JP2012126231A - Master cylinder apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a master cylinder apparatus of great practical use.SOLUTION: The master cylinder apparatus 50 includes: an input piston 156 that has a closing unit 178 for closing a cylindrical portion 176 and a front side of the cylindrical portion and is arranged posterior to a pressurization piston 152; a second housing member 160 integrated with a first housing member 158 in a state that the front side of the second housing member is inserted into the cylindrical portion; and a reactive force generator 250 for applying an elastic reaction force to the advance of the input piston. A first input chamber R1 between the pressurization piston and the input piston, and a second input chamber R2 positioned behind the back end of the cylindrical portion of the input piston between the inner peripheral surface of the housing and the outer peripheral surface of an inner cylinder are each partitioned to input an operating fluid from a high-pressure source device 58; and a biasing force posterior to the input piston and a biasing force anterior thereto, both depending on the pressure of the operating fluid of each input chamber, are balanced.

Description

  The present invention relates to a master cylinder device for pressurizing and supplying hydraulic fluid to a brake device provided on a wheel.

  Generally, in a master cylinder device, a pressure piston for pressurizing hydraulic fluid supplied to a brake device and an input piston that moves forward by a driver's brake operation are arranged in series in a cylindrical housing. Has been. In addition, liquid chambers filled with hydraulic fluid are formed between the pistons and between the piston and the housing. In the master cylinder device described in the following patent document, a flange is formed on the outer periphery of the input piston, and the rear of the flange is from a high pressure source so that a forward biasing force acts on the input piston. A liquid chamber into which a high-pressure working fluid is input is provided. This liquid chamber is partitioned by the input piston and the housing, and the input piston is not advanced so that the liquid chamber is partitioned even when the input piston is advanced by the brake operation. In this state, it has a portion that extends backward beyond the liquid chamber.

JP 2008-24098 A

  Since the master cylinder device has a portion where the input piston extends rearward, the entire length of the master cylinder device is relatively long. As a result, there is a problem that a relatively large space is required for mounting the master cylinder device on the vehicle. There are many other areas for improvement in the master cylinder device, including improvements to address this problem. Therefore, if any improvement is made, it is possible to improve the practicality of the master cylinder device. This invention is made | formed in view of such a situation, and makes it a subject to improve the practicality of a master cylinder apparatus.

  In order to solve the above-described problems, a master cylinder device of the present invention includes a housing body, a pressurizing piston in which a pressurizing chamber is partitioned forward, a cylindrical cylindrical portion, and a closing portion that closes the front side thereof. An input piston disposed behind the pressure piston, an inner cylinder inserted into the cylinder and fixed to the housing body at the rear end, and an elastic reaction force applied to the advance of the input piston And a first input chamber between the pressure piston and the input piston, the rear end of the cylindrical portion of the input piston between the inner peripheral surface of the housing body and the outer peripheral surface of the inner cylinder The second input chambers are partitioned so that the hydraulic fluid from the high pressure source is input to the rear of each of the second input chambers, and the forward biasing force to the input piston and the front depending on the pressure of the hydraulic fluid in each input chamber It is configured to balance the urging force to And wherein the door.

  According to this master cylinder device, even if the input piston does not have a portion extending rearward beyond the second input chamber, the second input chamber is partitioned. Therefore, according to this master cylinder device, the overall length of the input piston can be made relatively short, and as a result, the overall length of the master cylinder device can be made considerably short. As a result, the master cylinder device is highly practical.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following terms, (1) corresponds to claim 1, (2) corresponds to claim 2, (3) corresponds to claim 3, (4) corresponds to claim 4, Each corresponds.

(1) A master cylinder device for supplying pressurized hydraulic fluid to a brake device that is provided on a wheel and operates by the pressure of the hydraulic fluid,
A cylindrical housing body whose front side is closed;
A pressurizing piston disposed in the housing body such that a pressurizing chamber for pressurizing the hydraulic fluid supplied to the brake device is partitioned in front of itself;
A tubular portion having a tubular shape and a closed portion that closes the front side of the tubular portion, disposed in the housing body behind the pressure piston, and connected to a brake operation member at the closed portion; Input piston,
An inner cylinder that is inserted into the cylinder portion of the input piston and is fixed to the housing main body at the rear end portion thereof and constitutes a housing of the master cylinder device together with the housing main body;
A reaction force applying mechanism that applies an elastic reaction force to the advance of the input piston, and
A first input chamber into which hydraulic fluid from a high pressure source is input between the pressure piston and the input piston is the input between the inner peripheral surface of the housing body and the outer peripheral surface of the inner cylinder. Second input chambers into which hydraulic fluid from the high pressure source is input are respectively defined behind the rear end of the cylindrical portion of the piston,
A rearward biasing force with respect to the input piston that depends on the pressure of the hydraulic fluid in the first input chamber and a forward biasing force with respect to the input piston that depends on the pressure of the hydraulic fluid in the second input chamber. Master cylinder device configured to balance.

  In this master cylinder device, since the rearward biasing force acting on the input piston and the forward biasing force are balanced, the input piston hardly moves depending on the pressure of the hydraulic fluid in the two input chambers. Become. In other words, when the input piston moves, the pressure of the hydraulic fluid in the two input chambers hardly affects the movement. Therefore, in this master cylinder device, the input piston can be advanced depending on the operating force regardless of the pressure of the hydraulic fluid in the two input chambers. Further, the reaction force applying mechanism applies an elastic reaction force to the input piston with respect to the forward movement, and the driver can recognize the elastic reaction force as an operation reaction force. That is, the reaction force imparting mechanism can be considered as one component of a stroke simulator that generates a reaction force against the operation while allowing the driver to perform a brake operation. It should be noted that the magnitude of the rearward biasing force acting on the input piston and the magnitude of the forward biasing force do not need to be exactly the same, and may be almost the same. If these forces are almost the same magnitude, the input piston hardly moves even when the hydraulic fluid at a high pressure from the high pressure source is input to the first input chamber and the second input chamber. On the other hand, the pressurizing piston can move depending on the pressure of the hydraulic fluid in the first input chamber, and the pressure of the hydraulic fluid input from the high pressure source to the first input chamber regardless of the movement of the input piston. The hydraulic fluid in the pressurizing chamber can be pressurized.

  In order to balance the rearward biasing force and the forward biasing force, for example, in the input piston, the first pressure receiving area where the pressure of the hydraulic fluid in the first input chamber acts, and the second input chamber It is only necessary that the second pressure receiving area on which the pressure of the hydraulic fluid acts is substantially equal. In the master cylinder device configured as described above, the backward biasing force acting on the input piston and the forward biasing force are balanced by the pressure of the hydraulic fluid input from the high pressure source. Further, when the first pressure receiving area and the second pressure receiving area are substantially equal, when the input piston moves, the volume change of the first input chamber and the volume change of the second input chamber are substantially the same. It becomes. That is, the amount of hydraulic fluid flowing out from one input chamber is substantially equal to the amount of hydraulic fluid flowing into the other input chamber. Therefore, for example, if the first input chamber and the second input chamber are communicated, when the input piston moves, the volume of each input chamber changes while the hydraulic fluid moves between the two input chambers. become.

  Further, according to the present master cylinder device, the input piston is roughly disposed in the housing main body with the cylindrical portion sandwiched between the inner peripheral surface of the housing main body and the outer peripheral surface of the inner cylinder. Can be considered. In order to seal the second input chamber, for example, the outer peripheral surface of the cylindrical portion of the input piston is in sliding contact with the inner peripheral surface of the housing body, and the inner peripheral surface of the cylindrical portion is in sliding contact with the outer peripheral surface of the inner cylinder. That's fine. Therefore, according to this master cylinder device, even if the input piston does not have a portion that extends rearward beyond the second input chamber, the second input chamber is defined. Therefore, according to the master cylinder device, the overall length of the input piston can be made relatively short, and the overall length of the master cylinder device can be considerably shortened.

  The reaction force applying mechanism in the master cylinder device is, for example, formed with a reaction force chamber filled with hydraulic fluid as described later, and applies an elastic reaction force to the input piston via the hydraulic fluid. The mechanism may be an elastic body such as a spring that directly applies an elastic reaction force to the input piston.

(2) In the master cylinder device,
The inner peripheral surface of the cylindrical portion of the input piston is in sliding contact with the outer peripheral surface of the inner cylinder through a seal, and the seal is fitted to the rear end of the inner peripheral surface of the cylindrical portion of the input piston (1 The master cylinder device according to the item).

  In this master cylinder device, the inner peripheral surface of the cylindrical portion is in sliding contact with the outer peripheral surface of the inner cylinder through a seal regardless of the position of the input piston in the housing body by the brake operation. Therefore, the axial length of the inner cylinder is the maximum stroke of the input piston, that is, the position of the seal when the brake is not operated, and the seal when the input piston is most advanced by the brake operation. It is better to be more than the difference from the position. Further, according to the master cylinder device, since the seal is disposed at the rear end of the cylindrical portion of the input piston, the brake operation is not performed, that is, the input piston is located at the rearmost position. The interval between the rear end portion of the inner cylinder and the seal can be considerably reduced. This also makes it possible to make the length of the inner cylinder in the axial direction almost the same as the maximum stroke of the input piston. Therefore, according to this master cylinder device, the length of the inner cylinder can be made relatively short, and the length in the axial direction of the cylinder portion of the input piston in which the inner cylinder is inserted can be made relatively short. You can also. As a result, the overall length of the master cylinder device can be considerably shortened.

(3) The housing main body has a front small-diameter portion that is located on the front side and has a small inner diameter, and a rear large-diameter portion that is located on the rear side and has a large inner diameter,
The input piston has a flange on the outer periphery of the rear end of the cylindrical portion;
The closed portion is positioned at the front small-diameter portion, and the rod is positioned at the rear large-diameter portion, whereby the second input chamber is partitioned behind the rod and filled with the hydraulic fluid in front of the rod. The reaction force chamber is divided,
The master cylinder device has a pressure accumulating chamber that communicates with the reaction force chamber and is filled with the working fluid, and includes a pressurizing mechanism that elastically pressurizes the working fluid in the accumulating chamber,
The master cylinder device according to any one of (1) or (2), wherein the reaction force applying mechanism includes the reaction force chamber and a pressurizing mechanism.

  The mode of this section is a mode in which a limitation is imposed on the reaction force application mechanism. According to the above configuration, the volume of the reaction force chamber decreases when the input piston moves forward and increases when the input piston moves backward. In accordance with the change in the volume, the hydraulic fluid in the reaction force chamber flows into or out of the pressure accumulation chamber communicating with the reaction force chamber. In addition, since the pressure of the hydraulic fluid in the pressure accumulating chamber is elastically pressurized by the pressurizing mechanism, if the hydraulic fluid in the reaction force chamber flows into the pressure accumulating chamber due to a brake operation and the volume of the pressure accumulating chamber increases, The pressure of the working fluid in the chamber will increase. The pressure acts on the flange of the input piston, and a backward force is generated in the input piston. The force becomes a reaction force, and the driver can realize that the reaction force from the brake operation member increases as the amount of brake operation increases. The pressure accumulating chamber and the pressurizing mechanism may be provided outside the housing body, for example, and in that case, the main components of the stroke simulator are provided outside the housing.

  (4) The master cylinder device according to (3), wherein the master cylinder device includes a reaction force chamber opener for opening the reaction force chamber to a low pressure source.

  This aspect of the master cylinder device is preferable when the hydraulic fluid in the pressurizing chamber cannot be pressurized depending on the high-pressure hydraulic fluid from the high-pressure source and the hydraulic fluid in the pressurizing chamber is pressurized depending on the operating force. It has become. More specifically, when the reaction force chamber is opened to a low pressure source, the pressurizing mechanism cannot pressurize the hydraulic fluid, and the reaction force applying mechanism cannot function. Therefore, the operating force is not used for pressurizing the working fluid in the pressurizing mechanism, but is used for pressurizing the working fluid in the pressurizing chamber. For this reason, it is possible to pressurize the hydraulic fluid in the pressurizing chamber by effectively using the operating force, and it is possible to generate a relatively large hydraulic braking force depending on the operating force. In order to pressurize the hydraulic fluid in the pressurizing chamber depending on the operating force, for example, when the input piston moves forward, the master cylinder device is arranged so that the front end of the input piston comes into contact with the rear end of the pressurizing piston. Need only be configured. The contact allows the input piston to directly advance the pressure piston.

(5) The operation of the high pressure source is electrically controlled,
The master cylinder device according to item (4), wherein the reaction force chamber opener is configured to open the reaction force chamber to the low pressure source in the event of electrical failure.

  According to the above configuration, the reaction force application mechanism does not function when high pressure hydraulic fluid is not input from the high pressure source due to electrical failure. Therefore, when the hydraulic fluid in the pressurizing chamber cannot be pressurized depending on the high pressure source, the hydraulic fluid in the pressurizing chamber can be pressurized using the operating force effectively.

  (6) The reaction force chamber opener includes a reaction force chamber communication passage for communicating the reaction force chamber and a low pressure source, and a normally open electromagnetic on-off valve provided in the reaction force chamber communication passage. The master cylinder device according to (4) or (5), which is configured to include the master cylinder device.

  The mode of this section is a mode in which a limitation is added with respect to means for opening the reaction force chamber to a low pressure source in the event of electrical failure. According to the above configuration, the reaction force chamber is automatically opened to the low pressure source at the time of electrical failure.

It is a schematic diagram which shows the drive system and braking system of a hybrid vehicle carrying the master cylinder apparatus of the Example of claimable invention. It is a figure which shows the hydraulic brake system comprised including the master cylinder apparatus of the Example of claimable invention. FIG. 3 is a diagram showing a pressure increasing / decreasing device that regulates hydraulic fluid that has been set to high pressure by a high pressure source in the hydraulic brake system shown in FIG. 2. It is a figure which shows the pressurization mechanism of the reaction force provision mechanism employ | adopted as the master cylinder apparatus shown in FIG.

  Hereinafter, embodiments of the claimable invention will be described in detail with reference to the drawings. The claimable invention is not limited to the following examples and modifications, and can be implemented in various modes with various changes and improvements based on the knowledge of those skilled in the art.

≪Vehicle configuration≫
FIG. 1 schematically shows a drive system and a braking system for a hybrid vehicle equipped with the master cylinder device of the embodiment. In the vehicle, an engine 10 and an electric motor 12 are mounted as power sources, and a generator 14 that generates electric power by the output of the engine 10 is also mounted. The engine 10, electric motor 12, and generator 14 are connected to each other by a power split mechanism 16. By controlling the power split mechanism 16, the output of the engine 10 can be divided into an output for operating the generator 14 and an output for rotating one of the four wheels 18 as a driving wheel. The output of the electric motor 12 can be transmitted to the drive wheels. That is, the power split mechanism 16 functions as a transmission related to the driving force transmitted to the drive wheels via the speed reducer 20 and the drive shaft 22. In addition, some components such as “wheel 18” correspond to the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel, respectively, when indicating that they correspond to any of the four wheels. The subscripts “FL”, “FR”, “RL”, and “RR” are used. According to this notation, the driving wheels in the vehicle are the wheel 18RL and the wheel 18RR.

  The electric motor 12 is an AC synchronous motor and is driven by AC power. The vehicle is provided with an inverter 24, and the inverter 24 can convert electric power from direct current to alternating current or from alternating current to direct current. Therefore, by controlling the inverter 24, the AC power output from the generator 14 is converted into the DC power for storing in the battery 26, or the DC power stored in the battery 26 is converted into the electric motor. 12 can be converted into AC power for driving the motor 12. Like the electric motor 12, the generator 14 has a configuration as an AC synchronous motor. That is, in the vehicle of the present embodiment, it can be considered that two AC synchronous motors are mounted, and one is used mainly as an electric motor 12 for outputting driving force, and the other is a generator. 14 is mainly used for power generation by the output of the engine 10.

  Further, the electric motor 12 can also generate power (regenerative power generation) by using the rotation of the wheels 18RL and 18RR accompanying the traveling of the vehicle. At this time, in the electric motor 12 connected to the wheels 18RL and 18RR, electric power is generated and a resistance force for stopping the rotation of the electric motor 12 is generated. Therefore, the resistance force can be used as a braking force for braking the vehicle. That is, the electric motor 12 is used as a regenerative brake means for braking the vehicle while generating electric power. Therefore, the vehicle is braked by controlling the regenerative brake together with the engine brake and a hydraulic brake described later. On the other hand, the generator 14 generates power mainly by the output of the engine 10, but also functions as an electric motor when power is supplied from the battery 26 via the inverter 24.

  In the present vehicle, the above-described brake control and various types of control relating to other vehicles are performed by a plurality of electronic control units (ECUs). Of the plurality of ECUs, the main ECU 30 has a function of supervising these controls. For example, the hybrid vehicle can travel by driving the engine 10 and the electric motor 12. The driving of the engine 10 and the driving of the electric motor 12 are comprehensively controlled by the main ECU 30. . Specifically, the distribution of the output of the engine 10 and the output of the electric motor 12 is determined by the main ECU 30, and the engine ECU 32 that controls the engine 10, the electric motor 12, and the motor that controls the generator 14 based on the distribution. Commands for each control are output to the ECU 34.

  A battery ECU 36 that controls the battery 26 is also connected to the main ECU 30. The battery ECU 36 monitors the state of charge of the battery 26, and outputs a charge request command to the main ECU 30 when the amount of charge is insufficient. The main ECU 30 that has received the charge request command outputs a power generation command from the generator 14 to the motor ECU 34 in order to charge the battery 26.

  The main ECU 30 is also connected to a brake ECU 38 that controls the brake. The vehicle is provided with a brake operation member (hereinafter sometimes simply referred to as an “operation member”) that is operated by the driver, and the brake ECU 38 has a brake operation amount (hereinafter referred to as an operation amount of the operation member). May be simply referred to as an “operation amount”) and a brake control force that is a driver's force applied to the operation member (hereinafter, also referred to simply as “operation force”). The power is determined and this target braking force is output to the main ECU 30. The main ECU 30 outputs this target braking force to the motor ECU 34, and the motor ECU 34 controls the regenerative braking based on the target braking force, and the execution value thereof, that is, the generated regenerative braking force is supplied to the main ECU 30. Output to. In the main ECU 30, the regenerative braking force is subtracted from the target braking force, and the target hydraulic braking force to be generated in the hydraulic brake system 40 mounted on the vehicle is determined by the subtracted value. The main ECU 30 outputs the target hydraulic braking force to the brake ECU 38, and the brake ECU 38 performs control so that the hydraulic braking force generated by the hydraulic brake system 40 becomes the target hydraulic braking force.

≪Configuration of hydraulic brake system≫
The hydraulic brake system 40 mounted on the hybrid vehicle configured as described above will be described in detail with reference to FIG. In the following description, “front” represents the left side in FIG. 2, and “rear” represents the right side in FIG. In addition, “front side”, “front end”, “forward”, “rear side”, “rear end”, “reverse”, and the like are also represented in the same manner. In the following description, the character [] is a symbol used when a sensor or the like is shown in the drawings.

  FIG. 2 schematically shows a hydraulic brake system 40 provided in the vehicle. The hydraulic brake system 40 has a master cylinder device 50 for pressurizing hydraulic fluid. The driver of the vehicle can operate the master cylinder device 50 by operating the operating device 52 connected to the master cylinder device 50, and the master cylinder device 50 pressurizes the hydraulic fluid by its own operation. The pressurized hydraulic fluid is supplied to a brake device 56 provided on each wheel via an antilock device 54 connected to the master cylinder device 50. The brake device 56 generates a force for stopping the rotation of the wheel 18, that is, a hydraulic braking force, depending on the pressure of the pressurized hydraulic fluid (hereinafter referred to as “output pressure”), so-called master pressure. Let

  The hydraulic brake system 40 has a high pressure source device 58 for increasing the pressure of the hydraulic fluid as a high pressure source. The high pressure source device 58 is connected to the master cylinder device 50 via the pressure increasing / decreasing device 60. The pressure increasing / decreasing device 60 is a device that controls the pressure of the hydraulic fluid (hereinafter referred to as “high pressure source pressure”), which has been increased by the high pressure source device 58, to a pressure equal to or lower than that pressure, and is input to the master cylinder device 50. The pressure of the hydraulic fluid (hereinafter referred to as “input pressure”) is increased and decreased. That is, the input pressure is a pressure at which the high pressure source pressure is controlled, and can also be referred to as a controlled high pressure source pressure. The master cylinder device 50 is configured to be operable by increasing or decreasing the input pressure. The hydraulic brake system 40 has a reservoir 62 that stores hydraulic fluid under atmospheric pressure as a low pressure source. The reservoir 62 is connected to each of the master cylinder device 50, the pressure increasing / decreasing device 60, and the high pressure source device 58.

  The operation device 52 includes a brake pedal 70 as a brake operation member and an operation rod 72 connected to the brake pedal 70. The brake pedal 70 is rotatably held by the vehicle body at the upper end portion. The operation rod 72 is connected to the brake pedal 70 at the rear end, and is connected to the master cylinder device 50 at the front end. The operation device 52 includes an operation amount sensor [SP] 74 for detecting the operation amount of the brake pedal 70 and an operation force sensor [FP] 76 for detecting the operation force. The operation amount sensor 74 and the operation force sensor 76 are connected to the brake ECU 38, and the brake ECU 38 determines a target braking force based on the detection values of these sensors.

  The brake device 56 is connected to the master cylinder device 50 via liquid passages 80 and 82. These fluid passages 80 and 82 are fluid passages for supplying hydraulic fluid pressurized to the output pressure by the master cylinder device 50 to the brake device 56. The liquid passage 80 is provided with an output pressure sensor [Po] 84 (so-called master pressure sensor). Although not described in detail, each brake device 56 includes a brake caliper, a wheel cylinder (brake cylinder) and a brake pad attached to the brake caliper, and a brake disk that rotates with each wheel. . The liquid passages 80 and 82 are connected to the brake cylinder of each brake device 56 via the antilock device 54. Incidentally, the fluid passage 80 is connected to the rear-wheel brake devices 56RL and 56RR, and the fluid passage 82 is connected to the front-wheel brake devices 56FL and 56FR. The brake cylinder presses the brake pad against the brake disc depending on the output pressure of the hydraulic fluid pressurized by the master cylinder device 50. Due to the friction generated by the pressing, each brake device 56 generates a hydraulic braking force that stops the rotation of the wheel, and the vehicle is braked.

  The anti-lock device 54 is a general device, and simply has four pairs of on-off valves corresponding to each wheel. One of the pair of on-off valves is a pressure-increasing on-off valve. When the wheel is not locked, the valve is in an open state, and the other is a pressure-reducing on-off valve. When not locked, the valve is closed. When the wheel is locked, the pressure increasing on / off valve blocks the flow of hydraulic fluid from the master cylinder device 50 to the brake device 56, and the pressure reducing on / off valve allows the hydraulic fluid to flow from the brake device 56 to the reservoir. It is configured to allow and unlock the wheels.

  The high-pressure source device 58 includes a hydraulic pump 90 that sucks the hydraulic fluid from the reservoir 62 and increases the hydraulic pressure of the hydraulic fluid, and an accumulator 92 that stores the increased hydraulic fluid. Incidentally, the hydraulic pump 90 is driven by an electric motor 94. Further, the high-pressure source device 58 includes a high-pressure source pressure sensor [Ph] 96 for detecting the pressure of the hydraulic fluid that is set to a high pressure. The brake ECU 38 monitors the detected value of the high-pressure source pressure sensor 96, and the hydraulic pump 90 is controlled and driven based on the detected value. By this control drive, the high-pressure source device 58 always supplies the hydraulic pressure higher than the set pressure to the pressure increasing / decreasing device 60.

  The pressure increasing / decreasing device 60 includes a pressure adjusting valve device 100 that adjusts the working fluid according to the pressure of the working fluid introduced therein, a pressure increasing linear valve 102 connected to the high pressure source device 58, and a pressure reducing valve connected to the reservoir 62. And a linear valve 104. The pressure regulating valve device 100 is connected to the pressure-increasing linear valve 102 and the pressure-decreasing linear valve 104. The pressure-regulating fluid is regulated by the operation of the pressure-increasing linear valve 102 and the pressure-decreasing linear valve 104, and the working fluid is adjusted to the master cylinder. The device 50 can be supplied.

  As shown in FIG. 3, the pressure regulating valve device 100 includes a generally cylindrical housing 110 whose both ends are closed, a columnar first plunger 112 disposed in the housing 110, and a first plunger 112. It has a columnar second plunger 114 disposed below, and a cylindrical pressure adjusting cylinder 116 disposed above the first plunger 112. The first plunger 112, the second plunger 114, and the pressure adjusting cylinder 116 are slidably fitted to the housing 110, respectively. On the inner periphery of the housing 110, a step surface is formed by making the diameters different from each other. Generally, the diameter increases toward the upper side. Further, stepped surfaces are formed on the outer circumferences of the first plunger 112, the second plunger 114, and the pressure adjusting cylinder 116 by making the diameters different from each other. The pressure adjusting cylinder 116 is provided with a through hole 118 penetrating itself in the axial direction and the radial direction, and an opening of the through hole 118 is provided on each of the upper end surface, the lower end surface, and the side surface. The upper end of the first plunger 112 can be seated in the opening provided in the lower end surface of the pressure adjusting cylinder 116. On the other hand, a pin 120 supported on the upper end surface of the housing 110 is fitted into an opening provided on the upper end surface of the pressure adjusting cylinder 116, and the pressure adjusting cylinder 116 is movable with respect to the pin 120. Yes. An annular buffer rubber 122 is provided above the pressure adjusting cylinder 116 to prevent the pressure adjusting cylinder 116 from coming into contact with the housing 110. A spring 124, which is a compression spring, is provided between the first plunger 112 and the pressure adjusting cylinder 116, and the first plunger 112 and the pressure adjusting cylinder 116 are biased by the spring 124 so as to be separated from each other. Has been. A spring 126, which is a compression spring, is also provided between the pressure adjusting cylinder 116 and the housing 110, and the pressure adjusting cylinder 116 is urged downward by the spring 126.

  Inside the housing 110, a plurality of liquid chambers are formed by the inner peripheral surface and end surfaces of the housing 110 and the outer peripheral surfaces and end surfaces of the first plunger 112, the second plunger 114, and the pressure adjusting cylinder 116. . Specifically, a first liquid chamber 130 is defined between the lower end surface of the second plunger 114 and the inner bottom surface of the housing 110, and the upper end surface of the second plunger 114 and the first plunger 112 A second liquid chamber 132 is defined between the lower end surface. The outer diameter of the upper portion of the pressure adjusting cylinder 116 is smaller than the inner diameter of the housing 110, and a third liquid chamber 134 is defined between the pressure adjusting cylinder 116 and the housing 110. The outer diameter of the lower portion of the pressure adjusting cylinder 116 is slightly smaller than the inner diameter of the housing 110, and a fourth liquid chamber 136 is defined between the pressure adjusting cylinder 116 and the housing 110. Further, a fifth liquid chamber 138 is defined by the outer peripheral surface of the upper portion of the first plunger 112, the lower end surface of the pressure adjusting cylinder 116, and the inner peripheral surface of the housing 110.

  These liquid chambers communicate with each other through communication holes provided in the housing 110, and the hydraulic fluid in each liquid chamber has a predetermined pressure. Specifically, the first liquid chamber 130 is connected to a liquid passage that branches from the liquid passage 80, and hydraulic fluid that has been output by the master cylinder device 50 is supplied to the first liquid chamber 130. . The second liquid chamber 132 is connected to the pressure-increasing linear valve 102 and the pressure-reducing linear valve 104, and the working fluid in the second liquid chamber 132 has a pressure adjusted by the pressure-increasing linear valve 102 and the pressure-reducing linear valve 104. It has become. The fourth liquid chamber 136 is connected to the high pressure source device 58, and the hydraulic fluid in the fourth liquid chamber 136 has a high pressure source pressure. The fifth liquid chamber 138 is connected to the reservoir 62, and the pressure of the hydraulic fluid in the fifth liquid chamber 138 is atmospheric pressure. Further, the pressure of the hydraulic fluid in the third liquid chamber 134 is adjusted by the operation of the pressure regulating valve device 100 as described later. The third liquid chamber 134 is connected to the master cylinder device 50, and the hydraulic fluid having the adjusted pressure is input to the master cylinder device 50. That is, the pressure of the hydraulic fluid in the third fluid chamber 134 is an input pressure to the master cylinder device 50.

  The pressure of the hydraulic fluid in the third liquid chamber 134 is normally adjusted in accordance with the pressure of the hydraulic fluid supplied to the second liquid chamber 132 (hereinafter sometimes referred to as “control hydraulic pressure”). The control hydraulic pressure can be increased or decreased by controlling the power to the pressure increasing linear valve 102 and the pressure reducing linear valve 104. When power is not supplied to the pressure increasing linear valve 102 and the pressure reducing linear valve 104, the pressure increasing linear valve 102 is closed and the pressure reducing linear valve 104 is opened, and the control hydraulic pressure is It becomes atmospheric pressure. If the maximum current in the set range is supplied to the pressure reducing linear valve 104 and the power to the pressure increasing linear valve 102 is controlled, the pressure increasing linear valve 102 is opened while the pressure reducing linear valve 104 is closed. The pressure is controlled. At this time, the control hydraulic pressure is increased in accordance with an increase in power to the pressure-increasing linear valve 102. On the other hand, if the power to the pressure-reducing linear valve 104 is controlled without supplying power to the pressure-rising linear valve 102, the valve opening pressure of the pressure-reducing linear valve 104 is closed. Is controlled. At this time, the control hydraulic pressure is decreased in accordance with a decrease in power to the pressure-reducing linear valve 104.

  When the control hydraulic pressure is increased as described above, the first plunger 112 moves upward against the elastic force of the coil spring 124 and opens at the lower end of the through hole 118 of the pressure adjusting cylinder 116 (hereinafter, referred to as “the first plunger 112”). It sits on the “fifth liquid chamber side opening”. When the first plunger 112 further moves upward, the pressure adjusting cylinder 116 also moves upward, and the outer peripheral surface of the pressure adjusting cylinder 116 is separated from the step surface formed in the housing 110. Therefore, the flow of hydraulic fluid from the fourth liquid chamber 136 to the third liquid chamber 134 is allowed, and the pressure of the hydraulic fluid in the third liquid chamber increases. Further, when the control hydraulic pressure is decreased, the outer peripheral surface of the pressure adjusting cylinder 116 is seated on the step surface formed in the housing 110 in a state where the first plunger 112 is seated on the fifth fluid chamber side opening. When the control hydraulic pressure is further decreased, the first plunger 112 is separated from the fifth liquid chamber side opening, and the third liquid chamber 134 communicates with the reservoir 62 via the fifth liquid chamber 138.

  Further, the pressure regulating valve device 100 is based on the pressure of the hydraulic fluid in the first fluid chamber 130, that is, the operation of the master cylinder device 50 when power is not supplied to the pressure increasing linear valve 102 and the pressure reducing linear valve 104. Depending on the output pressure, the pressure of the hydraulic fluid in the third liquid chamber 134 can be increased or decreased. That is, when the pressure of the hydraulic fluid in the first liquid chamber 130 increases, the second plunger 114 moves upward, so that the first plunger 112 is also moved upward. Further, if the pressure of the hydraulic fluid in the first liquid chamber 130 decreases, the second plunger 114 moves downward and the first plunger 112 also moves downward. Therefore, as the pressure of the hydraulic fluid in the first liquid chamber 130 increases or decreases, the pressure of the hydraulic fluid in the third liquid chamber 134 increases or decreases as described above. That is, the pressure regulating valve device 100 can be operated using the output pressure as the pilot pressure. Further, the pressure regulating valve device 100 adjusts the pressure of the hydraulic fluid in the third fluid chamber 134 based on the pilot pressure, similarly to the case where electric power is supplied to the pressure-increasing linear valve 102 and the pressure-decreasing linear valve 104. It is possible.

<Configuration of master cylinder device>
The master cylinder device 50 includes a housing 150 that is a housing of the master cylinder device 50, a first pressure piston 152 and a second pressure piston 154 that pressurize the hydraulic fluid supplied to the brake device 56, and a driver's operation. An input piston 156 that is input through the operation device 52 is included. FIG. 2 shows a state where the master cylinder device 50 is not operating, that is, a state where the brake operation is not performed. Incidentally, as is the case with a general master cylinder device, this master cylinder device 50 also has several liquid chambers in which the working fluid is accommodated, and between those liquid chambers, between these liquid chambers and the outside. Some communication passages are formed to communicate with each other, and several seals are disposed between the components in order to ensure their liquid tightness. These seals are general, and in consideration of the simplification of the description of the specification, the description thereof will be omitted unless particularly described.

  The housing 150 mainly includes a first housing member 158 and a second housing member 160. The first housing member 158 has a generally cylindrical shape with the front end closed, and a flange 162 is formed on the outer periphery of the rear end, and is fixed to the vehicle body at the flange 162. Further, in the first housing member 158, a portion having a generally small inner diameter located on the front side is a small inner diameter portion 164, and a portion on the rear side is a large inner diameter portion 166 having a generally large inner diameter.

  The second housing member 160 has a generally cylindrical shape, and a portion having a generally small outer diameter located on the front side is a small outer diameter portion 168, and a portion having a generally large inner diameter located on the rear side is large. The outer diameter portion 170 is used. The second housing member 160 is a step in which the small outer diameter portion 168 is located in the large inner diameter portion 166 of the first housing member 158 and the large outer diameter portion 170 is provided at the rear end of the large inner diameter portion 166. The first housing member 158 is integrated with the first housing member 158 in a state of being fitted into the portion.

  The first pressurizing piston 152 and the second pressurizing piston 154 each have a bottomed cylindrical shape whose rear end is closed, and can slide on the small inner diameter portion 164 of the first housing member 158. It is fitted. The first pressure piston 152 is disposed behind the second pressure piston 154. A first pressurizing chamber for pressurizing hydraulic fluid supplied to the brake devices 56RL and RR provided on the two rear wheels between the second pressurizing piston 154 and the front of the first pressurizing piston 152. R1 is partitioned and the second pressurizing chamber R2 for pressurizing the hydraulic fluid supplied to the brake devices 56FL and FR provided on the two front wheels is provided in front of the second pressurizing piston 154. Is partitioned. In the first pressurizing chamber R1 and the second pressurizing chamber R2, compression coil springs (hereinafter sometimes referred to as “return springs”) 172 and 174 are arranged, respectively. The first pressurizing piston 152 and the second pressurizing piston 154 are biased toward the rear while being biased in the direction in which they are separated from each other.

  The input piston 156 has a cylindrical cylindrical portion 176 and a closing portion 178 that closes the front of the cylindrical portion 176. Further, a flange 180 is formed on the input piston 156 on the outer periphery of the rear end of the cylindrical portion 176. The input piston 156 is fitted with a seal 182 on the front outer peripheral surface, a seal 184 on the outer periphery of the flange 180, and a seal 186 on the rear end of the inner peripheral surface. It is installed. Specifically, in the input piston 156, the seal 182 is in sliding contact with the inner peripheral surface of the small inner diameter portion 164 of the first housing member 158, the seal 184 is in sliding contact with the inner peripheral surface of the large inner diameter portion 166, and the seal 186 is (2) The housing member 160 is fitted in the housing 150 in a state of being in sliding contact with the outer peripheral surface of the small outer diameter portion 168. In this state, the small outer diameter portion 168 of the second housing member 160 is inserted into the cylindrical portion 176 of the input piston 156 as a cylindrical portion. Therefore, the cylindrical portion 176 of the input piston 156 is sandwiched between the inner peripheral surface of the large inner diameter portion 166 of the first housing member 158 and the outer peripheral surface of the small outer diameter portion 168 of the second housing member 160. Yes.

  With the master cylinder device 50 configured as described above, two liquid chambers into which the pressure from the high pressure source device 58 is input are formed in the master cylinder device 50. One is a liquid chamber (hereinafter sometimes referred to as “first input chamber”) R3 defined between the rear end surface of the first pressure piston 152 and the front end surface of the input piston 156, and the other is , A liquid chamber defined between the rear end surface of the flange 180 of the input piston 156 and the step surface formed at the boundary between the small outer diameter portion 168 and the large outer diameter portion 170 of the second housing member 160 ( Hereinafter, it may be referred to as “second input chamber”) R4. Incidentally, the second input chamber R4 is shown in a substantially collapsed state in FIG.

  The input piston 156 has a first pressure receiving area, that is, a pressure receiving area of the front end surface on which the pressure of the hydraulic fluid in the first input chamber R3 acts, and a second pressure receiving area, that is, the hydraulic fluid in the second input chamber R4. It is formed so that the pressure receiving area of the rear end face of the flange 180 on which the pressure acts is substantially equal. Further, an annular liquid chamber (hereinafter referred to as “a”) is formed between the front end surface of the flange 180 of the input piston 156 and the step surface formed at the boundary between the small inner diameter portion 164 and the large inner diameter portion 166 of the first housing member 158. R5 is defined as a compartment.

  Behind the closing portion 178 of the input piston 156, the operation rod 72 is provided so that the operating force of the brake pedal 70 is transmitted to the input piston 156 and the input piston 156 is advanced and retracted according to the operation amount of the brake pedal 70. The front end is connected. The input piston 156 is restricted from retreating by the hook 180 being locked on the step surface of the second housing member 160. The operation rod 72 is provided with a disk-shaped spring seat 188, and a compression coil spring (hereinafter referred to as “return spring”) may be provided between the spring seat 188 and the second housing member 160. 190) is disposed, and the operation rod 72 is urged rearward by the return spring 190.

  The first pressurizing chamber R1 communicates with a liquid passage 80 connected to the antilock device 54 via a communication hole 200 whose opening serves as an output port, and a communication hole 202 provided in the first pressurizing piston 152 and The opening can communicate with the reservoir 62 through a communication hole 204 serving as a drain port. On the other hand, the second pressurizing chamber R2 communicates with a liquid passage 82 connected to the antilock device 54 via a communication hole 206 whose opening serves as an output port, and a communication hole provided in the second pressurizing piston 154. 208 and a communication hole 210 whose opening serves as a drain port can communicate with the reservoir 62.

  The inner diameter of the first housing member 158 is slightly larger than the outer diameter of the first pressurizing piston 152 in the portion where the rear portion of the first pressurizing piston 152 is located. Therefore, a liquid passage 212 having a certain flow path area and connected to the first input chamber R3 is formed between the inner peripheral surface of the first housing member 158 and the outer peripheral surface of the first pressurizing piston 152. Yes. The first housing member 158 has a communication hole 214 having one end opened to the outside and the other end opened to the liquid passage 212. Therefore, the first input chamber R3 communicates with the outside via the liquid passage 212 and the communication hole 214. The first housing member 158 has a communication hole 216 having one end opened to the outside and the other end opened to the second input chamber R4. Therefore, the second input chamber R4 communicates with the outside through the communication hole 216. Further, the first housing member 158 is formed with a communication hole 218 having one end opened to the outside and the other end opened to the reaction force chamber R5. Therefore, the reaction force chamber R5 communicates with the outside through the communication hole 218.

  In the master cylinder device 50 in which the communication hole and the liquid passage are formed in this way, one end of the communication hole 214 is connected to the pressure increasing / reducing device 60, specifically, the third liquid chamber 134 of the pressure regulating valve device 100. The other end of the passage 220 is connected. In addition, one end of a liquid passage branched from the communication passage 220 is connected to the communication hole 216. That is, the first input pressure R3 and the second input chamber R4 communicate with each other through the communication path 220. Accordingly, the hydraulic fluid having the pressure adjusted by the pressure regulating valve device 100 is input to the first input chamber R3 and the second input chamber R4. An input pressure sensor [Pi] 224 for detecting the pressure of the hydraulic fluid in the first input chamber R3 is provided in the middle of the communication path 220.

  The other end of the external communication path 226 whose one end is connected to the reservoir 62 is connected to the communication hole 218. An electromagnetic on-off valve 228 is provided in the middle of the external communication path 226 so that the reaction force chamber R5 can communicate with the reservoir 62. Note that the on-off valve 228 is a normally open valve that is opened in a non-excited state, and is normally closed. Thus, in the master cylinder device 50, the reaction force chamber communication passage is formed including the external communication passage 226, and the reaction force chamber R5 is used as a low pressure source including the external communication passage 226 and the on-off valve 228. A reaction force chamber opener for opening is configured. Further, a reaction force generator 250 through which hydraulic fluid in the reaction force chamber R5 flows in and out is provided between the communication hole 218 of the external communication path 226 and the on-off valve 228.

  FIG. 4 is a cross-sectional view of the reaction force generator 250. The reaction force generator 250 includes a housing 252 that is a housing, and a piston 254 and a compression coil spring 256 disposed inside the housing 252. The housing 252 has a cylindrical shape with both ends closed. The piston 254 has a disc shape and is slidably disposed on the inner peripheral surface of the housing 252. One end of the spring 256 is supported on the inner bottom surface of the housing 252, and the other end is supported on one end surface of the piston 254. Therefore, the piston 254 is elastically supported on the housing 252 by the spring 256. An accumulator chamber R6 is defined in the housing 252 by the other end face of the piston 254 and the housing 252. That is, the hydraulic fluid in the pressure accumulation chamber R6 is elastically pressurized by the spring 256, and the reaction force generator 250 functions as a pressure mechanism that elastically pressurizes the hydraulic fluid in the pressure accumulation chamber R6. The housing 252 is provided with a communication hole 258 having one end opened to the pressure accumulation chamber R6 and the other end serving as a connection port. A liquid passage branched from the external communication passage 226 is connected to the connection port of the communication hole 258. Therefore, the pressure accumulation chamber R6 communicates with the reaction force chamber R5, and the hydraulic fluid in the reaction force chamber R5 can be elastically pressurized by the compression coil spring 256. Therefore, it can be considered that a reaction force application mechanism that includes the reaction force generator 250 and the reaction force chamber R5 and applies an elastic reaction force to the advance of the input piston 156 is configured. The mechanism can be considered as a constituent element of a stroke simulator that allows the driver to perform a brake operation and generates a reaction force to the operation.

  The reaction force generation mechanism 250 employed in the master cylinder device 50 may be a so-called diaphragm type reaction force generation mechanism. That is, it is also possible to employ a reaction force generating mechanism in which the pressure accumulating chamber R6 is partitioned by a diaphragm instead of the piston 254, and the hydraulic fluid is pressurized by the pressurizing mechanism through the diaphragm.

≪Operation of master cylinder device≫
The operation of the master cylinder device 50 will be described below. At normal time, that is, when the hydraulic brake system 40 can operate normally, the on-off valve 228 is energized and closed. Therefore, when the driver depresses the brake pedal 70 and the input piston 156 moves forward by the operating force, the hydraulic fluid in the reaction force chamber R5 flows into the pressure accumulation chamber R6 of the reaction force generator 250. Since the volume of the pressure accumulating chamber R6 increases with the advance, the elastic force of the spring 256 increases. That is, the pressure of the hydraulic fluid in the pressure accumulation chamber R6 and the reaction force chamber R5 increases. The pressure of the hydraulic fluid acts on the flange 180 of the input piston 156 and becomes an operation reaction force against the forward movement of the input piston 156, that is, the brake operation. Therefore, the reaction force generator 250 can pressurize the working fluid in the reaction force chamber R5, and the reaction force application mechanism that applies the reaction force to the force that causes the input piston 156 to move backward, that is, the brake operation. It is said that.

  When the input piston 156 moves as described above, the input piston 156 has the first pressure receiving area and the second pressure receiving area substantially equal to each other. The rearward biasing force acting on the piston 156 and the forward biasing force are balanced. Therefore, the input piston 156 is hardly moved depending on the pressure of the hydraulic fluid in the first input chamber R3 and the pressure of the hydraulic fluid in the second input chamber R4. Therefore, the operating force is not used for pressurizing the hydraulic fluid in the first pressurizing chamber R1 and the second pressurizing chamber R2, but exclusively used for generating the elastic reaction force in the reaction force generator 250. Therefore, the driver feels almost only the elastic reaction force as the operation reaction force. Further, since the hydraulic fluid in the first input chamber R3 and the hydraulic fluid in the second input chamber R4 communicate with each other via the communication path 220, the volume change of the first input chamber R3 is caused when the input piston 156 moves. The volume change of the second input chamber R4 is substantially the same. That is, the amount of hydraulic fluid flowing out from one input chamber is substantially equal to the amount of hydraulic fluid flowing into the other input chamber. Therefore, when the input piston 156 moves, the volume of each input chamber changes while the hydraulic fluid moves between the two input chambers.

  In order to generate the hydraulic braking force during the braking operation, the hydraulic fluid from the high pressure source device 58 may be input to the first input chamber R3. As described above, in the vehicle in which the master cylinder device 50 is mounted, a braking force is generated by the regenerative brake. Therefore, when the target braking force exceeds the regenerative braking force, the target hydraulic braking force is determined and the target hydraulic pressure control is performed. According to the power, the pressure of the hydraulic fluid from the high pressure source device 58 is adjusted by the pressure increasing / decreasing device 60, and the hydraulic fluid having the adjusted pressure is introduced into the first input chamber R3. In the master cylinder device 50, the first pressurizing piston 152 moves forward to pressurize the working fluid in the first pressurizing chamber R1 solely depending on the pressure of the working fluid, and depending on the pressure of the working fluid, The second pressurizing piston 154 also moves forward to pressurize the hydraulic fluid in the second pressurizing chamber R2. Pressurized hydraulic fluid is supplied to each brake device 56 via the antilock device 54, and a hydraulic braking force is generated in each brake device 56. The brake ECU 38 monitors the detected value of the input pressure sensor 224, and the pressure increasing / decreasing device 60 is controlled so that the detected value becomes the input pressure corresponding to the target hydraulic braking force.

  Next, the operation of the master cylinder device 50 in a situation where electric power is not supplied to the hydraulic brake system 40 due to electrical failure will be described. In the case of an electrical failure, the hydraulic pump 90 of the high pressure source device 60 cannot operate, and the pressure increasing linear valve 102 and the pressure reducing linear valve 104 of the pressure increasing and decreasing device 60 cannot be operated. However, if the front end surface of the input piston 156 contacts the rear end surface of the first pressurizing piston 152, the first pressurizing piston 152 can be advanced depending on the operating force. Therefore, the master cylinder device 50 can pressurize the hydraulic fluid in the pressurizing chambers R1 and R2 solely depending on the operating force. In the case of electrical failure, the on-off valve 228 is opened without being excited. That is, since the reaction force chamber R5 communicates with the reservoir 62, the reaction force generator 250 cannot generate an operation reaction force for the brake operation by the driver. Therefore, since the operating force is not used for pressurizing the hydraulic fluid in the reaction force chamber R5 and the pressure accumulating chamber R6, the operating force is effectively used for pressurizing the hydraulic fluid in the pressurizing chambers R1 and R2. Therefore, a relatively large hydraulic braking force can be generated depending on the operating force. In addition, when pressurizing the hydraulic fluid in the pressurizing chambers R1 and R2 by the operating force, the driver may actually feel the reaction force due to the pressure of the hydraulic fluid in the pressurizing chambers R1 and R2 as the operating reaction force. it can. Further, even when the hydraulic fluid is pressurized by the operating force in this way, as described above, the pressure regulating valve device 100 can be operated using the output pressure as the pilot pressure. Therefore, when the hydraulic fluid whose pressure has been increased remains in the accumulator 92, the pressure regulating valve device 100 can be operated to regulate the hydraulic fluid, and the master cylinder device 50 includes a pressure regulating valve device. The hydraulic fluid having the pressure adjusted by 100 is supplied.

  In addition, when the input piston 156 advances while being in contact with the first pressurizing piston 152 in this way, the input piston 156 is in the most advanced state. In this state, the seal 186 advances to a position where it comes into sliding contact with the outer peripheral surface near the front end of the small outer diameter portion 168 of the second housing member 160. Accordingly, the axial length of the small outer diameter portion 168 of the second housing member 160 is the maximum stroke of the input piston 156, that is, the position of the seal 186 when the brake operation is not performed, and the input piston depending on the brake operation. The length is slightly longer than the difference from the position of the seal 186 in the state where 156 is most advanced. That is, in the master cylinder device 50, the length of the small outer diameter portion 168 of the second housing member 160 is relatively short. Further, in the movement of the input piston 156, the length in the axial direction of the cylindrical portion 176 into which the small outer diameter portion 168 enters and exits is approximately the same as the length of the small outer diameter portion 168. It is relatively short. As a result, the overall length of the master cylinder device 50 is considerably shortened.

  Further, in the master cylinder device 50, even when the input piston 156 is located at the rearmost position, the input piston 156 does not have a portion that extends rearward beyond the second input chamber R4. The total length of the input piston 156 is relatively short. For this reason, the overall length of the master cylinder device 50 is also considerably shortened.

50: Master cylinder device 56: Brake device 58: High pressure source device (high pressure source) 62: Reservoir (low pressure source) 70: Brake pedal (brake operating member) 152: First pressure piston (pressure piston) 156: Input piston 158: First housing member (housing main body) 164: Small inner diameter part (front small diameter part) 166: Large inner diameter part (rear large diameter part) 168: Small outer diameter part (inner cylinder) 176: Cylindrical part (cylindrical part) 178 : Closure part 180: 鍔 186: Seal 226: External communication path (reaction force chamber communication path) 228: Electromagnetic on-off valve 250: Reaction force generator (pressurization mechanism) 256: Compression coil spring (pressurization mechanism) R1: First pressurizing chamber (pressurizing chamber) R3: first input chamber (first input chamber) R4: second input chamber (second input chamber) R5: reaction force chamber (reaction force applying mechanism) R6: pressure accumulation Room

Claims (4)

A master cylinder device for supplying pressurized hydraulic fluid to a brake device that is provided on a wheel and operates by the pressure of the hydraulic fluid,
A cylindrical housing body whose front side is closed;
A pressurizing piston disposed in the housing body such that a pressurizing chamber for pressurizing the hydraulic fluid supplied to the brake device is partitioned in front of itself;
A tubular portion having a tubular shape and a closed portion that closes the front side of the tubular portion, disposed in the housing body behind the pressure piston, and connected to a brake operation member at the closed portion; Input piston,
An inner cylinder that is inserted into the cylinder portion of the input piston and is fixed to the housing main body at the rear end portion thereof and constitutes a housing of the master cylinder device together with the housing main body;
A reaction force applying mechanism that applies an elastic reaction force to the advance of the input piston, and
A first input chamber into which hydraulic fluid from a high pressure source is input between the pressure piston and the input piston is the input between the inner peripheral surface of the housing body and the outer peripheral surface of the inner cylinder. Second input chambers into which hydraulic fluid from the high pressure source is input are respectively defined behind the rear end of the cylindrical portion of the piston,
A rearward biasing force with respect to the input piston that depends on the pressure of the hydraulic fluid in the first input chamber and a forward biasing force with respect to the input piston that depends on the pressure of the hydraulic fluid in the second input chamber. Master cylinder device configured to balance. In the master cylinder device,
The inner peripheral surface of the cylindrical portion of the input piston is in sliding contact with the outer peripheral surface of the inner cylinder through a seal, and the seal is fitted to the rear end of the inner peripheral surface of the cylindrical portion of the input piston. The master cylinder device according to 1. The housing body has a front small diameter portion that is positioned on the front side and the inner diameter is reduced, and a rear large diameter portion that is positioned on the rear side and the inner diameter is increased,
The input piston has a flange on the outer periphery of the rear end of the cylindrical portion;
The closed portion is positioned at the front small-diameter portion, and the rod is positioned at the rear large-diameter portion, whereby the second input chamber is partitioned behind the rod and filled with the hydraulic fluid in front of the rod. The reaction force chamber is divided,
The master cylinder device has a pressure accumulating chamber that communicates with the reaction force chamber and is filled with the working fluid, and includes a pressurizing mechanism that elastically pressurizes the working fluid in the accumulating chamber,
The master cylinder device according to claim 1 or 2, wherein the reaction force applying mechanism includes the reaction force chamber and a pressurizing mechanism.   The master cylinder device according to claim 3, further comprising a reaction force chamber opener for releasing the reaction force chamber to a low pressure source.

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