JP2010202063A - Brake device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an increase of distortion on a side of an inner periphery of an elastic body of a stroke simulator, even if operation force of a brake operation member becomes larger, and to prevent lowering of operation feeling, in a brake device for a vehicle including a stroke simulator constituted to store the elastic body in a control piston and to insert a guide shaft into the elastic body. <P>SOLUTION: The elastic body 127 is formed so that at least a part of an inner peripheral surface may be a tapered surface 127b in a non-operated state of load. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention has a cylindrical control piston that operates so that the reaction force based on the hydraulic pressure of the boosted hydraulic pressure chamber facing the back of the master piston provided in the master cylinder and the brake operation input from the brake operation member are balanced. A brake operation member is provided between the brake operation member and a hydraulic pressure booster that adjusts the hydraulic pressure of the hydraulic pressure generation source to act on the boost hydraulic chamber in response to the axial movement of the control piston. A stroke simulator is provided for obtaining a feeling of the operation stroke, and the stroke simulator is connected to the brake operation member and accommodated in the control piston so as to be slidable in the axial direction, and accompanying the forward movement of the simulator piston A cylinder to elastically contact the inner periphery of the control piston by bending according to the action of the axial compression force And an elastic body that is interposed between the simulator piston and the control piston and is accommodated in the control piston, and guides the axial movement of the simulator piston in the control piston and the elastic body. The present invention relates to a vehicle brake device including a guide shaft that is inserted into the elastic body so as to restrict bending inward in the radial direction.

  Patent Document 1 discloses a vehicle brake device including a stroke simulator in which a cylindrical elastic body having an inner diameter and an outer diameter that are constant over the entire axial length is accommodated in a control piston, and a guide shaft is inserted into the elastic body. Is known.

JP 2006-282012 A

  However, in the one disclosed in Patent Document 1, the elastic body is formed in a cylindrical shape whose inner diameter and outer diameter are constant over the entire length in the axial direction, and the elastic body is compressed in accordance with the operation of the brake operation member. When the operating force of the brake operating member is increased in the process, the distortion is increased on the inner peripheral side of the elastic body pressed against the guide shaft, and the operation feeling may be reduced.

  The present invention has been made in view of the above circumstances, and prevents an increase in distortion on the inner peripheral side of the elastic body of the stroke simulator even when the operation force of the brake operation member is increased, and the operation feeling is reduced. It is an object of the present invention to provide a vehicular brake device that does not have to be performed.

  In order to achieve the above object, the present invention operates so that the reaction force based on the hydraulic pressure of the boosted hydraulic pressure chamber facing the back of the master piston provided in the master cylinder and the brake operation input from the brake operation member are balanced. A hydraulic booster having a cylindrical control piston and adjusting the hydraulic pressure of a hydraulic pressure generation source to act on the boost hydraulic chamber in response to the axial movement of the control piston; and the brake operating member A stroke simulator for obtaining a feeling of operation stroke of the brake operation member is provided, and the stroke simulator is connected to the brake operation member and accommodated in the control piston so as to be axially slidable, The control piston is bent by bending according to the action of the axial compression force accompanying the forward movement of the simulator piston. An elastic body that is formed in a cylindrical shape so as to be elastically contacted with the periphery and is interposed between the simulator piston and the control piston and is accommodated in the control piston; and the simulator piston in the control piston A vehicular brake device comprising: a guide shaft inserted into the elastic body so as to guide axial movement and restrict the bending of the elastic body in the radially inward direction. The first feature is that at least a part of the inner peripheral surface is a tapered surface in the non-actuated state.

  In addition to the structure of the first feature, the second feature of the present invention is that the elastic body is formed so that the entire inner peripheral surface is tapered when a load is not applied.

  The third feature of the present invention is that, in addition to the configuration of the first feature, an inner peripheral surface of the elastic body in a non-acting state of a load is composed of a cylindrical surface having the same inner diameter and the tapered surface. And

  According to the present invention, in addition to the configuration of the first feature, the tapered surface of the inner periphery of the elastic body in a non-acting state of the load changes an angle with respect to the axis of the elastic body in the middle of the axial direction. The fourth feature is to be formed as follows.

  In addition to any of the configurations of the first to fourth features, the present invention provides that at least a part of the outer peripheral surface of the elastic body has a larger diameter toward the simulator piston side in a non-acting state of a load. A fifth feature is that the outer peripheral taper surface is formed.

  According to the sixth aspect of the present invention, in addition to any one of the configurations of the first to fifth features, a part of the inner peripheral surface of the control piston is formed in a tapered shape having a smaller diameter toward the front. Features.

  Furthermore, in addition to any of the configurations of the first to sixth features, the present invention has a seventh feature that the elastic body is made of rubber.

  The brake pedal 11 according to the embodiment corresponds to the brake operation member of the present invention.

  According to the first to seventh features, since at least a part of the inner periphery of the elastic body included in the stroke simulator is tapered in a non-acting state of the load, the guide shaft can be operated even when the operating force of the brake operating member increases. It is possible to prevent an increase in distortion on the inner peripheral side of the elastic body pressed against the elastic body, to suppress a decrease in operation feeling, and to contribute to an improvement in durability.

  In particular, according to the second, third, and fourth features, the enlargement ratio of the elastic body toward the radially inward side is adjusted by selecting the shape of the inner peripheral surface of the elastic body, and the operation feeling Improvements can be made.

  In particular, according to the fifth feature, the rear outer periphery of the elastic body can be brought into early contact with the inner periphery of the control piston, and the sliding resistance can be utilized as an operation reaction force of the brake operation member. Since the filling effect in the control piston is accelerated, it is possible to improve the operation feeling in a region where the brake operation force is large.

  Furthermore, particularly according to the sixth feature, the deformation of the front portion of the elastic body can be regulated at an early stage to improve the operation feeling.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a brake hydraulic pressure system diagram illustrating an overall configuration of a vehicle brake device according to a first embodiment. It is a longitudinal cross-sectional view which shows a hydraulic pressure booster and a part of stroke simulator. It is an expanded longitudinal cross-sectional view of the pressure booster vicinity in a hydraulic booster. It is an enlarged vertical sectional view of a stroke simulator. It is a characteristic view which shows the relationship between the operation load and stroke in a stroke simulator. FIG. 5 is a cross-sectional view corresponding to FIG. 4 of the second embodiment. FIG. 5 is a cross-sectional view corresponding to FIG. 4 of Example 3. FIG. 5 is a cross-sectional view corresponding to FIG.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  The first embodiment of the present invention will be described with reference to FIGS. 1 to 5. First, in FIG. 1, a brake device for a four-wheel vehicle is input from a tandem master cylinder M and a brake pedal 11 as a brake operation member. A hydraulic pressure booster 13 that adjusts the hydraulic pressure of the hydraulic pressure generation source 12 according to the brake operating force applied to the master cylinder M, and a stroke simulator interposed between the brake pedal 11 and the hydraulic pressure booster 13. 14A.

  A casing 15 common to the master cylinder M and the hydraulic booster 13 is formed in a cylindrical shape with a bottomed cylindrical cylinder body 16 having a closed front end and an inward flange portion 17a at the rear end. A body 17 is coaxially coupled to the rear portion of the body 16, and a ring body 18, a separator 19, and a sleeve 20 that are sandwiched between the rear end of the cylinder body 16 and the body 17. The rear end of the cylinder body 16 is fluid-tightly fitted to the front portion of the body 17, the ring body 18 is fluid-tightly fitted to the body 17 and abuts against the rear end of the cylinder body 16, and the sleeve 20 is The annular step portion 21 provided at the inner peripheral intermediate portion of the body 17 is fitted to the front portion of the body 17 so that the retreat limit is restricted, and the separator 19 is sandwiched between the ring body 18 and the sleeve 20. Is done.

  The master cylinder M has a rear surface facing the boost hydraulic chamber 22 and a rear master piston 23 that is spring-biased rearward is slidably fitted to the cylinder body 16 and spring-biased rearward. The front master piston 24 disposed in front of the rear master piston 23 is slidably fitted to the cylinder body 16, and a rear output hydraulic chamber is provided between the rear master piston 23 and the front master piston 24. 25 is formed, and a front output hydraulic pressure chamber 26 is formed between the front end closing portion of the cylinder body 16 and the front master piston 24.

  The cylinder body 16 is provided with a rear output port 27 that communicates with the rear output hydraulic chamber 25 and a front output port 28 that communicates with the front output hydraulic chamber 26. Further, a rear return spring 29 for urging the rear master piston 23 rearward is provided between the rear master piston 23 and the front master piston 24 in the rear output hydraulic pressure chamber 25, so that the inside of the front output hydraulic pressure chamber 26 is reduced. Thus, between the front closed end of the cylinder body 16 and the front master piston 24, a front return spring 30 that biases the front master piston 24 rearward is contracted.

  The master cylinder M is provided with a reservoir 31, and the reservoir 31 is formed with first, second, and third liquid reservoir chambers 31a, 31b, and 31c partitioned from each other. Thus, the cylindrical rear connection tube portion 32 that communicates with the second liquid reservoir chamber 31b and the cylindrical front connection tube portion 33 that communicates with the first liquid reservoir chamber 31a are spaced upward in a direction along the axis. And is provided integrally with the cylinder body 16.

  Between the outer periphery of the rear master piston 23 and the inner surface of the cylinder body 16, a rear replenishing liquid chamber 36 communicating with the rear connecting cylinder 32 is formed in an annular shape, and replenished from the second liquid reservoir chamber 31 b of the reservoir 31. The brake fluid is supplied to the rear replenishing fluid chamber 36. A front replenishing liquid chamber 37 communicating with the inside of the front connecting cylinder 33 is formed in an annular shape between the outer periphery of the front master piston 24 and the inner surface of the cylinder body 16, and the first liquid reservoir chamber 31 a of the reservoir 31 is formed. Brake fluid replenished from the front is supplied to the front replenishing fluid chamber 37.

  The rear master piston 23 is fitted with a well-known center valve 38 for communicating between the rear output hydraulic pressure chamber 25 and the rear replenishment fluid chamber 36 when the rear master piston 23 returns to the retreat limit position. The piston 24 is provided with a conventionally known center valve 39 for communicating between the front output hydraulic pressure chamber 26 and the front replenishing fluid chamber 37 when the front master piston 24 returns to the retreat limit position.

  That is, the master cylinder M replenishes the rear master piston 23 and the front master piston 24 with brake fluid from the reservoir 31 to the rear and front output hydraulic chambers 25 and 26 when the master pistons 23 and 24 are retracted. The center valve is configured to be fitted with center valves 38 and 39 that open. Further, between the rear and front master pistons 23, 24, there is provided a maximum interval regulating means 40 for regulating the maximum interval between the master pistons 23, 24.

  The rear output port 27 of the master cylinder M is connected to the right front wheel brake B1 and the left rear wheel brake B2 via a hydraulic pressure modulator 41, and the front output port 28 connects the hydraulic pressure modulator 41 to the hydraulic pressure modulator 41. To the left front wheel brake B3 and the right rear wheel brake B4. Thus, the hydraulic pressure modulator 41 can freely control the brake hydraulic pressure output from the rear and front output ports 27 and 28 to execute anti-lock brake control at the time of brake operation, and in a non-brake operation state. This is a well-known one that can execute automatic brake control such as traction control.

  In FIG. 2, the hydraulic pressure booster 13 includes a cylindrical backup piston 44 housed in the casing 15 with its front end facing the boosted hydraulic pressure chamber 22, and a pressure increasing valve 42 and a pressure reducing valve 43. The pressure regulating valve means 45 is regulated so that the reaction force based on the hydraulic pressure in the boost hydraulic pressure chamber 22 and the brake operation input inputted from the brake pedal 11 are balanced. A first reaction force piston 47 interposed between the pressure regulating valve means 45 and the control piston 46 so as to apply a reaction force based on the hydraulic pressure of the control piston 46 and the boosted hydraulic pressure chamber 22 to the control piston 46. When the brake operation input by the brake pedal 11 becomes large, in addition to the reaction force from the first reaction force piston 47, the output hydraulic pressure of the hydraulic pressure source 12 and And a second reaction force piston 48 to the reaction force of the force the spring 77 so as to impart to the control piston 46 is interposed between the backup piston 44 and the first reaction force piston 47.

  A body 17 that constitutes a part of the casing 15 and is coaxially coupled to the rear portion of the cylinder body 16 is fitted with a rear end of the cylinder body 16, a ring body 18, a separator 19, and a sleeve 20 from the front end side. An annular stepped portion 21 is formed between the diameter hole 49 and the rear end of the large diameter hole 49 so as to be coaxially connected to the rear end of the large diameter hole 49 and to have a smaller diameter than the large diameter hole 49. The inward flange portion 17a provided in the rear end of the body 17 so as to define the rear end of the medium diameter hole 50 is formed with a small diameter hole 51 having a smaller diameter than the medium diameter hole 50. To do.

  The ring body 18 and the sleeve 20 are arranged between the rear end of the cylinder body 16 and the stepped portion 21 so as to sandwich a separator 19 having an inner diameter larger than the inner diameter of the ring body 18 and the sleeve 20. The backup piston 44 is slidably fitted to the ring body 18 and the sleeve 20 so as to be sandwiched between the large-diameter hole 49 so as to be sandwiched.

  The body 17 includes a connection port 54 that opens to the inner surface of the large-diameter hole 49 at a position corresponding to the space between the cylinder body 16 and the ring body 18 of the master cylinder M, and communicates with the boost hydraulic chamber 22. An input port 55 that opens to the inner surface of the large-diameter hole 49 at a position corresponding to 20, and an output port 56 that opens to the inner surface of the large-diameter hole 49 at the axially intermediate portion of the sleeve 20 and is connected to the connection port 54. And a release port 57 that opens to the inner surface of the front portion of the medium-diameter hole 50 are provided in order from the front, and the release port 57 is connected to the third liquid reservoir chamber 31 c of the reservoir 31.

  The fluid pressure generating source 12 is connected to the input port 55. The hydraulic pressure generation source 12 includes a pump 58 that draws up brake fluid from the third liquid reservoir chamber 31c of the reservoir 31, and an accumulator 59 that is connected to the discharge side of the pump 58. The hydraulic pressure generation source 12 is controlled according to the hydraulic pressure of the accumulator 59 detected by the pressure sensor 60, and the hydraulic pressure generation source 12 can output a high constant fluid pressure regardless of the operation of the brake pedal 11. The hydraulic pressure output from is supplied to the input port 55. A relief valve 61 is provided between the discharge side of the hydraulic pressure generation source 12 and the third liquid reservoir chamber 31 c of the reservoir 31. Thus, the hydraulic pressure path connecting the input port 55 and the connection port 54 and the relief valve 61 are provided in the body 17 in the casing 15, and the hydraulic pressure sensor 60 is also provided in the body 17.

  The front portion of the backup piston 44 is fitted to the ring body 18 in a liquid-tight and slidable manner, and the intermediate portion of the backup piston 44 is fitted in the sleeve 20 in a liquid-tight and slidable manner. Further, between the ring body 18 and the sleeve 20 of the casing 15 and the outer periphery of the backup piston 44 at a portion where the separator 19 sandwiched between the ring body 18 and the sleeve 20 is disposed, The input-side annular chamber 63 is formed so as to communicate with the input port 55, and the input-side annular chamber 63 is divided into the separator 19 disposed in the input-side annular chamber 63. A plurality of through-holes 64 are provided so as not to be present. An output-side annular chamber 65 is formed between the inner periphery of the sleeve 20 and the backup piston 44 so as to communicate with the input-side annular chamber 63 in a fluid-tight manner.

  A ring-shaped stopper 66 is in contact with the inward flange portion 17 a of the body 17, and a retainer 68 that contacts and engages with a retaining ring 67 mounted on the outer periphery of the rear end portion of the backup piston 44 from the front side. A coiled spring 69 surrounding the back half of the backup piston 44 is contracted between the sleeve 20 and the sleeve 20, and the backup piston 44 is spring-biased backward by the spring force of the spring 69. Thus, the position where the retaining ring 67 is brought into contact with the stopper 66 which is in contact with the inward flange portion 17a of the body 17 is the backward limit of the backup piston 44, and the front end of the backup piston 44 in the backward limit is doubled. While facing the hydraulic pressure chamber 22, it is in contact with the outer peripheral edge of the rear surface of the rear master piston 23 in the non-operating state over the entire circumference, and the rear master piston 23 is also in the retreat limit in this state.

  A release chamber 70 surrounding the backup piston 44 so as to accommodate the spring 69 between the sleeve 20 and the inward flange portion 17a in the body 17 so as to liquid-tightly seal with the output-side annular chamber 65. Formed.

  An inward flange portion 44a projecting radially inward is integrally provided on the inner surface of the intermediate portion in the axial direction of the backup piston 44, and the backup piston 44 has a stepped cylindrical shape in front of the inward flange portion 44a. The second reaction force piston 48 is slidably fitted, and the first reaction force piston 47 is coaxially and relatively slidably fitted to the second reaction force piston 48.

  In FIG. 3, an end wall member 71 that faces the front surface of the boosted hydraulic pressure chamber 22 is fluid-tightly fitted to the front end portion of the backup piston 44, and the outer peripheral edge portion of the end wall member 71 is seen from the front. A retaining ring 72 that contacts and engages is attached to the inner periphery of the front end of the backup piston 44. Further, the rear portion of the filter frame 73 formed into a bottomed cylindrical shape having a plurality of openings 74 in the circumferential direction is press-fitted into the front end of the second reaction force piston 48, and is inserted into the inner surface of the filter frame 73. A filter 76 is configured by providing the mesh member 75, and the second reaction force piston 48 is formed in the backup piston 44 by the spring force of the reaction force spring 77 contracted between the filter 76 and the end wall member 71. It is urged to the side that comes into contact with the facing flange 44a from the front.

  An input chamber 78 is formed in the backup piston 44 between the second reaction force piston 48 and the filter 76 and the end wall member 71, and the input chamber 78 communicates with the input-side annular chamber 63. That is, high-pressure brake fluid from the hydraulic pressure source 12 is introduced into the input chamber 78.

  An annular step 48a facing forward is provided on the inner surface of the intermediate portion of the second reaction force piston 48, and the second reaction force piston 48 is liquid-tightly fitted to the front portion of the second reaction force piston 48. A stepped cylindrical valve seat member 79 is fitted so as to abut against the stepped portion 48a, and is pressed into the front end of the second reaction force piston 48 and the stepped portion 48a. A valve seat member 79 is sandwiched therebetween. As a result, the valve seat member 79 is liquid-tightly fitted and fixed to the front portion of the second reaction force piston 48 and is supported by the backup piston 44 via the second reaction force piston 48.

  On the other hand, as shown in FIG. 2, the first reaction force piston 47 is fitted in a liquid-tight and slidable manner at the rear portion of the second reaction force piston 48. A pressure regulating chamber 80 is formed so that the back surface of the valve seat member 79 faces and the front end of the first reaction force piston 47 faces. The pressure regulating chamber 80 communicates with the output-side annular chamber 65, that is, the output port 56.

  Referring also to FIG. 4, the control piston 46 is formed in a bottomed cylindrical shape having an end wall 46 a at the front end, and has a small diameter formed by the inward flange portion 17 a at the rear end of the body 17. The backup piston 44 is coaxially inserted into the hole 51 while being slidably fitted in the hole 51. In addition, on the outer surface of the control piston 46, a regulating protrusion 46b that regulates the retreat limit of the control piston 46 by abutting and engaging with the inner peripheral edge of the inward flange portion 17a from the front side is integrally formed over the entire circumference. Projected.

  A release chamber 82 is formed between the backup piston 44 and the control piston 46 behind the inward flange portion 44a. The release chamber 82 communicates with the release chamber 70 through a communication hole 83 provided in the stopper 66. To do. That is, the release chamber 82 communicates with the third liquid reservoir chamber 31 c in the reservoir 31 through the communication hole 83, the release chamber 70 and the release port 57.

  The rear end of the first reaction force piston 47 is always in contact with the end wall 46 a of the front end of the control piston 46. 2 and 3 show a spring 84 that exerts a spring force that biases the rear end of the first reaction force piston 47 into contact with the end wall 46a of the control piston 46. The spring force of the spring 84 is set very weakly.

  Further, the second reaction force piston 48 is coaxially and integrally provided with an extension cylinder portion 48b that coaxially surrounds the rear portion of the first reaction force piston 47 and is inserted into the inner periphery of the inwardly facing flange portion 44a. In the state where the second reaction force piston 48 is in the retreat limit position in contact with the inward flange portion 44a of the backup piston 44, the rear end of the extension cylinder portion 48b of the second reaction force piston 48 is the first reaction force. It is arranged in front of the rear end of the piston 47.

  Therefore, when the control piston 46 moves forward with respect to the backup piston 44, the first reaction force piston 47 moves forward together with the control piston 46, and the rear end of the second reaction force piston 48 is controlled by an increase in brake operation input by the brake pedal 11. When the forward movement amount of the piston 46 exceeds a predetermined value, the piston 46 comes into contact with the end wall 46a at the front end of the control piston 46.

  Referring again to FIG. 3, the pressure-increasing valve 42 is first and second valve means 87 arranged in the axial direction of the control piston 46 so as to sequentially open in response to an increase in brake operation input from the brake pedal 11. 88, the seal diameter of the second valve means 88 is set larger than the seal diameter of the first valve means 87, and the second valve means 88 has a maximum flow rate from the opened first valve means 87. Configured to begin valve opening before

  The first valve means 87 includes a cylindrical sliding member 90 provided with a first valve seat 89 at the front end, and a retainer 92 that internally forms a valve chamber 91 that communicates with an input chamber 78 that communicates with the hydraulic pressure source 12. A valve body 93 slidably fitted to the retainer 92 while being able to be seated on the first valve seat 89 facing the inside of the valve chamber 91, and the valve body 93 as a first valve seat The first valve spring 94 provided between the retainer 92 and the valve body 93 while being urged so as to be seated on the 89, and the control piston 46 which can be brought into contact with the valve body 93 are connected to and coupled to the control piston 46. It is comprised with the press rod 95 inserted in the moving member 90 so that an axial direction relative movement is possible.

  The second valve means 88 slidably fits the valve member 96 provided on the sliding member 90, which is a common component with the first valve means 87, to the sliding member 90, and the second valve means 88. A stepped cylindrical valve seat member 79 provided with a valve seat 97 at the front end, the retainer 92 which is a component common to the first valve means 87, and the valve portion 96 are seated on the second valve seat 97. The second valve spring 98 provided between the retainer 92 and the sliding member 90 and a pressing rod 95 which is a common component with the first valve means 87.

  The retainer 92 is attached to the outer periphery of the front end portion of the valve seat member 79 by press fitting. In the retainer 92, a valve chamber 91 is formed to face the first valve seat 89 at the front end of the sliding member 90 and the second valve seat 97 at the front end of the valve seat member 79. The valve chamber 91 communicates with the input chamber 78 that communicates therewith.

  The valve body 93 of the first valve means 87 is formed by fixing a spherical body 100 that can be seated on the first valve seat 89 to the rear part of the slide member 99 that is slidably fitted to the front part of the retainer 92. It is. That is, the valve body 93 is slidably fitted to the retainer 92, and the first valve spring 94 is contracted between the front end portion of the retainer 92 and the slide member 99.

  The sliding member 90 includes a first valve hole 103 having a front end opened at the center of the first valve seat 89, and a diameter larger than that of the first valve hole 103. A sliding hole 104 is formed coaxially with the rear end opened. On the other hand, the valve seat member 79 has a second valve hole 105 whose front end is opened at the center of the second valve seat 97 and the second valve hole 105 having the same diameter as the second valve hole 105. A sliding hole 106 that is passed through the front end and opened at the rear end is provided coaxially, and the sliding member 90 can be moved through the second valve hole 105 coaxially and can slide in the sliding hole 106. Fitted.

  The pressing rod 95 has a front end portion disposed in the first valve hole 103 and is slidably fitted in the sliding hole 104 of the sliding member 90. The rod 95 is integrally provided with a pressing collar portion 95a that abuts the rear end of the sliding member 90 so that the sliding member 90 can be pushed and moved forward. A regulating collar 79 a that regulates the retreat limit of the pressing rod 95 by coming into contact with the collar 95 from the rear is integrally provided so as to protrude radially inward from the rear inner surface of the sliding hole 106.

  The pressing rod 95 is provided with a sliding portion 95b in sliding contact with the inner surface of the sliding hole 104 in front of the pressing flange portion 95a. The pressing rod 95 is slid in front of the sliding portion 95b. An annular chamber 107 is formed between the moving member 90 and the inner surface of the moving member 90 so as to have a small diameter.

  Thus, when the valve element 93 is pressed by the front end of the pressing rod 95 and the valve element 93 is separated from the first valve seat 89, the valve chamber 91 communicates with the annular chamber 107. Moreover, the distance between the front end of the pressing rod 95 and the valve body 93 is smaller than the distance between the rear end of the sliding member 90 and the pressing flange 95a in a state where the pressing flange 95a is in contact with the regulation step 79a. When the push rod 95 moves forward, the slide member 90 is pushed forward by the push rod portion 95a as the push rod 95 further moves forward after the valve element 93 is separated from the first valve seat 89. It will be.

  The valve portion 96 of the second valve means 88 is provided on the sliding member 90 behind the first valve seat 89, and from the seal diameter when the valve body 93 is seated on the first valve seat 89. Can also be seated on the second valve seat 97 with a large seal diameter. Thus, after the first valve means 87 is opened, the pressing rod 95 further advances and the sliding member 90 is pressed forward, whereby the valve portion 96 is separated from the second valve seat 97, and the first The two-valve means 88 is opened.

  The inner surface of the sliding hole 106 in the valve seat member 79 is provided with a plurality of flow grooves 108 that open the rear end to the rear end of the valve seat member 79. The sliding member 90 includes the annular chamber. A plurality of communication holes 109 are provided for communicating 107 with the respective flow grooves 108.

  The rear portion of the pressing rod 95 is plunged into the pressure adjusting chamber 80, and the pressing rod 95 in the pressure adjusting chamber 80 allows the brake fluid from the first and second valve means 87 and 88 to the pressure adjusting chamber 80. The disc-shaped rectifying member 110 that rectifies the circulation is fitted to the central portion of the slidable portion. Thus, the rectifying member 110 can close the opening end of the sliding hole 106 to the pressure regulating chamber 80 by contacting the surface of the valve seat member 79 facing the pressure regulating chamber 80.

  A spring receiving member 111 is press-fitted and fixed to the pressing rod 95 behind the rectifying member 110, and a spring 112 is contracted between the rectifying member 110 and the spring receiving member 111. On the other hand, as shown in FIG. 2, the front end of the first reaction force piston 47 is also plunged into the pressure regulating chamber 80 coaxially with the pressing rod 95, and the front portion of the first reaction force piston 47 and the rectifying member. A spring 84 is contracted between 110. Thus, the rectifying member 110 is urged toward the valve seat member 79 by the spring force of the springs 84 and 112. The spring force of the springs 84 and 112 is determined by the rectifying member 110. In response to the hydraulic pressure from the hydraulic pressure generating source 12 acting on the rectifying member 110 by opening the first valve means 87 in contact with the surface facing the pressure regulating chamber 80, the rectifying member 110 is moved to the valve seat. It is set to such an extent that it can be separated from the member 79.

  The pressure reducing valve 43 includes a rear end portion of the pressing rod 95 and a front end portion of the first reaction force piston 47, and the first reaction force piston 47 includes a rear end portion of the pressing rod 95. Valve hole 113 opened at the front end of the first reaction force piston 47 so as to close when it contacts the front end portion of the first reaction force piston 47, and the front end is formed with a larger diameter than the valve hole 113. A release path 114 that extends through the hole 113 and extends to the rear end of the first reaction force piston 47 is provided coaxially. An end wall 46 a at the front end of the control piston 46 is formed at the rear end of the first reaction force piston 47. Since it always contacts, the rear end of the release path 114 is substantially closed.

  As shown in FIG. 4, a plurality of communication holes 115... That allow the inner end of the first reaction force piston 47 to pass through the inner end of the release path 114 are provided, and the pressure reducing valve 43 is connected to the pressing rod 95. When the valve end 113 is opened by separating the rear end portion from the front end portion of the first reaction force piston 47, the hydraulic fluid from the release passage 114 causes the communication hole 115, the primary storage chamber 116 and the orifice 117 to pass through. Through the release chamber 82.

  The primary storage chamber 116 is formed between the first and second reaction force pistons 47, 48, and has an annular step 47 b provided on the outer periphery of the first reaction force piston 47 facing the rear side, A ring-shaped step portion 48 c provided on the inner periphery of the second reaction force piston 48 facing the front side so as to face the step portion 47 b is formed in an annular shape surrounding the first reaction force piston 47. In addition, the communication holes 115 are provided in the first reaction force piston 47 so as to be at a position corresponding to the primary storage chamber 116 at least when the pressure reducing valve 43 starts to open from the closed state.

  The orifice 117 is formed between the outer periphery of the rear portion of the first reaction force piston 47 and the inner periphery of the extension cylinder portion 48b of the second reaction force piston 48, and the rear portion of the first reaction force piston 47. The orifice 117 is formed by setting an annular gap corresponding to the diameter difference between the outer periphery and the inner periphery of the extension cylinder portion 48b.

  In such a hydraulic booster 13, a brake operation input from the brake pedal 11 is input to the control piston 46 via the stroke simulator 14 </ b> A, and a forward pressing force is applied from the control piston 46 to the first reaction force piston 47. Works. Thus, when the movement amount of the control piston 46 in the forward direction relative to the backup piston 44 is less than a predetermined value, only the first reaction force piston 47 is in contact with the control piston 46, and the first reaction force piston 47 advances. Accordingly, the pressure reducing valve 43 is closed, the pressure regulating chamber 80 and the release chamber 82 are shut off, and the control piston 46, the first reaction force piston 47, and the pressing rod 95 are further advanced. In response to the forward movement of the pressing rod 95, in the pressure increasing valve 42, the first valve means 87 is first opened, and then the second valve means 88 is opened.

  In the closed state of the pressure reducing valve 43, the hydraulic pressure in the pressure regulating chamber 80 acts on the front end of the first reaction force piston 47, and is based on the brake operation input from the brake pedal 11 and the hydraulic pressure in the pressure regulating chamber 80. The first reaction force piston 47 and the control piston 46 are moved backward so as to balance the fluid pressure, whereby the pressure reducing valve 43 is opened and the pressure increasing valve 42 is closed, and the pressure increasing valve 42 and the pressure reducing valve 43 are opened and closed. By repeating the above, the output hydraulic pressure of the hydraulic pressure generating source 12 is adjusted to the boost hydraulic pressure corresponding to the brake operation input from the brake pedal 11 and acts on the pressure adjusting chamber 80. When the amount of movement of the control piston 46 in the forward direction with respect to the backup piston 44 exceeds a predetermined value, not only the first reaction force piston 47 but also the second reaction force piston 48 comes into contact with the control piston 46, and the input chamber The hydraulic pressure that presses the second reaction force piston 48 backward by the hydraulic pressure 78 and the spring force of the reaction force spring 77 are also added as reaction forces, so that the reaction force acting on the control piston 46 increases.

  Referring to FIG. 4, the stroke simulator 14 </ b> A is fitted with the control piston 46 in a fluid-tight and axially slidable manner by forming a stroke liquid chamber 121 between the front end wall 46 a of the control piston 46. Simulator piston 122, and a resilient means 123 accommodated in the stroke liquid chamber 121 so as to be interposed between the simulator piston 122 and the end wall 46a of the control piston 46, and are incorporated in the control piston 46. The

  The simulator piston 122 is slidably fitted to the rear part of the control piston 46 so that the retreat limit position is regulated by a retaining ring 124 attached to the rear end part of the control piston 46, and continues to the brake pedal 11. A front end portion of the input rod 125 as an input member is connected to the simulator piston 122 so as to be able to swing. That is, a brake operating force corresponding to the operation of the brake pedal 11 is input to the simulator piston 122 via the input rod 125, and the simulator piston 122 moves forward in response to the input of the brake operating force. In addition, an annular seal member 126 slidably contacting the inner periphery of the control piston 46 is mounted on the outer periphery of the simulator piston 122.

  The elastic means 123 includes an elastic body 127 formed in a cylindrical shape by an elastic material such as rubber, and a metal coil spring 128 having a spring load set smaller than that of the elastic body 127 so that the control piston 46 can slide. An elastic body 127 is interposed between the slide member 129 and the simulator piston 122, and a coil spring 128 is connected to the end wall 46 a at the front end of the control piston 46 and the elastic member 127. It is interposed between the slide members 129.

  In addition, the elastic body 127 and the coil spring 128 exert a spring force exerted by the coil spring 128 on the control piston 46 at the initial stage of brake operation of the brake pedal 11, and the slide member 129 contacts the end wall 46 a at the front end of the control piston 46. What is interposed in series between the simulator piston 122 and the control piston 46 so that the elastic deformation of the elastic body 127 is started after the action of the spring force of the coil spring 128 on the control piston 46 is completed by contact. It is.

  The set load of the coil spring 128 is set to be smaller than the set load of other spring members connected in series with the coil spring 128 so as to exert a spring force in the front-rear direction. Is set smaller than the set load of the spring 84 connected in series to the coil spring 128 via the first reaction force piston 47 and the end wall 46 a of the control piston 46 and accommodated in the pressure regulating chamber 80.

  The front end portion of the guide shaft 130 that is coaxial with the control piston 46 and passes through the elastic body 127 is press-fitted into the center portion of the slide member 129, and the rear end portion of the guide shaft 130 slides on the simulator piston 122. Can be fitted. That is, in the central portion of the simulator piston 122, a slide hole 131 that allows the rear end portion of the guide shaft 130 to be slidably fitted, and a rear portion of the slide hole 131 that is formed to have a larger diameter than the slide hole 131. A bottomed hole 132 having a front end connected to the bottom and a closed rear end is provided coaxially, and the rear end portion of the guide shaft 130 allows the simulator piston 122 to move forward relative to the guide shaft 130. Accordingly, it is inserted into the bottomed hole 132.

  The front end wall 46a of the control piston 46 has a plurality of openings 133 that communicate with the stroke liquid chamber 121 with the release chamber 82 facing the front surface of the end wall 46a. The stroke liquid chamber 121 in the control piston 46 communicates with the release chamber 82 when the opening 133 is opened.

  Each of the openings 133 is closed by a seal stopper 135 that is fixed to the backup piston 44 when the control piston 46 moves forward by a predetermined forward stroke or more. The retainer 136 is fixed to the backup piston 44 so as to be in contact with the inward flange portion 44a by being press-fitted into the inner periphery of the inner periphery of the shaft, and an elastic seal member 137 is held by the retainer 136.

  The retainer 136 is formed in a ring shape from a rigid material such as metal, and the backup piston 44 is formed so as to form an annular minute gap between the extension cylinder portion 48 b of the second reaction force piston 48. It is press-fitted into.

  The elastic seal members 137 are formed so as to close the openings 133 by contacting the front surface of the end wall 46a inside and outside the openings 133 along the radial direction of the control piston 46. It is baked and glued to.

  Further, on the back surface of the retainer 136, a communication groove 138 that allows the inner side of the retainer 136 to communicate with the outer portion of the control piston 46 in the release chamber 82 with the end wall 46 a of the control piston 46 in contact with the elastic seal member 137. Is provided.

  That is, in a state where the end wall 46a of the control piston 46 is in contact with the elastic seal member 137, the extension cylinder part 48b of the second reaction force piston 48 is also in contact with the end wall 46a, and the retainer 136 and the extension cylinder part 48b are not connected. The elastic seal member is connected to the outer portion of the control piston 46 in the release chamber 82 through the minute gap and the communication groove 138, and the end wall 46a of the control piston 46 is in contact with the elastic seal member 137. The space where the rear portion of the retainer 136 faces inward of 137 does not become negative pressure in accordance with the retreat of the control piston 46, and is maintained at atmospheric pressure.

  The control piston 46 is formed in a bottomed cylindrical shape as a tapered shape having a smaller diameter toward the front part of the inner peripheral surface. In the first embodiment, the control piston 46 is located on the front side of the simulator piston 122. A part near the front half of the control piston 46 is formed as a tapered cylindrical portion 46b having an inner peripheral surface as a tapered surface 140 as a tapered surface 140 having a smaller diameter toward the front part of the inner peripheral surface. The slide member 129 is slidably accommodated in the control piston 46 in front of the tapered surface 140.

  Further, the elastic body 127 interposed between the slide member 129 and the simulator piston 122 is elastically deformed according to the action of the axial compressive force accompanying the forward operation of the simulator piston 122 and according to the increase of the axial compressive force. It is formed in a cylindrical shape so that deformation is prevented by restraint by the control piston 46, and in a natural state where the load is in a non-acting state, at least a part of the inner peripheral surface is a tapered surface. An elastic body 127 is formed. Thus, in the first embodiment, the inner peripheral surface of the elastic body 127 in a non-acting state of load has the same inner diameter corresponding to the outer diameter of the guide shaft 130 so that the guide shaft 130 can be inserted. The elastic body 127 is formed to include a cylindrical surface 127a in the front half and a tapered surface 127b having a larger diameter away from the outer surface of the guide shaft 130 toward the rear.

  Further, at least a part of the outer peripheral surface of the elastic body 127 is formed as an outer peripheral taper surface 127c having a diameter increasing toward the simulator piston 122 in a non-acting state of the load. The elastic body 127 is formed so that the outer circumferential surface of substantially the entire length excluding a part near the rear portion of the elastic body 127 becomes the outer circumferential tapered surface 127c in a natural state in a non-acting state of the load.

  By the way, the guide shaft 130 having the simulator piston 122 supported by the rear end portion by being fitted to the simulator piston 122 is formed in a cylindrical shape having a release path 141 coaxially extending over the entire axial direction thereof. In the simulator piston 122, a plurality of passages 142 having inner ends opened in the bottomed holes 132 communicating with the release path 141 are provided in the radial direction of the simulator piston 122 in front of the portion where the seal member 126 is mounted. It is provided along. Thus, each passage 142... And the bottomed hole 132 communicate between the elastic body 127 and the control piston 46 in the stroke liquid chamber 121 to the release path 141 of the guide shaft 130.

  The slide member 129 is provided with a release path 143 coaxially connected to the front end of the release path 141. When the slide member 129 comes into contact with the end wall 46a of the front end of the control piston 46, the release path 143 becomes the end wall 46a. Are provided in the front end surface of the slide member 129 along the radial direction.

  With such a configuration, the elastic body 127 and the control piston 46 in the control piston 46 are closed until the opening 133 is closed by the seal stopper 135 when the control piston 46 moves forward and the stroke fluid chamber 121 is in the hydraulic pressure locked state. The space communicates with the release chamber 82 through a passage 142, a bottomed hole 132, release paths 141, 143, a groove 144, and an opening 133. That is, the elastic body 127 and the control piston 46 are communicated with the release chamber 82, that is, the reservoir 31 in the forward stroke of the control piston 46 until the hydraulic fluid is sealed in the control piston 46.

  Next, the operation of the first embodiment will be described. Between the hydraulic booster 13 and the brake pedal 11, a stroke simulator 14A for obtaining an operational stroke feeling of the brake pedal 11 is provided. 14 </ b> A is accommodated in a cylindrical control piston 46 constituting a part of the hydraulic booster 13 so as to be axially slidable and connected to the brake pedal 11, and accompanying the advance operation of the simulator piston 122. By bending according to the action of the axial compression force, it is formed in a cylindrical shape so as to elastically contact the inner periphery of the control piston 46 and is accommodated in the control piston 46 between the simulator piston 122 and the control piston 46. A cylindrical elastic body 127 made of rubber and a simulator piston 122 A guide shaft 130 that is inserted into the elastic body 127 so as to guide the axial direction in the control piston 46 and restrict the bending of the elastic body 127 in the radially inward direction. 127 is formed so that at least a part of the inner peripheral surface thereof becomes a tapered surface 127b when the load is inoperative. In the first embodiment, the inner periphery of the elastic body 127 in the state of non-operation of the load is formed. The surface is inserted through the guide shaft 130 so as to be separated from the front half cylindrical surface 127a having the same inner diameter corresponding to the outer diameter of the guide shaft 130 and from the outer surface of the guide shaft 130 toward the rear. An elastic body 127 is formed so as to include a tapered surface 127b having a large diameter.

  According to such a shape of the elastic body 127, even when the brake operation force by the brake pedal 11 is increased, the elastic body 127 is deformed and filled on the tapered surface 127 b side of the elastic body 127, so that it is pressed against the guide shaft 130. It is possible to prevent an increase in distortion on the inner peripheral side of the elastic body 127, to suppress a decrease in operation feeling, and to contribute to an improvement in durability.

  Here, the relationship between the stroke and the load in the stroke simulator 14A changes as shown by the solid line in FIG. 5, whereas in the conventional case where the elastic body does not have a tapered surface, 5, and the elastic body 127 exhibits the same characteristics in the elastic region where the elastic body 127 is elastically bent between the control piston 46 and the guide shaft 130, but the elastic body 127 is restrained by the control piston 46. In the filling region where deformation is prevented, there is room for the elastic body 127 to bend inward in the radial direction, thereby preventing distortion from increasing on the inner peripheral side of the elastic body 127. It is possible to increase the change in load more than that of the object, and to suppress the deterioration of the operation feeling and contribute to the improvement of durability.

  In addition, since at least a part of the outer peripheral surface of the elastic body 127 is formed as an outer peripheral taper surface 127c that increases in diameter toward the simulator piston 122 in the non-acting state of the load, the outer periphery of the rear portion of the elastic body 127 is controlled. The sliding resistance can be utilized as an operation reaction force of the brake pedal 11 at an early contact with the inner periphery of the piston 46, and the charging effect of the elastic body 127 in the control piston 46 is accelerated, so that the braking operation force is reduced. The operational feeling can be improved in a large area.

  Furthermore, since a part of the inner peripheral surface of the control piston 46 is formed in a tapered shape having a smaller diameter toward the front, the deformation of the front portion of the elastic body 127 is regulated at an early stage to improve the operation feeling. Can do.

  A second embodiment of the present invention will be described with reference to FIG. 6, but the portions corresponding to the first embodiment are only given the same reference numerals and are not illustrated in detail.

  The stroke simulator 14B includes a simulator piston 122 that forms a stroke liquid chamber 121 between the front end wall 46a of the control piston 46 and is fitted in the control piston 46 in a fluid-tight and axially slidable manner. The simulator piston 122 and the resilient means 147 accommodated in the stroke liquid chamber 121 so as to be interposed between the end wall 46 a of the control piston 46 and incorporated in the control piston 46.

  The elastic means 147 is configured such that an elastic body 148 formed in a cylindrical shape by an elastic material such as rubber and a metal coil spring 128 having a spring load set smaller than that of the elastic body 148 are slidable on the control piston 46. The elastic body 148 is interposed between the slide member 129 and the simulator piston 122, and the coil spring 128 is connected to the end wall 46 a at the front end of the control piston 46 and the elastic member 148. It is interposed between the slide members 129.

  The elastic body 148 is formed in a cylindrical shape so that the guide shaft 130 can be inserted, and in a natural state where the load is in a non-acting state, at least a part of the inner peripheral surface becomes a tapered surface. An elastic body 148 is formed. Thus, in the second embodiment, the entire inner peripheral surface of the elastic body 148 in the non-acting state of the load is tapered away from the outer surface of the guide shaft 130 as it goes rearward and becomes a tapered surface 148a. The elastic body 148 is formed so that As described above, the entire inner peripheral surface of the elastic body 148 is formed as the tapered surface 148a, thereby improving the releasability from the inner mold that forms the inner peripheral side of the elastic body 148 when the elastic body 148 is molded. This can contribute to improving the formability of the body 148.

  Further, at least a part of the outer peripheral surface of the elastic body 148 is formed as an outer peripheral taper surface 148b having a diameter that increases toward the simulator piston 122 when the load is not acting. The elastic body 148 is formed so that the outer circumferential surface of substantially the entire length excluding a part near the rear portion of the elastic body 148 becomes the outer circumferential side tapered surface 148b in a natural state in which the load is not applied.

  The effect similar to that of the first embodiment can be achieved by the second embodiment, and the shape of the inner peripheral surface of the elastic body 148 is different from that of the first embodiment, so that the elastic body 148 can move radially inward. By adjusting the enormous percentage of the image, it is possible to provide a smooth curved rising characteristic, to secure a sense of rigidity, and to increase the stroke, thereby improving the operational feeling.

  A third embodiment of the present invention will be described with reference to FIG. 7, but the portions corresponding to the first and second embodiments are indicated by the same reference numerals, and detailed description thereof will be omitted.

  The stroke simulator 14C has a stroke fluid chamber 121 formed between the front end wall 46a of the control piston 46 and is fitted to the control piston 46 in a fluid-tight and axially slidable manner. It is provided with a resilient means 150 accommodated in the stroke liquid chamber 121 so as to be interposed between the simulator piston 122 and the end wall 46 a of the control piston 46, and is built in the control piston 46.

  In the elastic means 150, an elastic body 151 formed in a cylindrical shape by an elastic material such as rubber and a metal coil spring 128 having a spring load set smaller than that of the elastic body 151 are slidable on the control piston 46. The elastic member 151 is interposed between the slide member 129 and the simulator piston 122, and the coil spring 128 is connected to the end wall 46 a at the front end of the control piston 46 and the elastic member 151. It is interposed between the slide members 129.

  The elastic body 151 is formed in a cylindrical shape so that the guide shaft 130 can be inserted, and in a natural state where the load is in a non-acting state, at least a part of the inner peripheral surface is a tapered surface. An elastic body 151 is formed. Thus, in this third embodiment, the inner peripheral surface of the elastic body 151 in a non-acting state of the load becomes a taper surface at the front portion that becomes larger in diameter so as to be separated from the outer surface of the guide shaft 130 toward the front. 151a and an intermediate cylindrical surface 151b having the same inner diameter corresponding to the outer diameter of the guide shaft 130 so as to be inserted through the guide shaft 130 and continuing to the small diameter end of the tapered surface 151a, and a guide as it goes rearward An elastic body 151 is formed so as to be formed of a tapered surface 151c at the rear portion having a small diameter end connected to the cylindrical surface 151b so as to be separated from the outer surface of the shaft 130.

  Further, at least a part of the outer peripheral surface of the elastic body 151 is formed as an outer peripheral taper surface 151d having a diameter that increases toward the simulator piston 122 when the load is not acting. The elastic body 151 is formed so that the outer circumferential surface of substantially the entire length excluding a part near the rear portion of the elastic body 151 becomes the outer circumferential tapered surface 151d in a natural state in which the load is inactive.

  The effect similar to the said Example 1, 2 can be show | played also by this Example 3, and the radial direction of the elastic body 151 is made by making the shape of the internal peripheral surface of the elastic body 151 different from Example 1,2. By adjusting the enormous inward ratio and reducing the contact area of the small-diameter end of the elastic body 151, it is possible to feel the initial stroke and to easily adjust the braking force at the time of low pedaling force. Improvements can be made. Further, the tapered surface 151c formed on the inner circumference on the small diameter end side of the elastic body 151 serves as an insertion guide at the time of assembling, and the assembling property can be improved.

  A fourth embodiment of the present invention will be described with reference to FIG. 8, but the portions corresponding to the first to third embodiments are only denoted by the same reference numerals and are not described in detail.

  The stroke simulator 14D includes a simulator piston 122 that forms a stroke liquid chamber 121 between the front end wall 46a of the control piston 46 and is fitted to the control piston 46 in a fluid-tight and axially slidable manner, A resilient piston 153 accommodated in the stroke fluid chamber 121 so as to be interposed between the simulator piston 122 and the end wall 46 a of the control piston 46 is incorporated in the control piston 46.

  The elastic means 153 includes an elastic body 154 formed in a cylindrical shape by an elastic material such as rubber, and a metal coil spring 128 having a spring load set smaller than that of the elastic body 154 so that the control piston 46 can slide. The elastic body 154 is interposed between the slide member 129 and the simulator piston 122, and the coil spring 128 is connected to the end wall 46a at the front end of the control piston 46 and the elastic member 154. It is interposed between the slide members 129.

  The elastic body 154 is formed in a cylindrical shape so as to allow the guide shaft 130 to be inserted, and in a natural state where the load is in a non-operating state, at least a part of the inner peripheral surface is a tapered surface. An elastic body 154 is formed. Thus, in the fourth embodiment, the first half in which the inner peripheral surface of the elastic body 154 in the non-acting state of the load has the same inner diameter corresponding to the outer diameter of the guide shaft 130 so that the guide shaft 130 can be inserted therethrough. A cylindrical surface 154a of the portion, and a tapered surface 154b having a diameter that increases away from the outer surface of the guide shaft 130 toward the rear, and the tapered surface 154b has an angle with respect to the axis of the elastic body 154 in the axial direction. It is formed to change in the middle.

  Further, at least a part of the outer peripheral surface of the elastic body 154 is formed as an outer peripheral taper surface 154c having a diameter that increases toward the simulator piston 122 when the load is not acting. The elastic body 154 is formed so that the outer peripheral surface of substantially the entire length excluding a part near the rear portion of the elastic body 154 becomes the outer peripheral tapered surface 154c in a natural state in a non-acting state of the load.

  The effect similar to the said Examples 1-3 can be show | played also by this Example 4, The radial direction of the elastic body 154 is made by making the shape of the internal peripheral surface of the elastic body 154 different from Examples 1-3. The feeling of operation can be improved by adjusting the enormous ratio toward the inward side. In particular, the taper surface 154b is changed stepwise by changing the angle with respect to the axis of the elastic body 154 in the middle of the axis, thereby increasing the inflection point of the load and obtaining a smoother curved load characteristic. be able to.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

DESCRIPTION OF SYMBOLS 11 ... Brake pedal 12 which is a brake operation member ... Fluid pressure generation source 13 ... Fluid pressure booster 14A, 14B, 14C, 14D ... Stroke simulator 22 ... Boost fluid pressure chamber 23 ... Master piston 46 ... Control piston 122 ... Simulator pistons 127, 148, 151, 154 ... Elastic bodies 127a, 151b ... Cylindrical surfaces 127b, 148a, 151a, 151c, 154b ... Tapered surfaces 127c , 148b, 151d, 154c ... outer peripheral side taper surface 130 ... guide shaft M ... master cylinder

Claims (7)

  The master cylinder (M) operates so that the reaction force based on the hydraulic pressure of the boost hydraulic chamber (22) facing the back of the master piston (23) provided in the master cylinder (M) and the brake operation input from the brake operation member (11) are balanced. It has a cylindrical control piston (46) and adjusts the hydraulic pressure of the hydraulic pressure generation source (12) in response to the axial movement of the control piston (46) to increase the hydraulic pressure chamber (22). A stroke simulator (14A, 14B, 14C, 14D) for obtaining a feeling of operation stroke of the brake operation member (11) is provided between the hydraulic pressure booster (13) acting on the brake and the brake operation member (11). The stroke simulator (14A,) is connected to the brake operation member (11) and accommodated in the control piston (46) so as to be slidable in the axial direction. A cylindrical shape to flexibly contact the inner periphery of the control piston (46) by bending according to the action of the axial compression force accompanying the forward movement of the simulator piston (122) and the simulator piston (122). And an elastic body (127, 148, 151, 154) that is interposed between the simulator piston (122) and the control piston (46) and is accommodated in the control piston (46), and the simulator piston (122) guides the axial movement of the control piston (46) in the axial direction and restricts the elastic body (127, 148, 151, 154) from bending inward in the radial direction. In the vehicular brake device including a guide shaft (130) inserted into (127, 148, 151, 154), the elastic body (127, 1 8, 151, 154) is formed so that at least a part of the inner peripheral surface thereof becomes a tapered surface (127b; 148a; 151a, 151c; 154b) when the load is not applied. apparatus.   The vehicular brake device according to claim 1, wherein the elastic body (148) is formed such that the entire inner peripheral surface thereof is tapered when a load is not applied.   An inner peripheral surface of the elastic body (127, 151) in a non-acting state of a load is composed of a cylindrical surface (127a, 151b) having the same inner diameter and the tapered surface (127b, 151a, 151c). The vehicle brake device according to claim 1.   The tapered surface (154b) on the inner periphery of the elastic body (154) in a non-acting state of the load is formed so as to change the angle of the elastic body (154) with respect to the axis in the middle of the axial direction. The vehicle brake device according to claim 1.   At least a part of the outer peripheral surface of the elastic body (127, 148, 151, 154) has an outer peripheral tapered surface (127c, 148b) that becomes larger in diameter toward the simulator piston (122) in a non-acting state of the load. , 151d, 154c), the vehicle brake device according to any one of claims 1 to 4.   The vehicle brake device according to any one of claims 1 to 5, wherein a part of the inner peripheral surface of the control piston (46) is formed in a tapered shape having a smaller diameter toward the front.   The vehicle brake device according to any one of claims 1 to 6, wherein the elastic body (127, 148, 151, 154) is made of rubber.

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