Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
  • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
  • B60T8/40—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system
  • B60T8/4068—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system the additional fluid circuit comprising means for attenuating pressure pulsations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
  • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
  • B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60Y—INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY
  • B60Y2400/00—Special features of vehicle units
  • B60Y2400/81—Braking systems

Definitions

• the present invention relates to a damping device, a hydraulic control unit, and a brake system.
• a hydraulic control unit is provided to control the braking force applied to the wheels.
• a plurality of valves and a pump are provided in the flow path within the hydraulic control unit.
• the opening and closing states of each valve are set to specific states, and the pump is driven.
• a reciprocating plunger pump is mainly used as the pump. Therefore, the pump pressurizes the brake fluid intermittently. Therefore, when the pump is driven, pressure pulsation occurs, which is a phenomenon in which the hydraulic pressure of the brake fluid pulsates in the flow path in the hydraulic control unit. The sound generated by such pressure pulsation may be perceived as noise by the vehicle occupants, and may be a factor that reduces comfort. Therefore, from the viewpoint of improving comfort, it is desirable to appropriately damp the pressure pulsation of the hydraulic control unit.
• the present invention aims to provide a damping device capable of damping pressure pulsations of a hydraulic control unit, a hydraulic control unit, and a brake system.
• a damping device in a hydraulic control unit that controls a braking force generated on a wheel, and has an inlet port connected to a discharge side of a pump and an outlet port that communicates with the inlet port, and damps pressure pulsation.
• the damping device includes a first fluid chamber that communicates with the inlet port via a first opening, a second fluid chamber that communicates with the first fluid chamber via a communication hole and communicates with the outlet port via a second opening, a first piston that is slidably provided in the first fluid chamber and is arranged on the opposite side of the first opening to the second opening with respect to the first opening, a first biasing member that biases the first piston toward the first opening, a second piston that is slidably provided in the first fluid chamber and is arranged on the second opening side with respect to the first opening with respect to the first opening, and a second biasing member that biases the second piston toward the first opening.
• the valve includes a second biasing member, a first valve body provided in the second liquid chamber and capable of opening and closing the second opening side of the communication hole, and a third biasing member biasing the first valve body toward the first opening side.
• the hydraulic control unit is equipped with the above damping device.
• the brake system is equipped with the above hydraulic control unit.
• FIG. 1 is a schematic diagram showing a schematic configuration of a brake system according to an embodiment of the present invention.
• FIG. 2 is a cross-sectional view showing a schematic configuration of a damping device according to an embodiment of the present invention.
• Figure 3 A figure showing a state in which the first piston has moved to the left compared to the state in Figure 2 in the damping device according to an embodiment of the present invention.
• Figure 4 A figure showing a state in which the second piston has moved to the right compared to the state in Figure 3 in the damping device according to an embodiment of the present invention.
• Figure 5 A figure showing a state in which the second piston has moved to the right compared to the state in Figure 4 in the damping device according to an embodiment of the present invention.
• a vehicle having four wheels 17 will be described as an example of a vehicle.
• the vehicle to which the present invention is applied is not limited to a vehicle having four wheels 17.
• the vehicle may be a vehicle having one, two, or three wheels 17, or a vehicle having five or more wheels 17.
• Fig. 1 is a schematic diagram showing the general configuration of a brake system 1.
• the brake system 1 is installed in a vehicle and is a system for controlling the braking force generated in the vehicle.
• the brake system 1 includes a brake pedal 11, a brake multiplier 12, a master cylinder 13, a reservoir 14, a hydraulic control unit 15, a brake device 16, and wheels 17.
• Brake system 1 is mounted on a vehicle having four wheels 17, and each wheel 17 is braked by a brake device 16 provided on each wheel 17.
• the braking force generated on each wheel 17 is controlled by a hydraulic control unit 15.
• FIG. 1 shows only a portion of brake system 1 related to one of the front wheels and rear wheels, and does not show a portion related to the other of the front wheels and rear wheels.
• the number of wheels 17 whose braking force is controlled by the hydraulic control unit according to the present invention may be other than four.
• the number of wheels 17 whose braking force is controlled by the hydraulic control unit 15 may be two.
• the brake system 15 may be installed in a vehicle having two wheels 17.
• the brake pedal 11 is used by the driver to apply the brakes. In applying the brakes, the driver depresses the brake pedal 11.
• the brake booster 12 is connected to the brake pedal 11 and amplifies the force applied to the brake pedal 11.
• the master cylinder 13 is connected to the brake booster 12 and has a built-in piston that reciprocates in conjunction with the brake pedal 11, generating fluid pressure according to the amount of braking operation.
• the reservoir 14 is attached to the master cylinder 13 and stores brake fluid.
• the hydraulic control unit 15 has a base 15a in which a flow path for brake fluid is formed.
• the master cylinder 13 and each brake device 16 are connected to the base 15a of the hydraulic control unit 15.
• the flow path for brake fluid in the base 15a of the hydraulic control unit 15 is connected to the wheel cylinder of the brake device 16.
• a braking force corresponding to the hydraulic pressure of the brake fluid in the wheel cylinder of the brake device 16 is generated in the wheel 1?.
• a main flow path 21, a sub-flow path 22, and a supply flow path 23 are formed in a base body 15a of a hydraulic control unit 15 as flow paths for brake fluid.
• the main flow path 21 circulates the brake fluid in the master cylinder 13 to the wheel cylinder of the braking device 16.
• the sub-flow path 22 releases the brake fluid in the wheel cylinder of the braking device 16.
• the supply flow path 23 supplies the brake fluid in the master cylinder 13 to the sub-flow path 22.
• the base 15a of the hydraulic control unit 15 is provided with an inlet valve (EV) 31, a release valve (AV) 32, a first valve (USV) 33, a second valve (HSV) 34, an accumulator 35, a pump 36, and a motor 37 as components for controlling the braking force generated on each wheel 17.
• EV inlet valve
• AV release valve
• HSV second valve
• accumulator 35 accumulator
• pump 36 pump
• motor 37 motor 37
• a hydraulic control unit according to the present invention may be different from the configuration of hydraulic control unit 15 shown in Fig. 1 as long as it has pump 36.
• a hydraulic control unit according to the present invention also includes a hydraulic control unit obtained by omitting supply flow path 23, first valve 33, and second valve 34 from hydraulic control unit 15 shown in Fig. 1.
• the main flow path 21 communicates between the master cylinder 13 and the wheel cylinder of the braking device 16.
• the main flow path 21 includes a first main flow path 21a and two second main flow paths 21b.
• the first main flow path 21a is connected to the master cylinder 13.
• the two second main flow paths 21 branch off from the first main flow path 21a and are connected to each braking device 16.
• a first valve 33 is provided in the first main flow path 21a.
• An inlet valve 31 is provided in the second main flow path 21b.
• the sub-path 22 communicates between the brake device 16 side of the main path 21 via the inlet valve 31, the master cylinder 13 side of the main path 21 via the inlet valve 31, and the brake device 16 side via a first valve 33.
• the sub-path 22 includes two first sub-paths 22a and a second sub-path 22b. Each of the first sub-paths 22a is connected to the brake device 16 side of the main path 21 via the inlet valve 31.
• the second sub-path 22b connects the joining point of the two first sub-paths 22a to the master cylinder 13 side of the main path 21 via the inlet valve 31 and to the brake device 16 side of the first valve 33.
• a release valve 32 is provided in the first sub-path 22a.
• An accumulator 35 and a pump 36 are provided in the second sub-path 22b, in this order from the first sub-path 22a side.
• the pump 36 is driven by the motor 37, and sucks brake fluid from the first sub-path 22a side and discharges it to the main path 21 side.
• the pump 36 is a reciprocating plunger pump. Specifically, the plunger of the pump 36 reciprocates by being intermittently pressed by an eccentric cam provided on the output shaft of the motor 37. This causes the pump 36 to pump out brake fluid.
• the supply flow path 23 communicates between the master cylinder 13 side of the first valve 33 in the main flow path 21 and the suction side of the pump 36 in the sub-flow path 22.
• a second valve 34 is provided in the supply flow path 23.
• the inlet valve 31 is, for example, a solenoid valve that is opened in a de-energized state and closed in an energized state.
• the release valve 32 is, for example, a solenoid valve that is closed in a de-energized state and opened in an energized state.
• the first valve 33 is, for example, a solenoid valve that is opened in a de-energized state and closed in an energized state.
• the second valve 34 is, for example, a solenoid valve that is opened in a de-energized state and closed in an energized state.
• the valve 34 is, for example, an electromagnetic valve that is closed when de-energized and is opened when energized.
• the braking force acting on each wheel 11 is controlled by controlling the operation of these valves and the motor 37.
• the inlet valve 31 is opened, the release valve 32 is closed, the first valve 33 is opened, and the second valve 34 is closed.
• the brake fluid flows from the master cylinder 13 to the wheel cylinder of the brake device 16 only through the main flow path 21, without passing through the sub-flow path 22 and the supply flow path 23.
• the piston of the master cylinder 13 is pressed, increasing the hydraulic pressure of the brake fluid in the wheel cylinder, and applying a braking force to the wheel 17.
• the antilock brake control is a control for preventing the wheels 17 from locking.
• the inlet valve 31 is closed, the release valve 32 is opened, the first valve 33 is opened, and the second valve 34 is closed.
• the brake fluid that has flowed into the accumulator 35 is returned to the main flow path 21 via the sub-flow path 22 by driving the pump 36.
• both inlet valve 31 and release valve 32 are closed, stopping the flow of brake fluid between main flow path 21 and sub flow path 22 and the wheel cylinder, maintaining the hydraulic pressure of the brake fluid in the wheel cylinder and maintaining the braking force applied to the wheel 17. Thereafter, inlet valve 31 is opened and release valve 32 is closed, restarting the flow of brake fluid between main flow path 21 and the wheel cylinder, increasing the hydraulic pressure of the brake fluid in the wheel cylinder, and increasing the braking force applied to the wheel 17.
• Anti-skid control is a control for stabilizing the behavior of a vehicle.
• the driving force and braking force of the vehicle are appropriately controlled.
• the inlet valve 31 is opened, the release valve 32 is closed, the first valve 33 is closed, and the second valve 34 is opened.
• the brake fluid flows from the master cylinder 13 to the wheel cylinder of the brake device 16 through the supply flow path 23 and the sub-flow path 22.
• the pump 36 is driven to increase the hydraulic pressure of the brake fluid in the wheel cylinder, and a braking force that brakes the wheel 17 is generated.
• the hydraulic control unit 15 controls the driving of the pump 36.
• pressure pulsation occurs, which is a phenomenon in which the hydraulic pressure of the brake fluid pulsates in the flow path in the hydraulic control unit 15.
• the sound generated by such pressure pulsation may be perceived as noise by the vehicle occupants, which may cause a decrease in comfort. Therefore, the hydraulic control unit 15 is provided with a damping device 100 that damps the pressure pulsation.
• the damping device 100 is provided in the sub-flow path 22 (specifically, the second sub-flow path 22b) downstream of the pump 36.
• the damping device 100 has an inlet port P1 and an outlet port P2.
• the inlet port P1 is connected to the discharge side of the pump 36.
• the inlet port P1 and the outlet port P2 are communicated with each other. Therefore, the brake fluid discharged from the pump 36 flows into the damping device 1xxx via the inlet port P!, passes through the damping device 1xxx, and then flows out of the damping device 1xxx via the outlet port P2. [ 0 0 3 3 ]
• Fig. 2 is a cross-sectional view showing a schematic configuration of a damping device 100.
• the damping device 100 shown in Fig. 2 is merely one example of a damping device according to the present invention, and as will be described later, damping devices according to the present invention also include those obtained by adding various modifications to the example of Fig. 2.
• the damping device 100 is shown so that the axial direction of the housing 101 is the left-right direction, the first opening PO1 connected to the inlet port P1 is located on the left side of the axial direction, and the second opening PO2 connected to the outlet port P2 is located on the right side of the axial direction.
• the left-right direction which is the axial direction of the housing 101, is also simply referred to as the axial direction.
• the first opening PO1 side means the side facing the first opening PO1 in the axial direction, or the upstream side of the flow direction of the brake fluid from the first opening PO1 to the second opening PO2.
• the second opening PO2 side means the side facing the second opening PO2 in the axial direction, or the downstream side of the flow direction of the brake fluid from the first opening PO1 to the second opening PO2.
• the damping device 100 includes a housing 101, a first cover 111, a second cover 112, a third cover 113, a fourth cover 114, a fifth cover 115, a first piston 121, a second piston 122, a third piston 123, a first seal member 131, a second seal member 132, a third seal member 133, a first urging member 141, a second urging member 142, a third urging member 143, a fourth urging member 144, and a fifth cover 115.
• the valve assembly includes a biasing member 145, a first valve body 151, a second valve body 152, and a protrusion member 161.
• the housing 101 is formed, for example, in a cylindrical shape having a hollow space inside.
• the axial direction of the housing 101 is the left-right direction.
• the housing 101 has an internal space that penetrates from the left end face to the right end face.
• the internal space of the housing 101 includes a first hole portion 101a and a second hole portion 101b.
• Each of the first hole portion 101a and the second hole portion 101b has a cylindrical shape and is arranged coaxially with the central axis of the housing 101.
• the first hole portion 101a and the second hole portion 101b are continuous in this order from the left side.
• the diameter of the second hole portion 101b is smaller than the diameter of the first hole portion 101a.
• a third cover 113 is fitted into the first hole portion 101a.
• the third cover 113 has a generally circular plate shape.
• a left end portion of the outer circumferential surface of the third cover 113 expands in diameter radially outward.
• the portion of the third cover 113 that expands in diameter radially outward is fitted into the first hole portion 101a.
• a fourth cover 114 is fitted into the second hole portion 101b.
• the fourth cover 114 has a substantially cylindrical shape.
• the fourth cover 114 has a first cylindrical portion 114a and a second cylindrical portion 114b.
• the first cylindrical portion 114a and the second cylindrical portion 114b have a cylindrical shape and are arranged coaxially with each other.
• the first cylindrical portion 114a and the second cylindrical portion 114b are continuous in this order from the right side.
• the outer diameter of the second cylindrical portion 114b is smaller than the outer diameter of the first cylindrical portion 114a.
• the first cylindrical portion 114a is fitted into the right end portion of the second hole portion 101b.
• the outer peripheral surface of the second cylindrical portion 114b is radially spaced apart from the inner peripheral surface of the second hole portion 101b.
• a recessed portion 114c is formed in the center of the left side surface of the second cylindrical portion 114b.
• the recessed portion 114c has a cylindrical shape and is disposed coaxially with the second cylindrical portion 114b.
• a base portion 161b of a protrusion member 161, which will be described later, is fitted into the recessed portion 114c.
• a first opening PO1 is formed in the peripheral wall of the housing 10! between the third cover 113 and the fourth cover 114.
• the first opening PO1 communicates with the second hole 101b.
• the first liquid chamber S1 is defined by the right surface of third cover 113, the left surface of fourth cover 114, and the inner circumferential surface of second hole portion 101b of housing 101.
• third cover 113 covers the first liquid chamber S1 from the left side.
• Fourth cover 114 covers the first liquid chamber S1 from the right side.
• the left surface of fourth cover 114 forms the right wall surface of the first liquid chamber S1.
• the first liquid chamber S1 has a substantially cylindrical shape.
• the first liquid chamber S1 is connected to inlet port P1 via first opening PO1.
• a second liquid chamber S2 is defined by the inner circumferential surface of the first cylindrical portion 114a of the fourth cover 114.
• the second liquid chamber S2 communicates with the recessed portion 114c via the communicating hole 114d.
• the recessed portion 114c, the communicating hole 114d and the second liquid chamber S2 are continuous in this order from the left side and are arranged coaxially with one another.
• the second liquid chamber S2 communicates with the first liquid chamber S1 via the communicating hole 114d.
• the second cover 112 is fitted to the right end of the inner circumferential surface of the first cylindrical portion 114a of the fourth cover 114.
• the second cover 112 is formed in a generally circular plate shape having a second opening PO2.
• the second opening PO2 is connected to the outlet port P2.
• the second opening PO2 is disposed radially outward from the center of the second cover 112. In the example of FIG. 2, there are multiple second openings PO2. However, the number of second openings PO2 may be one.
• the right end of the inner circumferential surface of the first cylindrical portion 114a of the fourth cover 114 is expanded in diameter.
• the second cover 112 is fitted into the expanded diameter portion of the inner circumferential surface of the first cylindrical portion 114a.
• the second liquid chamber S2 is defined by the left surface of the second cover 112.
• the left surface of the second cover 112 forms the right wall surface of the second liquid chamber S2.
• the second liquid chamber S2 communicates with the outlet port P2 via the second opening PO2.
• the first piston 121 is housed in the second hole portion 101b.
• the first piston 121 has a generally cylindrical shape.
• the first piston 121 is disposed coaxially with the central axis of the second hole portion 101b.
• the outer peripheral surface of the first piston 121 is slidable against the inner peripheral surface of the second hole portion 101b. Therefore, the first piston 121 is provided in the first liquid chamber S1 so as to be slidable in the axial direction.
• the first piston 121 is disposed on the left side of the first opening PO1 in the first liquid chamber S1.
• the first piston 121 is disposed on the opposite side of the first opening PO1 to the second opening PO2 in the first fluid chamber S!.
• An annular groove 121a is formed on the outer circumferential surface of the first piston 121.
• the annular groove 121a extends in the circumferential direction of the first piston 121.
• a first seal member 131 is fitted into the annular groove 121a.
• the first seal member 131 is, for example, an O ring.
• the first seal member 131 is pressed against the inner circumferential surface of the second hole portion 101b. This provides a liquid-tight seal to the gap between the outer circumferential surface of the first piston 121 and the inner circumferential surface of the second hole portion 101b.
• the first piston 121 is urged to the right by a first urging member 141.
• the first urging member 141 is an elastic member such as a spring.
• the first urging member 141 is disposed between the first piston 121 and the third cover 113.
• One end (the right end in FIG. 2) of the first urging member 141 abuts against a recessed portion 121 b of the first piston 121.
• the recessed portion 121 b is provided in the center of the left side surface of the first piston 121.
• the other end (the left end in FIG. 2 ) of the first biasing member 141 abuts against the right side surface of the third cover 113.
• the first biasing member 141 expands and contracts in the left-right direction.
• the first biasing member 141 is in a contracted state relative to its natural length.
• the second piston 122 is housed inside the second hole portion 101b.
• the second piston 122 has a substantially cylindrical shape.
• the second piston 122 is disposed coaxially with the central axis of the second hole portion 101b.
• the outer peripheral surface of the second piston 122 is slidable relative to the inner peripheral surface of the second hole portion 101b. Therefore, the second piston 122 is provided in the first fluid chamber S1 so as to be axially slidable.
• the second piston 122 is disposed on the right side of the first opening P01 in the first fluid chamber S!. In other words, the second piston 122 is disposed on the second opening P02 side of the first opening P0! in the first fluid chamber S!.
• An annular groove 122a is formed on the outer circumferential surface of the second piston 122.
• the annular groove 122a extends in the circumferential direction of the second piston 122.
• a second seal member 132 is fitted into the annular groove 122a.
• the second seal member 132 is, for example, an O ring.
• the second seal member 132 is pressed against the inner circumferential surface of the second hole portion 101b. This provides a liquid-tight seal to the gap between the outer circumferential surface of the second piston 122 and the inner circumferential surface of the second hole portion 101b.
• annular grooves 122a are arranged with a gap between them in the axial direction, and a second seal member 132 is fitted into each of the annular grooves 122a.
• the number of the annular grooves 122a may be one, or three or more.
• the second piston 122 is urged leftward by the second urging member 142.
• the second urging member 142 is, for example, an elastic member such as a spring.
• the second urging member 142 is disposed between the second piston 122 and the fourth cover 114.
• One end (the left end in FIG. 2) of the second urging member 142 abuts against a right end surface of the second piston 122.
• the other end (the right end in FIG. 2) of the second urging member 142 abuts against a left surface of the first cylindrical portion 114a of the fourth cover 114.
• the second urging member 142 expands and contracts in the left-right direction.
• the second biasing member 142 is in a contracted state relative to its natural length.
• a hole 122b is formed in the second piston 122.
• the hole 122b is a portion of the second piston 122 that is recessed from the left side to the right side.
• the hole 122b is recessed from the left end face of the second piston 122 to the right side.
• the hole 122b is disposed coaxially with the central axis of the housing 101. However, the hole 122b does not have to be disposed coaxially with the central axis of the housing 101.
• a fifth cover 115 is fitted into the left end of the inner circumferential surface of hole 122b.
• the fifth cover 115 is formed in a disk shape with a through hole 115a in the center.
• the through hole 115a penetrates the fifth cover 115 from the left side to the right side.
• the left end of the inner circumferential surface of hole 122b has an expanded diameter.
• the fifth cover 115 is fitted into the expanded diameter portion of the inner circumferential surface of hole 122b.
• the space of the first fluid chamber S! to the left of the second piston 122 and hole 122b communicate with each other via the through hole 115a of the fifth cover 115.
• a hole 122c is formed in the second piston 122.
• the hole 122c is a portion of the second piston 122 that is recessed from the right side to the left side.
• the hole 122c is recessed from the right end face of the second piston 122 to the left side.
• the hole 122c is disposed coaxially with the central axis of the housing 101. However, the hole 122c does not have to be disposed coaxially with the central axis of the housing 101.
• a first cover 111 is fitted into the right end portion of the inner circumferential surface of hole 122c.
• the first cover 111 is formed in a generally cylindrical shape.
• the right end portion of the outer circumferential surface of first cover 111 has an expanded diameter.
• the expanded diameter portion of the outer circumferential surface of first cover 111 is fitted into the right end portion of the inner circumferential surface of hole 122c. In this way, first cover 111 covers hole 122c from the right side.
• first through hole 122d penetrates second piston 122 from the left side to the right side.
• Hole portion 122b, first through hole 122d, and hole portion 122c are continuous in this order from the left side and are arranged coaxially with each other.
• the inner diameter of first through hole 122d is the inner diameter of hole portion 122b and the inner diameter of hole portion 122c. In the example of Fig. 2, the inner diameter of hole 122b is smaller than the inner diameter of hole 122c. However, the inner diameter of hole 122b may be the same as the inner diameter of hole 122c or may be larger than the inner diameter of hole 122c.
• a plurality of fourth through holes 122e are formed in the second piston 122.
• the fourth through holes 122e penetrate the second piston 122 from the left side to the right side.
• the fourth through holes 122e are arranged around the first through hole 122d and extend from the right side of the inner surface of the hole 122b to the left side of the inner surface of the hole 122c.
• the inner diameter of the fourth through hole 122e is, for example, about 0.4 mm to 0.5 mm in diameter.
• the fourth through hole 122e extends in the axial direction.
• the path of the fourth through hole 122e is not particularly limited, and for example, the fourth through hole 122e may extend in a direction inclined with respect to the axial direction, or may be curved or bent.
• the fourth through holes 122e are arranged at equal intervals in the circumferential direction of the second piston 122.
• the arrangement of the fourth through holes 122e is not limited to this example.
• the fourth through holes 122e may be arranged at unequal intervals in the circumferential direction.
• the number of the fourth through holes 122e may be one.
• the brake fluid can flow from the left side to the right side of the second piston 122 through the fourth through hole 122e.
• the second valve body 152 which will be described later, is in a closed state, the brake fluid can flow from the left side to the right side of the second piston 122 through the fourth through hole 122e.
• the fourth through hole 122e is provided to enhance the effect of reducing pressure pulsation. The function of the fourth through hole 122e will be described later.
• the second valve body 152 is provided in the hole portion 122 b and can open and close the left side of the first through hole 122 d.
• the second valve body 152 has, for example, a spherical shape. However, the shape of the second valve body 152 may be a shape other than a spherical shape.
• the fourth biasing member 144 is, for example, an elastic member such as a spring. The fourth biasing member 144 is disposed between the fifth cover 115 and the second valve body 152. The direction in which the fourth biasing member 144 expands and contracts is the left-right direction. The fourth biasing member 144 is in a contracted state relative to its natural length. Therefore, the second valve body 152 is biased to the right by the fourth biasing member 144.
• the third piston 123 is housed in the hole 122c.
• the third piston 123 has a substantially cylindrical shape.
• the third piston 123 is disposed coaxially with the central axis of the hole 122c.
• the outer peripheral surface of the third piston 123 is slidable against the inner peripheral surface of the hole 122c. Therefore, the third piston 123 is provided in the hole 122c so as to be slidable in the axial direction.
• An annular groove 123a is formed on an outer circumferential surface of the third piston 123.
• the annular groove 123a extends in the circumferential direction of the third piston 123.
• a third seal member is inserted in the annular groove 123a.
• the third seal member 133 is, for example, a round ring.
• the third seal member 133 is pressed against the inner circumferential surface of the hole 122 c. This creates a liquid-tight seal in the gap between the outer circumferential surface of the third piston 123 and the inner circumferential surface of the hole 122 c.
• the third piston 123 is urged leftward by a fifth urging member 145.
• the fifth urging member 145 is, for example, an elastic member such as a spring.
• the fifth urging member 145 urges the third piston 123 leftward.
• the fifth urging member 145 is disposed between the third piston 123 and the first cover 111.
• One end (the left end in FIG. 2) of the fifth urging member 145 abuts against the recessed portion 123 b of the third piston 123.
• the recessed portion 123 b is formed in an annular shape along the inner circumferential edge of the third piston 123 on the right-hand surface of the third piston 123. The other end (the right end in FIG.
• the fifth urging member 145 abuts against the recessed portion Illa of the first cover 111.
• the recessed portion Illa is formed in an annular shape along the inner circumferential edge of the first cover 111 on the left-hand surface of the first cover 111.
• the direction in which the fifth urging member 145 expands and contracts is the left-right direction.
• the fifth urging member 145 is in a contracted state relative to its natural length.
• a plurality of second through holes 111b are formed in the first cover 111.
• the second through holes 111b penetrate the first cover 111 from the left side to the right side.
• the second through holes 111b extend from the recessed portion Illa to the right side surface of the first cover 111.
• the inner diameter of the second through holes 111b is, for example, about 0.4 mm to 0.5 mm in diameter.
• the second through holes 1lib extend in the axial direction.
• the path of the second through holes 1lib is not particularly limited, and for example, the second through holes 1lib may extend in a direction inclined with respect to the axial direction, and may be curved or bent.
• the second through holes 111b are arranged at equal intervals in the circumferential direction of the first cover 111.
• the arrangement of the second through holes 111b is not limited to this example.
• the second through holes 111b may be arranged at unequal intervals in the circumferential direction.
• the number of second through holes 111b may be one.
• the brake fluid can flow from the left side to the right side of the first cover 111 through the second through hole 111b.
• the second through hole 111b is provided to enhance the effect of reducing pressure pulsation. The function of the second through hole 111b will be described later.
• the protrusion member 161 is provided for opening and closing the second valve body 152.
• the protrusion member 161 is disposed on the right side of the second valve body 152.
• the protrusion member 161 has a protrusion portion 161a and a base portion 161b.
• the base portion 161b has a substantially circular plate shape.
• the base portion 161b is fitted into the recessed portion 114c of the fourth cover 114. Therefore, the base portion 161b covers the left side of the communication hole 114d.
• the protrusion portion 161a is connected to the base portion 161b.
• the protrusion 161 a protrudes to the left from the center of the base 161 b.
• the protrusion 161a is disposed coaxially with the first cover 111, the third piston 123, and the first through hole 122d.
• the protrusion 161a is inserted through a hollow portion in the center of the first cover 111 and a hollow portion in the center of the third piston 123.
• the second piston 122 moves to the right from the position in FIG. 2
• the protrusion 161a is inserted through the first through hole 122d, and a tip of the protrusion 161a can come into contact with the second valve body 152.
• the position of the second valve body 152 is maintained by the tip of the protrusion 161a abutting against the second valve body 152.
• the second piston 122 moves further to the right, causing the second valve body 152 to open. In this manner, the protrusion 161a can be inserted into the first through hole 122d and can abut against the second valve body 152.
• a third through hole 161c is formed in the base 161b.
• the third through hole 161c penetrates the base 161b from the left side to the right side.
• the inner diameter of the third through hole 161c is, for example, about 0.4 mm to 0.5 mm in diameter.
• the path of the third through hole 161c is not particularly limited to the example of FIG. 2.
• the number and arrangement of the branched portions of the third through hole 161c may be different from the example of FIG. 2.
• the first valve body 151 is provided in the second fluid chamber S2 and is capable of opening and closing the right side of the communication hole 114d.
• brake fluid can flow through the communication hole 114d. This state is referred to as an open state of the first valve body 151 and a closed state of the communication hole 114d.
• Fig. 4 is a diagram showing a state in which the second piston 122 in the damping device 100 has moved to the right compared to the state in Fig. 3. In the state in Fig. 4, pressure is stored in the space between the first piston 121 and the second piston 122 in the first liquid chamber S1.
• the second piston 122 is pressed to the right by the pressure in the space between the first piston 121 and the second piston 122 in the first liquid chamber S1, and the second piston 122 has moved to the right compared to the state in Fig. 3.
• the second biasing member 142 expands and contracts, and as a result, it contracts.
• the force acting on the second piston 122 is absorbed by the second biasing member 142.
• the second biasing member 142 expands and contracts as the second piston 122 moves, thereby attenuating the pressure pulsation.
• a small gap is interposed between the inner circumferential surface of the third piston 123 and the protrusion 161a of the protrusion member 161. Therefore, in the hole 122c, the brake fluid flows from the left side of the third piston 123 to the right side.
• the brake fluid sent to the right side from the third piston 123 passes through the second through hole 111b of the first cover 111 and is sent to a space in the first fluid chamber S1 to the right of the second piston 122.
• the inner diameter of the second through hole 111b is small, and a large resistance is applied to the brake fluid flowing through the second through hole 111b. Therefore, pressure pulsations are also damped by the brake fluid flowing through the second through hole 111 b.
• the second piston 122 is formed with the fourth through hole 122e.
• the brake fluid can flow from the hole 122b to the hole 122c through the fourth through hole 122e of the second piston 122.
• the brake fluid can pass through the fourth through hole 122e and be sent from the hole 122b to the hole 122c.
• the inner diameter of the fourth through hole 122e is small, and a large resistance is applied to the brake fluid flowing through the fourth through hole 122e. Therefore, the pressure pulsation is also attenuated by the brake fluid flowing through the fourth through hole 122e.
• Fig. 5 is a diagram showing a state in which the second piston 122 in the damping device 100 has moved to the right as compared to the state in Fig. 4.
• the second piston 122 has moved further to the right as compared to the state in Fig. 4.
• the brake fluid sent to the space in the first fluid chamber S! that is on the right side of the second piston 122 flows through the third through hole 161c of the base 161b of the protruding member 161.
• the first valve body 151 moves to the right and is separated from the communication hole 114d, and the first valve body 151 opens, allowing the brake fluid to flow through the communication hole 114d.
• the brake fluid passes through the communication hole 114d and flows out from the second fluid chamber S2 via the second opening PO2.
• the inner diameter of the third through hole 161c is small, and large resistance is applied to the brake fluid flowing through the third through hole 161c. Therefore, the pressure pulsation is also attenuated by the brake fluid flowing through the third through hole 161c.
• the first valve body 151 when the first valve body 151 is in an open state, the first valve body 151 can come into contact with the second cover 112.
• the first shaft portion 151b and the second shaft portion 151c of the first valve body 151 move along the central axis of the housing 101.
• the second cover 112 in addition to the second opening PO2, the second cover 112 is formed with a through hole 112a.
• the inner diameter of the through hole 112a is larger than the outer diameter of the second shaft portion 151c and smaller than the outer diameter of the first shaft portion 151b. Therefore, the step surface between the first shaft portion 151b and the second shaft portion 151c of the first valve body 151 can abut against the second cover 112. As a result, even when the first valve body 151 is in the open state, the first valve body 151 does not vibrate, and the posture of the first valve body 151 is stabilized.
• the damping device 100 includes a first fluid chamber S! communicating with an inlet port P1 via a first opening PO1, a second fluid chamber S2 communicating with the first fluid chamber S! via a communication hole 114d and communicating with an outlet port P2 via a second opening PO2, a first piston 121 slidably provided in the first fluid chamber S1 and disposed on the opposite side of the first fluid chamber S1 to the second opening PO2 with respect to the first opening PO1, a first biasing member 141 biasing the first piston 121 toward the first opening PO1, and a second biasing member 141 slidably provided in the first fluid chamber S! and biasing the first piston 121 toward the first opening PO1.
• the valve includes a second piston 122 disposed on the second opening PO2 side, a second biasing member 142 biasing the second piston 122 toward the first opening PO1 side, a first valve body 151 provided in the second liquid chamber S2 and capable of opening and closing the second opening PO2 side of the communication hole 114d, and a third biasing member 143 biasing the first valve body 151 toward the first opening PO1 side.
• the first biasing member 141 and the second biasing member 142 gradually expand, so that the pressure on the second opening PO2 side decreases slower than the second piston 122 compared to the pressure on the first opening PO1 side.
• the first valve body 151 is opened, and the brake fluid can be appropriately discharged from the second fluid chamber S2 through the second opening PO2. In this way, the damping device 100 can damp the pressure pulsation of the hydraulic control unit 15.
• the damping device 100 includes a first through hole 122d that is provided in the second piston 122 and penetrates from the first opening PO1 side to the second opening PO2 side, a second valve body 152 that can open and close the first opening PO1 side of the first through hole 122d, a fourth biasing member 144 that biases the second valve body 152 toward the second opening PO2 side, and a protrusion member 161 that is arranged on the second opening PO2 side with respect to the second valve body 152 and can be inserted into the first through hole 122d and has a protrusion portion 161a that can come into contact with the second valve body 152.
• the second valve body 152 can be opened by the protrusion 161a of the protrusion member 161. Therefore, the brake fluid can be appropriately sent from the second piston 122 to the second opening PO2.
• the damping device 100 is formed in the second piston 122 such that it is recessed from the second opening PO2 side toward the first opening PO1 side, and a hole portion 12 communicating with the first through hole 122d is
• the pump includes a third piston 123 slidably provided in the hole 122c, and a fifth biasing member 145 that biases the third piston 123 toward the first opening PO1.
• the third piston 123 When the fifth biasing member 145 is driven, in addition to the movements of the first piston 121 and the second piston 122, the third piston 123 also moves.
• the fifth biasing member 145 expands and contracts in accordance with the movement of the third piston 123, so that the pressure pulsation can be further attenuated. Therefore, the pressure pulsation can be more effectively attenuated.
• the damping device 100 includes a first cover 111 that covers the hole 122c from the second opening PO2 side, and the first cover 111 has at least one second through hole 1lib that penetrates from the first opening PO1 side to the second opening PO2 side. This allows the brake fluid to flow through the second through hole 1lib to also damp the pressure pulsation.
• a plurality of second through holes 1lib are formed in the first cover 111, and the plurality of second through holes 1lib are arranged at equal intervals in the circumferential direction of the first cover 111.
• the protruding member 161 has a base 161b connected to the protruding portion 161a and covering the first opening PO1 side of the communication hole 114d, and a third through hole 161c is formed in the base 161b, penetrating from the first opening PO1 side to the second opening PO2 side. This allows the brake fluid to flow through the third through hole 161c, thereby damping the pressure pulsation.
• the second piston 122 is formed with at least one fourth through hole 122e penetrating from the first opening PO1 side to the second opening PO2 side.
• the second piston 122 may be stuck and unable to move. In such a situation, the brake fluid can flow from the first opening PO1 side of the second piston 122 to the second opening PO2 side through the fourth through hole 122e. Therefore, an excessive increase in pressure in the space in the first fluid chamber S1 on the first opening PO1 side relative to the second piston 122 is suppressed.
• a plurality of fourth through holes 122e are formed in the second piston 122, and the plurality of fourth through holes 122e are arranged at equal intervals in the circumferential direction of the second piston 122.
• a force generated by the brake fluid flowing through the fourth through hole 122e acts uniformly on the second piston 122 in the circumferential direction. Therefore, the force acting on the second piston 122 due to the brake fluid flowing through the fourth through hole 122e This prevents the second piston 122 from tilting with respect to the sliding direction.
• the damping device 100 includes a second cover 112 that covers the second fluid chamber S2 from the second opening PO2 side, and the first valve body 151 can abut against the second cover 112. This makes it possible for the first valve body 151 to not vibrate when the first valve body 151 is in an open state, and the posture of the first valve body 151 is stabilized. This makes it possible to facilitate the opening and closing operation of the first valve body 151.
• the elastic modulus of the first biasing member 141 is lower than the elastic modulus of the second biasing member 142. This appropriately realizes the first piston 121 to move before the second piston 122. This makes it possible to prevent a situation in which the first piston 121 does not move and energy is not absorbed by the first biasing member 141 from occurring.
• damping device 100 has been described above with reference to Fig. 2.
• damping devices according to the present invention may include those that are modified in various ways from the example of Fig. 2.
• the sliding direction of the first piston 121 and the second piston 122 may be different from the axial direction of the housing 101.
• the sliding direction of the first piston 121 and the second piston 122 is different from the axial direction of the housing 101.
• the cross-sectional shape perpendicular to the sliding direction of the first liquid chamber S1, the first piston 121, and the second piston 122 does not have to be a circle.
• the cross-sectional shape may be, for example, an ellipse or a polygon.
• the circumferential direction of each of the first piston 121 and the second piston 122 is a direction along the outer circumferential edge of each of the first piston 121 and the second piston 122, and is a direction around the central axis of each of the first piston 121 and the second piston 122.
• the cross-sectional shape perpendicular to the axial direction of the first cover 111 does not have to be circular.
• the cross-sectional shape may be, for example, an ellipse or a polygon.
• the circumferential direction of the first cover 111 is the direction along the outer circumferential edge of the first cover 111, and is the direction around the central axis of the first cover 111.
• the damping device according to the present invention may also include one in which the second through hole 1lib is omitted from the example of Fig. 2. Even when the second through hole 1lib is omitted, a small gap is present between the inner circumferential surface of the first force bar 111 and the protrusion portion 161a of the protrusion member 161, and brake fluid can pass through the gap from the left side to the right side of the first cover 111.
• the damping device according to the present invention may also include the example shown in Fig. 2 in which the fourth through hole 122e is omitted.
• the fourth through hole 122e is omitted, for example, a groove extending in the axial direction may be provided on the inner circumferential surface of the second hole portion 101b, and the brake fluid may be able to flow from the left side to the right side of the second piston 122 through the groove.
• the shape of the first valve body 151 may be changed to another shape, such as a spherical shape, and the first valve body 151 may not come into contact with the second cover 112.
• the configuration of the second piston 122 may be changed from the example of Fig. 2.
• the second piston 122 to the third piston 123 may be omitted from the example of Fig. 2.
• the first through hole 122d, the second valve body 152, the fourth biasing member 144, and the protrusion member 161 may be omitted from the example of Fig. 2.
• a groove extending in the axial direction may be provided on the inner peripheral surface of the second hole portion 101b, and the brake fluid may be able to flow from the left side to the right side of the second piston 122 through the groove.
• the second piston 122 may be capable of abutting against the first valve body 151, and the first valve body 151 may be brought into an open state by being pressed by the second piston 122.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Regulating Braking Force (AREA)

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• 2023
  • 2023-10-13 DE DE112023004366.3T patent/DE112023004366T5/de active Pending
  • 2023-10-13 KR KR1020257015792A patent/KR20250074683A/ko active Pending
  • 2023-10-13 CN CN202380073314.1A patent/CN120129626A/zh active Pending
  • 2023-10-13 WO PCT/IB2023/060346 patent/WO2024084356A1/ja not_active Ceased
  • 2023-10-13 JP JP2024550925A patent/JPWO2024084356A1/ja active Pending

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