JP5126039B2 - Master cylinder with built-in stroke simulator - Google Patents

Description

  The present invention relates to a master cylinder employed in a vehicle hydraulic brake device, and more particularly to a master cylinder incorporating a stroke simulator.

A hydraulic brake device for a vehicle that employs a master cylinder with a built-in stroke simulator is disclosed in, for example, Patent Literature 1 or Patent Literature 2 below, and includes a hydraulic pressure control device including an external hydraulic pressure source (for example, a hydraulic pump). Therefore, in the normal state, the communication between the master hydraulic chamber of the master cylinder (formed in the cylinder bore of the cylinder body) and the wheel cylinder is shut off, and the external liquid is adjusted according to the movement of the brake operation member. The hydraulic pressure supplied from the pressure source is adjusted and supplied to the wheel cylinder. When the hydraulic pressure control device is abnormal, the master hydraulic pressure chamber of the master cylinder and the wheel cylinder are communicated with each other, The hydraulic pressure according to the operating force is configured to be supplied from the master hydraulic pressure chamber of the master cylinder to the wheel cylinder.
JP 2004-359215 A JP 2005-170361 A

  In the hydraulic brake device described in Patent Document 1 described above, the stroke simulator includes an inner hole provided in the axial center of the master cylinder piston (an inner hole formed coaxially with the cylinder inner hole of the cylinder body). ) Is mounted so as to be movable in the axial direction, and a simulator hydraulic pressure chamber is formed in the forward direction. The stroke simulator piston is pushed forward in accordance with the operating force of the brake operating member, and the stroke provided in the simulator hydraulic pressure chamber. A simulator spring for biasing the simulator piston backward is provided.

  In this stroke simulator, when the hydraulic pressure control device is normal, that is, when the communication between the master hydraulic pressure chamber of the master cylinder and the wheel cylinder is interrupted, it is pushed forward according to the operating force of the brake operating member. As the stroke simulator piston moves forward, the master cylinder piston moves forward by a predetermined amount (idle stroke amount) from the initial position, and the master hydraulic chamber is provided to the master cylinder piston even after the communication with the reservoir is shut off. The simulator hydraulic chamber is set to communicate with the reservoir through the communication passage that is always in communication with the simulator hydraulic chamber and the communication passage that is provided in the cylinder body and that is in constant communication with the reservoir. Brake operation by moving forward against the spring Is configured to stroke is generated corresponding to the brake operating force to wood.

  On the other hand, in the hydraulic brake device described in Patent Literature 2 described above, the stroke simulator is formed coaxially with an inner hole (in the cylinder inner hole of the cylinder body) provided in the axis of the master cylinder piston. Stroke simulator piston which is assembled to the inner hole) so as to be movable in the axial direction, forms a simulator hydraulic pressure chamber in the forward direction, and is pushed forward according to the operating force of the brake operating member, and provided in the simulator hydraulic pressure chamber And a simulator spring for biasing the stroke simulator piston backward.

  In this stroke simulator, when the hydraulic pressure control device is normal, that is, when the communication between the master hydraulic pressure chamber of the master cylinder and the wheel cylinder is interrupted, it is pushed forward according to the operating force of the brake operating member. As the stroke simulator piston moves forward, the master cylinder piston moves forward by a predetermined amount (idle stroke amount) from the initial position, and the master hydraulic chamber is provided to the master cylinder piston even after the communication with the reservoir is shut off. The simulator hydraulic chamber is connected to the reservoir through the communication passage always communicating with the simulator hydraulic chamber, the annular communication passage formed between the master cylinder piston and the cylinder body, and the communication passage provided in the cylinder body and always communicating with the reservoir. Is set to communicate with the stroke simulator piston By moving forward against the emulator unit spring, and is configured to stroke is generated corresponding to the brake operating force to the brake operating member.

  By the way, although the stroke simulator described in Patent Document 1 described above has various advantages, the communication / blocking of the master hydraulic pressure chamber and the reservoir is provided in the master cylinder piston and always communicates with the master hydraulic pressure chamber. Connected to the communication passage (first communication passage), the communication passage (second communication passage) provided in the cylinder body and always communicating with the reservoir, and the cylinder bore of the cylinder body for axial movement of the master cylinder piston. Accordingly, an annular seal member that communicates and blocks between the first communication path and the second communication path is configured. In addition, the communication / blocking between the simulator hydraulic chamber and the reservoir is provided in the master cylinder piston and is always in communication with the simulator hydraulic chamber (third communication passage), the second communication passage described above, and the cylinder body. An annular seal member that is assembled in the cylinder bore and communicates and blocks between the third communication path and the second communication path according to the axial movement of the master cylinder piston is configured. It is also used.

  Therefore, according to the axial movement of the master cylinder piston, the radially outer end of the first communication passage passes while engaging the inner peripheral portion of the annular seal member described above, and the third communication passage radially outwards. The end passes while engaging with the inner peripheral portion of the annular seal member, and the radial outer end of the (first or third) communication path engages with the inner peripheral portion of the annular seal member. The frequency of passing is high, and the inner peripheral portion of the annular seal member is easily damaged.

  On the other hand, although the stroke simulator described in Patent Document 2 described above has various advantages, the communication / blocking of the simulator hydraulic chamber and the reservoir is an annular communication path formed between the master cylinder piston and the cylinder body. The annular seal member that is assembled to the outer periphery of the master cylinder piston and can open and close the annular communication passage according to the axial movement of the master cylinder piston is configured. For this reason, in the state where the above-described annular communication path is closed by the annular seal member, the annular seal member is slidably engaged with the cylinder bore of the cylinder body, and between the cylinder body and the annular seal member. The movement of the master cylinder piston may be harmed by the generated sliding resistance.

  The present invention has been made to solve the above-described problems. A master cylinder with a built-in stroke simulator has a cylinder bore that is assembled to a vehicle body, and a front portion of the cylinder bore in the cylinder body. A master cylinder piston which is assembled so as to be movable in the cylinder axial direction and forms a master hydraulic pressure chamber which communicates and shuts off with respect to the reservoir in the front, and a cylinder at the rear portion of the cylinder bore in the cylinder body A simulator hydraulic pressure chamber that is assembled so as to be movable in the axial direction and communicated with and cut off from the reservoir is formed between the piston and the master cylinder piston, and is pushed forward according to the operating force of the brake operating member. Stroke simulator piston and the master cylinder piston provided behind the master hydraulic pressure chamber A master cylinder spring for biasing, a simulator spring interposed between the master cylinder piston and the stroke simulator piston in the simulator hydraulic pressure chamber to bias the stroke simulator piston backward, and the simulator hydraulic pressure The cylinder body is provided with a positioning mechanism for defining an initial position of the master cylinder piston, and the cylinder body is provided with a communication path for communicating the simulator hydraulic pressure chamber and the reservoir, and the stroke A cut that moves integrally with the master cylinder piston when the master cylinder piston moves forward by a predetermined amount from the initial position as the simulator piston moves forward and the master hydraulic chamber is disconnected from the reservoir. The member is a simulator of the communication path. Is characterized in that the spaced set amount in the axial direction from the chromatography data hydraulic chamber side opening. In this case, the pressure receiving area of the master cylinder piston can be set larger than the pressure receiving area of the stroke simulator piston.

  In the hydraulic brake device for a vehicle adopting the master cylinder with a built-in stroke simulator according to the present invention, the communication between the master hydraulic chamber of the master cylinder and the wheel cylinder is cut off by the hydraulic control device including the external hydraulic pressure source at the normal time. In addition, the hydraulic pressure supplied from the external hydraulic pressure source is adjusted according to the movement of the brake operation member and supplied to the wheel cylinder. Also, when the hydraulic control device is abnormal, the master hydraulic chamber of the master cylinder And the wheel cylinder are in communication with each other, and the hydraulic pressure corresponding to the operating force of the brake operating member is supplied from the master hydraulic pressure chamber of the master cylinder to the wheel cylinder.

  Further, in the master cylinder with a built-in stroke simulator according to the present invention, the stroke simulator is assembled so as to be movable in the cylinder axial direction at the rear part of the cylinder bore in the cylinder body, and is connected to the reservoir between the master cylinder piston. A simulator hydraulic pressure chamber that is communicated and cut off is formed, and a stroke simulator piston that is pushed forward according to the operating force of the brake operating member, and between the master cylinder piston and the stroke simulator piston in the simulator hydraulic pressure chamber A simulator spring that is interposed and biases the stroke simulator piston backward is provided.

  Further, the cylinder body is provided with a communication passage for communicating the simulator hydraulic pressure chamber and the reservoir, and the master cylinder piston is moved in accordance with the advancement of the stroke simulator piston that is pushed forward according to the operation force of the brake operation member. When the master hydraulic chamber is disconnected from the reservoir by a predetermined amount from the initial position, the master cylinder is assembled to one component of a positioning mechanism that can be engaged and disengaged from the master cylinder piston. A cut member that moves integrally with the piston is spaced apart from the opening of the communication passage in the simulator hydraulic pressure chamber side by a set amount in the axial direction.

  For this reason, when the hydraulic pressure control device is normal, that is, when the communication between the master hydraulic chamber of the master cylinder and the wheel cylinder is interrupted, the master cylinder piston moves forward by a predetermined amount from the initial position and the master hydraulic chamber is In a state where communication with the reservoir is blocked, the cutting member is axially spaced from the simulator hydraulic pressure chamber side opening of the communication path, and the simulator hydraulic pressure chamber and the reservoir communicate with each other through the communication path. Yes. Therefore, even when the master cylinder piston cannot move forward, the stroke simulator piston can move forward, and the stroke simulator piston moves forward against the simulator spring, so that the brake operation member can be braked. A stroke corresponding to the force is generated.

  On the other hand, when the hydraulic pressure control device is abnormal, that is, when the master hydraulic chamber of the master cylinder and the wheel cylinder are in communication, the stroke simulator piston that is pushed forward according to the operating force of the brake operating member moves forward. Accordingly, even after the master cylinder piston moves forward by a predetermined amount from the initial position and the master hydraulic chamber is disconnected from the reservoir, the master hydraulic chamber is in communication with the wheel cylinder and the master cylinder piston moves forward. Further, the simulator hydraulic pressure chamber and the reservoir communicate with each other through the communication passage, and the stroke simulator piston can move forward.

  Thus, when the master cylinder piston advances a predetermined amount from the initial position and further advances a set amount, the cut member that moves integrally with the master cylinder piston comes into contact with the simulator hydraulic pressure chamber side opening of the communication path and opens the opening. By closing, the communication between the simulator hydraulic chamber and the reservoir is blocked. Therefore, after that, with the simulator hydraulic chamber shut off from the reservoir and sealed, the master cylinder piston moves forward with the advancement of the stroke simulator piston, and the fluid according to the operating force of the brake operating member. Pressure is supplied to the wheel cylinder from the master hydraulic chamber of the master cylinder.

  By the way, in the present invention, a cut member that is assembled to one constituent member of a positioning mechanism that can be engaged and disengaged with respect to the master cylinder piston and moves integrally with the master cylinder piston is provided in the cylinder body. The simulator hydraulic pressure chamber and the reservoir are blocked from communicating with each other by closing the opening in contact with the simulator hydraulic pressure chamber side opening of the communication path for communicating the pressure chamber and the reservoir. For this reason, the cut member does not slide with respect to the cylinder body provided with the communication path, the cut member is not easily damaged by the simulator hydraulic pressure chamber side opening of the communication path, and the function is stable for a long time. Obtained.

  Further, according to the present invention, when the hydraulic pressure control device is abnormal, the master cylinder piston moves forward with the advancement of the stroke simulator piston in a state where the simulator hydraulic pressure chamber is shut off from the reservoir by the cut member and sealed. When doing so, the master cylinder piston is disengaged forward from one component of the positioning mechanism and is pushed forward by the fluid pressure in the simulator fluid pressure chamber. Therefore, the cut member does not give sliding resistance to the master cylinder piston, and the movement of the master cylinder piston is not harmed by the cut member.

  Further, when the pressure receiving area of the master cylinder piston is set larger than the pressure receiving area of the stroke simulator piston when the present invention is implemented, the pressure receiving area of the master cylinder piston is smaller than the pressure receiving area of the stroke simulator piston. Alternatively, the hydraulic pressure generated in the master hydraulic chamber of the master cylinder can be increased by pushing the master cylinder piston forward by the hydraulic pressure in the simulator hydraulic pressure chamber, as compared to the case where they are set equal. The stroke simulator built-in master cylinder can be provided with an assisting function (pressure increasing function).

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 schematically shows a hydraulic brake device for a vehicle adopting a master cylinder SMC with a built-in stroke simulator according to the present invention (hereinafter simply referred to as a master cylinder SMC in the embodiment). The master cylinder SMC and four brake wheel cylinders HC1, HC2, HC3, HC4 for braking each wheel are provided, and the hydraulic pressure provided between the master cylinder SMC and each brake wheel cylinder HC1, HC2, HC3, HC4 A control device 100 is provided.

  As shown in FIGS. 1 and 2, the master cylinder SMC includes a cylinder body 10 that is assembled to the vehicle body VB and has a stepped cylinder inner hole 10a, and a rear portion of the cylinder inner hole 10a in the cylinder body 10 ( The stroke simulator piston 21 assembled on the right side in the figure and a pair of master cylinder pistons 31 and 41 assembled on the front part (left side in the figure) of the cylinder bore 10a in the cylinder body 10 are provided. A pair of large and small simulator springs 22 and 23 for urging the piston 21 rearward, a master cylinder first spring 32 for urging the rear master cylinder piston (master cylinder first piston) 31 rearward, and a front master cylinder After piston (master cylinder second piston) 41 And a master cylinder second spring 42 for biasing.

  The cylinder body 10 includes connection ports 11a and 11b connected to a reservoir R that stores brake fluid, and a main body 11 that includes outlet ports 11c and 11d connected to pipes 111 and 112 of the hydraulic pressure control device 100. The guide sleeve 14 is assembled in a liquid-tight manner behind the main body 11 via an O-ring 12 and is prevented from coming off by a C-ring 13.

  The stroke simulator piston 21 is assembled to a rear portion of the cylinder bore 10a (inside the guide sleeve 14) via a pressure cup 24 so as to be fluid-tight and movable in the cylinder axial direction. A simulator hydraulic pressure chamber 25 is formed between the first hydraulic pressure chamber 31 and the second hydraulic pressure chamber 31. The stroke simulator piston 21 is detachably engaged with the front end portion of the guide sleeve 14 by a hook formed on the outer periphery of the front end portion, and is connected to a brake pedal 92 as a brake operation member via a rod 91. And is configured to move back and forth according to the movement of the brake pedal 92. The movement of the brake pedal 92 is detected by the stroke sensor SS and is input to the electric control unit ECU.

  The small-diameter simulator spring 22 is interposed between the stroke simulator piston 21 and the retainer 51, and the set load is set to f22. The large-diameter simulator spring 23 is interposed between the retainer 51 and the holder 52, and the set load is set to f23 (f23> f22).

  The simulator fluid pressure chamber 25 is a fluid pressure chamber that communicates with the reservoir R through the axial communication hole 11e provided in the main body 11 of the cylinder body 10 and the connection port 11a, and is provided with a pair of large and small simulator springs 22 and 23. A rear positioning mechanism 50 that defines the initial position of the master cylinder first piston 31 is interposed. The rear positioning mechanism 50 includes a retainer 51 assembled to the guide sleeve 14 so as to be engageable / detachable, a holder 52 assembled to the master cylinder first piston 31 so as to be engageable / detachable, and a holder 52 The rod 53 is fixed to the retainer 51 and supports the retainer 51 so that it can move a predetermined amount forward from the illustrated position.

  The master cylinder first piston 31 is assembled in a fluid-tight manner in the cylinder axial direction through a primary cup 33 and a pressure cup 34 at an intermediate portion of the cylinder inner hole 10a, and is forwardly moved to the first master hydraulic pressure. A chamber 35 is formed, and an atmospheric pressure chamber 36 is formed between the primary cup 33 and the pressure cup 34.

  The master cylinder first spring 32 is provided in the first master hydraulic pressure chamber 35 and is interposed between the retainer 61 and the stopper 62 of the central positioning mechanism 60, and the set load is set to f32. The central positioning mechanism 60 defines an initial separation distance between the master cylinder first piston 31 and the master cylinder second piston 41, and is interposed in the first master hydraulic chamber 35, so that the master cylinder first piston The retainer 61 assembled to the piston 31, the stopper 62 that engages with the master cylinder second piston 41, and the retainer 61 fixed to the retainer 61 so as to be movable forward by a predetermined amount from the illustrated position. A rod 63 is used.

  The first master hydraulic chamber 35 is a hydraulic chamber that communicates with the atmospheric pressure chamber 36 through a radial communication hole 31a provided in the master cylinder first piston 31 in the illustrated state, and the master cylinder first piston 31 is illustrated. By moving a predetermined amount forward from the initial position and the communication between the communication hole 31a and the atmospheric pressure chamber 36 is blocked by the primary cup 33, the communication with the atmospheric pressure chamber 36 is blocked and sealed. ing. The atmospheric pressure chamber 36 is a hydraulic pressure chamber that is always in communication with the connection port 11 a and is always in communication with the reservoir R.

  The master cylinder second piston 41 is assembled in a fluid-tight manner in the cylinder axial direction through a primary cup 43 and a pressure cup 44 at a front portion of the cylinder inner hole 10a. A chamber 45 is formed, and an atmospheric pressure chamber 46 is formed between the primary cup 43 and the pressure cup 44. The master cylinder second piston 41 is engaged with the master cylinder first piston 31 via the master cylinder first spring 32 and the central positioning mechanism 60, and the master cylinder first piston 31 according to the movement of the brake pedal 92. It is comprised so that it may move back and forth. The pressure receiving area of the master cylinder second piston 41 is set to be the same as the pressure receiving area of the master cylinder first piston 31.

  The master cylinder second spring 42 is provided in the second master hydraulic chamber 45 and is interposed between the retainer 71 and the stopper 72 of the front positioning mechanism 70, and the set load is set to f42 (f42 = f32). Has been. The front positioning mechanism 70 defines an initial position of the master cylinder second piston 41, is interposed in the second master hydraulic chamber 45, and includes a retainer 71 assembled to the master cylinder second piston 41. A stopper 72 that engages with the main body 11 and a rod 73 that is fixed to the retainer 71 and is assembled to the stopper 72 so as to be movable a predetermined amount forward from the illustrated position.

  The second master hydraulic chamber 45 is a hydraulic chamber that communicates with the atmospheric pressure chamber 46 through a radial communication hole 41a provided in the master cylinder second piston 41 in the illustrated state, and the master cylinder second piston 41 is illustrated. By moving a predetermined amount forward from the initial position and the communication between the communication hole 41a and the atmospheric pressure chamber 46 is blocked by the primary cup 43, the communication with the atmospheric pressure chamber 46 is blocked and sealed. ing. The atmospheric pressure chamber 46 is a hydraulic pressure chamber that is always in communication with the connection port 11 b and is always in communication with the reservoir R.

  By the way, in this master cylinder SMC, an annular rubber cut member 80 is fixed to the front surface of a holder 52 which is a constituent member of the rear positioning mechanism 50. When the holder 52 is engaged with the master cylinder first piston 31 and moves integrally with the master cylinder first piston 31, the cut member 80 moves integrally with the master cylinder first piston 31. Along with advancement of the stroke simulator piston 21, when both master cylinder pistons 31, 41 advance by a predetermined amount from the illustrated initial position and the respective master hydraulic pressure chambers 35, 45 are disconnected from the reservoir R, the communication holes 11e is set so as to be spaced apart from the simulator hydraulic pressure chamber side opening (rear end) by a set amount in the axial direction (so that the simulator hydraulic pressure chamber 25 and the reservoir R communicate with each other through a communication path including the communication hole 11e and the connection port 11a). Has been.

  In the master cylinder SMC, the set load f22 of the small-diameter simulator spring 22 is smaller than the set load f23 of the large-diameter simulator spring 23, and the set load f23 of the large-diameter simulator spring 23 is set. Is set to be larger than the set loads f32 and f42 of the master cylinder springs 32 and 42 (f23> f32 = f42> f22), and both the master cylinder pistons 31 and 41 and the stroke simulator piston 21 move the brake pedal 53. It is configured to move back and forth in response to. Further, the pressure receiving area of both the master cylinder pistons 31 and 41 (the diameter of the cylinder bore 10a at the part where the master cylinder pistons 31 and 41 are assembled) is the pressure receiving area of the stroke simulator piston 21 (the part where the stroke simulator piston 21 is assembled). The diameter of the cylinder inner hole 10a).

  The hydraulic pressure control device 100 is known per se and includes two systems of brake hydraulic pressure circuits 110 (pipes 111 and 112) that connect the master cylinder SMC and the brake wheel cylinders HC1, HC2, HC3, and HC4. In addition, a pair of separation valves V1, V2, an external hydraulic pressure supply source P, a pressure control valve device Vo, and an electric control device ECU are provided.

  One isolation valve V1 is a normally open type two-port two-position on-off valve, and is interposed in a pipe line 111 that connects the first master hydraulic chamber 35 of the master cylinder SMC and the brake wheel cylinders HC1 and HC2. Therefore, the conduit 111 can be communicated and blocked, and the opening / closing operation is controlled by the electric control unit ECU. The other separation valve V2 is a normally open type two-port two-position opening / closing valve, and is interposed in a pipe line 112 connecting the second master hydraulic chamber 45 of the master cylinder SMC and the brake wheel cylinders HC3, HC4. Therefore, the conduit 112 can be communicated and blocked, and the opening / closing operation is controlled by the electric control unit ECU.

  The external hydraulic pressure supply source P can supply hydraulic pressure to the brake wheel cylinders HC1, HC2, HC3, HC4 via the pressure control valve device Vo when both the separation valves V1, V2 are in the shut-off state. An electric motor 121 whose operation is controlled by the electric control unit ECU, a hydraulic pump 122 driven by the electric motor 121, and an accumulator 123 that stores the hydraulic fluid discharged from the hydraulic pump 122 are provided.

  The pressure control valve device Vo controls various hydraulic pressures supplied to the brake wheel cylinders HC1, HC2, HC3 and HC4 from the external hydraulic pressure supply source P when both the separation valves V1 and V2 are in the shut-off state. Control valves (not shown) are provided, and the operation of these control valves is controlled by the electric control unit ECU, whereby normal brake control, anti-skid control, or traction control is performed. The electric control unit ECU is configured to receive various detection signals necessary for normal brake control, anti-skid control or traction control.

  In this embodiment configured as described above, at the time of normal brake control, if the hydraulic control device 100 is normal, when the brake pedal 92 is depressed, both the separation valves V1, V2 are shut off by the electric control device ECU. In accordance with the movement of the brake pedal 92, the hydraulic pressure supplied from the external hydraulic pressure source P is adjusted by the pressure control valve device Vo and supplied to each brake wheel cylinder HC1, HC2, HC3, HC4. The

  Further, if the hydraulic pressure control device 100 is abnormal during normal brake control, when the brake pedal 92 is depressed, both the separation valves V1 and V2 are brought into communication with each other by the electric control device ECU. The hydraulic pressure corresponding to the pressure is supplied from the master hydraulic pressure chambers 35, 45 of the master cylinder SMC to the brake wheel cylinders HC1, HC2, HC3, HC4.

  By the way, in the master cylinder SMC of this embodiment, the stroke simulator is assembled so as to be movable in the cylinder axial direction at the rear portion of the cylinder bore 10a in the cylinder body 10 to form the simulator hydraulic pressure chamber 25 in the front. The stroke simulator piston 21 that is pushed forward in response to the operating force of the brake pedal 92 and the master cylinder first piston 31 and the stroke simulator piston 21 that are interposed in the simulator hydraulic pressure chamber 25 are used to Simulator section springs 22 and 23 for urging rearward are provided.

  The cylinder body 10 is provided with a communication path (connection port 11a, communication hole 11e) for communicating the simulator hydraulic pressure chamber 25 and the reservoir R, and is pushed forward according to the operating force of the brake pedal 92. When the master cylinder pistons 31 and 41 advance by a predetermined amount from the initial position as the stroke simulator piston 21 moves forward, and the master hydraulic chambers 35 and 45 are disconnected from the reservoir R, the master cylinder piston A cutting member 80 that is assembled to a holder 52 that can be engaged / disengaged with respect to one piston 31 and moves integrally with the first piston 31 of the master cylinder is set in the axial direction from the simulator hydraulic pressure chamber side opening of the communication hole 11e. The simulator hydraulic pressure chamber 25 and the reservoir R communicate with each other through a communication path (connection port 11a, communication hole 11e). There.

  Therefore, when the hydraulic control device 100 is normal, that is, the communication between the master hydraulic chambers 35, 45 of the master cylinder SMC and the brake wheel cylinders HC1, HC2, HC3, HC4 is blocked by the two separation valves V1, V2. In the state where both master cylinder pistons 31 and 41 are advanced by a predetermined amount from the initial position and the respective master hydraulic pressure chambers 35 and 45 are disconnected from the reservoir R, the communication passage (connection port 11a, Even if the simulator hydraulic pressure chamber 25 and the reservoir R communicate with each other through the communication hole 11e) and the master cylinder pistons 31 and 41 cannot move forward, the stroke simulator piston 21 can move forward. 21 moves forward against the simulator springs 22 and 23, so that Is configured to stroke is generated corresponding to the brake operating force to the pedal 92.

  On the other hand, when the hydraulic control device 100 is abnormal, that is, when the master hydraulic chambers 35, 45 of the master cylinder SMC are in communication with the brake wheel cylinders HC1, HC2, HC3, HC4, the operating force of the brake pedal 92 As the stroke simulator piston 21 pushed forward in response to the forward movement, the master cylinder pistons 31 and 42 advance by a predetermined amount from the initial position, and the master hydraulic pressure chambers 35 and 45 communicate with the reservoir R. The master hydraulic chambers 35 and 45 are in communication with the brake wheel cylinders HC1, HC2, HC3 and HC4 even after being shut off, and both the master cylinder pistons 31 and 42 can move forward, The simulator hydraulic chamber 25 and the reservoir R communicate with each other through the communication path (connection port 11a, communication hole 11e). Rourke simulator piston 21 is movable forward.

  Thus, when the master cylinder pistons 31 and 41 advance a predetermined amount from the initial position and further advance by a set amount, the cut member 80 that moves integrally with the master cylinder first piston 31 opens the communication hole 11e to the simulator hydraulic pressure chamber side. By closing the opening, the communication between the simulator hydraulic chamber 25 and the reservoir R is blocked. Therefore, thereafter, in the state where the simulator hydraulic pressure chamber 25 is closed and sealed with the reservoir R, both the master cylinder pistons 31 and 41 move forward as the stroke simulator piston 21 moves forward, and the brake pedal 92 is moved forward. The hydraulic pressure corresponding to the operating force is supplied from the master hydraulic pressure chambers 35, 45 of the master cylinder SMC to the brake wheel cylinders HC1, HC2, HC3, HC4.

  By the way, in this embodiment, the cut member 80 that is assembled to the holder 52 of the rear positioning mechanism 50 that can be engaged / disengaged with respect to the master cylinder first piston 31 and moves integrally with the master cylinder first piston 31 is provided. The simulator fluid pressure chamber 25 is connected to the simulator fluid pressure chamber side opening of the communication hole 11e provided in the cylinder body 10 to communicate the simulator fluid pressure chamber 25 and the reservoir R in the axial direction. The communication of the reservoir R is configured to be blocked. For this reason, the cut member 80 does not slide with respect to the cylinder body 10 provided with the communication path (connection port 11a, communication hole 11e), and the cut member 80 is on the simulator hydraulic pressure chamber side of the communication hole 11e. It is difficult to be damaged by the opening, and its function can be stably obtained for a long time.

  Further, in this embodiment, when the hydraulic pressure control device 100 is abnormal, the simulator fluid pressure chamber 25 is blocked from communicating with the reservoir R by the cut member 80 and sealed, and the stroke simulator piston 21 moves forward. When the master cylinder pistons 31 and 41 move forward, the master cylinder first piston 31 disengages from the holder 52 of the rear positioning mechanism 50 and is pushed forward by the fluid pressure in the simulator fluid pressure chamber 25. . Therefore, the cut member 80 does not give sliding resistance to the master cylinder pistons 31 and 41, and the movement of the master cylinder pistons 31 and 41 is not harmed by the cut member 80.

  In this embodiment, since the pressure receiving areas of the master cylinder pistons 31 and 41 are set larger than the pressure receiving area of the stroke simulator piston 21, the pressure receiving area of the master cylinder piston (31, 41) is set to the stroke simulator piston (21 The master cylinder pistons 31 and 41 are pushed forward by the hydraulic pressure in the simulator hydraulic pressure chamber 25 as compared to the case where the pressure receiving area is set to be smaller or equal to the pressure receiving area of The hydraulic pressure generated in both the master hydraulic pressure chambers 35 and 45 can be increased, and the master cylinder SMC can have an assisting function (pressure increasing function).

  In the above-described embodiment, the case where the pressure receiving area of the master cylinder pistons 31 and 41 is set larger than the pressure receiving area of the stroke simulator piston 21 has been described. The pressure receiving area may be set equal to the pressure receiving area of the stroke simulator piston, and the pressure receiving area of the master cylinder piston may be set smaller than the pressure receiving area of the stroke simulator piston.

  In the above-described embodiment, the stroke simulator piston 21 is configured to be urged backward by the small-diameter simulator spring 22 and the large-diameter simulator spring 23 provided in the simulator hydraulic chamber 25. The configuration (number, shape, and arrangement) of the simulator spring for biasing the stroke simulator piston 21 backward can be changed as appropriate, and is not limited to the above embodiment.

  In the above embodiment, the present invention is applied to a tandem master cylinder in which a master cylinder piston, a master cylinder portion spring, and a positioning mechanism are a pair. However, the present invention relates to a master cylinder piston, a master cylinder portion spring, It is also possible to carry out the same operation with a single master cylinder having a single positioning mechanism in a similar manner or with appropriate modifications.

1 is an overall configuration diagram schematically showing a hydraulic brake device for a vehicle that employs a master cylinder with a built-in stroke simulator according to the present invention. It is a vertical side view of the master cylinder with a built-in stroke simulator shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Cylinder body, 10a ... Cylinder inner hole, 11a, 11e ... Connection port, Communication hole (communication path), 21 ... Stroke simulator piston, 22, 23 ... Simulator spring, 25 ... Simulator hydraulic chamber, 31, 41 ... Master cylinder piston, 32, 42 ... Master cylinder part spring, 35, 45 ... Master hydraulic chamber, 50, 60, 70 ... Positioning mechanism, 52 ... Holder, 80 ... Cut member, 92 ... Brake pedal (brake operation member), R ... Reservoir, VB ... Body

Claims (2)

A cylinder body that is assembled to the vehicle body and has a cylinder inner hole, and is assembled to be movable in the cylinder axial direction at a front portion of the cylinder inner hole in the cylinder body, and is communicated and blocked forward with respect to the reservoir. A master cylinder piston that forms a master hydraulic pressure chamber and a cylinder body that is movably assembled in the rear part of the cylinder bore in the cylinder body and communicates with the reservoir between the master cylinder piston. A stroke simulator piston that forms a simulator hydraulic pressure chamber that is shut off and is pushed forward in accordance with the operating force of the brake operating member, and is provided in the master hydraulic pressure chamber to urge the master cylinder piston backward. Master cylinder spring, and the master cylinder piston and the simulator in the simulator hydraulic chamber A simulator spring that is interposed between the troking simulator pistons and biases the stroke simulator piston backward; and a positioning mechanism that is interposed in the simulator hydraulic chamber and defines the initial position of the master cylinder piston. ,
The cylinder body is provided with a communication passage for communicating the simulator hydraulic pressure chamber and the reservoir, and as the stroke simulator piston moves forward, the master cylinder piston moves forward by a predetermined amount from the initial position. When the hydraulic chamber is disconnected from the reservoir, it is assembled to one component of the positioning mechanism that can be engaged / disengaged with respect to the master cylinder piston and moves integrally with the master cylinder piston. A stroke simulator built-in master cylinder in which the cutting member to be separated is a set amount away from the simulator hydraulic pressure chamber side opening of the communication path in the axial direction.   The master cylinder with a built-in stroke simulator according to claim 1, wherein a pressure receiving area of the master cylinder piston is set larger than a pressure receiving area of the stroke simulator piston.

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