JP2005239002A - Brake device and master cylinder device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lighten operation feeling at start of pedal stepping during brake operation of a vehicle; and to secure sufficient pedal feeling. <P>SOLUTION: An end side of a detour communication passage 30 is connected between a hydraulic pressure chamber 8A of a cylinder 2 and a stroke simulator 21. The hydraulic pressure chamber 8A of the cylinder 2 is connected to a wheel cylinder 10A while detouring a fail-safe valve 12A by the detour communication passage 30. A spool valve 33 for selectively communicating and shutting the hydraulic pressure chamber 8A and a hydraulic pressure unit 13A with respect to the wheel cylinder 10A is provided on the end side of the detour communication passage 30. Until the stroke simulator 21 is operated at brake operation of the vehicle, the hydraulic pressure chamber 8A in the cylinder 2 is communicated to the wheel cylinder 10A through the detour communication passage 30 by the spool valve 33, and then, the hydraulic pressure chamber 8A is shut off from the detour passage 30. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a brake device and a master cylinder device that are suitably used in, for example, a vehicle brake-by-wire brake system.

  In general, vehicles such as four-wheel automobiles are equipped with brake devices composed of various brake systems. And a configuration in which an operation amount (stroke, pedaling force, etc.) of the brake pedal is detected and a brake fluid pressure corresponding to the operation amount is supplied from a fluid pressure source such as a fluid pressure pump toward the wheel cylinder on the wheel side. A brake-by-wire brake system (hereinafter referred to as a BBW system) is also known (see, for example, Patent Document 1).

  In this type of prior art BBW system, for example, a master cylinder for fail-safe is provided in case of system failure, and this master cylinder is replaced with an external hydraulic pressure source when the brake pedal is depressed. And actuating to supply brake fluid pressure to the wheel cylinder.

  A fail-safe valve is provided between the master cylinder and the wheel cylinder. During normal operation of the system, the fail-safe valve shuts off the master cylinder and the wheel cylinder so that the hydraulic pressure source fails. In this configuration, the hydraulic pressure can be supplied from the master cylinder to the wheel cylinder by opening the fail-safe valve.

  Also, in such a master cylinder, since the master cylinder and the wheel cylinder are disconnected by a fail-safe valve during normal operation of the system, the hydraulic pressure generated in the hydraulic chamber of the master cylinder due to the brake operation is reduced. A stroke simulator is provided for accumulating pressure.

  The stroke simulator accumulates the hydraulic pressure generated in the hydraulic pressure chamber and transmits the brake reaction force to the brake pedal, thereby giving the vehicle driver the pedal reaction force in the normal operation of the system. The brake is effective, so-called tread response.

JP 2001-526150 A

  By the way, in the above-described prior art, the stroke simulator includes a simulator case that is an outer shell, a simulator piston that is slidably provided in the simulator case and that defines a pressure accumulating chamber and a spring chamber in the simulator case, The spring is generally constituted by a spring disposed in the spring chamber and constantly urging the simulator piston toward the pressure accumulating chamber.

  The hydraulic pressure generated in the hydraulic pressure chamber of the master cylinder in response to the braking operation of the vehicle expands the pressure accumulating chamber by bending and deforming the spring of the stroke simulator, and a part of the hydraulic pressure is transferred to the pressure accumulating chamber. In addition to accumulating pressure, the reaction force at this time is transmitted to the brake pedal of the vehicle as a pedal reaction force.

  In this case, it is generally known that it is desirable for the feeling of operation of the brake pedal to give a tread response that is light at the start of the pedal and gradually increases as the brake pedal is depressed.

  However, with the conventional stroke simulator, a certain amount of fluid pressure is required until the spring begins to bend in response to the brake operation, which gives a heavy operational feeling at the beginning of the brake pedal and improves the operational feeling at the beginning of the step. There is a problem that cannot be made.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to improve the operational feeling at the start of stepping on, for example, a brake pedal, and to ensure a good tread response during brake operation. An object of the present invention is to provide a brake device.

  Another object of the present invention is to provide a master cylinder device that can improve the feeling of operation at the beginning of stepping on, for example, a brake pedal, and can ensure a good stepping response during brake operation.

  In order to solve the above-described problems, the present invention provides a master cylinder that is connected to a wheel cylinder on a wheel side via a brake pipe and generates a hydraulic pressure corresponding to a brake operation in an internal hydraulic pressure chamber, and a liquid in the master cylinder. Separately from the pressure chamber, a hydraulic pressure source for supplying hydraulic pressure to the wheel cylinder, and a hydraulic pressure by the hydraulic pressure source and a hydraulic pressure from the hydraulic pressure chamber of the master cylinder are selectively supplied to the wheel cylinder. A fail-safe valve provided in the middle of the brake pipe, and the master cylinder has the hydraulic pressure when the hydraulic chamber of the master cylinder and the wheel cylinder are blocked by the fail-safe valve. The present invention is applied to a brake device provided with a stroke simulator for accumulating indoor hydraulic pressure and generating a brake reaction force.

  The features of the configuration adopted by the invention of claim 1 are provided in a bypass path for bypassing the fail-safe valve and connecting the hydraulic chamber of the master cylinder to the wheel cylinder, and in the middle of the bypass path. The hydraulic pressure chamber of the master cylinder is connected to the wheel cylinder through the bypass passage until the stroke simulator is activated by a brake operation, and the hydraulic pressure chamber is disconnected from the wheel cylinder when the stroke simulator is activated. The configuration includes a valve.

  According to a second aspect of the present invention, the switching valve is configured to selectively communicate and block the hydraulic pressure chamber of the master cylinder and the hydraulic pressure source with respect to the wheel cylinder.

  According to a third aspect of the invention, the hydraulic pressure source is provided between the switching valve and the wheel cylinder and provided in the middle of the bypass passage.

  According to a fourth aspect of the present invention, the bypass passage has one end connected between the hydraulic chamber of the master cylinder and the stroke simulator, and the other end connected to the wheel cylinder.

  According to a fifth aspect of the present invention, the switching valve is provided between the hydraulic chamber of the master cylinder and a stroke simulator and provided in the middle of the bypass passage.

  On the other hand, the invention of claim 6 comprises a bottomed cylindrical cylinder, a piston that is slidable in the cylinder and that is displaced in the axial direction in response to a brake operation, and a piston that moves into the cylinder. A hydraulic chamber that is defined and connected to a wheel cylinder on a wheel side via a fail-safe valve; and when the hydraulic chamber and the wheel cylinder are blocked by the fail-safe valve, The present invention is applied to a master cylinder device having a stroke simulator that accumulates the hydraulic pressure generated in the hydraulic pressure chamber and generates a brake reaction force.

  The feature of the configuration adopted by the invention of claim 6 is provided in the middle of the bypass passage for bypassing the fail-safe valve and connecting the hydraulic chamber of the master cylinder to the wheel cylinder, and in the middle of the bypass passage. The hydraulic pressure chamber of the master cylinder is connected to the wheel cylinder through the bypass passage until the stroke simulator is activated by a brake operation, and the hydraulic pressure chamber is disconnected from the wheel cylinder when the stroke simulator is activated. The configuration includes a valve.

  As described above, according to the first aspect of the present invention, the spring in the stroke simulator begins to bend in accordance with the braking operation of the vehicle, and the hydraulic chamber in the master cylinder remains in the wheel until the stroke simulator starts to operate. For example, the invalid input at the start of stepping on the brake pedal can be bypassed and supplied to the wheel cylinder, and the reaction force at the start of the step can be prevented from increasing. . When the stroke simulator is actuated by further depressing operation of the brake pedal (when the spring in the stroke simulator starts to bend), the hydraulic pressure chamber in the master cylinder is changed to the wheel cylinder by switching the switching valve. Therefore, for example, the brake fluid pressure from the fluid pressure source can be supplied to the wheel cylinder to apply a braking force to the vehicle. During this time, the stroke simulator operates to generate a brake reaction force corresponding to the brake fluid pressure, and the brake reaction force at this time can give a sufficient treading response to the driver of the vehicle.

  Therefore, by supplying the invalid input generated in the hydraulic chamber of the master cylinder by detouring to the wheel cylinder at the beginning of the brake pedal, the operational feeling at the beginning of the brake pedal can be lightened. Can be improved. In addition, it is possible to give a good treading response to the driver of the vehicle at the time of the brake operation, and to ensure a good pedal feeling.

  According to the second aspect of the present invention, by using a switching valve, the hydraulic pressure source for supplying hydraulic pressure to the wheel cylinder and the hydraulic pressure chamber in the master cylinder are selectively communicated with and disconnected from the wheel cylinder. Therefore, until the stroke simulator is actuated by the brake operation (the spring in the stroke simulator begins to bend), the hydraulic chamber in the master cylinder is communicated with the wheel cylinder via the bypass path, and the brake pedal is The feeling of operation at the beginning of stepping can be lightened. When the stroke simulator spring begins to bend and operates, the hydraulic pressure chamber in the master cylinder is shut off from the wheel cylinder by switching the switching valve, and the hydraulic pressure source is communicated with the wheel cylinder via a bypass passage. The braking force can be applied to the vehicle by the brake fluid pressure from the fluid pressure source.

  The invention according to claim 3 is configured such that a hydraulic pressure source for supplying hydraulic pressure to the wheel cylinder is provided in the middle of the bypass passage at a position closer to the wheel cylinder than the switching valve. Regardless of the switching operation, the hydraulic pressure source can always be communicated with the wheel cylinder via the bypass path, and the braking force can be applied to the vehicle by the brake hydraulic pressure from the hydraulic pressure source. Until the stroke simulator is actuated by the brake operation of the vehicle, the hydraulic chamber in the master cylinder is communicated with the wheel cylinder via the bypass path, and the operational feeling at the beginning of the depression of the brake pedal can be reduced.

  In the invention according to claim 4, since one end side of the bypass passage is provided between the hydraulic chamber of the master cylinder and the stroke simulator, the master cylinder is operated until the stroke simulator starts to operate. The fluid pressure chamber inside is communicated with the wheel cylinder via a bypass passage by a switching valve, and for example, an invalid input at the start of a brake pedal can be bypassed and supplied to the wheel cylinder side, and the reaction force at the start of the step can be increased. It can be suppressed well.

  In the invention according to claim 5, since the switching valve is provided between the hydraulic pressure chamber and the stroke simulator and provided in the middle of the bypass passage, for example, the hydraulic pressure chamber in the master cylinder, the stroke simulator, The switching valve can be accommodated in a compact manner, the brake device and the master cylinder device as a whole can be reduced in size and weight, and workability during assembly can be improved.

  On the other hand, in the master cylinder device according to the sixth aspect of the invention, in the same manner as the brake device according to the first aspect of the invention, the invalid input generated in the hydraulic chamber of the cylinder at the start of the depression of the brake pedal is bypassed to the wheel cylinder side. Thus, it is possible to lighten the operational feeling at the beginning of the brake pedal and improve the operational feeling at the beginning of the step. In addition, it is possible to give a good treading response to the driver of the vehicle at the time of the brake operation, and to ensure a good pedal feeling.

  Hereinafter, a case where the brake device and the master cylinder device according to the embodiment of the present invention are applied to a vehicle BBW system (brake-by-wire type brake system) will be described as an example, and will be described in detail according to FIGS. To do.

  1 to 4 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes a master cylinder device according to the present embodiment. The master cylinder device 1 includes a cylinder 2, first and second pistons 4, 5, and first and second liquids, which will be described later, as shown in FIG. The pressure chambers 8A and 8B, a tilt valve 19, a stroke simulator 21, a bypass passage 30, a spool valve 33, and the like are included.

  Reference numeral 2 denotes a cylinder that constitutes a main part of the master cylinder device 1, and the cylinder 2 is formed in, for example, a bottomed cylindrical shape and constitutes a so-called tandem type master cylinder. In the cylinder 2, first and second hydraulic chambers 8A and 8B are defined by pistons 4 and 5 which will be described later.

  Reference numeral 3 denotes a reservoir as a hydraulic fluid tank in which brake fluid is accommodated. The reservoir 3 is connected to the cylinder 2 via pipes 3A and 3B as shown in FIG. The liquid is replenished. The reservoir 3 is provided with other pipes 3C and 3D for supplying brake fluid toward hydraulic pumps 14A and 14B described later.

  Reference numeral 4 denotes a primary piston (hereinafter referred to as a first piston 4) as a piston slidably provided in the cylinder 2, and reference numeral 5 denotes a cylinder 2 located on the deeper side of the cylinder 2 than the first piston 4. The secondary piston (henceforth the 2nd piston 5) as other pistons provided in the inside so that sliding is possible is shown.

  As shown in FIG. 1, the first and second pistons 4 and 5 are spaced apart from each other in the axial direction of the cylinder 2, and a return spring 9A described later is disposed therebetween. Further, a push rod 6 provided between the first piston 4 and a brake pedal 7 described later is connected.

  Reference numeral 7 denotes a brake pedal that the driver depresses when braking the vehicle. The brake pedal 7 moves the first piston 4 axially into the cylinder 2 via the push rod 6 (indicated by arrow A in FIG. 1). The operation is performed so as to push in the direction). A brake reaction force (pedal reaction force) to be described later is transmitted to the brake pedal 7 through the first piston 4 and the push rod 6.

  8A and 8B are first and second hydraulic chambers defined by pistons 4 and 5 in the cylinder 2, and the pistons 4 and 5 are axially arranged in the cylinder 2 in the hydraulic chambers 8A and 8B. The hydraulic pressure is generated in accordance with the displacement. And one end side of brake piping 11A and 11B mentioned later is connected to these hydraulic pressure chambers 8A and 8B.

  9A is a first return spring located in the cylinder 2 and disposed between the first piston 4 and the second piston 5, and 9B is between the second piston 5 and the bottom of the cylinder 2. Fig. 3 shows a second return spring disposed. These return springs 9A and 9B always urge the pistons 4 and 5 in the direction indicated by the arrow B in FIG. 1, and when the depression of the brake pedal 7 is released, the pistons 4 and 5 are shown in FIG. Return to the initial position.

  Reference numerals 10A and 10B denote first and second wheel cylinders provided on the vehicle wheel side as shown in FIG. 1, and the wheel cylinders 10A and 10B constitute a cylinder portion such as a drum brake or a disc brake, for example. . The wheel cylinders 10A and 10B apply braking force to the vehicle by supplying and discharging brake hydraulic pressure via the first and second brake pipes 11A and 11B shown in FIG.

  12A and 12B are first and second fail-safe valves provided in the middle of the brake pipes 11A and 11B. The fail-safe valves 12A and 12B are opened by a control signal from the control unit 40 described later (a ) To the valve closing position (b). That is, the fail-safe valves 12A and 12B are switched from the valve opening position (a) to the valve closing position (b) during normal operation of the system, and return to the valve opening position (a) when the system fails. It is.

  Reference numerals 13A and 13B denote first and second hydraulic pressure units constituting hydraulic pressure sources for supplying hydraulic pressure to the wheel cylinders 10A and 10B. Among the hydraulic pressure units 13A and 13B, the first hydraulic pressure unit 13A is provided. Is connected to the wheel cylinder 10A via a hydraulic pipe 28, a bypass passage 30, a spool valve 33 and the like which will be described later.

  As shown in FIG. 1, the first hydraulic unit 13A is connected to the reservoir 3 via the conduit 3C, and connected to the discharge side of the hydraulic pump 14A via the check valve 15A. The brake fluid pressure supply valve 16A is a normally open solenoid valve, and the brake fluid pressure discharge valve 17A is a normally closed solenoid valve provided between the supply valve 16A and the pipe 3C. It is what is done.

  The second hydraulic pressure unit 13B includes a hydraulic pump 14B connected to the reservoir 3 via a conduit 3D, and a normally open pressure connected to the discharge side of the hydraulic pressure pump 14B via a check valve 15B. A brake hydraulic pressure supply valve 16B made up of an electromagnetic valve and a discharge valve 17B made up of a normally closed electromagnetic valve provided between the supply valve 16B and the conduit 3D are used.

  The second hydraulic unit 13B is connected to the wheel cylinder 10B between the supply valve 16B and the discharge valve 17B in the middle of the brake pipe 11B located between the wheel cylinder 10B and the failsafe valve 12B. On the other hand, brake fluid pressure is supplied as will be described later.

  Reference numeral 18 denotes a fluid passage provided in the middle portion of the cylinder 2 in the longitudinal direction. The fluid passage 18 is disposed between the hydraulic chamber 8A in the cylinder 2 and a stroke simulator 21 described later. The hydraulic pressure is supplied (circulated) from the internal hydraulic chamber 8A to the stroke simulator 21 via a tilt valve 19 described later.

  Reference numeral 19 denotes a tilt valve as an on-off valve provided in the middle of the liquid passage 18. The tilt valve 19 is configured such that when the second piston 5 is in the initial position as illustrated in FIG. Thus, the hydraulic chamber 8A in the cylinder 2 is communicated with a stroke simulator 21 (described later) via the liquid passage 18.

  When the second piston 5 is pushed in the direction of arrow A in FIG. 1 against the return spring 9B, the tilt valve 19 follows this and switches from the valve opening position to the valve closing position. The hydraulic passage 8A in the cylinder 2 is blocked from the stroke simulator 21 by closing the liquid passage 18.

  Reference numeral 20 denotes an attachment member for attaching the stroke simulator 21 to the cylinder 2, which is attached to the attachment member 20 in a state where a cylindrical case 22 described later is in liquid-tight contact as shown in FIG. is there. Further, a stepped hole 20 </ b> A is formed in the mounting member 20 on the abutting surface side with the cylindrical case 22, and the stepped hole 20 </ b> A constitutes a part of the liquid passage 18.

  Reference numeral 21 denotes a stroke simulator that generates a brake (pedal) reaction force when a brake is operated. The stroke simulator 21 is externally attached to the cylinder 2 via a mounting member 20 at the position of the liquid passage 18 as shown in FIG. It has a cylindrical case 22 as a case, and a lid 23 that closes an end portion on the distal end side of the cylindrical case 22.

  The stroke simulator 21 is slidably fitted into the cylindrical case 22 and is a simulator piston 26 (hereinafter referred to as a covered piston) serving as a movable partition wall in which the cylindrical case 22 is defined by a pressure accumulating chamber 24 and a spring chamber 25. 26), and a spring 27 as an elastic body that is disposed in the spring chamber 25 and constantly biases the covered piston 26 toward the pressure accumulating chamber 24.

  Further, the cylindrical case 22 of the stroke simulator 21 is provided with a spool sliding hole 22A that constitutes a part of a spool valve 33 described later, and this spool sliding hole 22A is provided with a stepped hole 20A of the mounting member 20. It is formed as an axial passage that always communicates with the pressure accumulating chamber 24. When a hydraulic pressure is generated in the first hydraulic pressure chamber 8A as described later by the brake operation, the stroke simulator 21 is connected to the shaft hole 36 described later via the fluid passage 18, the tilt valve 19 and the like. Supplied from

  At this time, the stroke simulator 21 accumulates the hydraulic pressure in the pressure accumulating chamber 24 by slidingly displacing the covered piston 26 by the spring 27 being bent and deformed according to the magnitude of the hydraulic pressure. Then, the pressure in the pressure accumulating chamber 24 becomes a brake reaction force and is transmitted from the hydraulic pressure chamber 8A in the cylinder 2 to the brake pedal 7 via the first piston 4 to generate a pedal reaction force.

  A hydraulic pipe 28 is connected to the first hydraulic unit 13A. The hydraulic pipe 28 has one end connected between the supply valve 16B and the discharge valve 17B as shown in FIG. The other end is connected to a radial hole 29 described later as shown in FIG.

  Reference numeral 29 denotes a radial hole as a fluid passage hole provided in the cylindrical case 22 of the stroke simulator 21. The radial hole 29 is formed in the cylindrical case 22 as shown in FIG. It extends in the radial direction. The radial hole 29 is always in communication with the hydraulic unit 13A through the hydraulic pipe 28, and is communicated and blocked with a bypass passage 30 described later through a spool valve 33.

  Reference numeral 30 denotes a bypass passage that connects the hydraulic chamber 8A in the cylinder 2 to the wheel cylinder 10A by bypassing the fail-safe valve 12A. The bypass passage 30 includes a shaft hole 36, a liquid hole 37, and a shaft hole 36 formed in a spool 34, which will be described later. An annular groove 38, a radial hole 31 as another liquid passage hole formed in the radial direction of the cylindrical case 22 and spaced from the radial hole 29 in the axial direction of the spool sliding hole 22A, the diameter The directional hole 31 is constituted by a bypass pipe 32 that bypasses and connects the wheel cylinder 10A to the fail-safe valve 12A.

  A spool valve 33 is provided in the bypass passage 30 and serves as a switching valve for communicating and blocking the hydraulic chamber 8A in the cylinder 2 with respect to the wheel cylinder 10A. The spool valve 33 is configured as shown in FIG. The stepped cylindrical spool 34 inserted into the spool sliding hole 22A of the cylindrical case 22 is disposed between the stepped hole 20A of the mounting member 20 and the spool 34. The spool 34 is used as a stroke simulator. 21 is substantially constituted by a valve spring 35 that is always urged toward the closed piston 26 side (in the direction of arrow C in FIG. 2).

  On the one side in the axial direction of the spool 34, an annular flange 34A that is located in the stepped hole 20A of the mounting member 20 and protrudes outward in the radial direction is provided. As shown in FIG. 4, when the spool 34 is displaced in the spool sliding hole 22A in the direction indicated by the arrow C, it abuts on the end surface (abutting surface) side of the cylindrical case 22, and the spool 34 is further indicated by the arrow C The displacement in the direction is restricted.

  Further, the spool 34 is located on the inner peripheral side of the spool 34 so that the stepped hole 20 </ b> A (fluid passage 18) is always in communication with the pressure accumulation chamber 24 of the stroke simulator 21, and the spool 34 is formed in the radial direction of the spool 34. A liquid hole 37 provided and communicated with the shaft hole 36 and annular grooves 38 and 39 formed on the outer peripheral side of the spool 34 and spaced apart from each other in the axial direction are provided.

  Here, the annular groove 38 of the spool 34 always communicates with the shaft hole 36 through the liquid hole 37 and constitutes a part of the bypass passage 30 together with the shaft hole 36 and the liquid hole 37. Further, the annular groove 39 of the spool 34 is always in communication with the hydraulic unit 13A through the radial hole 29 and the hydraulic pipe 28, and when the spool 34 is displaced in the direction indicated by the arrow C as shown in FIGS. The radial holes 29 and 31 are communicated with each other.

  That is, as shown in FIG. 2, the spool valve 33 serving as a switching valve has an annular groove 38 of the spool 34 before the stroke simulator 21 is actuated (the covered piston 26 slides against the spring 27). 39, the radial hole 29 (hydraulic pipe 28) and the radial hole 31 (bypass pipe 32) are blocked, and the radial hole 31 is connected to the shaft hole 36 ( The hydraulic chamber 8A) in the cylinder 2 shown in FIG.

  However, as shown in FIGS. 3 and 4, when the stroke simulator 21 is actuated (the covered piston 26 slides in the direction of arrow C against the spring 27), the spool 34 is moved by the valve spring 35 to the side of the covered piston 26. Is pushed in the direction indicated by the arrow C, so that the radial holes 29 and 31 are communicated with each other by the annular groove 39 of the spool 34, and the shaft hole 36 of the spool 34 extends from the radial hole 31 (bypass pipe 32). It will be blocked.

  Thus, the spool valve 33 attached to the stroke simulator 21 allows the fluid pressure chamber 8A in the cylinder 2 shown in FIG. 1 to communicate with the wheel cylinder 10A via the bypass passage 30 until the stroke simulator 21 is operated. The pressure pipe 28 is blocked from the bypass passage 30 (bypass pipe 32). When the stroke simulator 21 is activated in accordance with the brake operation, the hydraulic chamber 8A shown in FIG. 1 is shut off from the bypass passage 30 and the hydraulic pipe 28 is communicated with the bypass passage 30 (bypass pipe 32, wheel cylinder 10A). It is something to be made.

  Reference numeral 40 denotes a control unit that constitutes a control device of the BBW system, and the control unit 40 is constituted by, for example, a microcomputer or the like. The cylinders 10A and 10B are connected to pressure sensors 42A and 42B on the side.

  In this case, the pedal sensor 41 detects a stroke or a pedaling force when the brake pedal 7 is depressed. Further, the pressure sensors 42A and 42B detect the brake fluid pressure supplied to the wheel cylinders 10A and 10B. The control unit 40 determines whether or not the BBW system is operating normally according to detection signals from the pedal sensor 41 and the pressure sensors 42A and 42B, and performs a brake fluid pressure control process as described later. It is.

  Further, the output side of the control unit 40 is connected to the fail safe valves 12A and 12B, the hydraulic pressure units 13A and 13B, and the like. The control unit 40 switches the fail-safe valves 12A and 12B to the closed position (b) during normal operation of the system and supplies power to the hydraulic units 13A and 13B to operate the hydraulic pumps 14A and 14B. The supply valves 16A and 16B and the discharge valves 17A and 17B are selectively opened and closed in order to increase, hold, or reduce the brake fluid pressure of the wheel cylinders 10A and 10B.

  The BBW system (brake device) using the master cylinder device 1 according to the present embodiment has the above-described configuration. Next, the operation thereof will be described.

  First, when the BBW system operates normally, the fail-safe valves 12A and 12B are switched from the valve-opening position (a) shown in FIG. The hydraulic chambers 8A and 8B are cut off from the wheel cylinders 10A and 10B.

  In this state, when the brake pedal 7 is depressed when the vehicle is braked, the hydraulic pressure chamber is reached when the pistons 4 and 5 are slightly pushed in the direction of arrow A in FIG. 8A and 8B are blocked from the conduits 3A and 3B of the reservoir 3 through a center valve (not shown) or the like.

  At this time, the second hydraulic pressure chamber 8B is shut off from the wheel cylinder 10B by the fail safe valve 12B and also from the pipe line 3B of the reservoir 3, so that the second piston 5 is hydraulically pressurized. In the locked state, further sliding displacement is suppressed, and the tilt valve 19 is maintained in the opened state illustrated in FIG.

  In the first hydraulic pressure chamber 8A, the hydraulic pressure increases as the first piston 4 slides and displaces in the direction of arrow A. The hydraulic pressure in the hydraulic pressure chamber 8A The gas is supplied into the cylindrical case 22 (pressure accumulation chamber 24) of the stroke simulator 21 through the tilt valve 19 and the like.

  At this time, in the stroke simulator 21, the spring 27 in the cylindrical case 22 is bent and deformed according to the magnitude of the hydraulic pressure, and the covered piston 26 is slid and displaced, thereby accumulating the hydraulic pressure in the accumulator chamber 24. The pressure in the pressure accumulating chamber 24 becomes a brake reaction force and is transmitted from the hydraulic pressure chamber 8A in the cylinder 2 to the brake pedal 7 via the first piston 4, so that a pedal reaction force can be generated. In addition, the brake effect, so-called tread response, can be given to the driver of the vehicle.

  By the way, the pedal feeling (stepping response) in this case is desirable to be such that the starting point of the brake pedal 7 is light and gradually increases as the brake pedal 7 is depressed. However, the stroke simulator 21 in this case requires a certain amount of fluid pressure until the spring 27 starts to bend with the brake operation, and the operational feeling tends to increase at the beginning of the depression of the brake pedal 7.

  Therefore, in the present embodiment, a bypass passage 30 that bypasses the failsafe valve 12A and connects the hydraulic chamber 8A of the cylinder 2 to the wheel cylinder 10A is provided between the hydraulic chamber 8A and the stroke simulator 21, A spool valve 33 is provided in the middle of the bypass passage 30 as a switching valve for selectively communicating and shutting off the hydraulic chamber 8A with respect to the wheel cylinder 10A.

  That is, the spool valve 33 in this case is attached to the cylindrical case 22 of the stroke simulator 21 as shown in FIGS. 2 to 4 and is slidably displaced in the directions of the arrows C and D in the spool sliding hole 22A. A cylindrical spool 34, a valve spring 35 that is disposed between the stepped hole 20A of the mounting member 20 and the spool 34, and constantly urges the spool 34 toward the covered piston 26 side of the stroke simulator 21; It is comprised by. The spool 34 is provided with a shaft hole 36, a liquid hole 37, and annular grooves 38, 39. The shaft hole 36, the liquid hole 37, and the annular groove 38 constitute a part of the bypass passage 30.

  Thus, in the present embodiment, before the stroke simulator 21 is actuated (the covered piston 26 slides against the spring 27), as shown in FIG. The fluid pressure chamber 8A) in the cylinder 2 shown in FIG. 1 is communicated with the wheel cylinder 10A via the fluid hole 37, the annular groove 38, the radial hole 31 and the bypass passage 32 (the bypass passage 30).

  As a result, the hydraulic pressure generated in the hydraulic chamber 8A shown in FIG. 1 is passed through the bypass passage 30 through the bypass passage 30 until the spring 27 of the stroke simulator 21 starts to bend when the brake pedal 7 is depressed during the braking operation of the vehicle. It can be supplied to the cylinder 10A side, and it is possible to eliminate a situation in which the hydraulic pressure at this time is confined between the stroke simulator 21 and the hydraulic pressure chamber 8A and a heavy pedal reaction force is generated.

  That is, of the operation amount when the brake pedal 7 is depressed, for example, at the beginning of the step (invalid input) corresponding to the first depression amount of about 1 mm, the liquid generated in the hydraulic chamber 8A shown in FIG. By supplying pressure (invalid input) to the wheel cylinder 10A via the bypass passage 30, it is possible to prevent the feeling of operation (pedal feeling) from becoming heavy at the start of the depression of the brake pedal 7. The feeling can be lightened.

  If the depression of the brake pedal 7 is continued at this stage, a higher hydraulic pressure is generated in the hydraulic chamber 8A, so that the covered piston 26 of the stroke simulator 21 resists the spring 27 as shown in FIG. As a result, the spool 34 is slid in the direction indicated by the arrow C, and the spool 34 is pushed by the valve spring 35 toward the covered piston 26 in the direction indicated by the arrow C.

  Therefore, the radial holes 29 and 31 are communicated with each other by the annular groove 39 of the spool 34, and the shaft hole 36 of the spool 34 can be blocked from the radial hole 31 (bypass pipe 32). Thereby, the brake hydraulic pressure corresponding to the depression operation of the brake pedal 7 can be supplied from the hydraulic pressure unit 13A in FIG. 1 to the wheel cylinder 10A via the hydraulic pressure pipe 28, the spool valve 33, and the bypass pipe 32.

  At this time, the spring 27 of the stroke simulator 21 is greatly bent and deformed in the direction of arrow C as shown in FIG. 4 according to the hydraulic pressure generated in the hydraulic pressure chamber 8A, and a part of the hydraulic pressure is stored in the pressure accumulating chamber 24. The reaction force at this time can be transmitted to the brake pedal 7 as a pedal reaction force, and the operational feeling of the brake pedal 7 can be improved.

  Further, when such a brake operation is performed, the depression operation of the brake pedal 7 is detected by the pedal sensor 41, so that a control signal is output from the control unit 40 to the hydraulic units 13A and 13B to operate the hydraulic pumps 14A and 14B. In addition, the supply valves 16A and 16B and the discharge valves 17A and 17B can be selectively opened and closed.

  Therefore, when braking the vehicle, the brake hydraulic pressure supplied from the hydraulic pumps 14A, 14B to the wheel cylinders 10A, 10B can be increased, held, or reduced according to the depression operation of the brake pedal 7, and the brake pedal 7 can be depressed. The brake fluid pressure corresponding to the operation can be supplied to the wheel cylinders 10A and 10B, and the braking force control of the vehicle can be performed with high accuracy.

  On the other hand, for example, when the hydraulic pumps 14A and 14B serving as the hydraulic pressure source fail or the control unit 40 fails, the automatic brake fluid pressure control by the BBW system as described above is invalidated. When such a system fails, no control signal is output from the control unit 40 to the fail-safe valves 12A and 12B, and the fail-safe valves 12A and 12B are automatically set to the valve opening position (a) shown in FIG. Return.

  For this reason, in the master cylinder device 1, the hydraulic chambers 8A, 8B in the cylinder 2 are in communication with the wheel cylinders 10A, 10B. In this state, when the brake pedal 7 is depressed when the vehicle is braked or the like, the pistons 4 and 5 are both pushed in the axial direction in the cylinder 2, and the brake chambers 7 A and 8 B have the brake pedal 7. The hydraulic pressure corresponding to the stepping-in operation is generated.

  The hydraulic pressure generated in the hydraulic pressure chambers 8A and 8B is supplied as brake hydraulic pressure to the wheel cylinders 10A and 10B via the brake pipes 11A and 11B. Even in this case, it corresponds to the depression operation of the brake pedal 7. Brake fluid pressure can be supplied to the wheel cylinders 10A and 10B.

  Further, the tilt valve 19 provided between the hydraulic pressure chamber 8A in the cylinder 2 and the spool valve 33 via the fluid passage 18 has an arrow in FIG. 1 in which the second piston 5 opposes the return spring 9B. By being pushed in the direction A, the valve opening position is switched to the valve closing position, and the liquid passage 18 is closed with respect to the stroke simulator 21.

  As a result, for example, when the system fails, the hydraulic pressure chamber 8A in the cylinder 2 can be shut off from the stroke simulator 21 and the bypass passage 30, and the hydraulic pressure in the hydraulic pressure chamber 8A is reduced at the stroke simulator 21 side. It is possible to prevent excessive consumption and to efficiently supply the hydraulic pressure generated in the hydraulic pressure chamber 8A to the wheel cylinder 10A via the brake pipe 11A.

  Therefore, according to the present embodiment, the invalid input generated in the hydraulic chamber 8A of the cylinder 2 at the start of the depression of the brake pedal 7 when the vehicle is braked is supplied to the wheel cylinder 10A via the bypass passage 30. By doing so, the operational feeling at the beginning of the depression of the brake pedal 7 (low depression force region) can be lightened, and the operational feeling at the beginning of the depression can be improved. In addition, it is possible to give a good treading response to the driver of the vehicle at the time of the brake operation, and to ensure a good pedal feeling.

  Further, since the spool valve 33 as a switching valve is provided between the hydraulic pressure chamber 8A of the cylinder 2 and the stroke simulator 21 and provided in the middle of the bypass passage 30, for example, the hydraulic pressure chamber 8A in the cylinder 2 is provided. The spool valve 33 can be compactly accommodated between the stroke simulator 21 via the mounting member 20 and the like, the master cylinder device 1 as a whole can be reduced in size and weight, and workability during assembly can be improved.

  Next, FIG. 5 shows a second embodiment of the present invention. The feature of this embodiment is that the switching valve provided in the middle of the bypass passage is constituted by an electromagnetic valve arranged at a position separated from the stroke simulator. There is. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, 51 is a stroke simulator employed in the present embodiment. The stroke simulator 51 is configured in substantially the same manner as the stroke simulator 21 described in the first embodiment, and has a pressure accumulating chamber 52 and a lid as a simulator piston. A piston 53 and a spring 54 are provided.

  However, in this case, the stroke simulator 51 is provided with a bypass passage 55 (described later) branched from between the pressure accumulation chamber 52 and the fluid passage 18 (the fluid pressure chamber 8A of the cylinder 2). A solenoid valve 59 to be described later is disposed in the middle of the bypass passage 55 at a position separated from the stroke simulator 51.

  Reference numeral 55 denotes a bypass passage, and the bypass passage 55 is configured in substantially the same way as the bypass passage 30 described in the first embodiment, and the hydraulic chamber 8A in the cylinder 2 is bypassed to the wheel cylinder 10A and the fail-safe valve 12A is bypassed. And connect.

  However, the bypass passage 55 in this case branches from between the pressure accumulating chamber 52 of the stroke simulator 51 and the fluid passage 18 and extends to the outside to the position of an electromagnetic valve 59 described later, One end side is configured by a bypass pipe 57 that is connected to the distal end side of the branch pipe line 56 via an electromagnetic valve 59, and the other end side is connected to the wheel cylinder 10A by bypassing the fail-safe valve 12A.

  Reference numeral 58 denotes a hydraulic pipe, and the hydraulic pipe 58 is configured in substantially the same manner as the hydraulic pipe 28 described in the first embodiment. However, the hydraulic pipe 58 in this case is different in that the tip side is connected to an electromagnetic valve 59 described later.

  59 is an electromagnetic valve as a switching valve provided between the branch pipe 56 and the bypass pipe 57 of the bypass passage 55. The electromagnetic valve 59 is connected between the hydraulic chamber 8A in the cylinder 2 and the hydraulic unit 13A. In order to selectively communicate or block either one with respect to the wheel cylinder 10 </ b> A, one of the branch pipe 56 and the hydraulic pipe 58 is connected to the bypass pipe 57.

  That is, the electromagnetic valve 59 is controlled to be switched to either the switching position (c) or (d) in accordance with a control signal from the control unit 60 described later. At the switching position (c), the branch valve 56 of the bypass passage 55 is routed. The bypass pipe 57 is communicated. When the solenoid valve 59 is switched from the switching position (c) to the switching position (d), the hydraulic unit 13A is communicated (connected) to the wheel cylinder 10A via the hydraulic pipe 58 and the bypass pipe 57. It is.

  Reference numeral 60 denotes a control unit as a control device employed in the present embodiment. The control unit 60 is configured in substantially the same manner as the control unit 40 described in the first embodiment, and switches the fail-safe valves 12A and 12B. Control, operation control of the hydraulic units 13A and 13B, and the like are performed.

  However, in this case, the control unit 60 switches and controls the electromagnetic valve 59 according to the operation of the stroke simulator 51, so that the input side is connected to a stroke sensor 61 described later and the output side is connected to the electromagnetic valve 59. The electromagnetic valve 59 is placed in the switching position (c) by a spring or the like in a normal non-excited state.

  Reference numeral 61 denotes a stroke sensor as position detecting means for detecting the operation of the stroke simulator 51. The stroke sensor 61 detects the movement of the covered piston 53, for example, so that the covered piston 53 resists the spring 54 in the stroke simulator 51. Then, it is detected whether or not the sliding displacement has occurred, and this detection signal is output to the control unit 60 as an operation determination signal of the stroke simulator 51. As the stroke sensor 61, various sensors such as a contact type sensor such as a limit switch and a non-contact type sensor such as a hall element can be used.

  Thus, even in the brake device according to the present embodiment configured as described above, the control unit 60 switches the electromagnetic valve 59 between the switching position (c) and the switching position (d) according to the detection signal from the stroke sensor 61. Thus, substantially the same operational effects as those of the first embodiment can be obtained.

  That is, in the present embodiment, the state before the stroke simulator 51 is actuated by the stroke sensor 61 (at the stage from when the brake pedal 7 starts to be depressed during the braking operation of the vehicle until the spring 54 of the stroke simulator 51 begins to bend) Therefore, the solenoid valve 59 is placed in the switching position (c).

  As a result, the hydraulic chamber 8A of the cylinder 2 is connected to the wheel cylinder 10A via the fluid passage 18, the branch conduit 56, and the bypass piping 57, so that the brake pedal 7 starts to enter the hydraulic chamber 8A. The generated hydraulic pressure (invalid input) can be supplied to the wheel cylinder 10 </ b> A via the bypass passage 55 (branch pipe 56, bypass pipe 57), and the operational feeling at the beginning of the brake pedal 7 is reduced. Can do.

  If the depression of the brake pedal 7 is continued at this stage, a higher hydraulic pressure is generated in the hydraulic pressure chamber 8A, so that the covered piston 53 of the stroke simulator 51 slides against the spring 54. However, at this time, since a signal that detects the operation of the stroke simulator 51 is output from the stroke sensor 61, the electromagnetic valve 59 is switched from the switching position (c) to the switching position (d), and the branch line 56 Can be shut off from the bypass pipe 57.

  For this reason, the hydraulic pressure generated in the hydraulic pressure chamber 8 </ b> A by the depression operation of the brake pedal 7 does not flow to the wheel cylinder 10 </ b> A side via the branch pipe 56 and the bypass pipe 57 of the bypass path 55. At this time, the brake hydraulic pressure corresponding to the depression operation of the brake pedal 7 is supplied from the hydraulic pressure unit 13A in FIG. 5 to the wheel cylinder 10A via the hydraulic pressure pipe 58, the electromagnetic valve 59 and the bypass pipe 57. it can.

  When the brake operation is released, the piston 4 in the cylinder 2 returns in the direction indicated by the arrow B, the hydraulic pressure in the hydraulic pressure chamber 8A decreases, and the stroke simulator 51 also returns to the initial position. It is possible to prepare for the next brake operation by returning to the switching position (c) again.

  Next, FIGS. 6 to 9 show a third embodiment of the present invention. The feature of this embodiment is that a hydraulic pressure source for supplying hydraulic pressure to the wheel cylinder is provided between the switching valve and the wheel cylinder. Therefore, the configuration is such that it is provided in the middle of the detour path. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, reference numeral 71 denotes a stroke simulator employed in the present embodiment, and the stroke simulator 71 is configured in substantially the same manner as the stroke simulator 21 described in the first embodiment. However, the stroke simulator 71 in this case has a cylindrical case 72 (described later) in which the pressure accumulating chamber 24, the spring chamber 25, the covered piston 26, the spring 27, and the like are provided in different shapes.

  Reference numeral 72 denotes a cylindrical case as a simulator case that constitutes the outer shell of the stroke simulator 71 together with the lid 23. The cylindrical case 72 is formed in substantially the same manner as the cylindrical case 22 described in the first embodiment. ing. However, the cylindrical case 72 in this case is provided to abut against a poppet valve device 77 described later, and a valve seat 72A is formed on the abutting surface side.

  Reference numeral 73 denotes an attachment member for attaching the stroke simulator 71 to the cylinder 2 via the poppet valve device 77. The attachment member 73 is configured in substantially the same manner as the attachment member 20 described in the first embodiment. A stepped hole 73 </ b> A that is a part of the liquid path 18 is provided. However, as shown in FIG. 7, the cylindrical case 72 is attached to the attachment member 73 in this case via a poppet valve device 77 described later.

  Reference numeral 74 denotes a bypass passage that connects the hydraulic chamber 8A in the cylinder 2 to the wheel cylinder 10A by bypassing the fail-safe valve 12A. The bypass passage 74 is formed in a valve case 78 of a poppet valve device 77 to be described later. The housing hole 78A, the radial hole 82, and a bypass pipe 75 that bypasses the fail safe valve 12A and connects the radial hole 82 to the wheel cylinder 10A.

  Reference numeral 76 denotes a hydraulic pipe connected to the hydraulic unit 13A. The hydraulic pipe 76 is configured in substantially the same manner as the hydraulic pipe 28 described in the first embodiment. However, the hydraulic pipe 76 in this case is different in that the tip end side is connected to a midway portion of the bypass pipe 75.

  Reference numeral 77 denotes a poppet valve device serving as a switching valve that is located in the middle of the bypass passage 30 and communicates and shuts off the hydraulic chamber 8A in the cylinder 2 with respect to the wheel cylinder 10A. The poppet valve device 77 is shown in FIG. A valve case 78 having a valve body accommodating hole 78A formed therein, and a valve body of the valve case 78. A poppet type valve element 79 disposed in the accommodation hole 78A and a valve spring 80 that constantly urges the valve element 79 toward the valve seat 72A of the cylindrical case 72 are configured.

  Here, the base end side of the valve element 79 of the poppet valve device 77 is slidably fitted into the stepped hole 73 </ b> A of the mounting member 73, and the distal end side of the valve element 79 is attached to and detached from the valve seat 72 </ b> A of the cylindrical case 72. Thus, the liquid passage 18 is communicated with or blocked from the bypass pipe 75. Further, a protruding portion 79 </ b> A that protrudes into the pressure accumulating chamber 24 via the valve seat 72 </ b> A of the cylindrical case 72 is provided on the distal end side of the valve body 79.

  The protrusion 79A of the valve body 79 is in contact with the covered piston 26 of the stroke simulator 71 so that the covered piston 26 is displaced in the direction indicated by the arrow D as shown in FIG. It is held in a state of being separated from the valve seat 72A against 80. Further, a fluid hole 81 extending in the axial direction and the radial direction of the valve body 79 is formed in the valve body 79 in order to allow the fluid passage 18 to communicate with the pressure accumulating chamber 24 of the stroke simulator 71.

  Further, the valve case 78 is formed with a radial hole 82 communicating with the internal valve body accommodation hole 78A, and one end side of the bypass pipe 75 is connected to the radial hole 82. The radial hole 82 constitutes a part of the bypass passage 74 together with the valve body accommodation hole 78A in the valve case 78 and the like.

  Thus, in the present embodiment configured as described above, the valve element 79 of the poppet valve device 77 provided between the cylindrical case 72 of the stroke simulator 71 and the mounting member 73 is the valve seat 72A of the cylindrical case 72. The liquid passage 18 is communicated with and disconnected from the bypass pipe 75, so that substantially the same effect as that of the first embodiment can be obtained.

  That is, in the stage before the stroke simulator 71 is operated, the poppet valve device 77 serving as a switching valve is in contact with the covered piston 26 of the stroke simulator 71 at the stage before the stroke simulator 71 is operated. Since the valve body 79 is held in a state of being separated from the valve seat 72A against the valve spring 80, the liquid passage 18 has a liquid hole 81 in the valve body 79, a valve body accommodation hole 78A, and a radial hole 82. And communicated with the wheel cylinder 10 </ b> A via the bypass pipe 75.

  6 is connected to the wheel cylinder 10A via the fluid passage 18, the poppet valve device 77, and the bypass passage 74 (bypass pipe 75), the brake pedal 7 of the cylinder 2 shown in FIG. The hydraulic pressure (invalid input) generated in the hydraulic chamber 8A at the beginning of the step can be supplied to the wheel cylinder 10A side via the bypass passage 74, and the operational feeling at the start of the depression of the brake pedal 7 can be reduced. it can.

  If the depression of the brake pedal 7 is continued at this stage, a higher hydraulic pressure is generated in the hydraulic chamber 8A, so that the covered piston 26 of the stroke simulator 71 resists the spring 27 and the arrow in FIG. Sliding displacement in the indicated C direction. At this time, the valve element 79 of the poppet valve device 77 is seated on the valve seat 72 </ b> A of the cylindrical case 72, so that the liquid passage 18 can be blocked from the radial hole 82 and the bypass pipe 75.

  Further, at this time, even if the brake hydraulic pressure from the hydraulic pressure unit 13A flows back into the valve body accommodating hole 78A via the bypass pipe 75 and the radial hole 82, as shown in FIG. The poppet type valve element 79 seated on the valve seat 72A has the same pressure receiving area in the front and rear in the valve element accommodating hole 78A, so that the valve element 79 is not affected by the reverse flow of the brake hydraulic pressure. The valve can be kept closed.

  For this reason, the hydraulic pressure generated in the hydraulic pressure chamber 8A by the depression operation of the brake pedal 7 does not flow to the wheel cylinder 10A side via the bypass pipe 75 of the bypass passage 74 and the like. At this time, the brake hydraulic pressure corresponding to the depression operation of the brake pedal 7 can be supplied from the hydraulic pressure unit 13A in FIG. 6 to the wheel cylinder 10A via the hydraulic pressure line 76 and the bypass line 75.

  At this time, the spring 27 of the stroke simulator 71 is greatly bent and deformed in the direction of arrow C as shown in FIG. 9 according to the hydraulic pressure generated in the hydraulic pressure chamber 8A, and a part of the hydraulic pressure is stored in the pressure accumulating chamber 24. The reaction force at this time can be transmitted to the brake pedal 7 as a pedal reaction force, and the operational feeling of the brake pedal 7 can be improved.

  On the other hand, when the brake operation is released, as the hydraulic pressure in the hydraulic pressure chamber 8A decreases, the covered piston 26 of the stroke simulator 71 is pushed back to the initial position shown in FIG. The protrusion 79A of the body 79 can be pushed against the valve spring 80 in the direction indicated by the arrow D to prepare for the next brake operation.

  Next, FIGS. 10 to 12 show a fourth embodiment of the present invention. The feature of this embodiment is that a switching valve provided in the middle of the bypass passage is configured as a check valve. In the present embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, 91 is a stroke simulator employed in the present embodiment, and the stroke simulator 91 is configured in substantially the same manner as the stroke simulator 21 described in the first embodiment. However, the stroke simulator 91 in this case has a cylindrical case 92 (to be described later) in which a pressure accumulating chamber 24, a spring chamber 25, a covered piston 26, a spring 27, and the like are provided in different shapes.

  Reference numeral 92 denotes a cylindrical case as a simulator case that constitutes the outer shell of the stroke simulator 91 together with the lid 23. The cylindrical case 92 is formed in substantially the same manner as the cylindrical case 22 described in the first embodiment. ing. However, in this case, the cylindrical case 92 is provided with a reduced diameter portion 92A on one end that is abutted with a mounting member 93 described later, and a check valve 96 described later is provided on the reduced diameter portion 92A side. Yes.

  Reference numeral 93 denotes an attachment member employed in the present embodiment, and the attachment member 93 is configured in substantially the same manner as the attachment member 20 described in the first embodiment. However, in this case, the attachment member 93 is provided with a liquid passage 93A which is a part of the liquid passage 18 and extends in the axial direction as shown in FIG. 10, and a reduced diameter portion 92A of the cylindrical case 92 is described later. Attached together with the check valve 96 in an abutting state.

  Reference numeral 94 denotes a communication passage formed in the reduced diameter portion 92A of the cylindrical case 92. The communication passage 94 extends in the axial direction in the reduced diameter portion 92A, and the liquid passage 93A (liquid passage passage 18) of the mounting member 93 is provided. ) Is communicated with the pressure accumulating chamber 24 of the stroke simulator 91.

  95 is a radial hole on the inlet side that extends in the radial direction of the communication path 94, and the radial hole 95 is located in the reduced diameter portion 92 </ b> A of the cylindrical case 92 and communicates with a later-described valve body receiving hole 97. 94, and is communicated and blocked with respect to the communication path 94 by a ball valve body 100 described later. And the radial direction hole 95 comprises a part of detour passage 102 mentioned later.

  Reference numeral 96 denotes a check valve as a switching valve provided between the reduced diameter portion 92A of the cylindrical case 92 and the attachment member 93. The check valve 96 is radially inward from the outer peripheral surface of the reduced diameter portion 92A. A valve body receiving hole 97 formed as a concave groove extending to the outer periphery of the valve body, and an outlet-side radial hole 98 provided so as to be fitted to the outer peripheral surface of the reduced diameter portion 92A so as to close the valve body receiving hole 97. The cylindrical lid 99, the ball valve body 100 and the valve spring 101 are configured.

  Here, the ball valve body 100 is disposed in the valve body housing hole 97 and is always biased toward the radial hole 95 on the inlet side by the valve spring 101. The ball valve body 100 is configured to selectively communicate and block the radial hole 95 on the inlet side and the radial hole 98 on the outlet side in the valve body housing hole 97 as shown in FIGS. ing.

  Reference numeral 102 denotes a bypass passage employed in the present embodiment. The bypass passage 102 includes a radial hole 95 communicating with the communication passage 94 in the reduced diameter portion 92A, a valve body accommodating hole 97 of the check valve 96 and a cylindrical shape. The lid body 99 includes the radial hole 98, the bypass pipe 75 described in the third embodiment, and the like.

  Thus, in the present embodiment configured as described above, the ball valve body 100 of the check valve 96 provided between the cylindrical case 92 of the stroke simulator 91 and the mounting member 93 is disposed in the valve body accommodating hole 97. By selectively opening and closing the radial hole 95 on the inlet side and the radial hole 98 on the outlet side, it is possible to obtain substantially the same operational effects as in the first embodiment.

  That is, the check valve 96 serving as a switching valve has a hydraulic pressure generated in the liquid passage 18 (the hydraulic pressure chamber 8A illustrated in FIG. 6) before the stroke simulator 91 is operated as shown in FIG. When the ball valve body 100 receives pressure through the communication passage 94 and the radial hole 95, the ball valve body 100 is opened against the valve spring 101 so as to open the radial hole 95 by the hydraulic pressure at this time.

  As a result, the hydraulic pressure at this time flows from the communication path 94 to the bypass pipe 75 and the wheel cylinder 10 </ b> A via the radial hole 95, the valve body accommodation hole 97, the radial hole 98, and the like. For this reason, the hydraulic pressure (invalid input) generated in the hydraulic pressure chamber 8A (see FIG. 6) at the start of the depression of the brake pedal 7 can be supplied to the wheel cylinder 10A side via the bypass passage 102. The feeling of operation at the beginning of stepping 7 can be lightened.

  If the depression of the brake pedal 7 is continued at this stage, a higher hydraulic pressure is generated in the hydraulic chamber 8A. Therefore, the covered piston 26 of the stroke simulator 91 resists the spring 27 and the arrow in FIG. Trying to slide in the indicated C direction. However, at this time, the brake fluid pressure from the fluid pressure unit 13A exceeds the fluid pressure in the fluid pressure chamber 8A, and this brake fluid pressure causes the ball valve body 100 to move toward the radial hole 95 as shown in FIG. Will sit down.

  Therefore, the fluid passage 18 (the communication passage 94, the radial hole 95 side) can be blocked from the radial hole 98 and the bypass pipe 75, and the hydraulic pressure generated in the hydraulic chamber 8A by depressing the brake pedal 7 is bypassed. There is no escape to the wheel cylinder 10A side via the bypass pipe 75 of the passage 102 or the like. At this time, the brake hydraulic pressure corresponding to the depression operation of the brake pedal 7 can be supplied from the hydraulic pressure unit 13A illustrated in FIG. 6 to the wheel cylinder 10A via the hydraulic pressure piping 76 and the bypass piping 75.

  At this time, the spring 27 of the stroke simulator 91 is greatly bent and deformed in the direction of arrow C as shown in FIG. 12 according to the hydraulic pressure generated in the hydraulic pressure chamber 8A. The reaction force at this time can be transmitted to the brake pedal 7 as a pedal reaction force, and the operational feeling of the brake pedal 7 can be improved.

  On the other hand, when the brake operation is released, as the hydraulic pressure in the hydraulic pressure chamber 8A decreases, the covered piston 26 of the stroke simulator 91 is pushed back to the initial position shown in FIG. The ball valve body 100 of the stop valve 96 can be prepared for the next brake operation while being urged toward the radial hole 95 by the valve spring 101.

  In the third embodiment, the case where the poppet valve device 77 as a switching valve is provided between the cylindrical case 72 of the stroke simulator 71 and the mounting member 73 has been described as an example. However, the present invention is not limited to this. For example, the hydraulic chamber 8A in the cylinder 2 communicates with the wheel cylinder 10A in the middle of the bypass pipe 75 between the stroke simulator 71 and the hydraulic pipe 76. A switching valve such as a solenoid valve to be shut off may be provided. This point is the same as in the fourth embodiment.

  In the first embodiment, the case where the one end side (the radial hole 31 or the like) of the bypass passage 30 is connected between the liquid passage 18 and the pressure accumulating chamber 24 of the stroke simulator 21 will be described as an example. did. However, the present invention is not limited to this, for example, a configuration in which one end side of the bypass passage is connected to the hydraulic pressure chamber 8A of the cylinder 2 at a position different from the liquid passage 18 and a switching valve is provided in the middle of the bypass passage. It is good. This also applies to the second to fourth embodiments.

1 is a brake hydraulic circuit diagram showing a master cylinder device according to a first embodiment of the present invention. It is principal part sectional drawing which expands and shows the stroke simulator in FIG. 1 with a spool valve. It is sectional drawing in the same position as FIG. 2 which shows the state which the stroke simulator started operating. It is sectional drawing in the same position as FIG. 2 which shows the state which the spring of the stroke simulator bent greatly and deformed. It is a brake hydraulic-pressure circuit diagram which shows the brake device by 2nd Embodiment. It is a brake fluid pressure circuit diagram showing the master cylinder device by a 3rd embodiment. It is principal part sectional drawing which expands and shows the stroke simulator in FIG. 6 with a poppet valve apparatus. It is sectional drawing in the same position as FIG. 7 which shows the state which the stroke simulator started operating. It is sectional drawing in the position similar to FIG. 7 which shows the state which the spring of the stroke simulator bent greatly and deformed. It is principal part sectional drawing which expands and shows the stroke simulator by 4th Embodiment with a non-return valve. It is sectional drawing in the same position as FIG. 10 which shows the state which the stroke simulator started operating. It is sectional drawing in the position similar to FIG. 10 which shows the state which the spring of the stroke simulator bent greatly and deformed.

Explanation of symbols

1 Master cylinder device 2 Cylinder (master cylinder)
3 Reservoir 4 First piston (piston)
5 Second piston 7 Brake pedal 8A, 8B Hydraulic chamber 9A, 9B Return spring 10A, 10B Wheel cylinder 11A, 11B Brake piping 12A, 12B Fail safe valve 13A, 13B Hydraulic unit (hydraulic pressure source)
14A, 14B Hydraulic pump 16A, 16B Supply valve 17A, 17B Discharge valve 18 Fluid passage 19 Tilt valve (open / close valve)
20, 73, 93 Mounting member 21, 51, 71, 91 Stroke simulator 22, 72, 92 Cylindrical case 24, 52 Pressure accumulating chamber 26, 53 Covered piston 27, 54 Spring (elastic body)
28, 58, 76 Hydraulic piping 30, 55, 74, 102 Bypass passage 31, 82, 95, 98 Radial hole 32, 57.75 Bypass piping 33 Spool valve (switching valve)
34 Spool 35, 80, 101 Valve spring 38, 39 Annular groove 40, 60 Control unit (control device)
56 Branch line 59 Solenoid valve (switching valve)
61 Stroke sensor 72A Valve seat 77 Poppet valve device (switching valve)
79 Valve body 96 Check valve (switching valve)
100 ball disc

Claims (6)

A master cylinder that is connected to a wheel cylinder on the wheel side via a brake pipe and generates a hydraulic pressure corresponding to a brake operation in an internal hydraulic pressure chamber, and a hydraulic pressure applied to the wheel cylinder separately from the hydraulic pressure chamber of the master cylinder A hydraulic pressure source to be supplied, and a fail-safe valve provided in the middle of the brake pipe for selectively supplying the hydraulic pressure from the hydraulic pressure source and the hydraulic pressure from the hydraulic pressure chamber of the master cylinder to the wheel cylinder The master cylinder accumulates the hydraulic pressure in the hydraulic pressure chamber and generates a brake reaction force when the hydraulic chamber of the master cylinder and the wheel cylinder are shut off by the fail-safe valve. In a brake device provided with a stroke simulator
A bypass passage for bypassing the failsafe valve and connecting the hydraulic chamber of the master cylinder to the wheel cylinder;
The hydraulic pressure chamber of the master cylinder is communicated with the wheel cylinder through the bypass passage until the stroke simulator is activated by a brake operation provided in the middle of the bypass passage. A brake device comprising: a switching valve that shuts off the chamber from the wheel cylinder.   2. The brake device according to claim 1, wherein the switching valve is configured to selectively communicate and block the hydraulic pressure chamber of the master cylinder and the hydraulic pressure source with respect to the wheel cylinder.   2. The brake device according to claim 1, wherein the hydraulic pressure source is provided between the switching valve and a wheel cylinder and provided in the middle of the bypass passage.   4. The brake according to claim 1, wherein the bypass passage has a configuration in which one end side is connected between a hydraulic chamber of the master cylinder and a stroke simulator and the other end side is connected to the wheel cylinder side. apparatus.   5. The brake device according to claim 4, wherein the switching valve is disposed between the hydraulic chamber of the master cylinder and a stroke simulator and is provided in the middle of the bypass passage. A bottomed cylindrical cylinder, a piston that is slidable in the cylinder and that is displaced in the axial direction in response to a brake operation, and is defined in the cylinder by the piston as a wheel cylinder on the wheel side. The hydraulic pressure generated in the hydraulic chamber by the brake operation when the hydraulic chamber connected via the failsafe valve and the hydraulic chamber and the wheel cylinder are blocked by the failsafe valve In a master cylinder device comprising a stroke simulator that accumulates pressure and generates a brake reaction force,
A bypass passage for bypassing the failsafe valve and connecting the hydraulic chamber of the master cylinder to the wheel cylinder;
The hydraulic pressure chamber of the master cylinder is communicated with the wheel cylinder through the bypass passage until the stroke simulator is activated by a brake operation and is provided in the middle of the bypass passage. A master cylinder device comprising a switching valve for shutting off the chamber from the wheel cylinder.

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