Hydraulic pressure generating device

Abstract

A hydraulic pressure generating device (PS) comprises an electric motor (MT) that delivers rotary power (Tm), a conversion mechanism (GH) that outputs the rotary power (Tm) input into a rotary component (BK) as linear motion power (Fn), a piston (NC) inserted into a cylinder (CC) that moves via the linear motion power (Fn) to increase hydraulic pressure (Pc) in the cylinder (CC), and an intermediate component (BE) located between the piston (NC) and the linear motion component (BD). A pressing surface (Mpe) of the intermediate component (BE) is displaceable with respect to a bottom surface (Mtn, Mqn) of the piston (NC), and an end surface (Mqe) of the intermediate component (BE) is displaceable with respect to an end surface (Mpd) of the linear motion component (BD).

Description

Technical field

[0001] The present disclosure relates to a hydraulic pressure generating device. State of the art

[0002] PTL 1 discloses a method for operating a brake system 10 for an automobile, in which a first brake circuit I is selectively supplied by a pump 50 and a second brake circuit II is selectively actuated by a linear actuator 40.

[0003] A hydraulic pressure generating device disclosed in PTL 2 is used as the actuator. The device comprises an electric motor 2, a planetary gear 3, a worm gear 4, a spindle 9, and a piston 5 that is displaceable in a cylinder. In such a device, an offset can occur between an axis of a pressure element (spindle) and an axis of a pressure element (piston). The offset between the two axes is referred to here as "axis offset".

[0004] PTL 3 discloses that a contact surface of a piston s with a screw is formed in a planar shape and a tip end 240 of the screw on the piston side is formed in a convex curved surface shape, so that the contact between a pressure element (screw 80a) and a pressure element (piston 88a) is stabilized even when an axial misalignment occurs.

[0005] Axial misalignment occurs in combination with angular misalignment, where two axes are offset at an angle, and parallel misalignment, where the two axes are offset parallel to each other. Here, angular misalignment (also referred to as deflection error) is a condition in which axis 1 and axis 2 intersect and are offset at an angle to each other. Furthermore, parallel misalignment (also referred to as parallel displacement) is a condition in which axis 1 and axis 2 are offset parallel to each other. In the device disclosed in PTL 3, the axial misalignment is compensated by the convex surface of the screw tip end 240. In this configuration, it is possible to manage the angular misalignment, but there is a problem in managing the parallel misalignment. Citation list for patent literature PTL 1: JP2023-0001906A PTL 2: US2021 / 0122342 PTL 3: JP2012-214068A Brief description of the invention: Technical problem

[0006] In view of the above-mentioned problem, one objective of the present invention is to provide a hydraulic pressure generating device with which the influence of a parallel offset can be reduced, while the influence of an axis offset can be compensated. Solution

[0007] A hydraulic pressure generating device (PS) according to the invention comprises an electric motor (MT) that delivers rotational power (Tm), a conversion mechanism (GH) that outputs the rotational power (Tm) input into a rotary component (BK) as linear motion power (Fn) of a linear motion component (BD), a piston (NC) inserted into a cylinder (CC) and moved by the linear motion power (Fn) to increase a hydraulic pressure (Pc) in the cylinder (CC), and an intermediate component (BE) located between the piston (NC) and the linear motion component (BD). A pressing surface (Mpe) of the intermediate component (BE) is displaceable with respect to a bottom surface (Mtn, Mqn) of the piston (NC), and an end surface (Mqe) of the intermediate component (BE) is displaceable with respect to an end surface (Mpd) of the linear motion component (BD).

[0008] According to the configuration above, slippage can occur at two points: between the linear motion component BD and the intermediate component BE, and between the intermediate component BE and the control piston NC. Therefore, the influence of parallel misalignment can be adequately reduced in the hydraulic pressure generation unit PS.

[0009] In the hydraulic pressure generating device (PS) according to the invention, the linear motion component (BD) is arranged such that it covers the rotary component (BK), the intermediate component (BE) has a cylindrical section (Ene), and the rotary component (BK) can enter the cylindrical section (Ene). If the intermediate component BE is additionally provided, there is a concern that a dimension in the axial direction Hj will increase. According to the above configuration, an increase in the dimension can be limited even when the intermediate component BE is provided.

[0010] The hydraulic pressure generating device (PS) according to the invention comprises two sealing components (SL) that seal the piston (NC) and the cylinder (CC). A length (Lbe) of the intermediate component (BE) in one direction (Hj) along a central axis (Jn) of the piston (NC) is longer than a distance between the two sealing components (SL). To suitably reduce the influence of parallel misalignment, it is desirable that the two movable parts be separated from each other to a certain degree. According to the above configuration, the parallel misalignment is suitably compensated, and the control piston NC and the control cylinder CC are reliably sealed. Brief description of the drawings Fig. Figure 1 is a schematic diagram illustrating the overall design of a brake control device SC. Fig. Figure 2 is a partial cross-sectional view illustrating a hydraulic pressure generating unit PS according to a first embodiment. Fig. Figure 3 is a partial cross-sectional view illustrating the compensation of axis offset by an intermediate component BE and the like. Fig. Figure 4 is a partial cross-sectional view illustrating the hydraulic pressure generating unit PS according to a second embodiment. Description of the exemplary implementations<Symbole für Bestandteile oder Ähnliches und Indizes am Ende von Symbolen>

[0011] In the following description, components, calculation processes, signals, characteristics, and values ​​designated with the same symbols as "CW" have the same function. The suffixes "f" and "r" added to the end of the symbols for the respective wheels are comprehensive symbols that indicate which system of front and rear wheels these suffixes refer to. For example, cylinders CW located in wheels are designated as "front wheel cylinder CWf, rear wheel cylinder CWr." Furthermore, the suffixes "f" and "r" at the end of the symbols can be omitted. When the suffixes "f" and "r" are omitted, each symbol represents a collective term. For example, "CW" is a collective term for wheel cylinders located on the front and rear wheels of a vehicle. Additionally, "CW" as a collective term is also expressed as "CW (= CWf, CWr)."

[0012] A first actuator YA of a first brake unit SA, a second actuator YB of a second brake unit SB, and a wheel cylinder CW are connected to each other via a fluid passage (connecting passage HS). Furthermore, various components (PS and the like) within the first and second actuators YA and YB are connected to each other via this fluid passage. Here, the "fluid passage" is a channel for moving brake fluid BF (operating fluid) and includes a pipe, a flow passage in an actuator, a hose, and the like. In the following description, the connecting passage HS, a reservoir passage HR, an inlet passage HN, a servo passage HU, a supply passage HH, and the like are referred to as fluid channels. <BREMSSTEUERUNGSVORRICHTUNG SC eines Fahrzeugs>

[0013] The overall design of the brake control device SC, including a hydraulic pressure generation unit PS, is described with reference to a schematic diagram in Fig. 1 described. For example, the brake control device SC is used in a hybrid vehicle or an electric vehicle that includes an electric motor for driving.

[0014] The vehicle includes a regeneration device KG. The regeneration device KG comprises a generator GN for energy recovery (also referred to as an "electric motor or generator" or "regenerative generator"), a control unit EG for the regeneration device KG (also referred to as a "regenerative control unit"), and a storage battery (not shown) for recovery. The regenerative generator GN also acts as an electric motor for propulsion. During regenerative braking, the electric motor or generator GN operates as a power generator, and the generated power is stored in the storage battery for regeneration via the regenerative control unit EG. At this time, a regenerative braking force Fg acts on the wheels. For example, the regenerative device KG is located on a front wheel WHf, and the regenerative braking force Fg is generated by the front wheel WHf.

[0015] The front and rear wheels WHf and WHr of the vehicle are equipped with brake devices SX (= SXf, SXr). The brake device SX comprises a brake caliper, a friction component (e.g., a brake pad), and a rotating component KT (e.g., a brake disc). The brake caliper (not shown) is fitted with the wheel cylinder CW (= CWf, CWr). The friction component (not shown) is pressed against the rotating component KT (= KTf, KTr) attached to each wheel WH by hydraulic pressure Pw in the wheel cylinder CW (referred to as "wheel pressure"), thus exerting a braking torque Tb on the wheel WH. This generates a hydraulic braking force Fp in the wheel WH.

[0016] The vehicle includes a brake actuation component BP and various sensors (SP and the like). The brake actuation component BP (for example, a brake pedal) is a component that is actuated by the driver to decelerate the vehicle. The vehicle is equipped with an actuation displacement sensor SP, which detects an actuation displacement Sp of the brake actuation component BP. The actuation displacement Sp is one of the state parameters (state variables) that specify the amount of brake actuation of the brake actuation component BP. In addition to the actuation displacement sensor SP, a hydraulic pressure Pn (referred to as the "input pressure") in an input chamber Rn (described later) is used as another state parameter that specifies the amount of brake actuation. The input pressure Pn is detected by an input pressure sensor PN. The actuation displacement Sp, the input pressure Pn, and the like are collectively referred to as the "amount of brake actuation Ba".A sensor that detects the brake actuation amount Ba, such as the actuation displacement sensor SP and the input pressure sensor PN, is referred to as the "brake actuation amount sensor BA".

[0017] The vehicle includes the brake control device SC. The brake control device SC uses a front-rear type (also referred to as "II type") dual-circuit braking system. The actual wheel pressure Pw of each cylinder CW is set by the brake control device SC. The brake control device SC comprises the two brake units SA and SB. <ERSTE Bremseinheit SA>

[0018] The first brake unit SA adjusts the hydraulic pressures Pwf and Pwr in the front and rear wheel cylinders CWf and CWr (front wheel pressure and rear wheel pressure) in response to actuation of the brake actuation component BP (brake pedal). The first brake unit SA comprises the first actuator YA and a first control device EA. <<ERSTES Stellglied YA> >

[0019] The first actuator YA comprises an application unit AP, the hydraulic pressure generation unit PS and an input unit NR. [Application unit AP]

[0020] In response to the actuation of the brake actuation component BP, the application unit AP outputs a supply pressure Pm. The application unit AP comprises a single-type master cylinder CM and a main piston NM.

[0021] The main piston NM is installed in the single-cylinder master cylinder CM. The interior of the master cylinder CM is divided into three hydraulic chambers Rm, Ru, and Rs by the main piston NM. The main chamber Rm is formed by a bottom section of the master cylinder CM and the main piston NM. Furthermore, the interior of the master cylinder CM is divided into the servo chamber Ru and the reaction force chamber Rs by a flange section Tu of the main piston NM. Here, the pressure-bearing area rm of the main chamber Rm and the pressure-bearing area ru of the servo chamber Ru are equal.

[0022] When the brakes are not applied, the master piston NM is in its furthest retracted position (i.e., a position where the volume of the main chamber Rm is greatest). In this state, the main chamber Rm of the master cylinder CM is connected to a main reservoir RV. The brake fluid BF is stored in the main reservoir RV (also referred to as the "atmospheric pressure reservoir"). When the brake actuator BP is actuated, the master piston NM moves forward in the direction Da (a direction in which the volume of the main chamber Rm decreases). The connection between the main chamber Rm and the main reservoir RV is blocked by this movement. As the master piston NM continues to move forward in the Da direction, the supply pressure Pm (an internal pressure of the main chamber Rm, also referred to as the "main pressure") increases from "0 (atmospheric pressure)."Accordingly, the brake fluid BF, pressurized by the supply pressure Pm, is dispensed (pumped) from the master cylinder CM (more precisely from the main chamber Rm). Hydraulic pressure generation unit PS

[0023] The hydraulic pressure generating unit PS (also referred to as the "hydraulic pressure generating device") generates the front wheel pressure Pwf and the rear wheel pressure Pwr using an electric motor MT as its power source. The front wheel pressure Pwf and the rear wheel pressure Pwr are adjusted by a servo pressure Pc generated by the electric motor MT. Specifically, the hydraulic pressure generating unit PS and the servo chamber Ru are connected via the servo passage HU (fluid passage). The hydraulic pressure generating unit PS and the rear wheel cylinder CWr are connected via a rear wheel connection passage HSr (fluid passage). Furthermore, the hydraulic pressure generating unit PS is connected to the main reservoir RV via the supply passage HH (fluid passage), so that brake fluid BF is supplied when the brake fluid BF in the hydraulic pressure generating unit PS is insufficient.

[0024] During operation of the hydraulic pressure generating unit PS (i.e., during braking), the supply passage HH is blocked. Consequently, the hydraulic pressure generating unit PS and the main reservoir RV are placed in a non-communicating state. In the front brake system, the supply pressure Pm (main pressure) is generated by supplying the servo pressure Pc to the servo chamber Ru. The hydraulic pressure Pwf of the front wheel cylinder CWf (the front wheel pressure) is then generated by the supply pressure Pm. In the rear brake system, however, the hydraulic pressure Pwr of the rear wheel cylinder CWr (the rear wheel pressure) is generated by directly supplying the servo pressure Pc to the rear wheel cylinder CWr. The hydraulic pressure generating unit PS is equipped with a servo pressure sensor PC to detect the servo pressure Pc. Details of the hydraulic pressure generating unit PS are described later. [Input unit NR]

[0025] Regenerative cooperative control is implemented by the input unit NR. Regenerative cooperative control is a control system that ensures the hydraulic braking force Fp (a braking force generated by the wheel pressure Pw) and the regenerative braking force Fg (a braking force generated by the regenerative generator GN) interact in such a way that the vehicle's kinetic energy can be efficiently recovered as electrical energy during braking. In regenerative cooperative control, a state occurs in which no wheel pressure Pw is generated, even though the brake actuation component BP is actuated. The input unit NR comprises an input cylinder CN, an input piston NN, a first control valve VA, a second control valve VB, a stroke simulator SS, and the input pressure sensor PN.

[0026] The input cylinder CN is attached to the master cylinder CM. The input piston NN is inserted into the input cylinder CN. The input piston NN is mechanically connected to the brake actuation component BP, so that it is movably locked to the brake actuation component BP (brake pedal). A gap Ks (also referred to as the "separation width") exists between an end face of the input piston NN and an end face of the master piston NM. Regenerative cooperative control is achieved by adjusting the separation width Ks using the servo pressure Pc.

[0027] The inlet chamber Rn of the input unit NR is connected to the reaction force chamber Rs of the application unit AP via the inlet passage HN (fluid passage). The first control valve VA, of the normally closed type, is located in the inlet passage HN. The inlet passage HN is connected to the main reservoir RV via the reservoir passage HR (fluid passage) between the first control valve VA and the reaction force chamber Rs. The reservoir passage HR is equipped with the second control valve VB, of the normally open type. On / off solenoid valves are used as the first and second control valves VA and VB, respectively. The stroke simulator SS is located in the inlet passage HN between the first control valve VA and the reaction force chamber Rs.

[0028] When the first and second control valves VA and VB are not energized, the first control valve VA is closed and the second control valve VB is open. The inlet chamber Rn is sealed by closing the first control valve VA, and the fluid is locked out. Consequently, the main piston NM moves integrally with the brake actuation component BP. The stroke simulator SS and the reaction force chamber Rs are connected to the main reservoir RV by opening the second control valve VB.

[0029] When the first and second control valves VA and VB are energized, the first control valve VA opens and the second control valve VB closes. Consequently, the main piston NM can be moved independently of the brake actuation component BP. Since, in this case, the inlet chamber Rn is connected to the stroke simulator SS, an actuation force of the brake actuation component BP is generated by the stroke simulator SS. The inlet pressure sensor PN is located in the inlet passage HN between the inlet chamber Rn and the first control valve VA to detect the inlet pressure Pn. The inlet pressure Pn is also a hydraulic pressure in the stroke simulator SS. <<ERSTE Steuerungseinrichtung EA> >

[0030] The first actuator YA is controlled by the first control unit EA. The first control unit EA comprises a microprocessor MP and a control circuit DR. The first control unit EA is connected to a communication bus BS, allowing signals (acquisition values, calculation values, control flags, and the like) to be exchanged with other control units (EB, EG, and the like).

[0031] Various signals, such as the operating range Sp (a reading from the actuation displacement sensor SP), the input pressure Pn (a reading from the input pressure sensor PN), the servo pressure Pc (a reading from the servo pressure sensor PC), and the motor rotation angle Ka (a reading from a rotation angle sensor KA), are directly input into the first control unit EA. Additionally, various signals, such as the supply pressure Pm and a limited regenerative braking force Fx, are input into the first control unit EA from the communication bus BS. A target regeneration braking force Fh (setpoint value of the regeneration braking force Fg) is output by the first control unit EA to the communication bus BS. The regeneration control unit EG controls the regeneration braking force Fg (actual value) based on the target regeneration braking force Fh (setpoint value) received from the communication bus BS.

[0032] An algorithm for pressure setting control is programmed in the first control unit EA (specifically the microprocessor MP). The "pressure setting control" is a control system for adjusting the wheel pressure Pw (= Pwf, Pwr) and includes regenerative cooperative control. The pressure setting control is executed based on the various signals described above (Sp, Pc, etc.). The electric motor MT and various electromagnetic valves (VA, etc.) are controlled by the control circuit DR based on the pressure setting control algorithm. In the control circuit DR, an H-bridge circuit (also referred to as an "inverter circuit") is implemented using a switching element (for example, a MOSFET) to drive the electric motor MT. The control circuit DR includes a switching element for driving various electromagnetic valves.Furthermore, the control circuit DR includes a motor current sensor (not shown) that detects a supply current Im (also referred to as "motor current") to the electric motor MT. The electric motor MT is equipped with the rotation angle sensor KA to detect the position Ka (rotation angle) of a motor shaft SM.

[0033] In the first control unit EA, the control signals Va and Vb for the first and second control valves VA and VB, as well as a control signal Mt for the electric motor MT, are calculated. The switching element is controlled according to the various control signals (Mt, etc.). Specifically, when controlling the electromagnetic valves, the power supply to the first and second control valves VA and VB is provided based on the control signals Va and Vb. Accordingly, the first control valve VA opens and the second control valve VB closes. When controlling the electric motor MT, a target pressure Pt is calculated based on the working stroke Sp, etc. The "target value Pt control unit" is a target value Pt control unit that corresponds to the servo pressure Pc (actual value).Then the first control unit EA controls the electric motor MT according to the target value Pt and the control signal Mt calculated on the basis of the servo pressure Pc, so that the servo pressure Pc (actual value) approaches and matches the target value Pt (target value). <ZWEITE Bremseinheit SB>

[0034] The second brake unit SB is located between the first brake unit SA and the wheel cylinders CW. Anti-lock braking system (ABS), traction control, lateral slip prevention, and similar functions are implemented by the second brake unit SB. In the brake system connected to the front wheel WHf (i.e., a front wheel linkage duct HSf), the supply pressure Pm is routed from the master cylinder CM to the second brake unit SB. In the brake system for the rear wheel WHr (i.e., in the rear wheel linkage duct HSr), however, the servo pressure Pc is routed directly from the hydraulic pressure generating unit PS to the second brake unit SB. Within the second brake unit SB, the supply pressure Pm and the servo pressure Pc are adjusted (increased or decreased) and output as hydraulic pressures Pwf and Pwr to the front and rear wheel cylinders CWf and CWr (the front and rear wheel pressures).Since the configuration of the second brake unit SB is known, a description of it is omitted.

[0035] Normally, during the execution of regenerative cooperative control, the operation of the second actuator YB (electric motor, fluid pump, electromagnetic valves, etc.) is stopped. Therefore, the second brake unit SB outputs the supply pressure Pm as front wheel pressure Pwf and the servo pressure Pc as rear wheel pressure Pwr. <HYDRAULIKDRUCKERZEUGUNGSEINHEIT PS gemäß erstem Ausführungsbeispiel >

[0036] The hydraulic pressure generating unit PS according to a first embodiment is described with reference to a partial cross-sectional view of Fig. 2. In the hydraulic pressure generating unit PS (hydraulic pressure generating device), the servo pressure Pc is generated using the electric motor MT as the pressure source (also referred to as the "power source"). Subsequently, the wheel pressure Pw (= Pwf, Pwr) is set by the servo pressure Pc. <<Formen der Bestandteile und Bewegungsrichtungen> >

[0037] First, the shapes, directions of movement, etc., of the elements comprising the hydraulic pressure generating unit PS are defined. In the hydraulic pressure generating unit PS, in a state where no axis misalignment occurs, the axis of rotation Jm of the electric motor MT (specifically the motor shaft SM), the axis of rotation Jk of a rotary component BK, the central axis Jn of a control piston NC, the central axis Jc of a control cylinder CC, and the central axis Je of an intermediate component BE are aligned in a straight line. The directions along the axes Jm, Jk, Jn, Jc, and Je (i.e., parallel directions) are referred to as the "axial direction Hj." Conversely, a direction perpendicular to the axes Jm, Jk, Jn, Jc, and Je is referred to as the "radial direction Hk." Therefore, the radial direction Hk is perpendicular to the axial direction Hj.

[0038] For elements (NC, BE, BD, and the like) that are movable along the axial direction Hj, a direction approaching the base surface Mbc of the control cylinder CC is designated as the "forward direction Ha." Conversely, a direction moving away from the base surface Mbc of the control cylinder CC is designated as the "reverse direction Hb." Therefore, when the control piston NC is moved in the forward direction Ha, the volume of a control chamber Rc decreases and the internal pressure Pc (servo pressure) of the control e increases. Conversely, when the control piston NC is moved in the reverse direction Hb, the volume of the control chamber Rc increases and the servo pressure Pc decreases.

[0039] In the relationship between the rotary motion of the electric motor MT and the linear motion of a linear motion component BD (i.e., the control piston NC), the normal direction of rotation Hs of the electric motor MT corresponds to the forward direction Ha of the linear motion component BD. Therefore, the rotary motion of the electric motor MT in a reverse direction Hg corresponds to the reverse direction Hb of the linear motion component BD. That is, when the electric motor MT rotates in its normal direction Hs, the linear motion component BD moves in the forward direction Ha. Accordingly, the volume of the control chamber Rc decreases and the servo pressure Pc increases. Conversely, when the electric motor MT rotates in the reverse direction Hg, the linear motion component BD moves in the reverse direction Hb. Accordingly, the volume of the control chamber Rc increases and the servo pressure Pc decreases. <<KONFIGURATION der Hydraulikdruckerzeugungseinheit PS> >

[0040] The hydraulic pressure generation unit PS includes a housing HG, the electric motor MT, the rotary angle sensor KA, a speed reducer GS, a conversion mechanism GH, a rotation prevention component MD, the control piston NC and the intermediate component BE.

[0041] The housing HG contains the components (MT, GS, and the like) that make up the hydraulic pressure generating unit PS. The housing HG is divided into several parts so that the individual components can be assembled. For example, the housing HG is divided into a cylinder housing HGc and a motor housing HGm. The motor housing HGm and the cylinder housing HGc are assembled and then integrated as the housing HG. Therefore, the housing HG is a collective term for the cylinder housing HGc and the motor housing HGm.

[0042] Furthermore, the control unit HG can be integrated with the first control unit EA. Specifically, the first control unit EA comprises a control board on which the microprocessor MP and the control circuit DR are mounted, as well as a control housing (not shown) that accommodates the control board. The control unit is then assembled and integrated with the housing HG. The speed reducer GS and the conversion mechanism GH are held by the housing HG (specifically the cylinder housing HGc). Additionally, the electric motor MT is held by the housing HG (specifically the motor housing HGm).

[0043] The control cylinder CC (corresponding to a "cylinder") is formed within the housing HG (specifically, the cylinder housing HGc). The control piston NC (corresponding to a "piston") is inserted into the control cylinder CC. The control cylinder CC and the control piston NC define the control chamber Rc (hydraulic chamber). An outlet section Au is provided in the control cylinder CC (specifically, in the control chamber Rc). The servo passage HU and the rear wheel connection passage HSr are connected to the outlet section Au. This means that the control chamber Rc is connected to the servo chamber Ru and the rear wheel cylinder CWr. Accordingly, the servo pressure Pc is supplied (outputted) to the servo chamber Ru and the rear wheel cylinder CWr.

[0044] The electric motor MT is a power source (pressure source) for generating the servo pressure Pc (hydraulic pressure in the control cylinder CC). Here, "power" is the energy required to move moving elements (BK, BD, and the like) in the hydraulic pressure generating unit PS. As a physical quantity, power is defined, for example, as energy per unit of time. The electric motor MT delivers a rotational power Tm (also referred to as "first rotational power"). The rotational power Tm of the electric motor MT is obtained by multiplying the shaft torque of the electric motor MT by the rotational speed of the electric motor MT (specifically, the motor shaft SM).The linear motion power Fn of the linear motion component BD (described later) is obtained by multiplying a thrust of the linear motion component BD (force acting in the axial direction Hj) with a linear velocity of the linear motion component BD (velocity in the axial direction Hj).

[0045] The electric motor MT is a three-phase brushless motor. The electric motor MT is mounted in the motor housing HGm. The electric motor MT comprises a motor coil CL, the motor shaft SM, and the rotation angle sensor KA. The motor coil CL (also simply referred to as the "coil (winding)") is fixed in the motor housing HGm. The motor coil CL is also called the "stator." A motor cable Lm is connected to the motor coil CL. The motor coil CL is powered via the motor cable Lm by the first control device EA (specifically the control circuit DR).

[0046] The motor shaft SM (also simply referred to as the "shaft") is rotatably mounted relative to the motor housing HGm (i.e., the motor coil CL) by a bearing BB fixed within the motor housing HGm. A motor magnet Mm (permanent magnet) is attached to an outer circumference of the shaft SM of the electric motor MT. For example, the motor magnet Mm is attached to the motor shaft SM by adhesive or a similar method. The motor shaft SM is also referred to as the "rotor".

[0047] In the three-phase brushless motor MT, the magnetic pole position of the rotor SM (i.e., an angle of rotation relative to the stator CL) is detected, and the current Im (motor current) flowing through the motor coil CL is switched. Here, the motor current Im is a collective term for the currents flowing through the U-phase, the V-phase, and the W-phase. The three-phase motor current Im, relative to the U-phase, the V-phase, and the W-phase, is switched based on the rotational position Ka (also referred to as the "angle of rotation") of the motor shaft SM. In the first control unit EA, the switching element of the drive circuit DR (inverter circuit) is controlled according to the angle of rotation Ka. Accordingly, the motor current Im flowing through the motor coil CL is switched, and the electric motor MT is set in motion. The rotational power Tm is delivered by the electric motor MT to the reduction gearbox GS.

[0048] The electric motor MT (brushless motor) is equipped with the rotary angle sensor KA to detect the rotation angle Ka. The rotary angle sensor KA comprises a sensor disk Ds, a sensor magnet Ms, a sensor substrate Kb, and a sensor wire Ls. The sensor disk Ds is attached to the motor shaft SM such that it rotates integrally with the motor shaft SM. The sensor magnet Ms is mounted on the sensor disk Ds. The sensor substrate Kb is attached to the motor housing HGm. A hole is formed in the sensor substrate Kb to allow the motor shaft SM to pass through. A detection unit with a magnetic field detection element is located around the hole to detect changes in the magnetic field generated when the motor shaft SM (i.e., the sensor magnet Ms) rotates. A signal detected by the magnetic field detection element is transmitted via the sensor wire Ls to the first control device EA (specifically, the microprocessor MP).

[0049] The first rotational power Tm delivered by the electric motor MT is reduced by the speed reducer GS, and a second rotational power Tn is delivered. Specifically, an input shaft of the speed reducer GS and the motor shaft SM are stationary. Furthermore, an output shaft of the speed reducer GS and the rotating component BK of the conversion mechanism GH are fixed. In the speed reducer GS, the rotational speed input from the electric motor MT is reduced, and the torque input from the electric motor MT is increased. Then, the second rotational power Tn is delivered from the speed reducer GS to the conversion mechanism GH.

[0050] For example, a planetary gear mechanism is used as the speed reducer GS. The "planetary gear mechanism" is a transmission in which several planet gears orbit a sun gear as they rotate. The speed reducer GS comprises a sun gear, planet gears, an internal gear, and a planet carrier. In the planetary gear mechanism, the planet gears are supported by the planet carrier, and rotary motion is provided. For example, in the speed reducer GS, the internal gear is attached to the cylinder housing HGc. The sun gear is attached to the motor shaft SM, and the first rotational power Tm from the electric motor MT is transmitted to the sun gear. The planet carrier of the speed reducer GS is attached to the rotating component BK, and the second rotational power Tn is transmitted from the planet carrier to the conversion mechanism GH.

[0051] The conversion mechanism GH comprises the rotary component BK, which performs a rotary motion, and the linear motion component BD, which performs a linear motion. In the conversion mechanism GH, the second rotary power Tn output by the speed reducer GS is input into the rotary component BK. This second rotary power Tn input into the rotary component BK is then converted into the linear motion power Fn of the linear motion component BD. The conversion mechanism GH is also referred to as a "rotary-to-linear motion conversion mechanism".

[0052] For example, a ball screw is used as the conversion mechanism GH. Specifically, in the conversion mechanism GH, the rotary component BK, which is a shaft component, is attached to the output shaft of the speed reducer GS. The rotary component BK is inserted into the cylindrical linear motion component BD. A ball screw groove Mzk is formed on the outer circumferential surface Mok of the rotary component BK. Similarly, a ball screw groove Mzd is also formed on an inner circumferential surface Mid of the linear motion component BD. A plurality of balls BL (steel balls) are inserted into the ball screw grooves Mzk and Mzd (see speech bubble XGH).

[0053] In the conversion mechanism GH, an element having a helical groove in its outer circumferential surface is called the "inner element." An element having a helical groove in its inner circumferential surface is called the "outer element." The outer element is arranged to cover the inner element, and the helical groove of the inner element and the helical groove of the outer element mesh with each other. In particular, in the ball screw, two ball screw grooves mesh with each other via a plurality of balls BL.

[0054] In the ball screw used as the conversion mechanism GH, a ball screw (the inner element, also referred to as the "shaft component") is used as the rotary component BK, and a ball screw (the outer element, also referred to as the "nut component") is used as the linear motion component BD. In this configuration, the helical groove Mzk is formed on the outer circumferential surface Mok of the rotary component BK (inner element), and the helical groove Mzd is formed on the inner circumferential surface Mid of the linear motion component BD (outer element). The outer circumferential groove Mzk and the inner circumferential groove Mzd then mesh with each other via the balls BL.

[0055] The linear motion component BD is provided with a flange section Fd at one end section on the side facing away from the control cylinder CC (specifically the control chamber Rc). The flange section Fd, as the end section of the cylindrical linear motion component BD, extends radially in the direction Hk in a flange shape. A notch is formed in the flange section Fd. This notch is located on the anti-rotation component MD.

[0056] The anti-rotation component MD is attached to the cylinder housing HGc. For example, an elongated rod-shaped element (e.g., a pin component) is used as the anti-rotation component MD. The housing HG is provided with a plurality of holes on one outer surface of the linear motion component BD (i.e., on a side that is away from the axis of rotation Jk with respect to the linear motion component BD). The multiple holes are formed at equal intervals around the axis of rotation Jk. The anti-rotation component MD is inserted into and secured to each of the multiple holes. The flange section Fd of the linear motion component BD is provided with a semicircular notch. The notch and the anti-rotation component MD then engage with each other, thus preventing the linear motion component BD from rotating about the axis of rotation Jk.When the rotary component BK is driven in a rotating manner, the linear motion component BD moves accordingly along the axial direction Hj (the forward direction Ha or the reverse direction Hb).

[0057] The control piston NC is inserted into the control cylinder CC, which is formed in the cylinder housing HGc. Specifically, the control piston NC comprises a bottom section Btn (also referred to as the "first bottom section") and a cylindrical section Enn (also referred to as the "first cylindrical section"). That is, the control piston NC has a cylindrical shape (cup shape) with the bottom section us Btn. The control chamber Rc (hydraulic chamber) is formed within the control cylinder CC by the control piston NC (specifically the first bottom section us Btn) inserted into the control cylinder CC.

[0058] An outer circumferential surface Mon of the control piston NC and an inner circumferential surface Mic of the control cylinder CC are sealed by two sealing elements SL. The two sealing elements SL are inserted into sealing grooves formed in the inner circumferential surface Mic of the control cylinder CC. A hole (not shown, also referred to as the "housing hole") that penetrates the control cylinder CC is provided in the cylinder housing HGc between the two sealing grooves. The housing hole is connected to the main reservoir RV via the feed channel HH. The control piston NC is provided with a hole (not shown, also referred to as the "piston hole") that extends from the outer circumferential surface Mon to the bottom section Btn to connect the housing hole and the control chamber Rc.

[0059] The intermediate component BE is positioned between the linear motion component BD and the control piston NC in the axial direction Hj. The intermediate component BE transmits the force between the linear motion component BD and the control piston NC. The linear motion power Fn from the linear motion component BD is transmitted to the control piston NC via the intermediate component BE. Accordingly, the linear motion component BD, the intermediate component BE, and the control piston NC can move integrally in the forward direction Ha. The linear motion component BD and the control piston NC are held by a retaining element ND, so that the linear motion component BD, the intermediate component BE, and the control piston NC can also move integrally in the reverse direction Hb.

[0060] Although the control piston NC is sealed against the control cylinder CC by the sealing component SL, the contact between the outer circumferential surface Mon of the control piston NC and the sealing component SL is not uniform if an axial misalignment occurs (in particular, a misalignment between a direction of linear motion Fn and a direction of movement of the control piston NC). This can lead to a reduction in sealing performance, uneven wear of the sealing component SL, and the like. The intermediate component BE is provided in the power transmission path from the linear motion component BD to the control piston NC to reduce the influence of the axial misalignment of the control piston NC and the like (i.e., a reduction in sealing performance, uneven wear of the sealing component SL, and the like).

[0061] The intermediate component BE comprises a bottom section Bte (also referred to as the "second bottom section") and a cylindrical section Ene (also referred to as the "second cylindrical section"). Similar to the control piston NC, the intermediate component BE has a cylindrical shape (i.e., a cup shape) with the second bottom section Bte. The intermediate component BE is housed inside the control piston NC. That is, the control piston NC and the intermediate component BE form a nested configuration. This structure is referred to as a "nested structure." In the nested structure, the outer control piston NC slides with the sealing component SL to seal the control chamber Rc, and the inner intermediate component BE compensates for the effect of axis misalignment. <<Einstellung des Servodrucks Pc> >

[0062] In the brake control device SC, the wheel pressure Pw is set by the servo pressure Pc, which is the output of the hydraulic pressure generating unit PS. In the hydraulic pressure generating unit PS, the rotational power Tm (i.e., the shaft torque) of the electric motor MT is converted by the conversion mechanism GH into the linear motion power Fn (i.e., the thrust) of the linear motion component BD (and thus of the control piston NC). When the control piston NC is moved by the linear motion power Fn, the servo pressure Pc is generated and set. The hydraulic pressure generating unit PS is equipped with the servo pressure sensor PC to detect the servo pressure Pc.

[0063] The conversion mechanism GH can perform both the conversion from rotary motion to linear motion and vice versa. During operation of the conversion mechanism GH, the former is referred to as "normal operation" and the latter as "reverse operation." Therefore, the movement of the control piston NC is determined by the ratio between the torque output of the electric motor MT (also referred to as "normal operating torque Qmt") and the torque input to the electric motor MT via the servo pressure Pc (also referred to as "reverse operating torque Qpc"). The adjustment (increasing or decreasing) of the servo pressure Pc is described below. <<Erhöhung des Servodrucks Pc> >

[0064] In Fig. Figure 2 shows a state above the axis of rotation Jk in which the hydraulic pressure generating unit PS does not generate servo pressure Pc. In this state, the control chamber Rc is connected to the main reservoir RV via the housing hole and the piston hole, and the servo pressure Pc is "0 (atmospheric pressure)." The positions of the linear motion component BD, the control piston NC, and the like in this state are referred to as the "starting positions." In the starting position, the control piston NC is displaced maximally in the reverse direction Hb, and the volume of the control chamber Rc is maximized.

[0065] As described above, the control piston NC and the intermediate component BE have a cylindrical shape with a base (cup shape) and are nested within each other, with the intermediate component BE housed inside the control piston NC. When the control piston NC is in its starting position, the rotary component BK penetrates the intermediate component BE. This structure reduces the size of the hydraulic pressure generating unit PS in the axial direction Hj.

[0066] When a brake request value (a state parameter specifying a request related to braking force, for example, the actuation travel Sp of the brake actuator BP) is increased, the setpoint pressure Pt is increased from "0". The setpoint pressure Pt is a target value corresponding to the servo pressure Pc (actual value). The setpoint pressure Pt increases when the brake request value rises. As the setpoint Pt increases, the normal operating torque Qmt becomes greater than the reverse torque Qpc, and the electric motor MT rotates in its normal direction Hs. That is, the electric motor MT generates the rotational power Tm in its normal direction Hs. The rotational power Tm is transmitted via the reduction gear GS to the conversion mechanism GH and output as the linear motion power Fn of the linear motion component BD. The intermediate component BE is pushed by the linear motion component BD, and the control piston NC is pushed by the intermediate component BE.Accordingly, the control piston NC is moved in the forward direction Ha (direction in which the volume of the control chamber Rc decreases). From the perspective of the intermediate component BE, the rotating component BK gradually emerges from the interior of the intermediate component BE.

[0067] Due to this movement, the piston hole formed in the control piston NC moves into the control chamber Rc, initially blocking the connection between the control chamber Rc and the main reservoir RV. As the control piston NC continues to move forward in the Ha direction, the servo pressure Pc (the internal pressure of the control chamber Rc) increases from "0 (atmospheric pressure)." The brake fluid BF, pressurized by the servo pressure Pc, is discharged (pumped) from the control chamber Rc of the control cylinder CC into the servo chamber Ru and the rear wheel cylinder CWr. <<Halten des Servodrucks Pc> >

[0068] When the brake demand value becomes constant, the set pressure Pt is maintained. The normal operating torque Qmt and the reverse operating torque Qpc are equal, and the rotation of the electric motor MT stops (i.e., the speed of the electric motor MT becomes "0"). When the movement of the control piston NC stops, the servo pressure Pc is held constant (see the section below the axis of rotation Jk in Fig. 2). <<Verringerung des Servodrucks Pc> >

[0069] When the brake demand value is reduced, the set pressure Pt is also reduced. Consequently, the rotational power Tm of the electric motor MT is reduced. The reverse operating torque Qpc due to the servo pressure Pc becomes greater than the normal operating torque Qmt due to the electric motor MT, and the electric motor MT rotates in the reverse direction Hg. The control piston NC moves in the reverse direction Hb, and the volume of the control chamber Rc increases. As the brake fluid BF is returned to the servo chamber Ru and the rear wheel cylinder CWr, the servo pressure Pc decreases. In the positional relationship between the intermediate component BE and the rotating component BK, the rotating component BK gradually penetrates the intermediate component BE. <AUSGLEICH des Einflusses des Achsenversatzes durch das Zwischenbauteil BE>

[0070] The reduction of the influence of the axis offset by the intermediate component BE is shown using a partial cross-sectional view in Fig. 3 described. Here, the reduction of the influence caused by the axis offset is referred to as "axis offset compensation". Fig. Figure 3 shows a situation in which no axis offset occurs and the rotation axis Jk of the rotary component BK, the central axis Je of the intermediate component BE, the central axis Jn of the control piston NC and the central axis Jc of the control cylinder CC are aligned on a straight line. < <achsenversatz>>

[0071] First, the axis misalignment is described. For power transmission, it is desirable that the axes Jk, Jn, and Jc lie on a straight line. However, since the conversion mechanism GH, the control piston NC, the control cylinder CC, and similar components are individual elements, the axes Jk, Jn, and Jc can deviate from a straight line and be offset. This offset of the axes Jk, Jn, and Jc is referred to as "axis misalignment." The axis misalignment is the eccentricity between the axes and is also referred to as "misalignment."

[0072] For example, two axes may intersect at an angle (i.e., insufficient parallelism). Such an axis misalignment is called an "angular misalignment (or deflection error)." Furthermore, the two axes may be parallel misaligned. Such an axis misalignment is called a "parallel misalignment (or parallelism error)." Axial misalignment typically occurs as a combination of angular and parallel misalignment.

[0073] If the axis misalignment (malalignment) occurs as described above, the contact between the outer circumferential surface Mon of the control piston NC and the sealing element SL becomes uneven, resulting in a decrease in the sealing performance of the sealing element SL and uneven wear. Furthermore, since the load in the conversion mechanism GH becomes uneven, uneven wear of the ball element BL, the screw grooves Mzk and Mzd, etc., can occur. The hydraulic pressure generating unit PS is equipped with the intermediate component BE for axis misalignment compensation. <<KONFIGURATION des Zwischenbauteils BE und dergleichen> >

[0074] Next, the detailed configurations of the conversion mechanism GH, the control piston NC, and the intermediate component BE are described. The conversion mechanism GH comprises the rotary component BK and the linear motion component BD. The rotary component BK is held in a state where translational movement (linear movement in the axial direction Hj) is restricted, but rotational movement relative to the housing HG is permitted. The linear motion component BD, on the other hand, is held in a state where rotational movement is restricted, but translational movement relative to the housing HG is possible. Accordingly, the conversion mechanism GH outputs the rotational power Tm applied to the rotary component BK as the linear motion power Fn of the linear motion component BD. Here, in the conversion mechanism GH, the linear motion component BD is positioned so that it covers the rotary component BK.For example, in a configuration where a ball screw mechanism is used as the conversion mechanism GH, the rotary component BK is a ball screw shaft and the linear motion component BD is a ball screw nut.

[0075] The flange section Fd is located at an end section of the linear motion component BD (more precisely, at an end section on a side opposite the bottom surface Mbc of the control cylinder CC or the bottom section Btn of the control piston NC). A notch is formed in an outer circumferential section of the flange section Fd. This notch engages with the anti-rotation component MD. The anti-rotation component MD is attached to the housing HG. Since the anti-rotation component MD prevents the rotational movement of the linear motion component BD relative to the housing HG, the rotational movement of the rotary component BK can be converted into the linear movement of the linear motion component BD.

[0076] The control piston NC is inserted into the control cylinder CC formed in the housing HG. The control piston NC has a cylindrical shape with a base (cup shape) and comprises the first base section Btn and the first cylindrical section Enn. Two sealing grooves are formed in the inner circumferential surface Mic of the control cylinder CC. The sealing elements SL are each inserted into the sealing grooves. The outer circumferential surface Mon of the cylindrical section Enn and the inner circumferential surface Mic of the control cylinder CC are sealed by the sealing elements SL. The control chamber Rc (hydraulic chamber) is formed in the control cylinder CC by the control piston NC (specifically the lower section Btn). A flat surface perpendicular to the central axis Jn of the control piston NC (i.e., the central axis of the first cylindrical section Enn) is formed on an inner base surface Mtn of the first lower section Btn.

[0077] An annular groove is formed in an inner circumferential surface Min of the cylindrical section Enn of the control piston NC. An annular groove is also formed in an outer circumferential surface Mod of the linear motion component BD. The retaining element ND (e.g., a snap ring) is inserted into these grooves. The retaining element ND limits the relative displacement between the control piston NC and the linear motion component BD, preventing them from becoming completely separated. The retaining element ND has a clearance (gap) in the axial direction Hj and in the radial direction Hk relative to the annular groove. Therefore, the control piston NC and the linear motion component BD can be displaced relative to each other within this clearance range in both the axial direction Hj and the radial direction Hk.

[0078] The intermediate component BE is positioned between the control piston NC and the linear motion component BD. Similar to the control piston NC, the intermediate component BE has a cylindrical shape with a base (cup shape) and comprises the second base section Bte and the second cylindrical section Ene. In the nested structure (i.e., a structure in which the intermediate component BE is positioned within the control piston NC), the base section Btn (first base section) of the control piston NC and the base section Bte (second base section) of the intermediate component BE are in sliding contact with each other. Here, "sliding" is a process in which two elements move while sliding in contact with each other.

[0079] In particular, sliding can occur between an outer bottom surface Mpe (also referred to as the "pressure surface") of the intermediate component BE and the inner bottom surface Mtn (also referred to as the "pressure-receiving surface") of the control piston NC. A spherical convex section with a radius Rq is formed on the pressing surface Mpe of the intermediate component BE. Within the intermediate component BE, a rounded corner (also referred to as "corner R") with a radius Rp is formed at a section (also referred to as the "corner section") where the pressing surface Mpe and an outer circumferential surface Moe of the cylindrical section Ene are connected. That is, the corner section of the bottom section Bte of the intermediate component BE is rounded. Here, the radius Rq of the spherical convex surface is significantly larger than the radius Rp of the rounded corner.A section in which the pressing surface Mpe (outer bottom surface) of the intermediate component BE and the pressure receiving surface Mtn (inner bottom surface) of the control piston NC are in contact with each other is referred to as the "first sliding section Sda".

[0080] An end surface Mqe (also referred to as the "intermediate end surface") of the cylindrical section Ene of the intermediate component BE is in sliding contact with an end surface Mpd (also referred to as the "linear motion end surface") of the linear motion component BD. For example, the end surface Mqe is a flat surface perpendicular to the central axis Je of the intermediate component BE (i.e., the central axis of the second cylindrical section Ene). The linear motion end surface Mpd is a flat surface perpendicular to the axis of rotation Jk. Therefore, the linear motion end surface Mpd and the intermediate end surface Mqe are in contact with each other on a plane perpendicular to the axial direction Hj and parallel to the radial direction Hk. Here, a section in which the intermediate end surface Mqe of the intermediate component BE and the linear motion end surface Mpd of the linear motion component BD are in contact with each other is referred to as the "second sliding section Sdb".

[0081] The configurations of the conversion mechanism GH, the control piston NC, and the intermediate component BE can be summarized as follows. The intermediate component BE is housed within a control piston NC. The intermediate component BE is located between the linear motion component BD (specifically, the linear motion end surface Mpd) and the control piston NC (specifically, the pressure-receiving surface Mtn). When the servo pressure Pc is increased, the intermediate end surface Mqe (flat surface) is pressed forward in the direction Ha by the linear motion end surface Mpd (flat surface), so that the pressure-receiving surface Mtn (flat surface) is pressed forward in the direction Ha by the pressing surface Mpe (convex surface). Accordingly, the control piston NC, the intermediate component BE, and the linear motion component BD move forward in the direction Ha.Conversely, when the servo pressure Pc is reduced, the pressing surface Mpe is pushed backwards by the pressure-receiving surface Mtn in the direction Hb, so that the linear motion end surface Mpd is pushed backwards by the intermediate end surface Mqe in the direction Hb. Accordingly, the control piston NC, the intermediate component BE, and the linear motion component BD move backwards in the direction Hb. Here, the intermediate component BE has two sections (i.e., a first and a second sliding section Sda and Sdb) along which sliding with the control piston NC and the linear motion component BD is possible.

[0082] The rotary component BK can enter the cylindrical section Ene of the intermediate component BE. In other words, the cylindrical section Ene of the intermediate component BE can enter a gap between the cylindrical section Enn (specifically the inner circumferential surface Min) of the control piston NC and the rotary component BK (specifically the outer circumferential surface Mok). Although the intermediate component BE and the control piston NC move according to the movement of the linear motion component BD, at least in the initial position (position corresponding to "Pc = 0"), part of the rotary component BK is located within the intermediate component BE.In the hydraulic pressure generating unit PS, a dimension in the axial direction Hj is reduced by "the control piston NC and the intermediate component BE having a cup shape and the control piston NC and the intermediate component BE being formed in a nested structure" and "the rotary component BK being accommodated within the intermediate element BE". < <achsenversatzausgleich>>

[0083] Finally, the axis misalignment compensation is described. The influence of the axis misalignment is compensated by allowing "slippage in the radial direction Hk between the force transmission elements (BD, BE, NC, and the like)" and by allowing "the intermediate component BE to rotate in contact between the control piston NC and the intermediate element BE." The force transmission elements have gaps Ska and Skb in the radial direction Hk. The linear motion component BD, the intermediate component BE, and the linear motion component BD can move while sliding between the elements due to the gaps Ska and Skb.

[0084] In the first sliding section Sda, the pressure-receiving surface Mtn (for example, a flat surface perpendicular to the central axis Jn of the first cylindrical section Enn) of the control piston NC and the pressing surface Mpe (for example, a convex surface) of the intermediate component BE are in contact with each other. The pressure-receiving surface Mtn and the pressing surface Mpe can be displaced radially Hk "within the area of ​​the gap Ska between the inner circumferential surface Min of the control piston NC and the outer circumferential surface Moe of the intermediate component BE" or "within the area of ​​the gap Skb between the inner circumferential surface Mie of the intermediate component BE and the outer circumferential surface Mok of the rotating component BK". Since the pressing surface Mpe is a convex surface (e.g.,Since the pressure-receiving surface Mtn is a spherical surface, the pressure-receiving surface Mtn and the pressing surface Mpe can also be subjected to a rotational displacement about a contact area between the pressure-receiving surface Mtn and the pressing surface Mpe. Such a rotational movement is called a "swivel movement." The influence of the axial misalignment (angular misalignment and parallel misalignment) of the control piston NC and the like is reduced by the oscillation and sliding (sliding) at the first sliding section Sda. As the rotational displacement (i.e., the degree of oscillation) between the pressure-receiving surface Mtn and the pressing surface Mpe increases, the pressure-receiving surface Mtn comes into contact with the corner section of the intermediate component BE. Because the corner section is rounded (rounded corner), the contact surface pressure between the pressure-receiving surface Mtn and the pressing surface Mpe is reduced even with excessive angular misalignment.

[0085] At the second sliding section Sdb, the linear end-surface Mpd (for example, a flat surface perpendicular to the axis of rotation Jk of the rotary component BK) of the linear motion component BD and the intermediate end-surface Mqe (for example, a flat surface perpendicular to the central axis Je of the second cylindrical section Ene) of the intermediate component BE come into contact with each other. At this point of contact, the linear end-surface Mpd and the intermediate end-surface Mqe are displaceable relative to each other. Therefore, the linear end-surface Mpd and the intermediate end-surface Mqe can be displaced relative to each other in the radial direction Hk "within the area of ​​the gap Ska between the inner circumferential surface Min of the control piston NC and the outer circumferential surface Moe of the intermediate element BE" or "within the area of ​​the gap Skb between the inner circumferential surface Mie of the intermediate element BE and the outer circumferential surface Mok of the rotary component BK".

[0086] The control piston NC is held in the housing HG by the sealing component SL. The conversion mechanism GH (specifically the linear motion component BD) is held by a bearing in the housing HG. The intermediate component BE is not directly held by the housing HG and serves as a floating connection. In particular, the intermediate component BE can slide in the radial direction Hk and move parallel to both the control piston NC and the linear motion component BD. Accordingly, the influence of the parallel misalignment is appropriately reduced. Since the intermediate component BE can oscillate relative to the control piston NC, the influence of the angular misalignment is appropriately reduced. Furthermore, due to the presence of the second sliding section Sdb, sliding and oscillation at the first sliding section Sda are not impeded. That is, since sliding and pivoting are likely to occur, the effect of compensating for the angular misalignment is enhanced.In the hydraulic pressure generation unit PS, the intermediate component BE not only reduces the influence of the parallel offset, but also appropriately compensates for the influence of the angular offset.

[0087] The distance Lbe between the first sliding section Sda and the second sliding section Sdb (i.e., the length of the intermediate component BE in the axial direction Hj) is preferably chosen to be greater than the distance between the two sealing components SL. This is based on the fact that the effect of axial misalignment compensation is greater when the first and second sliding sections Sda and Sdb are separated from each other to some extent. <HYDRAULIKDRUCKERZEUGUNGSEINHEIT PS gemäß zweitem Ausführungsbeispiel >

[0088] The hydraulic pressure generating unit PS according to a second embodiment is shown with reference to a partial cross-sectional view of Fig. 4. In the first embodiment, the rotary component BK is an inner member, and the linear motion component BD is an outer member. Conversely, in the second embodiment, the rotary component BK is an outer member and the linear motion component BD is an inner member. The following mainly describes the differences from the first embodiment. In this embodiment as well, the shapes of the components and the directions of movement are the same as in the first embodiment.

[0089] In the second embodiment, the control piston NC has the same configuration as disclosed in PTL 3 (JP2012-214068A). The control piston NC is inserted into the control cylinder CC and sealed by the sealing component SL. A return spring DC is provided in the control chamber Rc to push the control piston NC in the reverse direction Hb. In the second embodiment as well, the intermediate component BE is located between the linear motion component BD and the control piston NC. The intermediate component BE has a so-called cylindrical shape with a bottom (cup shape) comprising the bottom section Bte and the cylindrical section Ene. The intermediate component BE is held by a retaining element NE to prevent it from separating from the linear motion component BD. The linear motion component BD and the intermediate component BE can be displaced relative to each other in the axial direction Hj and the radial direction Hk within the range of play of the retaining element NE.

[0090] The pressing surface Mpe (outer bottom surface) of the intermediate component BE has a spherically convex section with a radius Rq. Furthermore, a rounded corner (corner R) with a radius Rp is formed at a corner (connection point between a bottom surface and a side surface) of the pressing surface Mpe on the intermediate component BE. The intermediate component BE presses against a bottom surface Mqn (a pressure-receiving surface, for example, a flat surface perpendicular to the central axis Jn) of the control piston NC, while it is displaceable and pivotable on the pressing surface Mpe as a spherically convex surface (one-sided end surface of the intermediate component BE). A section in which the pressing surface Mpe and the pressure-receiving surface Mqn are in contact with each other is the first sliding section Sda in the second embodiment.

[0091] The end surface Mqe of the intermediate component BE (intermediate end surface, other end surface of the intermediate component BE) is pressed against the end surface Mpd (linear motion end surface) of the linear motion component BD in a sliding manner. A section in which the linear motion end surface Mpd and the intermediate end surface Mqe are in contact with each other is the second sliding section Sdb in the second embodiment. Similar to the first embodiment, the intermediate component BE in the second embodiment also has two areas (i.e., the first and second sliding areas Sda and Sdb) in which sliding with the control piston NC and the linear motion component BD is possible. Accordingly, the influence of the parallel offset is reduced and the effect of the compensation of the influence of the angular offset is improved in the hydraulic pressure generation unit PS.

[0092] To reduce the axial dimensions (Hj) of the hydraulic pressure generation unit PS, a control piston NC with a cylindrical base can be used in the second embodiment, as in the first. In this configuration, the intermediate component BE is arranged inside the control piston NC, and the nested structure described above can be formed. However, in the second embodiment, the rotary component BK cannot enter the intermediate component BE. Therefore, from the perspective of axial dimensions (axial length), the first embodiment is more advantageous. <HYDRAULIKDRUCKERZEUGUNGSEINHEIT PS gemäß anderen Ausführungsbeispielen und dergleichen>

[0093] The hydraulic pressure generation unit PS is described below according to a further embodiment. In other embodiments, the hydraulic pressure generation unit PS achieves the same effects (axis offset compensation, etc.) as described above.

[0094] In the hydraulic pressure generating unit PS according to the embodiment described above, a ball screw is used as the conversion mechanism GH. Alternatively, a sliding screw (for example, a trapezoidal thread screw) can be used as the conversion mechanism GH. In a configuration using a sliding screw mechanism, an external thread is formed as a screw groove on an internal element. An internal thread is formed as a screw groove on an external element. The external thread and the internal thread then mesh directly with each other. The reverse process also occurs in the conversion mechanism GH that uses the sliding screw.

[0095] In the hydraulic pressure generating unit PS according to the embodiment described above, a configuration is used in which axis Jm and axes Jc, Jn, and Jk are aligned on a straight line. This configuration is referred to as a "coaxial configuration (or single-axis configuration)" because axis Jm, axis Jc, and the like exist coaxially. In the coaxial configuration, a mechanism (for example, a planetary gear mechanism) is used in the speed reducer GS in which a rotational axis of an input shaft and a rotational axis of an output shaft are coaxial. Alternatively, a "separate axis configuration (or dual-axis configuration)" can be used, in which axis Jm and axes Jc, Jn, and Jk lie on separate axes. In the separate axis configuration, a mechanism (e.g., a planetary gear mechanism) is used in the speed reducer GS.a gear train) is used in which the axis of rotation of the input shaft and the axis of rotation of the output shaft are different. In the separate-axis configuration, axis Jm and axes Jc, Jn, and Jk are separate axes, but arranged in parallel. Also in the separate-axis configuration, axes Jc, Jn, and Jk lie on a straight line.

[0096] The brake control device SC described above is used in a vehicle where the regeneration device KG is located on the front wheel WHf and regenerative cooperative control is implemented. In a vehicle where regenerative cooperative control is implemented, the regeneration device KG can be located on at least one of the front wheels WHf and one of the rear wheels WHr. The brake control device SC can also be used in a vehicle where the regeneration device KG is energy-saving and regenerative cooperative control is not implemented. That is, the brake control device SC can be applied to various vehicles regardless of whether regenerative cooperative control is present or absent.

[0097] In the brake control device SC configuration example described above, a single-type master cylinder CM is used. A tandem master cylinder CM can also be used in the brake control device SC. In this configuration, two master chambers Rm are formed within the CM. The servo pressure Pc is then routed from the hydraulic pressure generating unit PS to the servo chamber Ru, and the wheel pressure Pw is routed from the master chamber Rm to the wheel cylinder CW. In this configuration, the brake control device SC can utilize not only a front-rear type but also a diagonal type (also known as an "X-type") as a dual-circuit brake system. In the diagonal brake control device SC, one of the two master chambers Rm is connected to a right front wheel cylinder and a left rear wheel cylinder. The other of the two master chambers Rm is connected to a left front wheel cylinder and a right rear wheel cylinder.

[0098] In the brake control device SC configuration example described above, the supply pressure Pm is output via the master cylinder CM in the first brake unit SA. That is, the application unit AP and the hydraulic pressure generation unit PS are arranged in series in the hydraulic pressure transmission path, and the servo pressure Pc supplied by the hydraulic pressure generation unit PS is transmitted as the supply pressure Pm via the main piston NM. Alternatively, the application unit AP and the hydraulic pressure generation unit PS can be arranged in parallel. In particular, both the application unit AP (especially the master cylinder CM) and the hydraulic pressure generation unit PS are directly connected to the second actuator YB.Then, one of the connections, "Connection between the hydraulic pressure generating unit PS and the second actuator YB" and "Connection between the application unit AP and the second actuator YB," is selected by an on / off solenoid valve (referred to as a "changeover valve"). If the former is selected, the servo pressure Pc generated by the hydraulic pressure generating unit PS is output directly as the supply pressure Pm, without passing through the application unit AP. In this case, the application unit AP is connected to the lift simulator SS, and the actuation force of the brake actuation component BP is generated by the lift simulator SS. If, on the other hand, the latter is selected, the hydraulic pressure generated by the actuation of the brake actuation component BP is output in the main chamber Rm as the supply pressure Pm. At this point, the application unit AP is disconnected from the simulator SS.

[0099] In the brake control device SC configuration example described above, the pressure-absorbing area rm (main area) of the main chamber Rm and the pressure-absorbing area ru (servo area) of the servo chamber Ru in the application unit AP are set to the same value. The main area rm and the servo area ru do not have to be the same. In a configuration where the main area rm and the servo area ru are different, a conversion calculation between the supply pressure Pm (main pressure) and the servo pressure Pc can be performed based on the ratio of the servo area ru to the main area rm (i.e., a conversion calculation based on "Pm · rm = Pc · ru"). <KURZDARSTELLUNG der Ausführungsbeispiele>

[0100] Exemplary embodiments of the hydraulic pressure generating unit PS (hydraulic pressure generating device) are summarized. The hydraulic pressure generating unit PS is applied to the brake control device SC, which sets the wheel pressure Pw of the wheel cylinder CW in order to control the braking force of the wheel WH.

[0101] The hydraulic pressure generating unit PS comprises the electric motor MT, the conversion mechanism GH, the control piston NC, and the intermediate component BE. The electric motor MT delivers the rotary power Tm. The conversion mechanism GH delivers the rotary power Tm applied to the rotary component BK as the linear motion power Fn of the linear motion component BD. The control piston NC increases the hydraulic pressure Pc (servo pressure) of the control cylinder CC when it is moved by the linear motion power Fn. Specifically, the servo pressure Pc increases when the control piston NC moves in the direction Ha (forward direction) towards the base surface Mbc of the control cylinder CC. The intermediate component BE is located between the linear motion component BD and the control piston NC. The intermediate component BE exerts pressure on the control piston NC when it is pushed by the linear motion component BD.

[0102] In the hydraulic pressure generating unit PS, the pressing surface Mpe (outer bottom surface) of the intermediate component BE is displaceable relative to the bottom surfaces Mtn and Mqn (pressure-receiving surfaces) of the control piston NC, and the end surface Mqe (intermediate end surface) of the intermediate component BE is displaceable relative to the end surface Mpd (linear motion end surface) of the linear motion component BD. For example, the bottom surfaces Mtn and Mqn of the control piston NC are designed as flat surfaces perpendicular to the central axis Jc. The pressing surface Mpe of the intermediate component BE (one-sided end surface pressing on the control piston NC) can slide radially Hk along the flat surfaces Mtn and Mqn (see first sliding section Sda). The end surface Mpd of the linear motion component BD, which presses on the intermediate component BE, is designed as a flat surface perpendicular to the axis of rotation Jk.The end surface Mqe of the intermediate component BE (other end surface opposite the one-sided end surface Mpe and pressed by the linear motion component BD) can slide in radial direction Hk along the flat surface Mpd (see the second sliding section Sdb).

[0103] The axis misalignment results from a combination of parallel and angular displacement. In the configuration described above, slippage can occur at two points (i.e., the first and second sliding sections Sda and Sdb): one between the linear motion component BD and the intermediate component BE, and one between the intermediate component BE and the control piston NC. If the intermediate component BE is rigidly attached to the linear motion component BD, its movement relative to the control piston NC is restricted, and radial slippage Hk is less likely. Slippage can easily occur in the hydraulic pressure generation unit PS because the intermediate component BE and the linear motion component BD are not fixed. Accordingly, the influence of parallel misalignment can be appropriately reduced in the hydraulic pressure generation unit PS.

[0104] For example, the pressing surface Mpe of the intermediate component BE is designed as a spherical convex surface. The intermediate component BE can oscillate around a contact area between the spherical convex surface Mpe and the base surfaces Mtn and Mqn (flat surfaces). That is, in addition to a translational movement (sliding in the radial direction Hk), the intermediate component BE can also perform a rotational movement relative to the base surfaces Mtn and Mqn of the control piston NC. Similar to the above, the intermediate component BE is less likely to oscillate when it is rigidly attached to the linear motion component BD. Vibrations can easily occur in the hydraulic pressure generation unit PS because the intermediate component BE and the linear motion component BD are not fixed. Accordingly, the effect of angular misalignment compensation is also improved.This means that in the hydraulic pressure generation unit PS, the influence of the axis offset, including the parallel offset and the angular offset, is appropriately compensated.

[0105] In the conversion mechanism GH, the linear motion component BD is positioned to cover the rotary component BK. Furthermore, the intermediate component BE has the cylindrical section Ene, and the rotary component BK can enter this cylindrical section. Specifically, when the servo pressure Pc is "0", part of the rotary component BK is accommodated within the intermediate component BE. If an additional intermediate component BE is provided between the conversion mechanism GH (particularly the linear motion component BD) and the control piston NC to compensate for axis misalignment, there is a concern that the size of the device will increase in the axial direction (axial length). According to the configuration described above, even with the intermediate component BE, the increase in the overall device dimensions is kept to a necessary minimum.

[0106] The control piston NC and the control cylinder CC are sealed by two sealing components SL. The length Lbe of the intermediate component BE along Hj (direction along the central axis Jn of the control piston NC) is longer than the distance between the two sealing components SL. To adequately reduce the influence of the parallel misalignment, it is important that the first and second sliding sections Sda and Sdb are separated from each other to a certain degree. The control piston NC and the control cylinder CC are sealed by two sealing components SL, and the dimension (length) of the intermediate component BE in the axial direction Hj is greater than the distance between the two sealing components SL. This adequately compensates for the parallel misalignment, and the control piston NC and the control cylinder CC are reliably sealed. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2023-0001906A

[0005] US 2021 / 0122342

[0005] JP 2012-214068A [0005, 0089]< / achsenversatzausgleich> < / achsenversatz>

Claims

[1] Hydraulic pressure generating device with: an electric motor that outputs rotational power; a conversion mechanism which, as a linear motion power of a linear motion component, outputs the rotational power that is input to a rotational component; a piston that is inserted into a cylinder and moves through the linear motion power to increase hydraulic pressure in the cylinder; and an intermediate component located between the piston and the linear motion component, wherein a pressing surface of the intermediate component can slide with respect to a bottom surface of the piston, and an end surface of the intermediate component can slide with respect to an end surface of the linear motion component. [2] Hydraulic pressure generating device according to claim 1, wherein the linear motion component is arranged to cover the rotary component, the intermediate component has a cylindrical section, and the rotating component is able to enter the cylindrical section. [3] Hydraulic pressure generating device according to claim 1 or 2, further comprising: two sealing components that seal the piston and the cylinder, wherein The length of the intermediate component in one direction along a central axis of the piston is longer than the distance between the two sealing components.

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