Brake device, brake system and master cylinder

Abstract

Brake device, comprising: - a main cylinder housing (7) comprising a cylinder (60) therein; - a piston (51) which is provided inside the cylinder (60) and is movable in the direction of an axial line of the cylinder (60), - a magnet (96) which is provided and arranged inside the cylinder (60) partially in a circumferential direction of the piston (51) to be displaced according to a movement of the piston (51), the circumferential direction being a direction around the axial line; - a detection area (95) provided and configured on the main cylinder housing (7) to detect a range of motion of the piston (51); and - a rotation limitation mechanism (99) provided and configured within the cylinder (60) to limit movement of the magnet (96) in the circumferential direction, wherein: - the rotation limitation mechanism (99) comprises an engagement element (97) arranged in such a way that it can move in the circumferential direction while being limited with respect to movement in the direction of the axial line relative to the piston (51), and - the engagement element (97) comprises an engagement area (972) which is configured such that movement relative to the main cylinder housing (7) is restricted in the circumferential direction.

Description

Application area

[0001] The present invention relates to a braking device, a braking system and a master cylinder. State of the art

[0002] PTL1 discloses a technique which provides a ring-shaped magnet arranged on an outer circumference of a piston and detects a range of motion of the piston using a sensing area fixed to a main cylinder housing. Document reference list Patent literature

[0003] PTL1: Published Japanese patent application JP 2015-098289A.

[0004] Document JP 2015-098 289 A concerns a brake control system capable of accurately detecting the stroke of a brake pedal. The brake control system comprises a master cylinder with a piston that moves via an axial rod in accordance with the driver's actuation of the brake pedal, an oil channel in which the brake fluid circulates as it exits in accordance with the piston stroke, an electromagnetic valve that opens and closes the oil channel, a control unit that actuates the electromagnetic valve, and a stroke sensor mounted on the outer wall of the master cylinder that detects the stroke in the axial direction of the piston.

[0005] The conventional teaching of US 2014 / 0137550A1 describes a master brake cylinder arrangement with actuation detection for a motor vehicle brake system, comprising at least one piston arrangement with a piston that is displaceably guided in a receiving bore in a master brake cylinder housing, wherein the piston with the receiving bore delimits a pressure chamber fluidically coupled to a hydraulic brake circuit and is displaceable between a starting position and an actuation position along a displacement axis, wherein a position detection device is provided for detecting an actuation-induced movement of the piston within the receiving bore, wherein the position detection device comprises a sensor element movable according to a piston movement and a position detection sensor fixedly arranged on the master brake cylinder housing.To simplify the design, the sensor element is provided to be received and guided independently of the piston in the master brake cylinder housing and to be able to interact with the piston to deflect it according to the piston movement.

[0006] German patent application DE 11 2011 103 226 T5 describes a braking system comprising a pedal, a pedal simulator, and a brake pedal unit. The brake pedal unit has an input piston connected to the brake pedal for actuating the pedal simulator during normal braking. The brake pedal unit also has a first and a second output piston, which are actuated by the input piston during manual depressurization, such that the first output piston generates a brake actuation pressure at a first output of the brake pedal unit, and the second output piston generates a brake actuation pressure at a second output of the brake pedal unit. The braking system further comprises a hydraulic pressure source for supplying fluid with a controlled boost pressure and a hydraulic control unit suitable for hydraulic connection to the brake pedal unit and the hydraulic pressure source.The hydraulic control unit has a slip control valve arrangement and a switching base brake valve arrangement for switching the brake system between the normal brake mode, in which a boost pressure is supplied to a first and a second vehicle brake from the hydraulic pressure source, and the manual push-through mode, in which the brake actuation pressure is supplied to the first and second vehicle brake from the first and second output pistons.

[0007] The publication JP 2015-107 750 A discloses an input device for a brake system that facilitates the provision of an assembly station in a vehicle and reduces the assembly time, as well as the provision of a vehicle brake system. A brake actuation performed by an operator is inputted into an input device for a brake system, and the input device for the brake system comprises a base substance, a master cylinder provided on the base substance and generating brake fluid pressure through a piston connected to a brake regulator, a housing attached to the base substance, a control board housed in the housing, a stroke sensor attached to the control board and used to detect the sliding stroke of the piston, and a detection object element attached to the piston and detected by the stroke sensor. Summary of the invention: Technical problem

[0008] One possible configuration of the conventional technique described above involves positioning the magnet partially circumferentially around the piston to reduce manufacturing costs. However, this configuration presents a problem: as the piston rotates, the radial distance between the magnet and the sensing area increases, leading to a decrease in the accuracy of measuring the piston's movement.

[0009] One object of the present invention is to create a braking device, a braking system and a master cylinder that can accurately detect the range of motion of the piston while reducing manufacturing costs. Solution to the problem

[0010] The problem underlying the invention is solved according to the invention in the case of a braking device by the features of claim 1, in the case of a braking system by the features of claim 13, and in the case of a master cylinder by the features of claim 16. Advantageous embodiments are the subject of the respective dependent claims.

[0011] According to the present invention, a braking device comprises a rotation limitation mechanism which is provided and configured within a cylinder to limit the movement of a magnet in a circumferential direction.

[0012] According to the invention, the rotation limitation mechanism comprises an engagement element arranged such that it can move circumferentially while being limited with respect to movement along an axial line relative to an underlying piston. The engagement element, according to the invention, comprises an engagement area configured such that movement relative to an underlying main cylinder housing is limited in the circumferential direction.

[0013] According to the present invention, it is possible to accurately measure the range of motion of the piston while simultaneously reducing manufacturing costs. Brief description of the drawings Fig. Figure 1 schematically represents a configuration of a brake system according to a first embodiment together with a hydraulic circuit. Fig. Figure 2 is a perspective view of the braking system according to the first embodiment. Fig. Figure 3 is a right side view of a first unit 1A according to the first embodiment. Fig. Figure 4 is a left side view of the first unit 1A according to the first embodiment. Fig. Figure 5 is a front view of the first unit 1A according to the first embodiment. Fig. 6 is a cross-section that runs along a line S6-S6, which is in Fig. 3 is shown, recorded. Fig. 7 is a cross-section of the first embodiment, which is along a line S7-S7 that is in Fig. 5 is shown, recorded. Fig. 8 is a cross-section of the first embodiment, which is along a line S8-S8 that is in Fig. 4 is shown, recorded. Fig. Figure 9 is a partially perspective cross-sectional view of a main cylinder 5 according to the first embodiment. Fig. Figure 10 is a perspective exploded view of a stroke sensor 94 according to the first embodiment. Fig. 11 represents a ratio between a pushrod stroke and a sensor output of the stroke sensor 94. Fig. 12 is a cross-section of a second embodiment, which extends along a line S7-S7, which is in Fig. 5 is shown, recorded. Fig. 13 is a cross-section of the second embodiment, which is along the line S8-S8, which is in Fig. 4 is shown, recorded. Fig. 14 is a cross-section of a third embodiment, which extends along the line S8-S8, which is in Fig. 4 is shown, recorded. Fig. Figure 15 is a perspective view of a magnetic holder 97 according to a fourth embodiment. Description of embodiments [First embodiment]

[0014] Fig. Figure 1 schematically represents a configuration of a brake system according to a first embodiment together with a hydraulic circuit. Fig. Figure 2 is a perspective view of the braking system according to the first embodiment. Fig. Figure 3 is a right side view of a first unit 1A according to the first embodiment. Fig. Figure 4 is a left side view of the first unit 1A according to the first embodiment. Fig. Figure 5 is a front view of the first unit 1A according to the first embodiment. Fig. 6 is a cross-section that runs along a line S6-S6, which is in Fig. 3 is shown, recorded.

[0015] The braking system according to the first embodiment is used for an electric vehicle. The electric vehicle is, for example, a hybrid vehicle with a motor and a motor-generator as a drive unit that powers the wheels, or an electric car with only a motor-generator as a drive unit. The electric car can perform regenerative braking to slow the vehicle by regenerating electrical energy from the vehicle's kinetic energy using a regenerative braking device with the motor-generator. The braking system applies a frictional braking force to each of the vehicle's wheels FL to RR using hydraulic pressure. A brake actuation unit is provided on each of the wheels FL to RR. The brake actuation unit is a hydraulic pressure generating unit with a wheel cylinder W / C. The brake actuation unit is, for example, a disc brake and includes a brake caliper (a hydraulic brake caliper).The brake caliper comprises a brake disc and brake pads. The brake disc is a brake rotor that rotates as one unit with a tire. The brake pads are positioned at predetermined distances from the brake disc and make contact with it through movement caused by hydraulic pressure in the wheel cylinder (W / C). The frictional braking force is generated by the contact of the brake pads with the brake disc. The brake system comprises brake lines from two systems (a primary P-system and a secondary S-system). One brake line configuration is, for example, an X-split line configuration. The brake system may use a different line configuration, such as a front / rear split line configuration. Where an element designated for the P-system and an element designated for the S-system are to differ from each other, the indices P and S are added to the ends of the respective reference numbers.The braking system supplies brake fluid (hydraulic oil) to each of the brake actuation units via a brake line and generates a hydraulic brake pressure (working hydraulic pressure) in the wheel cylinder W / C. Through this actuation, the braking system applies a hydraulic braking force to each of the wheels FL to RR.

[0016] The brake system comprises a first unit 1A and a second unit 1B. The first unit 1A and the second unit 1B are located, for example, in an engine compartment that is isolated from the vehicle's interior. These units 1A and 1B are connected to each other by a plurality of lines. The plurality of lines includes master cylinder lines 10M (a primary line 10MP and a secondary line 10MS), wheel cylinder lines 10W, a backpressure chamber line 10X, and an intake line 10R. With the exception of the intake line 10R, each of the lines 10M, 10W, and 10X is a metallic brake line (a metal line), specifically a steel tube, such as a double-walled steel tube. Each of the lines 10M, 10W, and 10X comprises a linear section and a bent section and is arranged between fittings that are rotated in a different direction on the bent section.Both ends of each of the 10M, 10W, and 10X lines include a male line connection created by expansion. The 10R intake line is a brake hose (a hose assembly) designed to be flexible due to the use of a material such as rubber. The ends of the 10R intake line are connected to fittings 873 and the like via nipples 10R1 and 10R2. Nipples 10R1 and 10R2 are each resin-bonded connectors with a tubular section.

[0017] A brake pedal 100 is a brake actuation element that receives input from a driver applying the brakes. A pushrod 101 is vertically rotatably connected to the brake pedal 100. The first unit 1A is a master cylinder unit with a brake actuation unit mechanically connected to the brake pedal 100 and a master cylinder 5. The first unit 1A comprises a reservoir 4, a master cylinder housing 7, the master cylinder 5, a stroke sensor 94, and a stroke simulator 6. The reservoir 4 is a brake fluid source, storing the brake fluid, and a vacuum chamber open to atmospheric pressure.

[0018] Refill ports 40 and a supply port 41 are provided in the reservoir 4. The suction line 10R is connected to the supply port 41. The main cylinder housing 7 is a housing that contains (accommodates) the main cylinder 5 and the stroke simulator 6. The main cylinder housing 7 includes a cylinder 70 for the main cylinder 5, a cylinder 71 for the stroke simulator 6, and a plurality of oil lines (fluid lines). The cylinder 70 comprises a large diameter section 70a and a small diameter section 70b. The large diameter section 70a is located closer to the push rod 101 than the small diameter section 70b, and its associated inner diameter is larger than the inner diameter of the small diameter section 70b. An axial line of the large diameter section 70a intersects with an axial point of the small diameter section 70b (an axial line O).The push rod 101 includes a stop plate 101a to prevent removal from the cylinder 70. The plurality of oil lines includes fill oil lines 72, supply oil lines 73, and a pressure relief oil line 74. The main cylinder housing 7 includes a plurality of ports, each of which is open on an outer circumferential surface of the main cylinder housing 7. The plurality of ports includes fill ports 75P and 75S, supply ports 76, and a back pressure port 77. Fill ports 75P and 75S are connected to fill ports 40P and 40S of the reservoir 4, respectively. The main cylinder ports 10M are connected to supply ports 76, and the back pressure chamber line 10X is connected to back pressure port 77. One end and the other end of each of the fill oil lines 72 are connected to fill ports 75 and cylinder 70, respectively.

[0019] The master cylinder 5 is connected to the brake pedal 100 via the pushrod 101 and generates master cylinder hydraulic pressure in response to the driver's application of the brake pedal 100. The master cylinder 5 comprises pistons 51, which are axially movable in response to the application of the brake pedal 100. The pistons 51 are contained within the cylinder 70 and form the hydraulic chambers 50. The master cylinder 5 is a tandem cylinder and comprises, as piston 51, a primary piston 51P, which is pressed by the pushrod 101, and a secondary piston 51S, which is configured as a free piston. These pistons 51P and 51S are arranged in series. A primary chamber 50P is formed by the pistons 51P and 51S, and a secondary chamber 50S is formed by the secondary piston 51S. One end and the other end of each of the supply oil lines 73 are each connected to the hydraulic chamber 50 and the supply port 76.Each of the hydraulic chambers 50P and 50S is filled with brake fluid from reservoir 4 and generates the master cylinder hydraulic pressure through the movement of the piston 51 described above. A helical spring 52P, acting as a return spring, is located between these pistons 51P and 51S in the primary chamber 50P. A helical spring 52S, also acting as a return spring, is located between a base region of the cylinder 70 and the piston 51S in the secondary chamber 50S. Piston seals 541 and 542 are provided on an inner circumference of the small diameter region 70b of the cylinder 70. The piston seals 541 and 542 are a plurality of sealing elements that seal between an outer circumferential surface of each of the pistons 51P and 51S and an inner circumferential surface of the small diameter region 70b, while in sliding contact with each of the pistons 51P and 51S.Each piston seal is a known sealing element with a cup-shaped cross-section, comprising a lip area on an inner diameter side (a cap seal). Each piston seal allows brake fluid to flow in one direction and prevents or reduces flow in the opposite direction via the lip area in contact with the outer circumferential surface of the piston 51. A first piston seal 541 allows brake fluid to flow from the fill port 40 to the primary chamber 50P or the secondary chamber 50S and prevents or reduces brake fluid flow in the opposite direction. A second piston seal 542P prevents or reduces brake fluid flow to the large-diameter cylinder 70a, and a second piston seal 542S prevents or reduces brake fluid flow to the primary chamber 50P.

[0020] The stroke sensor 94 outputs a sensor signal corresponding to a movement (a stroke) of the primary piston 51P. The stroke sensor 94 comprises a sensing area 95 and a magnet 96. The sensing area 95 is located on a left outer circumferential surface of the main cylinder housing 7. The magnet 96 is located on the primary piston 51P. The sensing area 95 and the magnet 96 are positioned close to each other. The sensing area 95 is a Hall-effect integrated circuit (ICE) with a Hall element. A voltage, essentially proportional to a value of a magnetic flux density, is generated when a specific current is applied to the Hall element. The sensing area 95 outputs a sensor signal with a voltage corresponding to a value of the generated voltage.

[0021] The stroke simulator 6 is actuated according to the brake application performed by the driver and provides a reaction force and stroke to the brake pedal 100. The stroke simulator comprises a cylinder 60, a piston 61, a pressure chamber 601, a counter-pressure chamber 602, and elastic elements (a first spring 64, a second spring 65, and a damper 66). The cylinder 60 is located separately from the cylinder 70 in the main cylinder housing 7. The cylinder 60 comprises a large diameter section 60a and a small diameter section 60b. The pressure chamber 601 and the counter-pressure chamber 602 are formed by the piston 61, which is located at the small diameter section 60b of the cylinder 60. The elastic elements are located at the large diameter section 60a of the cylinder 60 and pre-tension the piston 61 in a direction that reduces the volume of the pressure chamber 601.A flat cylindrical retaining element 62 is arranged between the first spring 64 and the second spring 65. One end and the other end of the overpressure oil line 74 are each connected to a secondary-side supply oil line 73S and the overpressure chamber 601. The brake fluid is supplied from the master cylinder 5 (of the secondary chamber 50S) to the overpressure chamber 601 according to the brake actuation performed by the driver, which generates the pedal travel. The reaction force of the brake actuation performed by the driver is also generated as a result of the preload forces of the elastic elements. The first unit 1A does not include an engine vacuum booster that amplifies the brake actuation force by using an intake vacuum generated by a vehicle engine.

[0022] The second unit 1B is located between the first unit 1A and the brake actuation unit. The second unit 1B is connected to the primary chamber 50P via the primary line 10MP, to the secondary chamber 50S via the secondary line 10MS, to the wheel cylinders W / C via the wheel cylinder lines 10W, and to the backpressure chamber 602 via the backpressure line 10X. Furthermore, the second unit 1B is connected to the reservoir 4 via the suction line 10R. The second unit 1B comprises a second unit housing 8, a motor 20, a pump 3, a plurality of electromagnetic valves 21 and the like, a plurality of hydraulic pressure sensors 91 and the like, and an electronic control unit 90 (hereinafter referred to as ECU). The second unit housing 8 is a housing that contains (accommodates) the pump 3 and the valve bodies of the electromagnetic valves 21 and the like.The second unit housing 8 contains circuits (brake hydraulic circuits) of the two systems described above (the P-system and the S-system) through which the brake fluid flows. The circuits of the two systems are formed by a plurality of oil lines. The plurality of oil lines includes supply oil lines 11, a suction oil line 12, a discharge oil line 13, a pressure-regulating oil line 14, pressure-reducing oil lines 15, a back-pressure oil line 16, a first simulator oil line 17, and a second simulator oil line 18. The second unit housing 8 also includes an accumulator (an internal accumulator) 120, which is a fluid reservoir, and a damper 130. A plurality of ports are formed within the second unit housing 8, and these ports are open on an outer surface of the second unit housing 8.The majority of connections include master cylinder connections 871 (one primary connection 871P and one secondary connection 871S), one intake connection 873, one backpressure connection 874, and wheel cylinder connections 872. The primary line 10MP is connected to the primary connection 871P. The secondary line 10MS is connected to the secondary connection 871S. The intake line 10R is connected to the intake port 873. The backpressure chamber line 10X is connected to the backpressure port 874. Each of the wheel cylinder lines 10W is connected to each of the wheel cylinder connections 872.

[0023] Motor 20 is a rotary electric motor and includes a rotating shaft for driving pump 3. Motor 20 can be a brushless motor with a speed sensor, such as a rotary encoder that detects the angle of rotation or the rotational speed of the shaft, or it can be a brushed motor. Pump 3 draws the brake fluid from the reservoir 4 through the rotary drive of motor 20 and delivers the brake fluid to the wheel cylinders W / C. In the first embodiment, a piston pump comprising five pistons, which offers excellent noise and vibration performance, for example, is used as pump 3. Pump 3 is used jointly by both the S and P systems.Each of the electromagnetic valves 21 and the like is a solenoid valve that is actuated according to a control signal, and an associated valve body performs a stroke to switch the opening / closing of the oil line (establishing or blocking a connection through the oil line) according to a current supply to the solenoid. The electromagnetic valves 21 and the like each generate a control hydraulic pressure by controlling a connection state of the circuit described above in order to establish a flow state of the brake fluid. The majority of electromagnetic valves 21 and the like include shut-off valves 21, pressure boosting valves 22 (hereinafter referred to as SOL / V-INs), communication valves 23, a pressure regulating valve 24, pressure reducing valves 25 (hereinafter referred to as SOL / V-OUTs), a lift simulator IN valve 27 (hereinafter referred to as SS / V-IN) and a lift simulator OFF valve 28 (hereinafter referred to as SS / V-OUT).The shut-off valves 21, the SOL / V-INs 22, and the pressure regulating valve 24 are each normally open electromagnetic valves that are open when no current is supplied. The communication valves 23, the pressure reducing valves 25, the SS / V-IN 27, and the SS / V-OUT 28 are each normally closed electromagnetic valves that are closed when no current is supplied. The shut-off valves 21, the SOL / V-INs 22, and the pressure regulating valve 24 are each proportional control valves with an opening degree that is adjusted according to the current supplied to the solenoid. The communication valves 23, the pressure reducing valves 25, the SS / V-IN 27 and the SS / V-OFF ​​28 are each an ON / OFF valve whose opening / closing is controlled by switching between two values, that is, switching to be either open or closed. The proportional control valve can also be used for these valves.The hydraulic pressure sensors 91 and the like detect the delivery pressure of the pump 3 and the master cylinder hydraulic pressure. Most hydraulic pressure sensors comprise a master cylinder hydraulic pressure sensor 91, a delivery pressure sensor 93, and wheel cylinder hydraulic pressure sensors 92 (a primary pressure sensor 92P and a secondary pressure sensor 92S).

[0024] The following description refers to the brake hydraulic circuit of the second unit 1B with regard to Fig. 1. Elements corresponding to the respective wheels FL to RR are distinguished from one another, if necessary, by indices a to d, which are appended to the ends of the associated reference numerals. One end of the supply oil line 11P is connected to the primary port 871P. The other end of the supply oil line 11P branches into an oil line 11a for the front left wheel and an oil line 11d for the rear right wheel. Each of the oil lines 11a and 11d is connected to the corresponding wheel cylinder port 872. One end of the supply oil line 11S is connected to the secondary port 871S. The other end of the supply oil line 11S branches into an oil line 11b for the front right wheel and an oil line 11c for the rear left wheel. Each of the oil lines 11b and 11c is connected to the corresponding wheel cylinder port 872.The shut-off valves 21 are provided on the end faces of the supply oil lines 11 as described above. The SOL / V-IN 22 is provided in each of the oil lines 11 on the other end face as described above. A bypass oil line 110 is provided parallel to each of the oil lines 11, bypassing the SOL / V-IN 22, and a check valve 220 is provided in the bypass oil line 110. The check valve 220 allows only the flow of brake fluid introduced from one side, where the wheel cylinder connection 872 is located, to the other side, where the master cylinder connection 871 is located.

[0025] The suction oil line 12 connects the reservoir 120 and a suction port 823 of the pump 3. One end of the discharge oil line 13 is connected to a discharge port 821 of the pump 3. The other end of the discharge oil line 13 branches into an oil line 13P for the P-system and an oil line 13S for the S-system. Each of the oil lines 13P and 13S is connected to a section of the supply oil line 11 between the shut-off valve 21 and the SOL / V-EINs 22. The damper 130 is provided on the one end of the discharge oil line 13 described above. The communication valve 23 is provided on the other end of each of the oil lines 13P and 13S described above. Each of the oil lines 13P and 13S acts as a communication line connecting the supply oil line 11P of the P system and the supply oil line 11S of the S system.Pump 3 is connected to each of the wheel cylinder ports 872 via the communication lines described above (the delivery oil lines 13P and 13S) and the supply oil lines 11P and 11S. The pressure regulating oil line 14 connects a section of the delivery oil line 13 between the damper and the communication valve 23 and the accumulator 120. The pressure regulating valve 24 is located in the pressure regulating oil line 14. The pressure reducing oil line 15 connects a section of each of the oil lines 11a to 11d of the supply oil lines 11 between the SOL / V IN 22 and the wheel cylinder port 872 and the accumulator 120. The SOL / V OUT 25 is located in the pressure reducing oil line 15.

[0026] One end of the backpressure oil line 16 is connected to the backpressure port 874. The other end of the backpressure oil chamber 16 branches into the first simulator oil line 17 and the second simulator oil line 18. The first simulator oil line 17 is connected to a section of the supply oil line 11S between the shut-off valve 21S and the SOL / V-INs 22b and 22c. The SOL / V-IN 27 is provided in the first simulator oil line 17. A bypass oil line 170 runs parallel to the first simulator oil line 17, bypassing the SOL / V-IN 27, and a check valve 270 is provided in the bypass oil line 170. The check valve 270 allows only the flow of brake fluid, which is introduced from one side where the backpressure oil line 16 is located, to the other side where the supply oil line 11S is located. The second simulator oil line 18 is connected to the accumulator 120. The SS / V-AUS 28 is provided in the second simulator oil line 18.A bypass oil line 180 is provided in parallel with the second simulator oil line 18, bypassing the SS / V-AUS 28, and a check valve 280 is provided in the bypass oil line 180. The check valve 280 allows only the flow of brake fluid, which is introduced from one side where the accumulator 120 is located, to the other side where the backpressure oil line 16 is located.

[0027] The hydraulic pressure sensor 91 is located between the shut-off valve 21S and the secondary port 871S in the supply oil line 11S. The hydraulic pressure sensor 91 detects a hydraulic pressure in this area (a hydraulic pressure in the overpressure chamber 601 of the lifting simulator 6 or the master cylinder hydraulic pressure). The hydraulic pressure sensors 92 are located between the shut-off valves 21 and the SOLN-EINs 22 in the first oil lines 11. The hydraulic pressure sensors 92 detect hydraulic pressures in these areas (corresponding to the wheel cylinder hydraulic pressures). The hydraulic pressure sensor 93 is located between the damper 130 and the communication valves 23 in the discharge oil line 13. The hydraulic pressure sensor 93 detects a hydraulic pressure in this area (the pump discharge pressure).

[0028] For the sake of simplicity, a three-dimensional Cartesian coordinate system with an X-axis, a Y-axis, and a Z-axis is defined below. A Z-axis direction is defined as a vertical direction, and a positive Z-axis direction is defined as a top side in the vertical direction with the first unit 1A and the second unit 1B attached to the vehicle. An X-axis direction is defined as a longitudinal direction of the vehicle, and a positive X-axis direction is defined as a front side of the vehicle. A Y-axis direction is defined as a lateral direction of the vehicle.

[0029] In the first unit 1A, the pushrod 101 extends from one end on the negative X-axis direction side, which is connected to the brake pedal 100, to the positive X-axis direction side. A right-angled, plate-shaped flange part 78 is provided at one end of the master cylinder housing 7 on the negative X-axis direction side. A bolt hole is formed at each of the four corners of the flange part 78. A bolt B1 passes through the bolt hole. The bolt B1 is used to fix and fasten the first unit 1A to an instrument panel on one side of the vehicle body. The reservoir 4 is fixed on the positive Z-axis direction side of the master cylinder housing 7.

[0030] In the second unit 1B, the second unit housing 8 is essentially a cuboid block made of an aluminum alloy. The second unit housing 8 is fixed to the vehicle body side (a floor surface of the engine compartment) by means of an insulator (not shown) and a fastener. The motor 20 and a motor housing 200 are arranged and mounted on a left side surface 801 of the second unit housing 8. The ECU 90 is arranged on a right side surface of the second unit housing 8. In other words, the ECU 90 is integrally formed with the second unit housing 8. The ECU 90 comprises a control board (not shown) and a control unit housing (case) 901. The control board controls the states of a power supply to the motor 20 and the solenoids of the electromagnetic valves 21, and the like.Various types of sensors that detect the vehicle's state of motion, such as an accelerometer that detects the vehicle's acceleration and an angular velocity sensor that detects the vehicle's angular velocity (yaw rate), can be mounted on the control board. Additionally, a combination sensor, formed by unifying these sensors, can be mounted on the control board. The control board is contained within housing 901. Housing 901 is a cover element that is attached and secured to a rear surface of the second unit housing 8 using bolts.

[0031] The housing 901 is a cover element made of a synthetic resin. The housing 901 comprises a circuit board receiving area 902 and a connector area 903. The circuit board receiving area 902 contains the control board and parts of the solenoid of the electromagnetic valves 21 and the like. The connector area 903 projects beyond the circuit board receiving area 902 in the direction of a positive Y-axis orientation. As can be seen from the X-axis orientation, one terminal of the connector area 903 is oriented towards the positive Y-axis orientation and also extends towards the negative Y-axis orientation to connect to the control board. Each terminal of the connector area 903 (oriented towards the positive Y-axis orientation) can be connected to an external device or the stroke sensor 94 (hereinafter referred to as external device and the like).An electrical connection is established between the external device and the control board (the ECU 90) by inserting another connector, which is connected to the external device, into connector area 903 from the positive Y-axis direction side. Furthermore, current is supplied from an external power source (a battery) to the control board via connector area 903. A conductive element acts as a connection area that electrically connects the control board and the motor 20, and current is supplied from the control board to the motor 20 via this conductive element.

[0032] In the first embodiment, no electromagnetic valves or the like are provided in the first unit 1A, and the SS / V-IN 27 and the SS / V-OUT 28, which switch the actuation of the lifting simulator 6, are provided in the second unit 1B. As a result of this configuration, the present embodiment does not require a control unit to actuate the electromagnetic valves in the first unit 1A. Furthermore, the present embodiment does not require any wiring for controlling the electromagnetic valves between the first unit 1A and the second unit 1B. Therefore, the present embodiment can reduce costs. Furthermore, when the lifting simulator 6 in the first unit 1A and the second unit 1B are connected via lines, they are connected only via the backpressure chamber 602 and the backpressure chamber line 10X, without any connection established between the overpressure chamber 601 of the lifting simulator 6 and the second unit 1B.This embodiment allows the lifting simulator 6 to be actuated without the need for multiple lines, thereby reducing costs.

[0033] Information input to the ECU 90 includes readings from the lift sensor 94 and the hydraulic pressure sensors 91 and the like, as well as driving condition information transmitted from the vehicle. The ECU 90 controls the wheel cylinder hydraulic pressure of each wheel (FL to RR) by actuating the electromagnetic valves 21 and the like, and the motor 20, using the input information according to a built-in program. Through this control, the ECU 90 can execute various types of brake control (anti-lock braking control to prevent or reduce wheel slip during braking, amplification control to reduce the driver's required braking force, brake control to manage vehicle movement, and automatic brake control, such as adaptive cruise control, regenerative cooperative braking, and the like).The vehicle's movement control includes vehicle behavior stabilization control, for example, electronic stability control. In regenerative cooperative braking control, the ECU 90 controls the wheel cylinder hydraulic pressures to achieve a target deceleration (a target braking force) in conjunction with the regenerative brake.

[0034] The ECU 90 comprises a brake actuation extent detection area 90a, a target wheel cylinder hydraulic pressure calculation area 90b, a gain control area 90c, a sudden brake actuation state determination area 90d, and a second pressure force brake generation area 90e as a configuration for executing the brake control described above. The brake actuation extent detection area 90a detects a stroke (a movement extent) of the push rod 101 in response to the sensor signal from the stroke sensor 94. The target wheel cylinder hydraulic pressure calculation area 90b calculates a target wheel cylinder hydraulic pressure.In particular, the target wheel cylinder hydraulic pressure calculation area 90b calculates, based on the detected pedal travel, the target wheel cylinder hydraulic pressure that achieves a predetermined gain ratio, namely an ideal characteristic of the ratio between the pedal travel and a brake hydraulic pressure requested by the driver (a vehicle deceleration G requested by the driver). Furthermore, at the time of regenerative cooperative brake control, the target wheel cylinder hydraulic pressure calculation area 90b calculates the target wheel cylinder hydraulic pressure with respect to the regenerative braking force.The target wheel cylinder hydraulic pressure calculation area 90b, for example, calculates a target wheel cylinder hydraulic pressure such that the sum of the regenerative braking force input by a control unit of the regenerative braking device and a hydraulic braking force corresponding to the target wheel cylinder hydraulic pressure can achieve the vehicle deceleration requested by the driver. At the time of motion control, the target wheel cylinder hydraulic pressure calculation area 90b calculates the target wheel cylinder hydraulic pressure for each of the wheels FL to RR in order to achieve a desired vehicle motion state, for example, based on a detected vehicle motion state magnitude (lateral acceleration or the like).

[0035] The boost control section 90c actuates pump 3 and controls the shut-off valves 21 and the communication valves 23, respectively, in the closing and opening directions at the moment the brake is applied by the driver. Through this actuation and control, the boost control section 90c generates higher wheel cylinder hydraulic pressures than the master cylinder hydraulic pressure, using the delivery pressure of pump 3 as the hydraulic pressure source. This enables the brake system to perform boost control, generating a hydraulic braking force that is less than the driver's applied braking force. Specifically, the boost control section 90c achieves the target wheel cylinder hydraulic pressure by controlling the pressure regulating valve 24 while pump 3 is actuated for a predetermined number of revolutions, thus adjusting the amount of brake fluid supplied by pump 3 to wheel cylinder W / C.The braking system according to the first embodiment performs a boosting function that assists the brake actuation force by actuating the pump 3 of the second unit 1B instead of the motor vacuum booster. Furthermore, the boosting control area 90c controls the SS / V-IN 27 and the SS / V-OUT 28, each in a closing direction and an opening direction. Through this control, the boosting control area 90c causes the stroke simulator 6 to function.

[0036] The sudden brake actuation state determination area 90d detects a brake actuation state based on input from the brake actuation magnitude detection area 90a and the like, and determines (detects) whether the brake actuation state is in a predetermined sudden brake actuation state. For example, the sudden brake actuation state determination area 90d determines whether the amount of change in pedal travel per unit of time exceeds a predetermined threshold. If the brake actuation state is determined to be the sudden brake actuation state, the ECU 90 switches the control from generating the wheel cylinder hydraulic pressures through the boost control area 90c to generating the wheel cylinder hydraulic pressures through the second pressure brake generation area 90e.The second pressure brake generation area 90e actuates the pump 3 and controls the shut-off valves 21, the SS / V-IN 27, and the SS / V-OUT 28, each in the closing, opening, and closing directions. Through this actuation and control, the second pressure brake generation area 90e implements the second pressure brake, which generates the wheel cylinder hydraulic pressures using the brake fluid transferred from the counter-pressure chamber 602 of the lifting simulator 6, until the pump 3 is ready to generate sufficiently high wheel cylinder pressures. The second pressure brake generation area 90e can control the shut-off valves 21 in the opening directions.Furthermore, the second pressure force brake generation area 90e can control the SS / V-IN 27 in the closing direction, and in this case, the brake fluid is supplied from the counter-pressure chamber 602 to the wheel cylinder W / C side via the check valve 220 (brought into an open state, since the pressure on the wheel cylinder W / C side is even lower than on the counter-pressure chamber 602 side). In the first embodiment, the brake fluid can be efficiently supplied from the counter-pressure chamber 602 side to the wheel cylinder W / C side by controlling the SS / V-IN 27 in the opening direction.If, after this point, the brake actuation state stops determining the sudden brake actuation state, or a predetermined state indicating that the output power of pump 3 is sufficient is met, the ECU 90 switches the control from generating the wheel cylinder hydraulic pressures via the second pressure brake generation area 90e to generating the wheel cylinder pressures via the amplification control area 90c. The amplification control area 90c controls the SS / V-IN 27 and the SS / VV-OFF ​​28 in the closing and opening directions, respectively. With this control, the amplification control area 90c causes the lift simulator 6 to be operational. The ECU 90 can be actuated to switch the control to regenerative cooperative brake control after the second pressure brake.

[0037] Next, a configuration of the stroke sensor 94 according to the first embodiment will be described in detail with reference to Fig. 7 to 10 described. Fig. 7 is a cross-section that runs along a line S7-S7, which is in Fig. 5 is shown, recorded. Fig. 8 is a cross-section of the first embodiment, which is drawn along a line S8-S8 that is in Fig. 4 is shown, recorded. Fig. Figure 9 is a partially perspective cross-sectional view of the main cylinder 5 according to the first embodiment. Fig. Figure 10 is a perspective exploded view of the stroke sensor 94 according to the first embodiment.

[0038] The sensing area 95 of the stroke sensor 94 is fixed to an outer circumferential surface 7a (a left outer circumferential surface) of the main cylinder housing 7 on the positive Y-axis direction side using two screws 951. The outer circumferential surface 7a on the positive Y-axis direction side is located on an outer circumference of the large diameter area 70a and is positioned on the positive Y-axis direction side (the left side) of the large diameter area 70a. The outer circumferential surface 7a on the positive Y-axis direction side extends parallel to the Z-axis. A central position of the sensing area 95 in the Z-axis direction corresponds to a position of the axial line O of the cylinder 70 (the large diameter area 70a and the small diameter area 70b) in the Z-axis direction.Because the direction of the axial line O coincides with the X-axis direction, the direction of the axial line O will also be referred to below as the X-axis direction (or simply the axial direction). Furthermore, a direction extending around the axial line O is referred to as the circumferential direction, and a direction extending radially from the axial line O is referred to as the radial direction.

[0039] The magnet 96 of the stroke sensor 94, for example, is a neodymium magnet and is essentially semi-cylindrical in its vertical cross-section. One width of the magnet 96 (one length in the Z-axis direction) is shorter than one diameter of the primary piston 51P. In other words, the magnet 96 extends partially in the circumferential direction of the primary piston 51P. An outer circumferential region 96a of the magnet 96, facing the sensing region 95, has a circular arc shape centered on the same axial line O as the primary piston 51P and with a radius slightly smaller than the large diameter region 70a of the cylinder 70. A first engagement recess region 96b, extending in the X-axis direction, is provided at each of the positions in the vicinity of the two ends of the outer circumferential region 96a in the Z-axis direction.The magnet 96 is attached at a position in the vicinity of one end of the primary piston 51P in the negative X-axis direction via a magnet holder 97 (an engagement element).

[0040] The magnet holder 97 is an essentially cylindrical element made of a synthetic resin, and the primary piston 51P penetrates an inner circumferential face of the magnet holder 97. The magnet holder 97 is rotatable with respect to the primary piston 51P. The magnet holder 97 comprises a magnet holding area 971 and a two-face width area 972 (an engagement area). The magnet holding area 971 projects from one end of the magnet holder 97 in the positive Y-axis direction to the positive Y-axis direction side. The length from the axial line O to one end of the magnet holding area 971 in the positive Y-axis direction is shorter than the inner diameter of the large diameter area 70a. In other words, the magnet holding area 971 is not in contact with an inner circumferential face of the large diameter area 70a. The magnet holding area 971 includes a recessed magnet mounting area 971a.The magnetic mounting area 971a is shaped to match an outer shape of the magnet 96. The ends of the magnetic mounting area 971a are open in the positive X-axis and positive Y-axis directions. The first engagement claws 971b are provided on an opening edge on the end face of the magnetic mounting area 971a in the positive Y-axis direction. Both first engagement claws 971b are arranged opposite each other in the positive Y-axis direction. Furthermore, a first engagement claw 971c is provided on an opening edge on the side of the magnetic mounting area 971a in the positive X-axis direction. Each of the first engagement claws 971b engages with each of the first engagement recess areas 96b of the magnet 96 in the Y-axis direction when the magnet 96 is attached to the magnetic mounting area 971a.Furthermore, the first engagement claw 971c engages with an end face of the magnet 96 in the positive X-axis direction when the magnet 96 is attached to the magnet mounting area 971a. The magnet 96 is prevented from detaching from the magnet mounting area 971a as a result of each of the first engagement claws 971b and 971c. When the magnet 96 is attached to the magnet holder 97, a mean position of the magnet 96 in the Z-axis direction coincides with the position of the axial line O in the Z-axis direction.

[0041] The two-surface width section 972 projects from one end of the magnet holder in the negative Z-axis direction to the side opposite the negative Z-axis direction. The two-surface width section 972 comprises two flat surfaces facing each other in the Z-axis direction and extending parallel to one another. The length from the axial line O to one end of the two-surface width section 972 in the negative Z-axis direction is shorter than the inner diameter of the large diameter section 70a. In other words, the two-surface width section 972 is not in contact with the inner circumferential surface of the large diameter section 70a. A guide pin 98 is arranged between the two flat surfaces of the two-surface width section 972. The guide pin 98 is a metal rod and is arranged on the side opposite the negative Z-axis direction with respect to the primary piston 51P, and is positioned such that an associated longitudinal direction extends along the X-axis direction.One end face of the guide pin 98 in the positive X-axis direction is cantilevered on an end surface 701 of the large diameter region 17a in the positive X-axis direction. The guide pin 98 includes an external threaded region 98a at its corresponding end in the positive X-axis direction. The external threaded region 98a engages with an internal threaded region 701a formed on the end surface 701 in the positive X-axis direction. When the primary piston 51P is raised, the two flat surfaces of the two-surface width region 972 are in sliding contact with the guide pin 98. The guide pin 98 has a length (one dimension in the X-axis direction) that allows it to extend constantly between the two flat surfaces of the two-surface width region 972 throughout the entire stroke of the primary piston 51P.In other words, the guide pin 98 is adapted to the two-surface width area 972 in the circumferential direction, which helps to limit movement of the magnet holder 97 relative to the main cylinder housing 7 in the circumferential direction.

[0042] The magnetic holder 97 comprises a plurality of second engagement claws 973 projecting towards the positive X-axis direction side. Each of the second engagement claws 973 is provided at predetermined intervals in the circumferential direction. Each of the second engagement claws 973 is arranged to be aligned with the axial line O. Each of the second engagement claws 973 engages in the X-axis direction with an annular second engagement recess 512 formed on an outer circumferential region 511 of the primary piston 51B. The second engagement recess 512 is located in the vicinity of the end of the primary piston 51P in the negative X-axis direction. Movement of the magnet holder 97 relative to the primary piston 51P in the X-axis direction is limited by the engagement between the second engagement claws 973 and the second engagement recess area 512 in the X-axis direction.In the first embodiment, a rotation limitation mechanism 99, which limits movement of the magnet 96 in the circumferential direction, is formed by the magnet holder 97 and the guide pin 98.

[0043] In the braking system according to the first embodiment, the primary piston 51P is raised in the X-axis direction by pressure from the push rod 101 when the driver presses the brake pedal 100. At this point, the movement of the magnet holder 97 relative to the primary piston 51P in the X-axis direction is limited by the engagement between the second engagement claws 973 and the second engagement recess area 512 in the X-axis direction. This causes the magnet holder 97 and the magnet 96, which is attached to the magnet holder 97, to move concurrently with the primary piston 51P. The sensing area 95 outputs a sensor signal with a voltage proportional to the magnitude of the displacement of the magnet 96. Fig. Figure 11 shows an example of the relationship between the pushrod stroke and the sensor output of the stroke sensor 94, represented by a solid line. The sensor output has a range from Vmin to V2. However, an actual used range is from V0 to V1, and the sensor output changes linearly in a range from 0 to X1, which corresponds to normal use of the pushrod stroke. In a range from X1 to X2, where the pushrod stroke indicates a fault condition that may occur with respect to the system, the stroke sensor 94 outputs a constant sensor output (V1) and a limit value (V2) when the pushrod stroke exceeds the range corresponding to the fault condition. This allows a fault in the stroke sensor 94 to be distinguished from a fault in the pedal or the like if a fault has occurred in the braking system.The brake actuation extent detection area 90a can determine the stroke of the push rod 101 from the sensor output of the stroke sensor 94 by storing the ratio between the sensor output and the push rod stroke, which is represented by the solid line in . Fig. As shown in 11, capture in advance.

[0044] The primary piston 51P is now rotated when it experiences a circumferential force due to a deficiency limiting its rotation in the circumferential direction. For example, the helical spring 52P, which preloads the primary piston 51P, is twisted when it expands / compresses, allowing the primary piston 51P to rotate as the helical spring 52P expands / compresses. At this point, in the first embodiment, the two-surface width areas 972 of the magnet holder 97 and the guide pin 98 are aligned in the circumferential direction (one direction of rotation), thereby limiting (preventing) the rotation of the magnet holder 97. Even though this causes the primary piston 51P to rotate, it prevents the magnet holder 97 from rotating as well. As a result of this effect, the magnet 96 is raised while maintaining a constant minimum radial distance to the detected area 95.

[0045] The conventional brake system includes a ring-shaped magnet attached to the outer circumference of the primary piston. It detects the piston's primary stroke using the sensing area, which is fixed to the master cylinder housing. Although this causes the magnet to rotate along with the primary piston, it does not affect the accuracy of the pushrod stroke detection because the radial distance between the magnet and the sensing area remains constant. However, the magnet material (for example, neodymium) is expensive, and therefore the use of a ring-shaped magnet increases manufacturing costs.One possible solution is to partially position the magnet circumferentially around the primary piston, from the perspective of reducing manufacturing costs. However, in this case, the radial distance between the magnet and the sensing area increases as the magnet rotates with the primary piston. This separation allows the sensing area to detect the magnetic flux, resulting in an abnormal sensor output. This occurs when the pushrod stroke is zero, as indicated by the dashed line in the figure. Fig. If 11 is displayed, this leads to a reduction in the accuracy of the pushrod stroke measurement.

[0046] On the other hand, in the first embodiment, the rotation-limiting mechanism 99 (the magnet holder 97 and the guide pin 98) is provided as a rotation-prevention structure that limits the rotation of the magnet 96, thereby maintaining the radial distance between the magnet 96 and the detection area 95 at a predetermined distance (the shortest distance). As a result of this effect, the ratio between the pushrod stroke and the sensor output is maintained in a ratio that would be established if the stroke simulator 94 were normal, as indicated by the solid line in Fig. Figure 11 shows the stroke of the pushrod, and therefore the pushrod stroke can be accurately measured. Consequently, the present embodiment can accurately measure the stroke of the primary piston 51P (= the pushrod stroke), while reducing manufacturing costs by partially providing the magnet 96 in the circumferential direction of the primary piston 51P.

[0047] The first embodiment brings with it the following advantageous effects.

[0048] (1) The brake device comprises the master cylinder housing 7, which includes the cylinder 70, wherein the primary piston 51P is provided inside the cylinder 70 and is movable in the axial direction, where the axial direction is the direction of the axial line O of the cylinder 70; the magnet 96, which is provided inside the cylinder 70 partially in the circumferential direction of the primary piston 51P, where the circumferential direction is the direction around the axial line O, and is configured to be displaced according to the movement of the primary piston 51P; the sensing area 95, which is provided on the master cylinder housing 7 and configured to detect the stroke of the primary piston; and the rotation limiting mechanism 99, which is provided inside the cylinder 70 and configured to limit the movement of the magnet 96 in the circumferential direction.

[0049] This allows the first embodiment of the brake device to accurately measure the stroke of the primary piston 51P while reducing manufacturing costs.

[0050] (2) The rotation limitation mechanism 99 comprises the magnet holder 97, which is attached to the primary piston 51P in such a way as to be limited with respect to movement in the axial direction, and which is free to move in the circumferential direction. The magnet holder 97 comprises the two-surface wide area 972, which is configured such that the movement relative to the main cylinder housing 7 is limited in the circumferential direction.

[0051] The first embodiment thus allows the structure for preventing the rotation of the magnet 96 to be formed simply by another element of the primary piston 51P. In particular, in the first embodiment, the magnet holder 97 is made of synthetic resin and can therefore be easily shaped. Furthermore, the magnet holder 97 does not prevent the rotation of the primary piston 51P, and thus the first embodiment can prevent or reduce an increase in the sliding resistance between the primary piston 51P and the piston seals 541 and 542, an increase in the actuation reaction force of the brake pedal 100, and the like.

[0052] (3) The rotation limiting mechanism 99 comprises the guide pin 98. One end of the guide pin 98 in the axial direction is fixed to the main cylinder housing 7 and the other end of the guide pin 98 in the axial direction is adapted to the two-surface width area 972 in the circumferential direction.

[0053] Therefore, the first embodiment enables the braking device to reliably prevent the rotation of the magnet holder 97 due to the fitted engagement between the two-surface width area 972 and the guide pin 98. Furthermore, the guide pin 98 can be formed by fixing one end of the metal rod to the main cylinder housing 7, and thus the first embodiment can reduce machining costs compared to forming the guide pin 98 by machining the main cylinder housing 7.

[0054] (4) The magnet 96 is provided on the magnet holder 97. The outer circumferential region 96a of the magnet 96 on the other side in the radial direction is designed to correspond to the large diameter region 70a of the cylinder 70, when the radial direction is the direction extending radially from the axial line.

[0055] Even if the magnet 96 is rotated slightly, the braking device can accurately detect the range of motion of the primary piston 51P because the radial distance between the magnet 96 and the detection area 95 remains unchanged.

[0056] (5) The magnet holder 97 comprises the first engagement claws 971b and 971c, which are designed to hold the magnet 96.

[0057] The first embodiment allows the magnet 96 and the magnet holder 97 to be easily connected to each other by a so-called snap fastener without the use of a mechanical element such as a screw and adhesive. Consequently, the first embodiment can reduce component costs and the number of assembly steps.

[0058] (6) The primary piston 51P includes the second engagement recess area 512. The magnet holder 97 includes the second engagement claws 973, which are configured to engage with the second engagement recess area 512 in the axial direction.

[0059] Therefore, the first embodiment allows the magnet holder 97 to be easily attached to the primary piston 51P without the use of a mechanical element, such as a screw and adhesive. Furthermore, the first embodiment can implement the structure for attaching the magnet holder 97 to the primary piston 51P in a way that limits axial movement while allowing circumferential movement with a simple configuration.

[0060] (7) The main cylinder housing 7 includes the internal threaded area 701a. The guide pin 98 includes the external threaded area 98a on one end. The external threaded area 98a engages with the internal threaded area 701a.

[0061] The first embodiment thus enables the guide pin 98 to be reliably and easily fixed to the main cylinder housing 7. Furthermore, the first embodiment can prevent or reduce deformation of the main cylinder housing 7 compared to an interference fit of one end of the guide pin 98 in an opening formed on the main cylinder housing 7.

[0062] (8) The guide pin 98 is provided on its lower side, in the direction of gravity with respect to the primary piston 51P, with the brake device attached to the vehicle. The detection area 95 is provided on the side of the master cylinder housing 7 with the brake device attached to the vehicle.

[0063] The magnet 96 and the guide pin 98 should be positioned offset from each other in the circumferential direction to avoid mutual interference between the outer circumference of the primary piston 51P. Positioning the guide pin 98 on the underside of the primary piston 51P allows the magnet 96 to be located on either the left or right side of the primary piston 51P. Consequently, the first embodiment can improve the flexibility of changing the layout of the sensing area 95, which is arranged to face the magnet 96.

[0064] (9) The braking system comprises the master cylinder 5, the first unit 1A and the second unit 1B. The master cylinder 5 comprises the master cylinder housing 7, which includes the cylinder 70, the primary piston 51P, which is provided within the cylinder 70 and is movable in the axial direction, where the axial direction is the direction of the axial line O of the master cylinder 70, the magnet 96, which is provided within the cylinder 70 partially in the circumferential direction of the primary piston 51P, where the circumferential direction is the direction around the axial line, and is arranged to be offset according to the movement of the primary piston 51P, and the rotation limiting mechanism 99, which is provided within the cylinder 70 and is arranged to limit the movement of the magnet 96 in the circumferential direction.The first unit 1A comprises the sensing area 95, which is provided and configured on the master cylinder 5 to detect the range of motion of the primary piston 51P, and the stroke simulator 6, which is configured to introduce the brake fluid flowing from the master cylinder 5. The stroke simulator 6 is configured to generate the simulated actuation reaction force of the brake pedal 100. The second unit 1B comprises the second unit housing 8, which is connected to the first unit 1A and includes the oil lines within it, and the pump 3, which is provided and configured within the second unit housing 8 to generate the hydraulic pressures in the wheel cylinders W / C, which are attached to the wheels FL to RR, via the oil lines.

[0065] This first embodiment allows the brake device to accurately detect the stroke of the primary piston 51P, while reducing manufacturing costs.

[0066] (10) The master cylinder 5 forms the brake device and is configured to generate the brake hydraulic pressures by actuating the brakes. The master cylinder 5 comprises the master cylinder housing 7, which includes the cylinder 70, the primary piston 51P, which is provided within the cylinder 70 and is movable in the axial direction, where the axial direction is the direction of the axial line O of the cylinder 70, the magnet 96, which is provided within the cylinder 70 partially in the circumferential direction of the primary piston 51P, where the circumferential direction is the direction around the axial line, and is configured to be offset according to the movement of the primary piston 51P, and the rotation limiting mechanism 99, which is provided within the cylinder 70 and configured to limit the movement of the magnet 96 in the circumferential direction.

[0067] This first embodiment allows the brake device to accurately detect the stroke of the primary piston 51P, while reducing manufacturing costs. [Second embodiment]

[0068] Next, a second embodiment is described. The second embodiment has a basic configuration similar to the first embodiment and is therefore described focusing only on the differences.

[0069] Fig. 12 is a cross-section of the second embodiment, which is along the line S7-S7, which is in Fig. 5 is shown, recorded. Fig. 13 is a cross-section of the second embodiment, which is along the line S8-S8, which is in Fig. 4 is shown, recorded.

[0070] The magnet holder 97 according to the second embodiment comprises the magnet holding area 971 and a projection area 974 (the engagement area). The projection area 974 extends from the end of the magnet holder 97 in the negative Y-axis direction towards the negative Y-axis direction side. A distal end of the projection area 974 (an end in the negative Y-axis direction) is hemispherical. A central position of the projection area 974 in the Z-axis direction coincides with the position of the axial line O of the cylinder 70 in the Z-axis direction. The inner diameter of the large diameter area 70a is shorter than a length from the axial line O to the end of the magnet holding area 971 in the positive Y-axis direction and a length from the axial line O to the end of the projection area 974 in the negative Y-axis direction. An engagement groove 702 is formed on the large diameter area 70a at a position facing the projection area 974.The engagement groove 702 is adapted to the projection area 974 in the circumferential direction. As can be seen from the X-axis direction, the engagement groove 702 is shaped to match the shape of the projection area 974 and is in contact with it. The engagement groove 702 extends in the X-axis direction and has a length (one dimension in the X-axis direction) that allows it to be in constant engagement with the projection area 974 in the circumferential direction throughout the entire stroke of the primary piston 51B. This configuration helps to limit the movement of the magnet holder 97 relative to the main cylinder housing 7 in the circumferential direction. In the second embodiment, the rotation limiting mechanism 99, which limits the movement of the magnet 96 in the circumferential direction, is formed by the magnet holder 97 and the engagement groove 702.

[0071] A groove 703 is formed on the large diameter area 70a at a position facing the magnet holding area 971. The groove 703 extends in the X-axis direction and has the same length (dimension in the X-axis direction) as the engagement groove 702. As can be seen from the X-axis direction, the groove 703 is designed to match a shape of the magnet holding area 971. The magnet holding area 971 does not engage with an inner circumferential surface of the groove 703.

[0072] In the second embodiment, the rotation-limiting mechanism 99 (the magnet holder 97 and the projection area 974) is provided as a rotation-prevention structure that limits the rotation of the magnet 96, thus allowing the radial distance between the magnet 96 and the detection area 95 to be maintained at the predetermined distance (the shortest distance). As a result of this effect, the pushrod stroke can be accurately detected.

[0073] The second embodiment brings with it the following advantageous effects.

[0074] (11) The rotation limiting mechanism 99 includes the engagement groove 702, which is provided and arranged on the inner circumferential surface of the cylinder 70 to be adapted to the projection area 974 in the circumferential direction.

[0075] The second embodiment thus enables the braking device to reliably prevent the rotation of the magnet holder as a result of the fitted engagement between the projection area 974 and the engagement groove 702.

[0076] Furthermore, the engagement groove 702 is formed on the main cylinder housing 7, and therefore the second embodiment can reduce the number of components compared to an additional provision of an element adapted to the projection area 974.

[0077] (12) The magnet 96 is provided in a position opposite the protrusion area 974 in the circumferential direction.

[0078] The second embodiment thus enables the magnet holder 97 and the large diameter area 70a to be doubly symmetrical with respect to the axial line O due to the identical shapes of the projection area 974 and the magnet holding area 971 and the identical shapes of the engagement groove 702 and the groove area 703. Consequently, the second embodiment can improve assembly capability when the magnet holder 97 is attached to the primary piston 51P. [Third embodiment]

[0079] Next, a third embodiment is described. The third embodiment has a basic configuration similar to the second embodiment and is therefore described focusing only on the differences.

[0080] Fig. 14 is a cross-section of the third embodiment, which is drawn along the line S8-S8, as shown in Fig. 4 is shown, recorded.

[0081] The third embodiment differs from the second embodiment in that it omits the projection area 974 and the engagement groove 702, a connection between the magnet holding area 971 and the groove area 703, and the circumferentially adapted engagement between the magnet holding area 971 and the groove area 703. In other words, in the third embodiment, the magnet holding area 971 and the groove area 703 are used to function as a rotation limiting mechanism 99.

[0082] The third embodiment brings with it the following advantageous effects.

[0083] (13) The magnet 96 is provided on the magnet holding area 971 of the magnet holder 97. The magnet holding area 971 is adapted to the groove area 703, which is provided on the main cylinder housing 7 in the circumferential direction.

[0084] The third embodiment thus causes the magnet holding area 971 to hold the magnet 96 in order to serve as a rotation-prevention structure, thereby enabling the braking device to achieve a very simple rotation-prevention structure. [Fourth embodiment]

[0085] Next, a fourth embodiment is described. The fourth embodiment has a basic configuration similar to the first embodiment and is therefore described focusing only on the differences.

[0086] Fig. Figure 15 is a perspective view of the magnet holder 97 according to the fourth embodiment.

[0087] According to the fourth embodiment, the magnet 96 is connected to the magnet 97 by overmolding. During overmolding, the magnet 96 is first placed in a mold for forming the magnet holder. Then, resin is introduced into the mold and cured with the magnet 96, which is encased in molten resin. This process yields a magnet holder subassembly in which the magnet 96 and the magnet holder 97 are integrated.

[0088] The fourth embodiment produces the following advantageous effect.

[0089] (14) The magnet 96 is formed in one piece with the magnet holder 97 by overmolding.

[0090] The fourth embodiment allows the magnet 96 and the magnet holder 97 to be integrated during the molding of the resin, thereby preventing or reducing vibration of the magnet 96. Consequently, the fourth embodiment can improve the accuracy of detecting the stroke of the primary piston 51P. Furthermore, the fourth embodiment allows the magnet 96 and the magnet holder 97 to be joined together in a single molding step, thus increasing the efficiency of the process. [Other embodiments]

[0091] Having described the embodiments for implementing the present invention based on the exemplary embodiments, the specific configuration of the present invention is not limited to the configurations specified in the exemplary embodiments, and the present invention even includes design modifications and the like, which are carried out within a scope that does not deviate from the spirit of the present invention. Furthermore, the individual components described in the claims and the description can be arbitrarily combined or omitted within a scope that allows them to still be able to achieve at least some of the tasks described above or to produce at least some of the advantageous effects described above.

[0092] In the embodiments described above, for example, the first unit 1A comprises the main cylinder 5 and the stroke simulator 6, but the main cylinder 5 and the stroke simulator 6 can be provided separately as distinct units. Furthermore, the stroke simulator 6 can be integrally integrated into the second unit 1B instead of the first unit 1A. Additionally, in the embodiments described above, the sensing area 95 of the stroke sensor 94 is located outside the main cylinder housing 7, but it can be provided in another way, as long as the sensing area 95 and the magnet 96 are arranged close to each other. For example, the sensing area 95 can be integrally integrated within the main cylinder housing 7.

[0093] Furthermore, a PWM pulse signal corresponding to the voltage generated by the Hall element can be used as the sensor signal for the detection range. Alternatively, a coil can be used instead of the Hall element.

[0094] The following description outlines technical ideas that can be identified from the embodiments described above.

[0095] A braking device according to an associated configuration comprises a master cylinder housing comprising a cylinder, a piston provided within the cylinder and movable in an axial direction if the axial direction is a direction of an axial line of the cylinder, a magnet provided within the cylinder partially in a circumferential direction of the piston if the circumferential direction is a direction around the axial line and configured to be displaced according to a movement of the piston, a sensing area provided outside the master cylinder housing and configured to detect a degree of movement of the piston, and a rotation limiting mechanism provided within the cylinder and configured to limit movement of the magnet in the circumferential direction.

[0096] According to a more preferred configuration, the rotation limitation mechanism in the configuration described above comprises an engagement element arranged to be limited with respect to movement in the axial direction and to be able to move circumferentially relative to the piston. The engagement element includes an engagement area configured to limit movement relative to the main cylinder housing in the circumferential direction.

[0097] According to another preferred configuration in one of the configurations described above, the rotation limitation mechanism includes a guide pin. One end of the guide pin in the axial direction is fixed in a main cylinder housing, and the other end of the guide pin in the axial direction is adapted to the engagement area in the circumferential direction.

[0098] According to a further preferred configuration, in each of the configurations described above, the magnet is provided on the engagement element. An outer circumferential region of the magnet on an outer side in a radial direction is designed to coincide with an inner circumferential region of the main cylinder housing, where the radial direction is a direction extending radially from the axial line.

[0099] According to a further preferred configuration, in each of the configurations described above, the engagement element includes a first engagement claw designed to hold the magnet.

[0100] According to a further preferred configuration, in each of the configurations described above, the piston includes an engagement recess area. The engagement element comprises a plurality of secondary engagement claws arranged to engage with the engagement recess area in the axial direction.

[0101] According to a further preferred configuration, in each of the configurations described above, the main cylinder housing includes an internally threaded section. The guide pin includes an externally threaded section on one end. The externally threaded section is configured to engage with the internally threaded section.

[0102] According to a further preferred configuration, in each of the configurations described above, the magnet and the engagement element are formed in one piece by overmolding.

[0103] According to a further preferred configuration, in each of the configurations described above, the guide pin is located on a lower side facing the direction of gravity with respect to the piston and the brake device attached to the vehicle. The detection area is located on one side of the master cylinder housing with the brake device attached to the vehicle.

[0104] According to a further preferred configuration, in each of the configurations described above, the rotation limitation mechanism includes an engagement groove which is provided and arranged on an inner circumferential surface of the cylinder to be adapted to the engagement area in the circumferential direction.

[0105] According to a further preferred configuration, the magnet is provided on the engagement element in each of the configurations described above. The outer circumferential region of the magnet on the outer side in the radial direction is designed to coincide with the inner circumferential region of the main cylinder housing, where the radial direction is the direction extending radially from the axial line.

[0106] According to a further preferred configuration, in each of the configurations described above, the magnet is positioned opposite the engagement area in the circumferential direction.

[0107] According to yet another preferred configuration, the magnet is provided at the engagement area in each of the configurations described above.

[0108] According to another aspect, a braking system according to an associated configuration further comprises a master cylinder, a first unit, and a second unit. The master cylinder comprises a master cylinder housing, which includes a cylinder; a piston provided within the cylinder and movable in an axial direction, where the axial direction is a direction along the axial line of the cylinder; a magnet provided within the cylinder partially in a circumferential direction of the piston, where the circumferential direction is a direction around the axial line, and configured to be displaced according to a movement of the piston; and a rotation limiting mechanism provided within the cylinder and configured to limit movement of the magnet in the circumferential direction.The first unit comprises a sensing area, provided and configured outside the master cylinder, to detect the piston's range of motion, and a stroke simulator configured to receive brake fluid flowing from the master cylinder. The stroke simulator is configured to generate a simulated actuation response force of a brake actuator. The second unit comprises a second unit housing connected to the first unit, containing an oil line, and a hydraulic pressure source provided and configured within the second unit housing to generate hydraulic pressure in a wheel cylinder mounted on a wheel via the oil line.

[0109] Preferably, in the configuration described above, the rotation limitation mechanism comprises an engagement element that is mounted in such a way as to be limited with respect to movement in the axial direction and to be able to move circumferentially relative to the piston. The engagement element comprises an engagement area that is configured such that movement relative to the main cylinder housing is limited in the circumferential direction.

[0110] According to another preferred configuration, in each of the configurations described above, the rotation limitation mechanism comprises a guide pin. One end of the guide pin in the axial direction is fixed to the main cylinder housing, and the other end of the guide pin in the axial direction is adapted to the engagement area in the circumferential direction.

[0111] According to a further preferred configuration, in each of the configurations described above, the rotation limitation mechanism includes an engagement groove which is provided and arranged on an inner circumferential surface of the cylinder to be adapted to the engagement area in the circumferential direction.

[0112] Furthermore, according to another aspect, a master cylinder, in a related configuration, forms a braking device and is configured to generate brake hydraulic pressure through brake actuation. The master cylinder comprises a master cylinder housing, which includes a cylinder; a piston provided within the cylinder and movable in an axial direction, where the axial direction is a direction along the cylinder's axial line; a magnet provided within the cylinder partially in a circumferential direction around the piston, where the circumferential direction is a direction around the axial line, and configured to be displaced according to a movement of the piston; and a rotation limiting mechanism provided within the cylinder and configured to limit movement of the magnet in the circumferential direction.

[0113] Preferably, in the configuration described above, the rotation limitation mechanism comprises an engagement element that is mounted in such a way as to be limited with respect to movement in the axial direction and to be able to move circumferentially relative to the piston. The engagement element comprises an engagement area that is configured such that movement relative to the main cylinder housing is limited in the circumferential direction.

[0114] According to another preferred configuration, in each of the configurations described above, the rotation limitation mechanism includes a guide pin. One end of the guide pin, in the axial direction, is fixed to the main cylinder housing, and the other end of the guide pin, also in the axial direction, is adapted to the engagement area in the circumferential direction.

[0115] According to a further preferred configuration, in each of the configurations described above, the rotation limitation mechanism includes an engagement groove which is provided and arranged on an inner circumferential surface of the cylinder to be adapted to the engagement area in the circumferential direction. Reference symbol list W / C wheel cylinder 1A First Unit 1B Second Unit 3 Pump (hydraulic pressure source) 5 main cylinders 6 Hub Simulator 7 Main cylinder housing 51P Primary Piston 51S Secondary Piston 70 cylinders 94 Hub sensor 95 Detection area 96 Magnet 96a Outer perimeter 97 Magnetic holders (interface element) 98 guide pin 99 Rotation Limitation Mechanism 702 Intervention groove 972 Two-surface width area (intervention area)

Claims

[1] Braking device comprising: - a main cylinder housing (7) comprising a cylinder (60) therein; - a piston (51) which is provided inside the cylinder (60) and is movable in the direction of an axial line of the cylinder (60), - a magnet (96) which is provided and arranged inside the cylinder (60) partially in a circumferential direction of the piston (51) to be displaced according to a movement of the piston (51), the circumferential direction being a direction around the axial line; - a detection area (95) provided and configured on the main cylinder housing (7) to detect a range of motion of the piston (51); and - a rotation limitation mechanism (99) provided and configured within the cylinder (60) to limit movement of the magnet (96) in the circumferential direction, wherein: - the rotation limitation mechanism (99) comprises an engagement element (97) arranged in such a way that it can move in the circumferential direction while being limited with respect to movement in the direction of the axial line relative to the piston (51), and - the engagement element (97) comprises an engagement area (972) which is configured such that movement relative to the main cylinder housing (7) is restricted in the circumferential direction. [2] Braking device according to claim 1, wherein: - the rotation limiting mechanism (99) includes a guide pin (98), and - one end of the guide pin (98) is fixed in the direction of the axial line on the main cylinder housing (7) and an opposite end of the guide pin (98) is adapted to the engagement area (972) in the circumferential direction in the direction of the axial line. [3] Braking device according to claim 2, wherein: - the magnet (96) is provided on the engagement element (97), and - an outer circumferential region (96a) of the magnet (96) on an outer side in a radial direction extending radially from the axial line is designed such that it coincides with an outer circumferential region (511) of the piston (51) on the outer side in a radial direction. [4] Braking device according to claim 3, wherein the engagement element (97) comprises a first engagement claw (971b) configured to hold the magnet (96). [5] Braking device according to claim 4, wherein: - the piston (51) includes an engagement recess area (512), and - the engagement element (97) comprises a plurality of second engagement claws (973) which are arranged to engage with the engagement recess area (512) in the direction of the axial line. [6] Braking device according to claim 5, wherein: - the main cylinder housing (7) includes an internal thread area (701a), and - the guide pin (98) includes an external threaded area (98a) on one end side, wherein the external threaded area (98a) is configured to engage with the internal threaded area (701a). [7] Brake device according to claim 3, wherein the magnet (96) is formed in one piece with the engagement element (97) by overmolding. [8] Braking device according to claim 2, wherein: - the guide pin (98) is provided on a lower side in a direction of gravity with respect to the piston (51) with the brake device attached to a vehicle, and - the detection area (95) is provided on one side of the main cylinder housing (7) with the brake device attached to the vehicle. [9] Braking device according to claim 1, wherein the rotation limiting mechanism (99) comprises an engagement groove (702) which is provided on an inner circumferential surface of the cylinder (60) and is configured to be adapted to the engagement area (972) in the circumferential direction. [10] Brake device according to claim 9, wherein: - the magnet (96) is provided on the engagement element (97), and - an outer circumferential region (96a) of the magnet (96) on an outer side in a radial direction extending from the axial line is designed to coincide with an outer circumferential region (511) of the piston (51) on the outer side in the radial direction. [11] Braking device according to claim 10, wherein the magnet (96) is provided at a position opposite the engagement area (972) in the circumferential direction. [12] Braking device according to claim 10, wherein the magnet (96) is provided at the engagement area (972). [13] Braking system, comprehensive: - a main cylinder (5); - a first unit (1A); and - a second unit (1B); where: - the main cylinder (5) includes: - a main cylinder housing (7) comprising a cylinder (60) therein; - a piston (51) which is provided inside the cylinder (60) and is movable in the direction of an axial line of the cylinder (60), - a magnet (96) which is provided and arranged within the cylinder (60) partially in a circumferential direction of the piston (51) to be displaced according to a movement of the piston (51), the circumferential direction being a direction around the axial line; and - a rotation limiting mechanism (99) provided and arranged inside the cylinder (60) to limit movement of the magnet (96) in the circumferential direction. - the first unit (1A) includes: - a detection area (95) provided and set up on the main cylinder (5) to detect a range of motion of the piston (51), and - a stroke simulator configured such that the brake fluid flowing from the master cylinder (5) is introduced into it, the stroke simulator being configured to generate a simulated actuation response force of a brake actuation element, and - the second unit (1B) comprises: - a second unit housing (8) connected to the first unit (1A) and comprising an oil line (11) therein, and - a hydraulic pressure source (3) which is provided and set up within the second unit housing (8) to generate hydraulic pressure in a wheel cylinder (W / C) mounted on a wheel via the oil line (11), - the rotation limitation mechanism (99) comprises an engagement element (97) arranged so that it can move in the circumferential direction while being limited with respect to movement in the direction of the axial line relative to the piston (51), and - the engagement element (97) comprises an engagement area (972) which is configured such that movement relative to the main cylinder housing (7) is restricted in the circumferential direction. [14] Braking system according to claim 13, wherein: - the rotation limiting mechanism (99) includes a guide pin (98), and - one end of the guide pin (98) is fixed in the direction of the axial line on the main cylinder housing (7) and an opposite end of the guide pin (98) is adapted to the engagement area (972) in the circumferential direction in the direction of the axial line. [15] Braking system according to claim 13, wherein the rotation limiting mechanism (99) comprises an engagement groove (702) which is provided on an inner circumferential surface of the cylinder (60) and is configured to be adapted to the engagement area (972) in the circumferential direction. [16] Master cylinder (5) forming a brake device and designed to generate brake hydraulic pressure by actuating the brake, wherein the main cylinder (5) has: - a main cylinder housing (7) comprising a cylinder (60) therein; - a piston (51) which is provided inside the cylinder (60) and is movable in the direction of an axial line of the cylinder (60), - a magnet (96) which is provided and arranged within the cylinder (60) partially in the circumferential direction of the piston (51) to be displaced according to a movement of the piston (51), the circumferential direction being a direction around the axial line; and - a rotation limiting mechanism (99) provided and arranged inside the cylinder (60) to limit movement of the magnet (96) in the circumferential direction, and where: - the rotation limitation mechanism (99) comprises an engagement element (97) arranged so that it can move in the circumferential direction while being limited with respect to movement in the direction of the axial line relative to the piston (51), and - the engagement element (97) comprises an engagement area (972) which is arranged in such a way that movement relative to the main cylinder housing (7) is restricted in the circumferential direction. [17] Master cylinder (5) according to claim 16, wherein: - the rotation limiting mechanism (99) includes a guide pin (98), and - one end of the guide pin (98) is fixed in the direction of the axial line on the main cylinder housing (7) and an opposite end of the guide pin (98) is adapted to the engagement area (972) in the circumferential direction in the direction of the axial line. [18] Main cylinder (5) according to claim 16, wherein the rotation limiting mechanism (99) comprises an engagement groove (702) which is provided and arranged on an inner circumferential surface of the cylinder (60) to be adapted to the engagement area (972) in the circumferential direction.

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