JP4902701B2 - Brake device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a working fluid from being locked between a control piston and an elastic body before the advancing stroke of the control piston reaches the predetermined value by a stroke simulator, while avoiding any increase in the working cost and any complication of a structure in a vehicle brake device in which the stroke simulator is provided between the control piston of a hydraulic pressure booster and a brake operating member. <P>SOLUTION: An elastic body 127 to be molded is formed in a shape such that the circulation of working fluid is permitted from the front end to the rear end of the elastic body 127 until the advancing stroke of a control piston 46 is less than at least the predetermined value. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention has a control piston that is formed in a bottomed cylindrical shape with a front end wall at the front end, so that the reaction force based on the hydraulic pressure in the boost hydraulic chamber and the brake operation input from the brake operation member are balanced. A hydraulic pressure booster that adjusts the hydraulic pressure of the hydraulic pressure generation source to act on the boosted hydraulic pressure chamber in response to the axial movement of the control piston; and a stroke fluid chamber into which hydraulic fluid is introduced at the front end A simulator piston that is liquid-tightly and slidably fitted to the rear part of the control piston while being formed between the simulator piston, the front end wall, or the front end wall. A guide that is disposed coaxially in the control piston with the front end abutting against a slide member accommodated in the stroke liquid chamber, and whose rear portion is supported by the simulator piston so as to be relatively slidable. A shaft, and an elastic body that surrounds the guide shaft and is accommodated in the stroke fluid chamber while being interposed between the front end wall or the slide member and the simulator piston, and the control piston and the brake operation A stroke simulator provided between the members and configured to seal the hydraulic fluid in the stroke fluid chamber and prevent the simulator piston from moving forward with respect to the control piston in a forward stroke greater than a predetermined stroke of the control piston; And a brake device for a vehicle in which a master cylinder is operated according to the hydraulic pressure of the boost hydraulic chamber.

  A stroke simulator is provided between the control piston of the hydraulic booster and the brake operation member, and includes an elastic body interposed between the input piston and the control piston connected to the brake operation member, and a guide shaft that penetrates the elastic body. Patent Document 1 discloses that the hydraulic fluid introduced into the control piston is sealed in the control piston at the time of the forward stroke of the control piston more than a predetermined stroke to prevent the relative forward motion of the input piston with respect to the control piston. ing.

JP 2006-282012 A

  By the way, the elastic body is bent according to the brake operation of the brake operation member and abuts against the inner surface of the control piston, so that the relationship between the brake operation stroke and the brake operation input has hysteresis. If the hydraulic fluid is locked between the control piston and the elastic body due to the bending of the elastic body before the forward stroke reaches the predetermined stroke, a predetermined hysteresis cannot be obtained. The guide shaft and the slide member that abuts the front end portion of the guide shaft and is connected to the front end wall of the control piston are provided with a flow passage that allows the flow of the hydraulic fluid, and the forward stroke of the control piston is The hydraulic fluid is not locked between the control piston and the elastic body before the predetermined stroke is reached. Unishi to have. However, in such a structure, it is necessary to perform drilling for forming a flow path in the guide shaft and the slide member, which increases the processing cost and makes the structure complicated.

  The present invention has been made in view of such circumstances, while avoiding an increase in processing cost and complication of the structure, and before the advance stroke of the control piston reaches a predetermined stroke in the stroke simulator, between the control piston and the elastic body. It is an object of the present invention to provide a vehicular brake device in which the hydraulic fluid is not locked.

In order to achieve the above object, the present invention includes a control piston having a front end wall at the front end and formed in a bottomed cylindrical shape, and a reaction force based on the hydraulic pressure of the boost hydraulic chamber and a brake operation member. A hydraulic booster that adjusts the hydraulic pressure of the hydraulic pressure generation source to act on the boosted hydraulic pressure chamber in response to the axial movement of the control piston so that the brake operation input is balanced; A simulator piston that is fluid-tightly and slidably fitted to a rear portion of the control piston while forming a stroke fluid chamber between the front end wall and the front end wall or the front end wall The slide member housed in the stroke liquid chamber is connected to the front end portion of the slide member so as to be coaxially disposed in the control piston, and the rear portion corresponds to the simulator piston. A guide shaft that is slidably supported, and an elastic body that surrounds the guide shaft and is accommodated in the stroke liquid chamber while being interposed between the front end wall or the slide member and the simulator piston. The hydraulic fluid is provided between the control piston and the brake operation member, and the hydraulic fluid is sealed in the stroke fluid chamber in a forward stroke greater than a predetermined stroke of the control piston to prevent the simulator piston from moving forward with respect to the control piston. A vehicular brake device in which the master cylinder is operated in accordance with the hydraulic pressure of the boost hydraulic chamber, and the elastic body surrounds the guide shaft The elastic main body and the front and rear ends of the elastic main body A mold is formed so as to integrally have a pair of front and rear deformed portions formed so that the amount of bending at the initial stage of operation is larger than the amount of bending of the elastic body main portion. While the first groove is provided in the peripheral portion, the pair of front and rear irregularly shaped portions are respectively provided on the front and rear end surfaces around each of the plurality of protrusions protruding from the front and rear end surfaces of the elastic body main portion. A second groove formed, and the first groove and the second groove allow the operation from the front end to the rear end of the elastic body at least when the forward stroke of the control piston is less than the predetermined stroke. that flow passage to enable flow of the liquid is formed shall be the first feature.

According to the present invention, in addition to the configuration of the first feature, the elastic body has a through hole extending between the front end and the rear end, and the front end of the elastic body when the forward stroke of the control piston is less than the predetermined stroke. The second feature is that it is provided so as to constitute at least a part of the flow passage that enables the flow of the hydraulic fluid from the first to the rear end .

The present invention, in addition to any one of the first or second aspect, wherein the elastic member is a third feature in that it consists of rubber.

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

According to the present invention , the elastic body is molded, and the hydraulic fluid is locked between the control piston and the elastic body by the bending of the elastic body before the advance stroke of the control piston reaches the predetermined stroke. Since the elastic body is formed so as to form a flow passage for preventing the flow passage, the processing cost can be reduced compared to the conventional one in which the flow passage is formed in the guide shaft or the slide member. In addition, when the shape of the guide shaft and the front end portion of the guide shaft are in contact with the slide member connected to the front end wall of the control piston, the shape of the slide member can be simplified. In addition, the shape of the elastic body can be simplified and the elastic body can be easily molded at low cost.

In particular, the elastic body is provided at the cylindrical elastic body main part surrounding the guide shaft and the front and rear ends of the elastic body main part, and the amount of bending at the initial stage of the brake operation is the amount of bending of the elastic body main part. Since it is molded so as to have a pair of front and rear deformed shape parts formed so as to be larger than each other, in the initial load region where the brake operation load at the initial stage of brake operation is small, the shape change amount of the deformed shape part Is larger than the amount of change of the elastic body main part, it is possible to obtain a change in the characteristics of the invalid stroke and the effective stroke with a relatively small brake operation load at the initial stage of the brake operation. Therefore, the elastic body and the spring are connected in series. In the stroke simulator connected to, there is a difference in the characteristics of the transition period from the spring region to the elastic region, which may cause a sense of discomfort. It is possible to improve the initial brake operation feeling as smooth characteristic change can be obtained by Rourke and effective stroke. In addition, since the spring is not required, the number of parts can be reduced and the cost can be reduced, and the simulator characteristics by the stroke simulator can be freely changed by changing the shape of the deformed shape portion. The change is effective for adjusting the invalid stroke.

Further, the first groove is provided on the inner peripheral portion of the cylindrical elastic body main portion surrounding the guide shaft, and the pair of front and rear deformed portions protrude from the front and rear end surfaces of the elastic body main portion, respectively. And a second groove formed on each of the front and rear end surfaces around each protrusion, and the flow path is formed by the first groove and the second groove, so that the shape of the protrusion is changed. Thus, the initial characteristics can be easily changed, and the initial characteristics can be easily changed by changing the number of the protrusions. Further, by forming the second groove around each protrusion, distortion due to the deformation of the protrusion can be alleviated by letting the meat escape into the second groove, thereby further improving the operational feeling. be able to.

Brake hydraulic system diagram showing the overall configuration of the vehicle brake device of the first embodiment Longitudinal section showing part of hydraulic booster and stroke simulator Enlarged longitudinal section near the booster valve in the hydraulic booster Expanded longitudinal section of the stroke simulator Vertical section of elastic body 6 arrow view of FIG. Characteristic diagram showing the relationship between operation load and stroke in the stroke simulator Sectional drawing corresponding to FIG. 4 of Example 2 Sectional drawing corresponding to FIG. 4 of Example 3

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  A first embodiment of the present invention will be described with reference to FIGS. 1 to 7. 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 has a front end wall 46 a at the front end and is formed in a bottomed cylindrical shape, 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 front end wall 46 a of the front end of the control piston 46. Further, in the pressure regulating chamber 80, a spring 84 that exerts a spring force that biases the rear end of the first reaction force piston 47 to contact the front end wall 46 a of the control piston 46 is shown in FIGS. 2 and 3. 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 front end wall 46a of 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 holding 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 holding 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. A front end wall 46 a of 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 of only the diameter difference portion between the outer periphery and the inner periphery of the extension cylinder portion 48b.

  In such a hydraulic booster 13, when a brake operation input from the brake pedal 11 is input to the control piston 46 via the stroke simulator 14A, the first reaction force piston 47 is pushed forward from the control piston 46. Pressure acts. 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 forms a stroke liquid chamber 121 between the front end wall 46 a of the front end of the control piston 46 and is fitted in a liquid-tight and axially slidable manner at the rear part of the control piston 46. The simulator piston 122 to be combined, and a guide shaft 130 that is disposed coaxially in the control piston 46 with the front end abutting against the front end wall 46a and whose rear portion is supported by the simulator piston 122 so as to be relatively slidable. And an elastic body 127 that surrounds the guide shaft 130 and is accommodated in the stroke liquid chamber 121 while being interposed between the simulator piston 122 and the front end wall 46a of the control piston 46.

  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. The front end portion of the input rod 125 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.

  A disc portion 130 a is integrally provided at the front end portion of the guide shaft 130 so as to allow hydraulic fluid to flow between the outer periphery of the disc portion 130 a and the inner periphery of the control piston 46. The disc portion 130 a is brought into contact with the front end wall 46 a of the control piston 46. Further, a slide hole 131 in which the rear end portion of the guide shaft 130 is slidably fitted in the center portion of the simulator piston 122 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. Instead of the disc portion 130a, a disc member having a shape corresponding to the disc portion 130a may be brought into contact with the front end of the guide shaft 130.

  The front end wall 46a at the front end 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 front 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 front 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 in a state where the front end wall 46 a of the control piston 46 is in contact with the elastic seal member 137. Is provided.

  That is, in a state where the front 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 front end wall 46a, and the retainer 136 and the extension cylinder part 48b are not connected. The elastic seal member is communicated with the outer portion of the control piston 46 in the release chamber 82 through the minute gap and the communication groove 138, and the front 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 portion closer to the front half of the control piston 46 is formed as a tapered cylindrical portion 46c 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.

  Referring also to FIG. 5, the elastic body 127 is formed in a cylindrical shape by an elastic material such as rubber so as to penetrate the guide shaft 130 coaxially. It is elastically deformed according to the action of the axial compressive force accompanying the forward operation, and is prevented from being deformed by restraint by the control piston 46 according to the increase of the axial compressive force.

  Thus, in a natural state where no load is applied, the elastic body 127 includes a cylindrical elastic body main portion 127a and deformed shape portions 127b provided at both axial ends of the elastic body main portion 127a. And 127c are integrally formed. In addition, the deformed shape portions 127b and 127c are formed so that the amount of bending of the deformed shape portions 127b and 127c at the initial stage of the braking operation is larger than the amount of bending of the elastic body main portion 127a.

  Referring to FIG. 6 as well, a plurality of irregularly shaped portions 127b provided at the front end portion of the elastic body main portion 127a so as to contact the disc portion 130a at the front end portion of the guide shaft 130 are provided at a plurality of intervals. For example, four protrusions 148 are formed so as to protrude from the annular flat surface 147, and each protrusion 148 is formed in a truncated cone shape having a small diameter toward the disk portion 130a. The Further, grooves 149... Are formed in the flat surface 147 around the protrusions 148.

  The deformed portion 127c provided at the rear end portion of the elastic body main portion 127a so as to contact the simulator piston 122 has a plurality of, for example, four protrusions 151. The protrusions 151 are formed in a truncated cone shape having a small diameter toward the disk portion 130a. Further, grooves 152... Are formed on the flat surface 150 around the respective protrusions 151.

  Moreover, the elastic body 127 is a hydraulic fluid that extends from the front end to the rear end of the elastic body 127 at least in a state where the forward stroke of the control piston 46 is less than a predetermined stroke in which the stroke fluid chamber 121 is in a hydraulic pressure locked state. In order to enable the flow of the hydraulic fluid, at least one of the inner peripheral portion and the front and rear end portions of the elastic body 127 and the outer peripheral portion of the elastic body 127 circulates the hydraulic fluid from the front end to the rear end of the elastic body 127. A groove is provided so as to form a flow passage 145 that can be formed. In the first embodiment, the elastic body 127 has a plurality of grooves 146 provided on the inner peripheral portion of the elastic body 127 over the entire length in the axial direction. The flow passages 145 are formed by the grooves 149, 152, which are respectively provided at both front and rear ends.

  This flow passage 145 is a disk portion at the inner periphery of the control piston 46, the outer periphery of the guide shaft 130, and the front end of the guide shaft 130 in a filling region where deformation of the elastic body 127 is prevented by being restrained by the control piston 46. The elastic body 127 is formed so as to be closed when a filling rate of the elastic body 127, which is a ratio of the volume of the elastic body 127 to the volume of the space defined by the rear surface of the 130a and the front end surface of the simulator piston 122, is equal to or higher than a predetermined value. When closing the flow passage 145, the flow passage 145 may be closed by bringing the entire inner circumference including the grooves 146 of the elastic body 127 into close contact with the outer periphery of the guide shaft 130. At least one of the front and rear end portions of the elastic body 127 is in close contact with at least one of the front end wall 46a and the simulator piston 122. The flow passage 145 may be closed by the.

  Thus, the elastic body 127 includes the disc portion 130a of the guide shaft 130 that is in contact with the front end wall 46a of the front end of the control piston 46 when the brake pedal 11 is not operated, that is, the non-brake operated state, and the simulator piston. And 122 in a state where an axial compressive force is applied.

  By the way, in the simulator piston 122, a plurality of passages 142 having inner ends opened in the bottomed holes 132 are provided in front of a portion where the seal member 126 is mounted so as to extend along the radial direction of the simulator piston 122. It is done. As a result, the inside of the bottomed hole 132 is not pressurized or depressurized by the relative movement of the guide shaft 130 and the simulator piston 122 in the front-rear direction.

  With such a configuration, the stroke liquid chamber 121 passes through the opening 133 until the opening 133 is closed by the seal stopper 135 when the control piston 46 moves forward and the stroke liquid chamber 121 is in the hydraulic pressure locked state. And communicated with the release chamber 82.

  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 integrally formed with a cylindrical elastic body main portion 127a and deformed shape portions 127b and 127c provided at both axial ends of the elastic body main portion 127a. The deformed shape portions 127b and 127c are The bent portions 127b and 127c in the initial stage of the brake operation are formed so that the amount of bending is larger than the amount of bending of the elastic body main portion 127a.

  Therefore, in the initial load region where the brake operation load at the initial stage of the brake operation by the brake pedal 11 is small, the shape change amount of the deformed shape portions 127b and 127c is larger than the change amount of the elastic body main portion 127a. It is possible to obtain invalid stroke and effective stroke characteristics changes with a relatively small brake operation load. In a stroke simulator in which an elastic body and a spring are connected in series, the characteristics of the transition period from the spring area to the elastic body area While there may be a sense of incongruity due to the difference between the two, the initial brake operation feeling can be improved by obtaining a smooth characteristic change between the invalid stroke and the effective stroke. In addition, since the spring is not required, the number of parts and the cost can be reduced, and the simulator characteristics by the stroke simulator 14A can be freely changed by changing the shape of the deformed shape portions 127b and 127c. The change in the amount of deflection of the portions 127b and 127c is effective for adjusting the invalid stroke.

  Further, since the irregularly shaped portions 127b and 127c are formed so that the protrusions 148... 151 protrude from the flat surfaces 147 and 150, the shape of the protrusions 148. This makes it easy to change the initial characteristics. In addition, since the plurality of protrusions 148... 151 protrude from the flat surfaces 147 and 150, the initial characteristics can be easily changed by changing the number of the protrusions 148.

  Further, by forming groove-like recesses 149, 152 ... on the flat surfaces 147, 150 around the projections 148 ..., 151 ..., distortion due to deformation of the projections 148 ..., 151 ... can be reduced. It can relieve by letting meat escape in 152 ..., and can aim at the further improvement of operation feeling.

  Further, since the elastic body 127 is compressed in the axial direction when the brake pedal 11 is not operated and is interposed between the simulator piston 122 and the control piston 46, the elastic body 127 is sagned. Can also be absorbed by the irregularly shaped portions 127b and 127c.

  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.

  In addition, the elastic body 127 to be molded has a shape that allows the working fluid to flow from the front end to the rear end of the elastic body 127 at least when the forward stroke of the control piston 46 is less than the predetermined stroke. Therefore, the machining cost can be reduced and the shape of the guide shaft 130 can be simplified as compared with the conventional structure in which the flow passage is formed in the guide shaft 130.

  Here, the relationship between the stroke and the load in the stroke simulator 14A changes as shown by the solid line in FIG. 7, and the elastic body 127 moves between the control piston 46 and the guide shaft 130 as the stroke increases. The elastic body 127 enters the filling area where the elastic body 127 is restrained by the control piston 46 and is prevented from being deformed through the elastic area that is elastically bent. When the filling rate of the elastic body 127 reaches a predetermined value or more, Since the flow passage 145 is closed, the hydraulic fluid is sealed between the elastic body 127 and the control piston 46 in a part of the control piston 46 to generate an internal pressure. In the high pedaling force range of the brake pedal 11, the elastic body Stroke characteristics and stroke feeling can be improved by preventing 127 from being deformed more than necessary. That is, in the stroke simulator 14A, the effect of the elastic effect → the filling effect → the internal pressure of the control piston 46 can be exhibited stepwise to improve the stroke feeling by improving the stroke characteristics. On the other hand, in the configuration in which the flow passage 145 is not closed, the elastic body 127 may be deformed more than necessary in the high depression force region of the brake pedal 11 as shown by the dotted line in FIG.

  In addition, a plurality of grooves 146 provided in the inner peripheral portion of the elastic body 127 over the entire length in the axial direction, and the grooves 149... 152 provided in the front and rear end portions of the elastic body 127, respectively, from the front end of the elastic body 127. A flow passage 145 that allows the working fluid to reach the rear end is formed, and the grooves 146, 149, 152, can be formed simultaneously when the elastic body 127 is formed. It is not necessary to perform processing, and the shape, arrangement and number of the grooves 146... 149... 152 can be easily selected. And the predetermined value of the filling rate can be changed by changing the number.

  Further, the inner circumference of the elastic body 127 is in close contact with the outer periphery of the guide shaft 130, or at least one of the front and rear end portions of the elastic body 127 is in close contact with at least one of the front end wall 46a and the simulator piston 122. Since it closes, the special structure for closure of the flow path 145 is unnecessary, and the flow path 145 can be closed at low cost.

  A second embodiment of the present invention will be described with reference to FIG. 8, but the parts 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 front end of the control piston 46 and is fitted in a liquid-tight and axially slidable manner at the rear portion of the control piston 46. A guide shaft 130 having a front end abutting against the front end wall 46a and coaxially disposed in the control piston 46 and having a rear portion supported by the simulator piston 122 so as to be relatively slidable, the simulator piston 122, and And an elastic body 127 ′ surrounding the guide shaft 130 and being accommodated in the stroke liquid chamber 121 while being interposed between the front end walls 46 a of the control piston 46.

  Thus, in a natural state where no load is applied, the elastic body 127 'includes a cylindrical elastic body main portion 127a' and a deformed shape provided at both axial ends of the elastic body main portion 127a '. Molding is performed so as to integrally include the portions 127b and 127c.

  In addition, the elastic body 127 ′ extends from the front end to the rear end of the elastic body 127 ′ in a state where at least the forward stroke of the control piston 46 is less than a predetermined stroke in which the stroke fluid chamber 121 is hydraulically locked. In this second embodiment, the flow passage 155 that allows the working fluid to flow is formed in the elastic body main portion 127a ′ of the elastic body 127 ′ in a deformed shape. Through holes 156 configured in cooperation with the grooves 149... 152 (see the first embodiment) of the portions 127 b and 127 c are provided between the front end and the rear end of the elastic body main portion 127 a ′.

  In addition, the flow passage 155 is closed as the filling rate of the elastic body 127 exceeds a predetermined value in a filling region where the deformation of the elastic body 127 ′ is prevented by being restrained by the control piston 46. The flow passage 155 is closed by closing the through-hole 156 by deformation of the elastic body 127 ′ in a state where the outer periphery and inner periphery are restrained by the control piston 46 and the guide shaft 130. Alternatively, at least one of the front and rear end portions of the elastic body 127 ′ is closed by being in close contact with at least one of the front end wall 46 a and the simulator piston 122.

  The same effects as those of the first embodiment can be obtained by the second embodiment. In addition, since the through holes 156 can be formed simultaneously with the formation of the elastic body 127 ′, it is not necessary to process the elastic body 127 ′, and the shape, arrangement, and number of the through holes 156 can be easily selected. In addition, the stroke feeling can be improved by changing the predetermined value of the filling rate by changing the shape, arrangement, and number of the through holes 156.

  A third embodiment of the present invention will be described with reference to FIG. 9, but the portions corresponding to the first embodiment are only given the same reference numerals and are not illustrated in detail.

  The stroke simulator 14C includes a simulator piston 122 that forms a stroke liquid chamber 121 between the front end wall 46a of the front end of the control piston 46 and is fitted in a liquid-tight and axially slidable manner at the rear portion of the control piston 46. A spring 157 for bringing the front end into contact with the front end wall 46a, and a contact with the front end wall 46a of the control piston 46 through the spring 157 and in contact with the rear end of the spring 157. And a slide member 158 accommodated in the control piston 46. The slide member 158 is fitted and brought into contact with the slide member 158 so as to be coaxially disposed in the control piston 46, and the rear portion is supported by the simulator piston 122 so as to be relatively slidable. Between the cylindrical guide shaft 130 ′, the simulator piston 122 and the slide member 158 Interposed while to surround the guide shaft 130 'and an elastic member 127 accommodated in the stroke fluid chamber 121.

  According to the third embodiment, the machining cost can be reduced and the guide shaft 130 ′ and the slide member 158 can be reduced in comparison with the conventional one in which the flow path is formed in the guide shaft 130 ′ and the slide member 158. The shape of the can be simplified.

  As still another embodiment of the present invention, an elastic body is formed so that an annular gap is formed in the natural state of the elastic body between the inner peripheral portion of the elastic body housed in the control piston 46 and the guide shafts 130 and 130 '. In this case, the gap can be configured as at least a part of the flow path of the hydraulic fluid. In that case, when the flow passage is closed in accordance with the filling rate of the elastic body becoming a predetermined value or more in the filling region, the flow passage is closed by the outer periphery of the elastic body being in close contact with the inner periphery of the control piston 46. You may do it.

  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 ... Hydraulic pressure generation source 13 ... Hydraulic pressure boosters 14A, 14B, 14C ... Stroke simulator 22 ... Boost hydraulic chamber 46 ... Control Piston 46a ... front end wall 121 ... stroke fluid chamber 122 ... simulator piston 127, 127 '... elastic body 130, 130' ... guide shafts 145, 155 ... flow passages 146, 149, 152 ... groove 156 ... through hole 158 ... sliding member M ... master cylinder

Claims (3)

A control piston (46) having a front end wall (46a) at the front end and formed in a bottomed cylindrical shape, and a reaction force based on the hydraulic pressure in the boost hydraulic chamber (22) and the brake operating member (11) As the control piston (46) is operated in the axial direction so that the brake operation input of the engine is balanced, the hydraulic pressure of the hydraulic pressure generation source (12) is adjusted to act on the boost hydraulic chamber (22). A hydraulic booster (13) and a stroke fluid chamber (121) into which hydraulic fluid is introduced are formed between the front end wall (46a) and can be slid in a liquid-tight manner at the rear of the control piston (46). Is accommodated in the stroke fluid chamber (121) so as to be connected to the simulator piston (122) connected to the brake operation member (11), the front end wall (46a) or the front end wall (46a). Sula A guide shaft (130, 130) that is disposed coaxially within the control piston (46) with its front end abutting against the guide member (158) and is supported by the simulator piston (122) so as to be relatively slidable. ′), And the front end wall (46a) or the slide member (158) and the simulator piston (122), while interposing the guide shaft (130, 130 ′), the stroke liquid chamber (121 ) And is provided between the control piston (46) and the brake operation member (11) and has a forward stroke that is greater than or equal to a predetermined stroke of the control piston (46). Then, the hydraulic fluid is sealed in the stroke fluid chamber (121), and the control piston of the simulator piston (122) is sealed. A stroke simulator (14A, 14B, 14C) configured to prevent forward operation with respect to (46), and operates the master cylinder (M) according to the hydraulic pressure in the boost hydraulic chamber (22). In the vehicular brake device that is damped,
The elastic body (127, 127 ') includes a cylindrical elastic body main part (127a, 127a') surrounding the guide shaft (130, 130 ') and the elastic body main part (127a, 127a'). A pair of front and rear deformed portions (127b, 127c) provided at both front and rear ends, respectively, so that the amount of bending at the initial stage of braking operation is larger than the amount of bending of the elastic body main portion (127a, 127a '); Are molded so as to have
A first groove (146) is provided in the inner peripheral part of the elastic body main part (127a, 127a '), while the pair of front and rear deformed parts (127b, 127c) are the elastic body main part (127a, 127a). ′) A plurality of protrusions (148, 151) respectively protruding from the front and rear end faces, and second grooves (149, 152) formed on the front and rear end faces around the protrusions (148, 151), respectively. The elastic body (127, 127 ') is provided by the first groove (146) and the second groove (149, 152) at least when the advance stroke of the control piston (46) is less than the predetermined stroke. vehicle brake equipment, wherein a flow passage which allows the flow of hydraulic fluid from the front end up to the rear end (145) is formed. The elastic body (127 ′) has a through hole (156) extending between the front end and the rear end thereof. When the advance stroke of the control piston (46) is less than the predetermined stroke, the elastic body (127, 127 ′) The vehicular brake device according to claim 1, wherein the vehicular brake device is provided so as to constitute at least a part of a flow passage (155) capable of flowing hydraulic fluid from a front end to a rear end . The vehicle brake device according to claim 1 or 2 , wherein the elastic body (127, 127 ') is made of rubber.

Images