JP2012136092A - Fluid pressure booster for braking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid pressure booster for a braking device including a control piston on which an input brake operation acts in an advancing direction, and a reaction force based on fluid pressure of a booster fluid pressure generation chamber acts in a retracting direction, a pressure increasing valve provided between a valve chamber communicating with a fluid pressure generation source and the booster fluid pressure generation chamber so as to open according to the advance of the pressing rod at the time of advance of the control piston, and a pressure reducing valve provided between a release chamber communicating with a reservoir and the booster fluid pressure generation chamber so as to close at the time of advance of the control piston, while preventing abnormal noise due to abrupt fluid pressure flow when the pressure increasing valve is opened.SOLUTION: A contraction portion 140 for gradually increasing flow area depending on the movement of the pressing rod 124 to an advance side in a valve housing 97 is provided on a flow passage 135 that is formed in the valve housing 97 so as to allow the fluid pressure generation source to communicate with the booster fluid pressure generation chamber 40 when the pressure increasing valve 43 is opened.

Description

  The present invention provides a control piston in which a reaction force based on a hydraulic pressure in a boost hydraulic pressure generating chamber that generates a hydraulic pressure for operating a master piston of a master cylinder acts in a backward direction while a brake operation input acts in a forward direction; A cylindrical valve housing disposed coaxially with the axis of the control piston, and at least a pressing rod inserted coaxially into the valve housing so as to advance when the control piston moves forward; A pressure increasing valve interposed between the boosted hydraulic pressure generation chamber and the hydraulic pressure generation source so as to open when the control piston moves backward and close when the control piston moves backward; and closes when the control piston moves forward A release chamber communicating with the reservoir so as to open when the control piston is retracted, and a pressure reducing valve interposed between the boost hydraulic pressure generating chambers. About a rk device for hydraulic booster.

  A hydraulic booster for a brake device in which at least a part of the pressure increasing valve is configured to press and open the valve body with a pressing rod that moves forward in response to a brake operation input is already known from, for example, Patent Document 1 and the like. ing.

JP 2009-234525 A

  However, a large hydraulic pressure difference is generated between the hydraulic pressure generating source and the boost hydraulic pressure generating chamber at the initial stage of opening of the booster valve, and a sudden hydraulic pressure is generated based on the hydraulic pressure difference at the initial stage of opening of the booster valve. When flow occurs, the flow sound may be felt as an abnormal sound.

  The present invention has been made in view of such circumstances, and provides a hydraulic pressure booster for a brake device that can suppress the generation of abnormal noise due to a rapid hydraulic pressure flow at the initial stage of opening of the pressure increasing valve. With the goal.

  In order to achieve the above-mentioned object, the present invention is designed to reduce the reaction force based on the hydraulic pressure in the boosted hydraulic pressure generating chamber that generates the hydraulic pressure that activates the master piston of the master cylinder while the brake operation input acts in the forward direction. A control piston acting in a direction; a cylindrical valve housing arranged coaxially with the axis of the control piston, and a pressing rod inserted coaxially into the valve housing so as to advance when the control piston advances A pressure-increasing valve interposed between the boosted hydraulic pressure generation chamber and the hydraulic pressure generation source so as to open at the time of forward movement of the control piston and to close at the time of backward movement of the control piston; The valve is closed when the piston moves forward and opens when the control piston moves backward, and is interposed between the release chamber that leads to the reservoir and the boost hydraulic pressure generating chamber. A hydraulic pressure booster for a brake device comprising: a pressure reducing valve that is formed in the valve housing so that the hydraulic pressure generating source is communicated with the boosted hydraulic pressure generating chamber when the pressure increasing valve is open. A first feature is that a throttle portion is provided in the middle of the flow passage to gradually or gradually increase the flow area in accordance with the forward movement of the pressing rod in the valve housing.

  According to the present invention, in addition to the configuration of the first feature, a pressing collar portion that protrudes radially outward from the outer periphery of the pressing rod is provided on the pressing rod, and the retracting limit of the pressing rod with respect to the valve housing is reduced. A restricting flange that protrudes radially inward from the inner periphery of the valve housing so as to be restricted is provided in the valve housing so as to face the pressing flange from the rear, and the throttle portion is the restricting flange A second feature is that it is formed between the inner periphery of the press rod and the outer periphery of the pressing rod.

  According to the present invention, in addition to the configuration of the second feature, the outer diameter gradually decreases toward the outer periphery of the pressing rod at the portion corresponding to the inner periphery of the restriction rod portion toward the rear in the axial direction of the pressing rod. A third feature is that the tapered portion is formed.

  According to the present invention, in addition to the configuration of the second feature, the outer diameter of the pressing rod is gradually reduced as it goes rearward in the axial direction of the pressing rod at a portion corresponding to the inner periphery of the restriction rod portion. The fourth feature is to be formed as follows.

  Furthermore, in addition to any of the configurations of the first to fourth features, the present invention provides that the pressing rod and the valve housing are moved backward by a hydraulic pressure due to a hydraulic pressure difference before and after the throttle portion. A fifth feature is that the spring is formed to be biased.

  The rear master piston 23 of the embodiment corresponds to the master piston of the present invention.

  According to the first feature of the present invention, since the throttle portion is provided in the middle of the flow passage formed in the valve housing, the hydraulic pressure generating source and the boosted hydraulic pressure generating chamber are located at the initial stage of opening of the pressure increasing valve. Even if a large hydraulic pressure difference occurs, the flow velocity can be suppressed at the throttle portion, so that a rapid hydraulic pressure flow does not occur at the initial stage of opening of the pressure increasing valve, and the generation of abnormal noise can be suppressed. In addition, since the flow area of the throttle portion gradually or stepwise increases due to the forward movement of the pressing rod relative to the valve housing, the flow rate of the hydraulic fluid flowing through the flow passage gradually increases as the pressure rod advances in the forward direction. Or, it will increase step by step, and when the flow rate of the hydraulic fluid changes gradually, the flow rate of the hydraulic fluid is changed smoothly to prevent sudden fluctuations in the flow rate of the hydraulic fluid and suppress the generation of abnormal noise. In addition, when the flow rate of the hydraulic fluid changes in a stepwise manner, it is possible to suppress the generation of abnormal noise by suppressing the flow rate with a constant throttle degree within a predetermined range of the forward stroke of the pressing rod.

  Further, according to the second feature of the present invention, the valve housing is provided on the inner periphery of the valve housing so as to restrict the retreat limit of the pressure rod by coming into contact with the pressure lever provided on the outer periphery of the pressure rod from the rear. Since the restricting portion is formed between the inner periphery of the restricting flange and the outer periphery of the pressing rod, the restricting portion is utilized by using the restricting flange provided in the valve housing in order to restrict the retreat limit of the pressing rod. Thus, an increase in manufacturing cost due to the provision of the throttle portion can be suppressed.

  According to the third feature of the present invention, a simple configuration in which a tapered portion is formed on the outer periphery of the pressing rod at a portion corresponding to the inner periphery of the restriction rod portion, and according to the forward movement of the pressing rod with respect to the valve housing. Thus, the distribution area of the throttle portion can be gradually increased.

  According to the fourth feature of the present invention, it is a simple structure in which the outer diameter of the pressing rod is changed stepwise at the portion corresponding to the inner periphery of the restriction rod portion, and the pressing rod is moved forward with respect to the valve housing. The distribution area of the throttle portion can be increased stepwise by movement.

  Further, according to the fifth feature of the present invention, since the pressing rod is biased backward by the hydraulic pressure due to the hydraulic pressure difference before and after the throttle portion, the rapid forward movement of the pressing rod can be suppressed, and the brake operation fee can be reduced. The ring can be made good.

1 is a hydraulic system diagram showing an overall configuration of a vehicle brake device according to a first embodiment. It is a longitudinal cross-sectional view of a hydraulic pressure booster and a stroke simulator. It is an expansion longitudinal cross-sectional view of a hydraulic booster. FIG. 4 is an enlarged view of a portion indicated by an arrow 4 in FIG. 3. FIG. It is sectional drawing corresponding to FIG. 5 of 2nd Embodiment.

  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 5. First, in FIG. 1, a brake device for a four-wheel vehicle is inputted from a tandem master cylinder M and a brake pedal 11. The hydraulic pressure booster 13 adjusts the hydraulic pressure of the hydraulic pressure generation source 12 according to the brake operation force to be applied to the master cylinder M, and the stroke simulator 14 interposed between the brake pedal 11 and the hydraulic pressure booster 13. With.

  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. It is comprised with the body 17 couple | bonded coaxially with the rear part of the body 16. FIG. The rear end of the cylinder body 16 is liquid-tightly fitted to the front portion of the body 17, and the separator 18 that is liquid-tightly fitted to the body 17 is interposed between the rear end of the cylinder body 16 and the body 17. The sleeve 19 and the second sleeve 20 are sandwiched while the first sleeve 19 is sandwiched between the separator 18 and the second sleeve 20.

  A first cylinder hole 21 having a closed front end is formed in the cylinder body 16, and the master cylinder M has a rear master piston 23 that has a back surface facing the boost hydraulic pressure acting chamber 22 and is spring-biased rearward. Is slidably fitted in the first cylinder hole 21, and the front master piston 24 disposed in front of the rear master piston 23 is slidable in the first cylinder hole 21 while being spring-biased rearward. The rear output hydraulic pressure chamber 25 is formed between the rear master piston 23 and the front master piston 24, and the front output hydraulic pressure is between the front end closing portion of the cylinder body 16 and the front master piston 24. A chamber 26 is formed.

  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 chamber 25, and a cylinder is provided in the front output hydraulic chamber 26. Between the front closed end of the body 16 and the front master piston 24, a front return spring 30 that biases the front master piston 24 rearward is contracted.

  A reservoir 31 is attached to the master cylinder M. The reservoir 31 is formed by partitioning the first, second and third liquid reservoir chambers 31a, 31b and 31c. The cylindrical rear connection tube portion 32 communicating with the second liquid reservoir chamber 31b and the cylindrical front connection tube portion 33 communicating with the first liquid reservoir chamber 31a are integrally provided so as to protrude upward, The hydraulic fluid from the reservoir 31 is replenished to the rear output hydraulic pressure chamber 25 via the rear connection cylinder portion 32, and the hydraulic fluid from the reservoir 31 is replenished to the front output hydraulic pressure chamber 26 via the front connection cylinder portion 33. Is done.

  Further, the rear master piston 23 is provided with a center valve 34 which opens when the rear master piston 23 returns to the retreat limit position and returns the hydraulic fluid in the rear output hydraulic chamber 25 to the rear connecting cylinder portion 32 side. The front master piston 24 has a center valve 35 that returns the hydraulic fluid in the front output hydraulic pressure chamber 26 to the front connecting cylinder 33 side when the front master piston 24 returns to the retreat limit position. Installed. Further, between the rear and front master pistons 23, 24, a maximum interval regulating means 36 for regulating the maximum interval between the master pistons 23, 24 is provided.

  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 38, and the front output port 28 is connected to the hydraulic pressure modulator 38. To the left front wheel brake B3 and the right rear wheel brake B4. Thus, the hydraulic pressure modulator 38 can freely control the 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 booster 13 has a cylindrical backup piston 39 that is slidably accommodated in the body 17 of the casing 15 with the front end facing the boost hydraulic pressure working chamber 22, and a brake operation input in the forward direction. And a control piston 41 in which a reaction force based on a hydraulic pressure of a boost hydraulic pressure generating chamber 40 connected to the boost hydraulic pressure working chamber 22 acts in a backward direction, and according to the forward movement of the control piston 41 A pressure-increasing valve 43 provided between the valve chamber 42 and the boosted hydraulic pressure generation chamber 40 that opens and closes when the control piston 41 retreats, and communicates with the hydraulic pressure generation source 12, and the control piston 41 The release chamber 45 and the boosted hydraulic pressure generation chamber 4 communicated with the third oil reservoir chamber 31c of the reservoir 31 so as to be closed when the control piston 41 moves backward and open when the control piston 41 moves backward. A pressure reducing valve 44 interposed therebetween, a first reaction force piston 46 for applying a reaction force based on the hydraulic pressure in the boost hydraulic pressure generating chamber 40 to the control piston 41, and a brake operation input by the brake pedal 11 are provided. In addition to the reaction force from the first reaction force piston 46, the output piston pressure of the fluid pressure generating source 12 and the reaction force by the reaction force spring 48 are applied to the control piston 41 when it becomes larger. And a second reaction force piston 47 interposed between the first reaction force pistons 46.

  Referring also to FIG. 3, a body 17 that constitutes a part of the casing 15 and is coaxially coupled to the rear portion of the cylinder body 16 includes a rear end of the cylinder body 16, a separator 18, and a first sleeve 19. An annular step portion 50 is formed between the large-diameter hole 49 into which the second sleeve 20 is liquid-tightly fitted from the front end side and the rear end of the large-diameter hole 49 to form a rear end of the large-diameter hole 49. An inward flange portion 17 a provided at the rear end of the body 17 is provided with a medium diameter hole 51 that is coaxially connected and formed to have a smaller diameter than the large diameter hole 49 and that defines the rear end of the medium diameter hole 51. A small diameter hole 52 having a smaller diameter than the medium diameter hole 51 is formed.

  The separator 18, the first sleeve 19 and the second sleeve 20 are fluid-tightly fitted into the large-diameter hole 49 so as to be sandwiched between the rear end of the cylinder body 16 in the master cylinder M and the stepped portion 50. The separator 18 has a short cylindrical shape that forms a second cylinder hole 54 having an inner diameter slightly smaller than the first cylinder hole 21 of the cylinder body 16 in the master cylinder M, and the first sleeve 19 It is a cylindrical one that forms a third cylinder hole 55 that has the same diameter as the first cylinder hole 21. Further, the second sleeve 20 forms a large-diameter portion 20a that fits into the large-diameter hole 49 of the body 17 and a fourth cylinder hole 56 that is smaller in diameter than the third cylinder hole 55, and is rearward from the large-diameter portion 20a. A stepped cylindrical shape is integrally formed with the extending small diameter portion 20 b, and the rear end of the large diameter portion 20 a is in contact with the stepped portion 50. Thus, the separator 18, the first sleeve 19, and the second sleeve 20 that are fitted and fixed in a fluid-tight manner in the body 17, cause the second to fourth cylinder holes 54, 55, which are coaxial with the first cylinder hole 21, 56 are formed in order from the front side.

  The backup piston 39 has a front small-diameter portion 39a slidably fitted in the second cylinder hole 54 and an outer diameter slightly smaller than the front small-diameter portion 39a, and slides into the fourth cylinder hole 56. The rear small-diameter portion 39b that can be fitted with the intermediate small-diameter portion 39c that connects the front small-diameter portion 39a and the rear small-diameter portion 39b and is slidably fitted into the third cylinder hole 55 is integrated. The intermediate large diameter portion 39c is formed in a stepped cylindrical shape having a larger diameter than the front small diameter portion 39a and the rear small diameter portion 39b.

  The body 17 has a connection port 57 that opens to the inner surface of the large-diameter hole 49 at a position corresponding to the cylinder body 16 of the master cylinder M and the separator 18, and a large diameter at a position corresponding to between the separator 18 and the first sleeve 19. An input port 58 that opens to the inner surface of the hole 49, an output port 59 that opens to the inner surface of the large-diameter hole 49 at the axially intermediate portion of the first sleeve 19, and a release port 60 that opens to the front inner surface of the medium-diameter hole 51. Are provided at intervals from the front.

  A fluid pressure source 12 is connected to the input port 58, and the fluid pressure source 12 includes a pump 61 that pumps hydraulic fluid from the third fluid reservoir chamber 31 c of the reservoir 31, and the pump 61. An accumulator 62 connected to the discharge side is provided, and the operation of the pump 61 is controlled in accordance with a detection value of a hydraulic pressure sensor 63 that detects the hydraulic pressure of the accumulator 62. Thus, a high constant fluid pressure is supplied from the fluid pressure generating source 12 to the input port 58. The release port 60 is connected to the third liquid reservoir chamber 31 c of the reservoir 31.

  On the inner surface of the large-diameter hole 49 in the body 17, an annular recess 66 that opens the inner end of the connection port 57, an annular recess 67 that opens the inner end of the input port 58, and an annular shape that opens the inner end of the output port 59. Recesses 68 are provided, and O-rings 69, 70, 71, 72, which are annular seal members for sealing the annular recesses 66, 67, 68 from both sides, are the cylinder body 16 of the master cylinder M and the separator 18. The first sleeve 19 and the second sleeve 20 are attached to the outer periphery.

  The front small diameter portion 39a of the backup piston 39 is fitted in the second cylinder hole 54 of the separator 18 in a liquid-tight and slidable manner, and the intermediate large diameter portion 39c of the backup piston 39 is the third cylinder hole of the first sleeve 19. 55 is liquid-tightly and slidably fitted, and an annular path 73 is formed between the outer periphery of the front small-diameter portion 39 a and the inner periphery of the first sleeve 19, and between the separator 18 and the first sleeve 19. Is formed with a flow path 74 that communicates with the annular path 73, and an annular recess 67 that communicates with the input port 58 communicates with the annular path 73.

  In addition, both the front and rear sides of the annular path 73 are sealed by an O-ring 75 interposed between the separator 18 and the backup piston 39 and an O-ring 76 interposed between the first sleeve 19 and the backup piston 39. The O-ring 75 is mounted on the inner periphery of the separator 18, that is, the inner surface of the second cylinder hole 54 so as to be resiliently slidably contacted with the outer periphery of the front small-diameter portion 39 a of the backup piston 39. The backup piston 39 is mounted on the outer surface of the intermediate large-diameter portion 39c so as to elastically contact the inner surface of the third cylinder hole 55 that is the inner periphery of the one sleeve 19.

  An O-ring 77 that elastically contacts the outer periphery of the rear small diameter portion 39b of the backup piston 39 is attached to the inner periphery of the small diameter portion 20b of the second sleeve 20, that is, the inner surface of the fourth cylinder hole 56. On the other hand, the first and second sleeves 19 and 20 are provided with a flow path 78 that allows the outer end to pass through an annular recess 68 provided on the inner surface of the body 17 so as to communicate with the output port 59. The open ends of the flow path 78 to the inner periphery of the sleeve 19 and the inner periphery of the small diameter portion 20 b of the second sleeve 20 are sealed from both the front and rear sides by the O-rings 76 and 77.

  In FIG. 2 again, a ring-shaped stopper 80 is in contact with the inward flange portion 17 a of the body 17, and is attached to a retaining ring 81 mounted on the outer periphery of the rear end portion of the rear small diameter portion 39 b of the backup piston 39. A coil-like spring 83 surrounding the back half of the backup piston 39 is provided between the retainer 82 whose inner periphery is in contact with and engaged from the front side and the second sleeve 20. The backup piston 39 is spring-biased backward by the force. Thus, the position where the retaining ring 81 is brought into contact with the stopper 80 which is in contact with the inward flange portion 17a of the body 17 is the backward limit of the backup piston 39, and the front end of the backup piston 39 in the backward limit is doubled. While facing the hydraulic / hydraulic working chamber 22, it contacts the outer peripheral edge of the rear surface of the rear master piston 23 in the non-operating state, and the rear master piston 23 is also in the retreat limit in this state.

  The rear end surface of the cylinder body 16 in the master cylinder M and the front end surface of the separator 18 are provided with a plurality of passages 84... Communicating between the annular recess 66 communicating with the connection port 57 and the boosting hydraulic pressure working chamber 22. Grooves for forming between the opposing end faces of the separator 18 are provided so as to extend in the radial direction. Thus, the connection port 57 communicates with the boost hydraulic chamber 22 through the annular recess 66 and the passage 84.

  A spring chamber 85 surrounding the backup piston 39 is formed between the second sleeve 20 and the inward flange portion 17 a in the body 17 so as to accommodate the spring 83. This spring chamber 85 is connected to the release port 60. Communicate.

  An inward flange portion 39d that projects radially inward is integrally provided on the inner surface of the intermediate portion in the axial direction of the backup piston 39, and the backup piston is configured so that the backward limit is regulated by the inward flange portion 39d. A stepped cylindrical second reaction force piston 47 is slidably fitted to 39, and a first reaction force piston 46 is fitted coaxially and slidably to the second reaction force piston 47. .

  Further, an end wall member 86 that faces the front surface of the boost hydraulic pressure working chamber 22 is fluid-tightly fitted to the front end portion of the backup piston 39, and comes into contact with the outer peripheral edge portion of the end wall member 86 from the front. The retaining ring 87 to be engaged is attached to the inner periphery of the front end portion of the backup piston 39. Furthermore, the front end of the second reaction force piston 47 is fitted with a filter 91 in which mesh members 90 are provided in a plurality of openings 88 provided in a filter frame 89 formed in a bottomed cylindrical shape, The second reaction force piston 47 is urged toward the side in contact with the inward flange 39d from the front by the spring force of the reaction force spring 48 contracted between the filter 91 and the end wall member 86.

  Thus, an input chamber 93 is formed in the backup piston 39 between the second reaction force piston 47 and the filter 91 and the end wall member 86, and this input chamber 93 is provided in the backup piston 39. It communicates with the annular path 73 through the communication hole 94. That is, high-pressure hydraulic fluid from the hydraulic pressure generation source 12 is introduced into the input chamber 93, and the gap between the input chamber 93 and the boost hydraulic pressure working chamber 22 is sealed on the outer periphery of the end wall member 86. An O-ring 95 that elastically contacts the inner periphery of the backup piston 39 is attached.

  Referring to FIG. 3, an annular stepped portion 47 a facing forward is provided on the inner surface of the intermediate portion of the second reaction force piston 47, and the second reaction force piston 47 is disposed at the front portion of the second reaction force piston 47. A stepped cylindrical valve housing 97 having an O-ring 96 resiliently contacting the inner periphery of 47 is fitted so as to abut against the stepped portion 47a, and is attached to the rear side by a reaction force spring 48. The valve housing 97 is sandwiched between the filter frame 89 attached to the front end of the second reaction force piston 47 and the stepped portion 47a. As a result, the valve housing 97 is liquid-tightly fitted and fixed to the front portion of the second reaction force piston 47, and is supported by the backup piston 39 via the second reaction force piston 47.

  On the other hand, the first reaction force piston 46 has an annular seal member 98 that elastically contacts the inner periphery of the rear portion of the second reaction force piston 47 and is slidably fitted to the rear portion of the second reaction force piston 47. In the second reaction force piston 47, there is formed a boosted hydraulic pressure generating chamber 40 that faces the back surface of the valve housing 97 and faces the front end of the first reaction force piston 46. An annular chamber 99 is formed between the outer periphery of the second reaction force piston 47 and the inner periphery of the backup piston 39, and a boosted hydraulic pressure generation chamber is provided through a communication hole 100 provided in the second reaction force piston 47. 40 communicates with the annular chamber 99. In addition, the rear small diameter portion 39b of the backup piston 39 is provided with a communication hole 101 that allows the annular chamber 99 to communicate with the flow path 78. The boost hydraulic pressure generation chamber 40 includes the communication hole 100, the annular chamber 99, and the communication. The output port 59 communicates with the hole 101 and the flow path 78. On the outer periphery of the second reaction force piston 47, O-rings 102 and 103 sandwiching the annular chamber 99 from the front and rear are mounted so as to elastically contact the inner periphery of the backup piston 39.

  A filter formed in a cylindrical shape in the second reaction force piston 47 between the rear end of the valve housing 97 and an annular step 47b provided on the inner periphery of the second reaction force piston 47 and facing forward. A filter 107 in which mesh members 106 are provided is fitted in a plurality of openings 105 provided in the frame 104, and the filter 107 is interposed between the boost hydraulic pressure generation chamber 40 and the communication hole 100. Intervened.

  Referring to FIG. 2, the control piston 41 is formed in a bottomed cylindrical shape having an end wall 41a at the front end, and is formed in a small diameter hole 52 formed by the inward flange portion 17a at the rear end of the body 17. While being slidably fitted, it is coaxially inserted into the rear small diameter portion 39b of the backup piston 39. In addition, an annular seal member 110 that elastically contacts the outer periphery of the control piston 41 is attached to the inner periphery of the inward flange portion 17a, that is, the inner surface of the small-diameter hole 52. A regulating projection 111 that regulates the backward limit of the control piston 41 by abutting and engaging with the inner peripheral edge of the portion 17a from the front side is integrally projected over the entire circumference. Thus, when the hydraulic pressure of the hydraulic pressure generating source 12 is lost, the restricting projection 111 presses the backup piston 39 in the forward direction via the stopper 80 as the control piston 41 moves forward by a brake operation input. As a result, the backup piston 39 directly pushes the rear master piston 23 of the master cylinder M.

  A release chamber 45 is formed between the backup piston 39 and the control piston 41 behind the inward flange portion 39d, and the release chamber 45 communicates with the spring chamber 85 via a communication hole 113 provided in the stopper 80. To do. That is, the release chamber 45 communicates with the third liquid reservoir chamber 31 c in the reservoir 31 through the communication hole 113, the spring chamber 85, and the release port 60.

  The first reaction force piston 46 has an extended cylindrical portion 46a that extends rearward through the inward flange portion 39d of the backup piston 39, and the rear end of the extended cylindrical portion 46a is integrally formed. The control piston 41 is always in contact with the end wall 41a at the front end. The boost hydraulic pressure generating chamber 40 exerts a spring force that urges the rear end of the first reaction force piston 46, that is, the rear end of the extended cylindrical portion 46a, to come into contact with the end wall 41a of the control piston 41. The spring 114 is accommodated, and the spring force of the spring 114 is set very weakly.

  The second reaction force piston 47 is coaxially and integrally formed with an extension tube portion 47c that coaxially surrounds the extension tube portion 46a of the first reaction force piston 46 and is inserted into the inner periphery of the inwardly facing flange portion 39d. The rear end of the extended cylindrical portion 47c of the second reaction force piston 47 is in a state where the second reaction force piston 47 is in the retracted limit position in contact with the inward flange portion 39d of the backup piston 39, Although located behind the seat stopper 115 that is in contact with the inward flange portion 39d of the backup piston 39 and is fixed to the backup piston 39, the first reaction force piston 46 is disposed in front of the rear end of the extended cylindrical portion 46a. Is done.

  Therefore, when the control piston 41 moves forward with respect to the backup piston 39, the first reaction force piston 46 moves forward together with the control piston 41, and the rear end of the second reaction force piston 47 is controlled by the brake operation input by the brake pedal 11 being increased. When the forward movement amount of the piston 41 exceeds a predetermined value, the piston 41 comes into contact with the end wall 41a at the front end of the control piston 41.

  In FIG. 4, the pressure increasing valve 43 includes first and second valve means 116 and 117 arranged in the axial direction of the control piston 41 so as to sequentially open in response to an increase in brake operation input from the brake pedal 11. The second valve means 117 is set so that the seal diameter of the second valve means 117 is larger than the seal diameter of the first valve means 116, and the second valve means 117 is before the flow rate from the opened first valve means 116 becomes maximum. Configured to start opening.

  The first valve means 116 has a cylindrical valve seat member 119 that is slidably inserted into the valve housing 97 such that a first valve seat 118 is provided at the front end, and an input that communicates with the hydraulic pressure source 12. A retainer 121 that internally forms a valve chamber 42 that communicates with the chamber 93, and a valve body that is slidably supported by the retainer 121 while allowing it to be seated on the first valve seat 118 that faces the valve chamber 42. 122, a first valve spring 123 provided between the retainer 121 and the valve body 122 while urging the valve body 122 to be seated on the first valve seat 118, and a contact with the valve body 122 And a push rod 124 that is linked to and connected to the control piston 41 and is inserted into the valve seat member 119 so as to be capable of relative movement in the axial direction.

  The second valve means 117 is provided with a valve portion 125 provided on the valve seat member 119, which is a common component with the first valve means 116, and a second valve seat 126 facing the valve chamber 42 at the front end. In this way, the stepped cylindrical valve housing 97 into which the valve seat member 119 is slidably fitted, the retainer 121 which is a common component with the first valve means 116, and the valve portion 125 are provided. A second valve spring 127 provided between the retainer 121 and the valve seat member 119 while being urged to be seated on the second valve seat 126, and a pressing rod 124 which is a common component with the first valve means 116, Consists of.

  The valve portion 125 of the second valve means 117 is provided on the valve seat member 119 behind the first valve seat 118, and is based on the seal diameter when the valve body 122 is seated on the first valve seat 118. Can also be seated on the second valve seat 126 with a large seal diameter.

  The retainer 121 forming the valve chamber 42 is attached to the outer periphery of the front end portion of the valve housing 97 by press fitting. In addition, a guide tube portion 121b formed in a bottomed cylindrical shape is integrally provided at the front portion of the retainer 121, with an end wall 121a having an open hole 128 communicating with the input chamber 93 in the center portion at the front end. The valve body 122 of the first valve means 116 is formed in a spherical shape, and the valve body 122 is fixed to the rear portion of the slide member 129 that is slidably fitted to the guide cylinder portion 121b. Is contracted between the end wall 121a and the slide member 129.

  The valve seat member 119 is provided with a valve hole 130 that opens to the center of the first valve seat 118 and a first insertion hole 131 that communicates coaxially with the valve hole 130. A second insertion hole 132 having an opening at the front end is provided at the center of the second valve seat 126, and the valve seat member 119 is coaxially inserted into the second insertion hole 132 so as to be movable.

  In the valve housing 97, the pressing rod 124 is integrally provided with a pressing collar portion 124 a that abuts on the rear end of the valve seat member 119 and allows the valve seat member 119 to be pressed and moved forward. 97, a restricting flange 97a that restricts the retreat limit of the pressing rod 124 by coming into contact with the pressing flange 124a from the rear so as to protrude radially inward from the rear inner surface of the second insertion hole 132. Provided integrally.

  In such a pressure increasing valve 43, the valve body 122 is pressed at the front end of the pressing rod 124 as the control piston 41 moves forward by the input of the brake operation force by the brake pedal 11, and the valve body 122 is moved to the first pressure valve 43. When separated from the valve seat 118, the first valve means 116 is opened, and after the first valve means 116 is opened, the pressing rod 124 is further advanced and the valve seat member 119 is moved forward by the pressing collar 124a. The valve portion 125 is separated from the second valve seat 126 by being pressed, and the second valve means 117 is opened.

  Thus, a flow passage 135 that allows the valve chamber 42 to communicate with the boosted hydraulic pressure generation chamber 40 by opening the pressure increasing valve 43 is formed in the valve housing 97. An annular inner peripheral passage portion 136 formed between the inner periphery of the valve seat member 119 and the outer periphery of the pressing rod 124 so that hydraulic fluid flows when the first valve means 116 is opened, and a second valve An annular outer peripheral passage portion 137 formed between the outer periphery of the valve member 119 and the inner periphery of the valve housing 97 so that hydraulic fluid flows when the means 117 is opened, and the inner peripheral passage portion 136 and The outer peripheral side passage portion 137 is formed of an annular common passage portion 138 formed between the inner periphery of the valve housing 97 and the outer periphery of the pressing rod 124 so as to communicate with the boost hydraulic pressure generation chamber 40.

  A flat surface 124b for ensuring a flow area of the inner peripheral side passage portion 136 is provided at a plurality of locations in the circumferential direction of the outer periphery of the pressing rod 124 corresponding to the inside of the valve seat member 119. On the outer periphery of the valve seat member 119, a plurality of flat surfaces 119a for securing a flow area of the outer peripheral side passage portion 137 are provided.

  By the way, when the second valve means 117 is closed after the first valve means 116 is opened in the pressure increasing valve 43, the valve hole 130 of the first valve means 116 serves as a throttle so that the hydraulic pressure generating source 12 When there is a large hydraulic pressure difference between the hydraulic pressure of the valve chamber 42 that communicates with the hydraulic pressure applied to the valve seat member 119 on the downstream side of the valve hole 130, the valve portion 125 of the second valve means 117 is provided integrally. The force that presses the valve seat member 119 to the valve closing side becomes large, and a large operating force is required to open the second valve means 117, which may cause a decrease in brake operation feeling. Therefore, on the downstream side of the flow passage 135, the hydraulic pressure difference between the hydraulic pressure of the valve chamber 42 and the hydraulic pressure applied to the valve seat member 119 on the downstream side of the valve hole 130 of the first valve means 116 is reduced. A restricting portion 140 is provided, and this restricting portion 140 restricts the flow of the working fluid in the common passage portion 138 in the flow passage 135 so that the restricting flange portion 97a provided in the valve housing 97 is restricted. It is formed between the circumference and the outer circumference of the pressing rod 124.

  Further, the pressure rod 124 and the valve are arranged so as to generate a hydraulic pressure difference in the downstream portion of the flow passage 145 so that the pressure rod 124 is energized backward when the pressure increasing valve 43 is opened. A housing 97 is formed, and such a hydraulic pressure difference is generated by the throttle unit 140.

  Referring also to FIG. 5, the throttle part 140 gradually increases the flow area in accordance with the advancement of the pressing rod 124 in the valve housing 97, and constitutes such a throttle part 140. For this purpose, a tapered portion 124c is formed on the outer periphery of the pressing rod 124 at the portion corresponding to the inner periphery of the restricting flange portion 97a so that the outer diameter gradually decreases toward the rear in the axial direction of the pressing rod 124. .

  In FIG. 4 again, the rear portion of the pressing rod 124 is plunged into the boosted hydraulic pressure generating chamber 40, and the pressing rod 124 slides on the central portion of the disc-shaped rectifying member 142 in the boosted hydraulic pressure generating chamber 40. It is movably fitted. The rectifying member 142 can close the opening end of the flow passage 135 to the boosted hydraulic pressure generating chamber 40 by contacting the surface of the valve housing 97 facing the boosted hydraulic pressure generating chamber 40. A surface of the 142 facing the flow passage 135 is formed as a flat surface 142a.

  A spring receiving member 143 is press-fitted and fixed to the pressing rod 124 behind the rectifying member 142, and the spring 144 is contracted between the rectifying member 142 and the spring receiving member 143. On the other hand, the front end of the first reaction force piston 46 is also inserted into the boost hydraulic pressure generation chamber 40 coaxially with the pressing rod 124 and is fitted and brought into contact with the front portion of the first reaction force piston 46. The spring 114 is contracted between the retainer 145 and the rectifying member 142. Thus, the rectifying member 142 is biased toward the valve housing 97 by the spring force of the springs 114 and 144, and the spring force of the springs 114 and 144 is caused by the opening of the first valve means 116. The rectifying member 142 is set to such an extent that the rectifying member 142 can be separated from the valve housing 97 in response to the hydraulic pressure from the hydraulic pressure generating source 12 acting on the flow passage 135.

  The retainer 145 fitted to the front portion of the first reaction force piston 46 forms a valve chamber 146 leading to the boost hydraulic pressure generation chamber 40 between the first reaction force piston 46 and the retainer 145. The rear end portion of the pressing rod 124 is slidably fitted to the center portion of the first rod portion. Further, a valve seat 147 is provided at the front end of the first reaction force piston 46 so as to face the valve chamber 146, and a valve portion formed in a hemispherical shape so as to be seated on the valve seat 147 at the rear end of the pressing rod 124. 148 is provided.

  The pressure reducing valve 44 is configured by the valve seat 147 and the valve portion 148 that can be seated on the valve seat 147, and the first reaction force piston 46 has an opening at the center of the valve seat 147. And a release passage 150 that has a diameter larger than that of the valve hole 149 and that allows the front end to communicate with the valve hole 149 and extends to the rear end of the first reaction force piston 46. Since the end wall 41a of the front end of the control piston 41 is always in contact with the rear end of the one reaction force piston 46, the rear end of the release path 150 is substantially closed.

  An intermediate portion of the first reaction force piston 46 is located between the outer periphery of the first reaction force piston 46 and the inner periphery of the second reaction force piston 47 behind the seal member 98 attached to the outer periphery of the first reaction force piston 46. Are provided with a plurality of communication holes 151 that allow the outer end to pass through and the release path 150 to pass through the inner end, and when the pressure reducing valve 44 is opened, the working fluid from the release path 150 passes through the communication holes 151. It flows into the release chamber 45 through the space between the outer periphery of the first reaction force piston 46 and the inner periphery of the second reaction force piston 47.

  In such a hydraulic booster 13, a brake operation input from the brake pedal 11 is input to the control piston 41 via the stroke simulator 14, and a forward pressing force is applied from the control piston 41 to the first reaction force piston 46. Works. Thus, when the movement amount of the control piston 41 in the forward direction relative to the backup piston 39 is less than a predetermined value, only the first reaction force piston 46 is in contact with the control piston 41, and the first reaction force piston 46 advances. Accordingly, when the valve portion 148 is seated on the valve seat 147, the pressure reducing valve 44 is closed and the boosted hydraulic pressure generating chamber 40 and the release chamber 45 are shut off, and the control piston 41, the first reaction force piston 46, and The pressing rod 124 further advances. In response to the forward movement of the pressure rod 124, in the pressure increasing valve 43, the valve body 122 is first separated from the first valve seat 118 at the front end of the valve seat member 119, and the first valve means 116 is opened, and then the pressure rod. As the valve 124 further moves forward, the valve seat member 119 is pushed by the pressing rod 124, the valve portion 125 is separated from the second valve seat 126, and the second valve means 117 is opened.

  When the pressure reducing valve 44 is closed, the hydraulic pressure in the boost hydraulic pressure generating chamber 40 acts on the front end of the first reaction force piston 46, and the brake operation input from the brake pedal 11 and the boost hydraulic pressure generating chamber are applied. The first reaction force piston 46 and the control piston 41 are moved backward so that the hydraulic pressure based on the hydraulic pressure of 40 is balanced, so that the pressure reducing valve 44 is opened and the pressure increasing valve 43 is closed. By repeating opening and closing of the pressure reducing valve 44, 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 boost hydraulic pressure generating chamber 40. Will do. When the amount of movement of the control piston 41 in the forward direction relative to the backup piston 39 exceeds a predetermined value, not only the first reaction force piston 46 but also the second reaction force piston 47 comes into contact with the control piston 41, and the input chamber Since the hydraulic pressure that presses the second reaction force piston 47 rearward by the hydraulic pressure 93 and the spring force of the reaction force spring 48 are also added as reaction forces, the reaction force acting on the control piston 41 increases.

  Referring to FIG. 1, a connection port 57 provided in the body 17 so as to communicate with the boost hydraulic pressure working chamber 22 is connected to a hydraulic pressure generating source via a normally closed automatic brake pressurizing linear solenoid valve 154. 12 and is connected to the third liquid reservoir chamber 31 c of the reservoir 31 via a normally closed regenerative coordination pressure-reducing linear solenoid valve 155. That is, a normally-closed automatic brake pressurizing linear solenoid valve 154 is interposed between the boosting hydraulic pressure working chamber 22 and the hydraulic pressure generating source 12, and a normally-closed regeneration is performed between the boosting hydraulic pressure working chamber 22 and the reservoir 31. A depressurizing linear solenoid valve 155 for cooperation is interposed. In addition, the automatic brake pressurizing linear solenoid valve 154 and the regeneration cooperative depressurizing linear solenoid valve 155 are disposed on the body 17 constituting a part of the casing 15 together with the hydraulic pressure sensor 63 provided in the hydraulic pressure generating source 12.

  The output port 59 leading to the boost hydraulic pressure generating chamber 40 is connected to the above-described series via a normally open type automatic brake pressure-reducing linear solenoid valve 156 and a normally open type regenerative coordination pressure linear solenoid valve 157 connected in series. The first one-way valve 158 is connected to the connection port 57 and is parallel to the automatic brake pressure-reducing linear solenoid valve 156 so as to allow the hydraulic fluid to flow from the output port 59 to the connection port 57 side. A second one-way valve 159 is connected in parallel to the regeneration coordination pressurizing linear solenoid valve 157 so as to allow the flow of hydraulic fluid from the connection port 57 to the output port 59 side. .

  A hydraulic pressure sensor 160 for detecting a brake operation amount is connected between the output port 59 and the linear solenoid valve 156 for automatic brake pressure reduction, and a hydraulic pressure for automatic brake feedback control is connected between the pressure linear solenoid valve 157 for regeneration coordination and the connection port 57. A sensor 161 is connected.

  As described above, the normally closed automatic brake pressurizing linear solenoid valve 154 is interposed between the hydraulic pressure generation source 12 and the boost hydraulic pressure working chamber 22, and the boost hydraulic pressure generating chamber 40 and the boost hydraulic pressure action are provided. Between the chambers 22, a normally open type automatic brake pressure-reducing linear solenoid valve 156 and an automatic brake are allowed so as to allow the flow of hydraulic fluid from the boosted hydraulic pressure generating chamber 40 to the boosted hydraulic pressure working chamber 22 side. By interposing the first one-way valve 158 connected in parallel with the pressure reducing linear solenoid valve 156, even when the brake pedal 11 is not operated, the automatic brake pressurizing linear solenoid valve 154 and the automatic brake reducing pressure are provided. By opening and closing the linear solenoid valve 156 and adjusting the hydraulic pressure in the boost hydraulic pressure working chamber 22, the hydraulic pressure is applied to the wheel brakes B1 to B4 in the non-brake operation state. It is possible to perform the dynamic brake control. In addition, when the brake pedal 11 is operated while the automatic brake pressure-reducing linear solenoid valve 156 is closed during automatic braking, the pressure-increasing valve 43 is actuated, and the liquid pressure higher than the hydraulic pressure in the boost hydraulic pressure chamber 22 is reached. When pressure is generated in the boosted hydraulic pressure generating chamber 40, the hydraulic pressure of the boosted hydraulic pressure generating chamber 40 can be applied to the boosted hydraulic pressure working chamber 22 via the first one-way valve 158. The master cylinder M can be operated in the same manner as when the brake is operated.

  Further, a normally closed regenerative coordination decompression linear solenoid valve 155 is interposed between the boost hydraulic pressure working chamber 22 and the reservoir 31, and between the boost hydraulic pressure generating chamber 40 and the boost hydraulic pressure working chamber 22, A normally open pressure linear solenoid valve 157 for regenerative cooperation and a pressure linear solenoid for regenerative cooperation so as to permit the flow of hydraulic fluid from the boost hydraulic pressure working chamber 22 to the boost hydraulic pressure generating chamber 40 side. Since the second one-way valve 159 connected in parallel with the valve 157 is interposed, the pressure linear solenoid valve 157 for regeneration cooperation and the pressure reduction linear solenoid valve 155 for regeneration cooperation at the time of regeneration in the brake operation state. By adjusting the hydraulic pressure in the booster hydraulic pressure working chamber 22 by opening / closing the hydraulic pressure, the hydraulic pressure in the state offset from that during normal braking can be output from the master cylinder M, and regeneration pressurization is applied. Linearso When returning the brake pedal 11 at the time of closing of the maytansinoid valve 157, it is possible to escape the boosted hydraulic fluid pressure in the pressure application chamber 22 via the second one-way valve 159 to the reservoir 31 side.

  1 and 2, the stroke simulator 14 forms a stroke liquid chamber 163 between the front end wall 41a of the control piston 41 and is capable of sliding in a liquid-tight and axial direction on the control piston 41. The input piston 164 to be fitted, the slide member 165 slidably accommodated in the control piston 41 in front of the input piston 164, and the input piston 164 and the slide formed in a cylindrical shape by an elastic material such as rubber. An elastic body 166 interposed between the members 165 and a coil spring 167 interposed between the slide member 165 and the end wall 41a of the control piston 41 with a spring load smaller than that of the elastic body 166 are provided.

  The input piston 164 is slidably fitted to the rear portion of the control piston 41 so that the backward limit position is regulated, and the front end portion of the input rod 168 connected to the brake pedal 11 is connected to the input piston 164 so as to be able to swing. Is done. That is, a brake operation force corresponding to the operation of the brake pedal 11 is input to the input piston 164 via the input rod 168, and the input piston 164 moves forward in response to the input of the brake operation force. In addition, an annular seal member 169 that slides on the inner periphery of the control piston 41 is mounted on the outer periphery of the input piston 164.

  In the elastic body 166 and the coil spring 167, the spring force exerted by the coil spring 167 acts on the control piston 41 at the initial stage of the brake operation of the brake pedal 11, and the slide member 165 contacts the end wall 41a at the front end of the control piston 41. Thus, after the action of the spring force of the coil spring 167 on the control piston 41 is completed, the elastic body 166 is started to be elastically deformed, and is interposed between the input piston 164 and the control piston 41 in series.

  A front end portion of a guide shaft 170 that is coaxial with the control piston 41 and passes through the elastic body 166 is press-fitted into the center portion of the slide member 165, and the rear end portion of the guide shaft 170 slides on the input piston 164. Can be fitted. The end wall 41a at the front end of the control piston 41 has a plurality of through holes 171 that allow the release chamber 45 facing the front surface of the end wall 41a to communicate with the stroke liquid chamber 163. The distance from the center of the control piston 41 is as follows. The hydraulic fluid is introduced into the stroke fluid chamber 163 in the control piston 41 through the through holes 171.

  Each of the through-holes 171 is closed by a seat stopper 115 fixed to the backup piston 39 when the control piston 41 advances by a predetermined forward stroke or more. Thus, until the through hole 171... Is closed by the sheet stopper 115 when the control piston 41 moves forward, the space between the elastic body 166 in the control piston 41 and the control piston 41 is in a hydraulic pressure locked state. It communicates with the release chamber 45 through the through holes 171. That is, the stroke fluid chamber 163 communicates with the release chamber 45, that is, the reservoir 31 during the forward stroke of the control piston 41 until the working fluid is sealed in the control piston 41.

  In such a stroke simulator 14, the input piston 164 moves forward according to the brake operation of the brake pedal 11, and the stroke is proportional to the input load by compressing the coil spring 167 until the forward stroke reaches a certain value. When the input piston 164 moves forward while compressing the elastic body 166 in the axial direction, the elastic body 166 elastically deforms in accordance with the axial compression, but the axial compression force increases. Accordingly, the elastic deformation of the elastic body 166 is sequentially prevented from the front due to the restriction by the inner periphery of the control piston 41, and the amount of change in the input load with respect to the operation stroke of the brake pedal 11 increases.

  When the through hole 171 at the front end of the control piston 41 is closed during a forward stroke of a predetermined amount or more of the control piston 41, the stroke liquid chamber 163 is sealed, and the input piston 164 moves relative to the control piston 41 in the forward direction. Therefore, the stroke of the brake pedal 11 and the increase in reaction force, which are invalidated by the stroke simulator 14 when the hydraulic pressure of the hydraulic pressure generating source 12 is lost, can be suppressed.

  Next, the operation of this embodiment will be described. The flow passage 135 that allows the hydraulic pressure generating source 12 to communicate with the boosted hydraulic pressure generating chamber 40 in the open state of the pressure increasing valve 43 surrounds at least a part of the pressing rod 124. A hydraulic pressure difference formed between the hydraulic pressure of the valve chamber 42 and the hydraulic pressure applied to the valve seat member 119 downstream of the first valve means 116 is formed in the valve housing 97 and downstream of the flow passage 135. Since the throttle part 140 is provided to be small, the hydraulic pressure in the valve chamber 42 when the first valve means 116 is in the open state and the second valve means 117 is in the closed state, and the first valve means The hydraulic pressure difference with the hydraulic pressure applied to the valve seat member 119 becomes smaller on the downstream side than 116, and the hydraulic pressure applied to the valve seat member 119 is made closer to the hydraulic pressure in the valve chamber 42 on the downstream side than the first valve means 116. , The second after the opening of the first valve means 116 The hydraulic pressure that pushes the valve seat member 119 toward the valve closing side of the second valve means 117 in the valve closed state of the means 117 is reduced, and the operating force required to open the second valve means 117 is reduced. Brake operation feeling can be obtained.

  In addition, the throttle portion 140 retreats the pressing rod 124 by abutting the outer periphery of the pressing rod portion 124a provided on the outer periphery of the pressing rod 124 to press the valve seat member 119 from the rear and the pressing flange portion 124a from the rear. The liquid is applied to the valve seat member 119 on the downstream side of the first valve means 116, and is formed between the inner periphery of the restricting flange 97a provided on the inner periphery of the valve housing 97 so as to restrict the limit. The throttle part 140 for reducing the operating force required to open the second valve means 117 by bringing the pressure closer to the hydraulic pressure in the valve chamber 42 can be easily formed.

  Further, the pressure rod 124 and the pressure rod 124 are arranged so that a fluid pressure difference is generated in the downstream portion of the flow passage 145 so that the pressure rod 124 is urged backward when the pressure increasing valve 43 is opened. A valve housing 97 is formed, and in this embodiment, the throttle portion 140 for generating the hydraulic pressure difference is formed between the pressing rod 124 and the valve housing 97, so that the pressure increasing valve 43 is opened. It is possible to prevent a sudden forward operation of the pressing rod 124 later and to improve the brake operation feeling. Further, even if a large hydraulic pressure difference occurs between the hydraulic pressure generation source 12 and the boost hydraulic pressure generation chamber 40 at the initial stage of opening of the pressure increasing valve 43, the flow rate can be suppressed by the throttle unit 140. An abrupt hydraulic flow does not occur at the initial stage of valve opening, and the generation of abnormal noise can be suppressed.

  In addition, the restricting portion 140 gradually increases the flow area in accordance with the forward movement of the pressing rod 124 in the valve housing 97, and accordingly, in response to an increase in the forward stroke of the pressing rod 124. The flow rate of the hydraulic fluid flowing through the flow passage 135 gradually increases, and by smoothly changing the flow velocity, the flow rate of the hydraulic fluid can be prevented from abruptly changing, and the generation of abnormal noise can be suppressed. .

  In addition, the flow passage 135 is an annular inner peripheral passage formed between the inner periphery of the valve seat member 119 and the outer periphery of the pressing rod 124 so that hydraulic fluid flows when the first valve means 116 is opened. Part 136, an annular outer peripheral passage part 137 formed between the outer periphery of the valve member 119 and the inner periphery of the valve housing 97 so that hydraulic fluid flows when the second valve means 117 is opened, An annular common passage formed between the inner periphery of the valve housing 97 and the outer periphery of the pressing rod 124 so that the inner peripheral side passage portion 136 and the outer peripheral side passage portion 137 communicate with the boost hydraulic pressure generation chamber 40. Since the throttle portion 140 is provided in the common passage portion 138, when the first valve means 116 is opened, the working fluid flows through the inner peripheral side passage portion 136 and the second valve means 117 is opened. Sometimes By causing the hydraulic fluid to circulate through the outer peripheral side passage portion 137 and disperse and distribute the high hydraulic pressure hydraulic fluid from the valve chamber 42 communicating with the hydraulic pressure generation source 12, a rapid hydraulic pressure flow is generated. It is possible to suppress the flow noise.

  Further, a taper portion 124c is formed on the outer periphery of the pressing rod 124 at a portion corresponding to the inner periphery of the restricting flange portion 97a provided in the valve housing 97. The taper portion 124c gradually decreases in outer diameter as it goes rearward in the axial direction of the pressing rod 124. Therefore, the flow area of the throttle portion 140 can be gradually increased according to the forward movement of the pressure rod 124 with respect to the valve housing 97 with a simple configuration in which the tapered portion 124 c is formed on the outer periphery of the pressure rod 124. .

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

  The pressure rod 124 and the valve housing 97 are arranged so that a hydraulic pressure difference is generated in the downstream portion of the flow passage 135 so that the pressure rod 124 is urged backward when the pressure increasing valve 43 is opened. And a restricting flange portion provided in the valve housing 97 so that the throttle portion 141 for generating the hydraulic pressure difference restricts the flow of hydraulic fluid in the common passage portion 138 in the flow passage 135. It is formed between the inner periphery of 97a and the outer periphery of the pressing rod 124.

  The throttle 141 increases the flow area stepwise in accordance with the advancement of the pressing rod 124 in the valve housing 97. In order to configure such a throttle 141, the restriction rod The outer periphery of the pressing rod 124 at a portion corresponding to the inner periphery of 97a has a step portion having a plurality of outer diameters (four in this embodiment) as it goes rearward in the axial direction of the pressing rod 124. It is formed to be smaller.

  The same effect as that of the first embodiment can be obtained also by the second embodiment. That is, since the flow area of the throttle 141 increases stepwise by the forward movement of the pressing rod 124 with respect to the valve housing 97, the flow rate of the hydraulic fluid flowing through the flow passage 135 in accordance with an increase in the forward stroke of the pressing rod 124. Will increase in a stepwise manner, and the forward stroke of the pressing rod can suppress the flow rate with a constant degree of throttle within a predetermined range, thereby suppressing the generation of abnormal noise and corresponding to the inner periphery of the restriction rod portion 97a. The flow area of the throttle portion 124 can be increased stepwise with a simple structure in which the outer diameter of the pressing rod 124 is changed stepwise at the portion where the pressure is applied.

  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.

  For example, in the above-described embodiment, the pressure increasing valve 43 including the first and second valve means 116 and 117 sequentially opened in response to an increase in brake operation input has been described. However, a single valve seat and a single valve have been described. It is also possible to apply the present invention to a hydraulic booster including a pressure increasing valve having a body.

12 ... Hydraulic pressure generating source 13 ... Hydraulic pressure booster 23 ... Rear master piston 31 which is a master piston ... Reservoir 40 ... Boosting hydraulic pressure generating chamber 41 ... Control piston 43 ... · Pressure increasing valve 44 ··· Pressure reducing valve 45 ··· Release chamber 97 ··· Valve housing 97a · · · Restricting rod portion 124 · · · Press rod 124a · · · pressing rod portion 124c · · · taper portion 135 ···・ Flow paths 140, 141 ... throttle M ... master cylinder

Claims (5)

A reaction force based on the hydraulic pressure in the boosted hydraulic pressure generating chamber (40) that generates the hydraulic pressure for operating the master piston (23) of the master cylinder (M) acts in the backward direction while the brake operation input acts in the forward direction. A control piston (41) to perform;
A cylindrical valve housing (97) disposed coaxially with the axis of the control piston (41), and inserted coaxially into the valve housing (97) so as to advance when the control piston (41) advances. At least a pressing rod (124) that opens when the control piston (41) moves forward and closes when the control piston (41) moves backward, and the boost hydraulic pressure generation chamber (40) and A pressure increasing valve (43) interposed between the hydraulic pressure generating sources (12);
The release chamber (45) that opens to the reservoir (31) and closes when the control piston (41) moves forward and opens when the control piston (41) moves backward, and the boosted hydraulic pressure generation chamber (40). A pressure reducing valve (44) interposed therebetween;
In a hydraulic booster for a brake device comprising:
A flow passage formed in the valve housing (97) in such a manner that the hydraulic pressure generation source (12) communicates with the boost hydraulic pressure generation chamber (40) in a state in which the pressure increasing valve (43) is opened. 135) in the middle of the valve housing (97) is provided with throttle portions (140, 141) that gradually or stepwise increase the flow area in accordance with the forward movement of the pressing rod (124) in the valve housing (97). A hydraulic pressure booster for a brake device.   The pressing rod (124a) is provided on the pressing rod (124) so as to project radially outward from the outer periphery of the pressing rod (124), thereby limiting the retreat limit of the pressing rod (124) with respect to the valve housing (97). The valve housing (97) has a restricting flange (97a) protruding radially inward from the inner periphery of the valve housing (97) so as to be opposed to the pressing flange (124a) from the rear. The brake device according to claim 1, wherein the throttle portion (140, 141) is formed between an inner periphery of the restriction rod portion (97a) and an outer periphery of the pressing rod (124). Hydraulic booster.   A taper portion (124c) whose outer diameter gradually decreases toward the rear in the axial direction of the pressing rod (124) on the outer periphery of the pressing rod (124) at a portion corresponding to the inner periphery of the restricting flange portion (97a). The hydraulic booster for a brake device according to claim 2, wherein:   The pressing rod (124) is formed at a portion corresponding to the inner periphery of the restricting flange (97a) so that the outer diameter gradually decreases as it goes rearward in the axial direction of the pressing rod (124). The hydraulic booster for a brake device according to claim 2.   The pressing rod (124) and the valve housing (97) are formed such that the pressing rod (124) is urged backward by a hydraulic pressure due to a hydraulic pressure difference between the front and rear of the throttle portion (140, 141). The hydraulic pressure booster for a brake device according to any one of claims 1 to 4, wherein the hydraulic pressure booster is used.

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