting surface 508 and is attached to the vehicle by the vehicle mounting surface 508. Therefore, the master cylinder 4 and the stroke simulator 5 can be easily attached to the vehicle via the stroke simulator housing 50. That is, the master cylinder housing 40 may be attached to the vehicle instead of the stroke simulator housing 50. However, in this case, if the stroke simulator housing 50 is to be fixed to the master cylinder housing 40 attached to the vehicle without changing the shape of the existing master cylinder housing 40 as much as possible (to improve versatility), the suitable portion of the master cylinder housing 40 to which the stroke simulator housing 50 can be joined is limited. That is, it is relatively not easy to attach the stroke simulator 5 to the vehicle via the master cylinder housing 40 (attached to the vehicle) while improving the versatility of the master cylinder 4. In contrast, there are fewer restrictions on changing the shape of the stroke simulator housing 50 than there are on the master cylinder housing 40. Therefore, if the stroke simulator housing 50 is attached to the vehicle and the master cylinder 4 is attached to the vehicle via the stroke simulator housing 50 as in this embodiment, the shape of the stroke simulator housing 50 can be set relatively freely, so that a portion to which the master cylinder housing 40 can be joined can be relatively easily secured. That is, the master cylinder 4 and the stroke simulator 5 can be easily attached to the vehicle while improving the versatility of the master cylinder 4. In addition, since the stroke simulator housing 50 is attached to the vehicle in this embodiment, the versatility of the stroke simulator housing 50 can be improved compared to when the master cylinder housing 40 is attached to the vehicle. That is, when the stroke simulator housing 50 is attached to the vehicle, the vehicle mounting portion (the fitting portion 40c in this embodiment) originally provided on the existing master cylinder housing can be selected as the portion of the master cylinder housing 40 to be joined to the stroke simulator housing 50. This vehicle mounting portion (the fitting portion 40c) is standardized to a certain extent. If the stroke simulator housing 50 is provided with a concave shape corresponding to this standardized vehicle mounting portion (the fitting portion 40c), it can be used as a general-purpose stroke simulator housing 50. In other words, it is possible to combine the above-mentioned general-purpose stroke simulator housing 50 with any master cylinder housing 40, making it easy to reuse the stroke simulator 5.

Because the master cylinder 4 (master cylinder housing 40) and the stroke simulator 5 (stroke simulator housing 50) are separated before assembly, it is preferable to provide brake pipes 70, 71 that form an oil passage connecting the two. In this embodiment, the pipe mounting portion 320a of the reservoir tank 3 and the connection port 58 of the stroke simulator 5 are provided on the same side (y-axis positive side) of the brake device 1, so that the brake pipe 71 can be shortened while improving the connection workability and handling of the brake pipe 71. The same applies to the brake pipe 70. In addition, of the brake pipes, at least the brake pipe 71 that is not subjected to high pressure is formed from a flexible material (such as rubber). Therefore, the layout and handling of the brake pipe 71 can be improved compared to when the brake pipe 71 is configured as a steel pipe.

In a conventional brake device in which the master cylinder and stroke simulator are integrally arranged, the stroke simulator is arranged at the horizontal position of the master cylinder (adjacent to the master cylinder in the horizontal direction, or overlapping when viewed from the horizontal direction) when mounted on the vehicle. Therefore, the occupied area of the brake device when viewed from above is large, and it is not possible to improve the vehicle mountability. In contrast, in the brake device 1, the master cylinder 4 and the stroke simulator 5 are arranged so that they overlap each other when viewed from the vertical direction (at upper and lower positions). Therefore, the projection area of the brake device 1 from above can be reduced. This reduces the area (occupied area) occupied by the brake device 1 in the engine room when viewed from above, and improves the vehicle mountability of the brake device 1 and the layout in the engine room. In addition, the workability when installing the brake device 1 in the engine room can be improved. In addition, space in the engine room can be saved. For example, when viewed from above, the brake device 1 can be installed overlapping the space required for installing the master back (space generated by excluding the master back). Therefore, the need to provide a separate space for installing the brake device 1 is reduced. It is sufficient if there is a range where the master cylinder 4 and stroke simulator 5 partially overlap when projected in the vertical direction, but it is preferable for more than half of the stroke simulator 5 to overlap with the master cylinder 4. In this embodiment, the stroke simulator 5 is positioned directly below the master cylinder 4, which increases the area where the two overlap in the vertical direction, thereby enhancing the above effect.

Specifically, the master cylinder 4 and the stroke simulator 5 are arranged so that they overlap each other in the axial direction (x-axis) of the master cylinder 4 (the two 4, 5 overlap when viewed from a direction perpendicular to the axis of the master cylinder 4). By arranging the two 4, 5 so that they overlap in the axial direction (longitudinal direction) in this way, it is possible to suppress an increase in the dimensions of the brake device 1 in the axial direction of the master cylinder 4. Furthermore, if the axis of the master cylinder 4 is installed so as to extend in the fore-and-aft direction of the vehicle, it is possible for the master cylinder 4 and the stroke simulator 5 to overlap when viewed from above. This makes it possible to reduce the above-mentioned occupied area of the brake device 1.

Also, the master cylinder 4 and the stroke simulator 5 are arranged so that their axial directions are in the same direction (approximately parallel to each other). In other words, the axial directions (longitudinal directions) of the master cylinder 4 and the stroke simulator 5 are aligned (aligned). Therefore, compared to when the axial directions are misaligned (there is an angle between the two axes), it is possible to reduce the area of the entire master cylinder 4 and the stroke simulator 5 projected from the axial direction of the master cylinder 4. In other words, it is possible to suppress an increase in the dimensions of the brake device 1 in a plane extending perpendicular to the axis of the master cylinder 4 (the dimensions of the entire device in the direction perpendicular to the axis of the master cylinder 4). Also, when the entire master cylinder 4 and the stroke simulator 5 are viewed from the direction perpendicular to the axis of the master cylinder 4, and when viewed from a direction in which the axes of both 4 and 5 are aligned on the same straight line, it is possible to minimize the dimensions of the entire device in the direction perpendicular to the axis of the master cylinder 4.

By arranging the master cylinder 4 and the stroke simulator 5 in parallel (approximately parallel to each other) so that they overlap in the axial direction (x-axis direction) of the master cylinder 4, it is possible to increase the overlapping area of the two 4, 5 when viewed perpendicular to the axis of the master cylinder 4 (see FIG. 4). In this embodiment, the axis of the master cylinder 4 and the axis of the stroke simulator 5 are positioned on approximately the same straight line when viewed from above, which increases the overlapping area of the two 4, 5. This makes it possible to further reduce the above-mentioned occupied area of the brake device 1.

In this embodiment, the area where the master cylinder 4 and the stroke simulator 5 overlap in the vertical direction is maximized, so that the overall vertical projection area of these can be minimized to enhance the above effect. As shown in FIG. 4, when viewed from the z-axis direction, the stroke simulator 5 (excluding a part of the connection part 50b of the stroke simulator housing 50 and the flange part 50c, etc.) fits within the contour of the master cylinder 4 (master cylinder housing 40). The master cylinder 4 (excluding a part of the flange part 40b) fits within the contour of the reservoir tank 3. Therefore, as shown in FIG. 3, the vertical projection area of the brake device 1 is approximately equal to the vertical projection area of the reservoir tank 3 (excluding the flange part 40b of the master cylinder housing 40, the connection part 50b of the stroke simulator housing 50, the pipe mounting part 320, and the brake pipes 70 and 71). Therefore, the vertical projection area of the brake device 1 can be made as small as possible.

In addition, the stroke simulator valve 6 is arranged so that the valve body 640 (plunger 64) of the stroke simulator valve 6 and the reaction piston 51 of the stroke simulator 5 are operated in approximately the same direction. In other words, the axial directions of the stroke simulator valve 6 and the stroke simulator 5 are aligned. Therefore, compared to the case where the axial directions are offset from each other (there is an angle between the two axes), it is possible to reduce the projection area of the entire stroke simulator valve 6 and the stroke simulator 5 from the axial direction of the stroke simulator 5. In other words, it is possible to suppress an increase in the dimensions of the brake device 1 in a plane extending perpendicular to the axis of the stroke simulator 5 (the dimensions of the entire device in the direction perpendicular to the axis of the stroke simulator 5). Therefore, when the axis of the stroke simulator 5 is installed so as to extend in the longitudinal direction of the vehicle, the area (occupied area) occupied by the brake device 1 in the engine room when viewed from the longitudinal direction can be reduced, and the vehicle mountability of the brake device 1 can be improved. Furthermore, by aligning the axial directions of the stroke simulator valve 6 and the stroke simulator 5, the axial directions of the master cylinder 4 and the stroke simulator valve 6 are aligned (approximately parallel to each other), which further reduces the area occupied by the brake device 1 when viewed from above, as described above.

The stroke simulator valve 6 is disposed in the axial direction of the stroke simulator 5. That is, the stroke simulator valve 6 is disposed so as to overlap with the stroke simulator 5 when viewed from the axial direction (x-axis direction). This makes it possible to reduce the axial projection area of the stroke simulator valve 6 and the stroke simulator 5 as a whole. In this embodiment, the stroke simulator valve 6 is disposed approximately coaxially with the stroke simulator 5. This makes it possible to maximize the overlapping area of the two valves 5, 6 when viewed from the axial direction (x-axis direction) and minimize the above-mentioned projection area.
Furthermore, the master cylinder 4 and the stroke simulator valve 6 are arranged so as to overlap each other in the x-axis direction. By arranging the master cylinder 4 and the stroke simulator valve 6 so as to overlap in the axial direction (longitudinal direction) in this manner, it is possible to suppress an increase in the dimension of the brake device 1 in the axial direction of the master cylinder 4. Furthermore, when the axis of the master cylinder 4 is installed so as to extend in the front-rear direction of the vehicle, it is possible to make the master cylinder 4 and the stroke simulator valve 6 overlap when viewed in the vertical direction. Therefore, it is possible to reduce the occupation area when viewed from above the brake device 1. Note that, although it is sufficient that the master cylinder 4 and the stroke simulator valve 6 partially overlap when projected in the vertical direction, it is preferable that more than half of the stroke simulator valve 6 overlaps with the master cylinder 4. In this embodiment, the above effect can be enhanced by maximizing the area where the master cylinder 4 and the stroke simulator valve 6 overlap in the vertical direction and minimizing the projected area in the vertical direction. As shown in FIG. 4, when viewed in the z-axis direction, the stroke simulator valve 6 fits within the contour of the master cylinder 4 (master cylinder housing 40). The positive x-axis end of stroke simulator valve 6 (connector portion 610) is located at approximately the same position in the x-axis direction as the positive x-axis ends of reservoir tank 3 and master cylinder 4. Therefore, the vertical projection area of brake device 1 can be made as small as possible.

By integrating the housing of the stroke simulator valve 6 and the housing of the stroke simulator 5 in the stroke simulator housing 50, the brake device 1 can be made smaller overall and the vehicle mountability can be improved. In addition, since the structure for connecting the two devices 5 and 6 and the brake piping are not required, the configuration can be simplified, improving installation workability and fail-safety. The controller 8b that controls the stroke simulator valve 6 is configured separately from the brake device 1 and is connected to the stroke simulator valve 6 via a harness. Therefore, the brake device 1 can be made smaller and the layout freedom of the brake device 1 can be improved compared to when the brake device 1 and the controller 8b are integrally provided. In other words, by integrating the hydraulic controller for controlling the wheel cylinder hydraulic pressure and the controller for controlling the stroke simulator valve 6 as the controller 8b, the layout flexibility of the brake device 1 can be improved.

The master cylinder 4 and stroke simulator 5 (and stroke simulator valve 6) are configured to fit within the width (y-axis dimension) of the flange portion 50c for mounting the brake device 1 (stroke simulator housing 50) to the vehicle. This allows the brake device 1 to be made smaller in size in the lateral direction of the vehicle (in other words, in the direction perpendicular to the axis of the master cylinder 4 and stroke simulator valve 6 when viewed from above). This further improves the vehicle mountability of the brake device 1 and saves space in the engine room. For example, when viewed from the front-rear direction of the vehicle, the brake device 1 can be installed so that it fits approximately within the space required for installing the master back (the space created by excluding the master back). This reduces the need to provide a separate space for installing the brake device 1.

In addition, the brake pipe 71 connecting the reservoir tank 3 and the stroke simulator 5 is arranged to fit within the width (y-axis dimension) of the flange portion 50c. This allows the brake device 1 to be made smaller in size in the lateral direction of the vehicle, and the vehicle mountability of the brake device 1 can be improved. Specifically, the fastening portion 40d of the master cylinder housing 40 and the fastening portion 50i of the stroke simulator housing 50 are arranged within the width (y-axis dimension) of the flange portion 50c while protruding toward the y-axis positive side. The pipe mounting portions 320a, 580 are arranged in the spaces above and below the fastening portions 40d, 50i, respectively. Both the pipe mounting portions 320a, 580 are bent so as to open toward the x-axis positive side (not toward the y-axis positive side), and are arranged to fit within the width (y-axis dimension) of the flange portion 50c. The brake pipe 71 attached to the pipe mounting portions 320a, 580 is arranged in a U-shape that bypasses the fastening portions 40d, 50i and the discharge port 44P. This allows the brake pipe 71 to fit within the width (y-axis dimension) of the flange portion 50c while eliminating interference with the fastening portion 40d and the like. By arranging the brake pipe 71 so that it does not protrude outward in the width direction from the flange portion 50c, interference between the brake pipe 71 and other components in the engine compartment can be avoided. This makes it possible to improve the vehicle mountability of the brake device 1 while suppressing damage to the brake pipe 71. In particular, when the brake pipe 71 is made of a flexible material (such as rubber), damage to the brake pipe 71 can be effectively suppressed.

The stroke simulator 5 is disposed below the master cylinder 4, and the reservoir tank 3 is disposed above the master cylinder 4 (when mounted on the vehicle, the order is reservoir tank 3, master cylinder 4, and stroke simulator 5 from the top). This improves the air bleeding performance of the brake device 1. That is, when the brake device 1 is installed on the vehicle or during maintenance (replacement of brake fluid), the air in the brake device 1 is bled. Air can be easily bled from the simulator oil passage on the stroke simulator 5 side (including the main chamber 54) from the stroke simulator valve 6 by the air bleeding bleeder 57. Here, the bleeder 57 is provided so as to open on the z-axis positive side of the main chamber 54 (cylindrical portion 50e) of the stroke simulator 5, that is, in the upper portion where air is likely to accumulate. This improves the air bleeding performance. On the other hand, air can be bled from the simulator oil passage on the master cylinder 4 side from the stroke simulator valve 6 via the brake piping 70 through the master cylinder 4 (hydraulic chamber 43P) and the reservoir tank 3 (supply port 30). Here, the stroke simulator 5 is located below the master cylinder 4, and the reservoir tank 3 is located above the master cylinder 4. This makes it easier for air (bubbles) to rise due to buoyancy and be removed from the reservoir tank 3 via the brake piping 70, etc., improving air removal performance.

[Effects of Example 1]
The invention and its effects as understood from the first embodiment will be listed below.
(1) A master cylinder 4 that generates brake fluid pressure in response to a driver's brake operation;
a stroke simulator 5 into which the brake fluid flowing out from the master cylinder 4 flows to generate a pseudo operation reaction force of the brake operating member;
The master cylinder 4 and the stroke simulator 5 are integrally disposed so as to overlap each other in the vertical direction (as viewed from the vertical direction) when mounted on the vehicle.
Therefore, the projection area of the brake device 1 from above can be reduced, and the ease of mounting the brake device on a vehicle can be improved.
(2) A reservoir tank 3 capable of supplying brake fluid to the master cylinder 4 is provided.
The stroke simulator 5 is disposed below the master cylinder 4 , and the reservoir tank 3 is disposed above the master cylinder 4 .
Therefore, the air removal performance can be improved.
(3) The stroke simulator 5 includes a reaction piston 51 (piston) that operates in the axial direction when brake fluid flows into the reaction piston 51.
The master cylinder 4 and the stroke simulator 5 are disposed so that their axial directions are in the same direction.
Therefore, by aligning both axial directions, the projection area of the brake device 1 from above can be further reduced.
(6) A flange portion 50c (flange) for fixing to a vehicle is provided,
The master cylinder 4 and the stroke simulator 5 are configured to fit within the width of the flange portion 50c.
Therefore, the brake device 1 can be made smaller in size in the lateral direction of the vehicle, and the ease of mounting the brake device on the vehicle can be further improved.
(17) An actuator 8 that controls the wheel cylinder hydraulic pressure in accordance with a brake operation state or a vehicle state;
A brake system including a brake device 1 that is provided separately from an actuator 8 and that operates in response to a brake operation by a driver,
The brake device 1 includes a master cylinder 4 that generates brake fluid pressure in response to a driver's brake operation,
a stroke simulator 5 into which the brake fluid flowing out from the master cylinder 4 flows and which generates a pseudo operation reaction force of a brake operating member;
a stroke simulator valve 6 for restricting the inflow of brake fluid into the stroke simulator 5;
A controller 8b for controlling the stroke simulator valve 6,
The master cylinder 4 and the stroke simulator 5 are integrally disposed so as to overlap each other in the vertical direction (as viewed from the vertical direction) when mounted on the vehicle.
The controller 8b is configured separately from the master cylinder 4, and the stroke simulator valve 6 and the controller 8b are connected via a harness.
Therefore, the same effect as that of (1) above can be obtained. In addition, by providing the controller 8b separately from the master cylinder 4, the brake device 1 can be made smaller and the degree of freedom in layout can be improved.

[Other embodiments]
The above describes the form for realizing the present invention based on the embodiment, but the specific configuration of the present invention is not limited to the embodiment, and even if there are design changes within the scope of the invention, the present invention is included. For example, the master cylinder and the stroke simulator may be formed using a common housing. Also, the master cylinder and the stroke simulator may be arranged separately (for example, spatially close but separated) rather than integrally. In these cases, the master cylinder and the stroke simulator may be arranged so as to overlap each other when viewed from the vertical direction when mounted on the vehicle, thereby improving the vehicle mountability. Also, as shown in FIG. 9, a spring (disc spring, etc.) 23 as a damper may be installed between the x-axis negative end of the master cylinder housing 40 (fitting portion 40c) and the flange portion 21 of the push rod 2 (the outer periphery of the piston 41P). When the operation amount of the brake pedal becomes equal to or greater than a predetermined amount, the flange portion 21 comes into contact with the x-axis negative end of the spring 23, and the spring 23 is compressed from the x-axis negative side by the flange portion 21. The compressively deformed spring 23 applies a reaction force to the brake pedal via the push rod 2, thereby adjusting the operating force of the brake pedal. This makes it possible to achieve desirable characteristics in the entire range of brake pedal operation. For example, instead of making the actuator 8 function as a booster, a link type booster using a link mechanism is installed between the brake pedal and the clevis 20. If the characteristics of the link mechanism are such that a predetermined boosting performance can be obtained under the constraints imposed when the actuator is mounted on the vehicle, there is a risk that desirable brake characteristics (relationship between the pedaling force, the stroke, and the deceleration) cannot be obtained, such as an excessive increase in the lever ratio in the pedal stroke range in the later stage of the brake operation. In contrast, if the spring 23 is installed, the spring 23 is compressed in the later stage of the brake operation to increase the pedal reaction force and attenuate the pedal force, making it possible to achieve desirable brake characteristics in the entire range of the brake pedal operation.

1 Brake device 4 Master cylinder 40 Master cylinder housing 41 Piston 5 Stroke simulator 50 Stroke simulator housing 51 Reaction piston 10 Bolt

Claims (2)

a master cylinder housing portion having a piston provided therein;
a reservoir tank capable of supplying brake fluid to the master cylinder housing;
a stroke simulator housing portion provided with a reaction piston that is actuated by brake fluid flowing therein;
Equipped with
The piston and the reaction piston are not arranged side by side in the axial direction of the master cylinder housing portion,
When a straight line extending in a direction in which the reservoir tank and the master cylinder housing portion overlap is defined as a first axis, and a straight line perpendicular to the first axis and perpendicular to the axial direction of a cylinder formed in the master cylinder housing portion is defined as a second axis,
the stroke simulator housing portion and the master cylinder housing portion are arranged such that there are overlapping portions when viewed from the direction of the first axis, and the overlapping portions overlap in the order of the stroke simulator housing portion and the master cylinder housing portion when viewed from a surface on which the reservoir tank is attached,
The master cylinder housing portion and the stroke simulator housing portion are arranged so that there are portions that overlap with each other when viewed from the direction of the second axis.
Brake device. 2. The brake device according to claim 1 ,
When viewed from the direction of the first axis, there is a portion where the master cylinder housing portion and the stroke simulator housing portion are arranged side by side.
Brake device.

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