JP6497735B2 - Cylinder device for vehicle and brake system for vehicle - Google Patents

Description

  The present invention relates to a cylinder device for a vehicle and a brake system for a vehicle.

Patent Document 1 discloses a configuration in which a spring mechanism having a spring for biasing a piston rearward is disposed in a hydraulic chamber of a plunger-type master cylinder as a vehicle cylinder device that generates a brake hydraulic pressure. . This spring mechanism has a configuration that regulates the spring length when it is restored to the maximum.

JP 2012-210837 A

However, the spring mechanism described in Patent Document 1 is assembled by applying an external force in advance and compressing the spring by a predetermined amount, and may be bent without being straight in the axial direction in the assembled state.

  When the spring mechanism is centered when the curved spring mechanism is assembled to the cylinder hole of the master cylinder, the distal end side of the spring mechanism moves in the radial direction toward the inner peripheral surface of the cylinder hole. Here, a concave portion into which the spring mechanism is inserted is formed on the front side of the piston. For this reason, the lateral load which acts from a spring mechanism arises with respect to the internal peripheral surface of the concave shaped part of a piston. When the driver operates the brake operator in this state and the piston moves forward, the sliding resistance between the spring and the inner peripheral surface of the concave portion of the piston increases. In addition, the lateral load from the spring mechanism to the inner peripheral surface of the concave portion of the piston causes the piston to fall (tilt), so the sliding resistance between the piston and the inner peripheral surface of the cylinder hole when the piston moves forward is large. Become. As a result, there is a possibility that the reaction force characteristic at the time of brake operation changes.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle cylinder device and a vehicle brake system that can suppress a change in reaction force characteristics during brake operation. .

The present invention for solving the above problems is a cylinder device for a vehicle that generates brake hydraulic pressure, and includes a piston disposed in a cylinder hole, and a spring disposed between the bottom surface of the cylinder hole and the piston. And a mechanism. The spring mechanism includes a cylindrical retainer, a guide pin that is inserted into the retainer and has a head locked to the tip of the retainer, and a stopper that is attached to the tip of the guide pin opposite to the head. And a spring contracted between the stopper and the base end of the retainer. And the recessed part which accommodates the front-end | tip part of the said guide pin is formed in the said bottom face of the said cylinder hole, The said recessed part has a cylindrical internal peripheral surface extended ahead from the said bottom face. The guide pin protrudes forward from the contact surface with the bottom surface of the stopper, and the depth dimension of the inner peripheral surface of the recess is longer than the protrusion length of the guide pin from the contact surface. large. The diameter of the circle passing through the outermost edge of the stopper is larger than the diameter of the inner peripheral surface of the recess and smaller than the diameter of the bottom surface of the cylinder hole.

  In this configuration, the stopper abuts against the bottom surface of the cylinder hole, while the tip end portion of the guide pin is accommodated in a recess having a cylindrical inner peripheral surface. For this reason, even when a curved spring mechanism is assembled into the cylinder hole of the master cylinder, the guide pin does not slide in contact with the inner surface of the recess, so that the spring mechanism is not centered. As a result, the lateral load acting from the spring mechanism can be suppressed, and the tilting (tilting) of the piston can be suppressed, so that the sliding resistance when the driver moves forward by operating the brake operator is reduced. . Therefore, it is possible to suppress a change in the reaction force characteristic during the brake operation, and it is possible to keep the driver's brake feeling good.

  In this configuration, an area where the stopper comes into contact with the bottom surface of the cylinder hole can be secured, so that the stopper does not fall into the recess. Thereby, it can prevent that the spring mechanism in a cylinder hole, and by extension, the position of the axial direction of a piston shifts.

  In the vehicle cylinder device, the diameter of the inner peripheral surface of the concave portion may be larger than twice the outer diameter of the distal end portion of the guide pin.

  In this configuration, it is possible to more reliably prevent the guide pin from slidingly contacting the inner surface of the recess.

  In the vehicle cylinder device, the piston may be connected to a brake operator operated by a driver.

  In this configuration, when the brake operator pushes the piston by the driver's operation, the sliding resistance when the piston moves forward is reduced, and a stable reaction force characteristic can be obtained.

  In the vehicle cylinder device, a primary piston located on the bottom surface side and a secondary piston located on the opposite side of the bottom surface may be disposed in the cylinder hole. The piston may be the primary piston.

  With this configuration, it is possible to suppress the fall (tilt) of the primary piston of the so-called tandem master cylinder. Further, it is possible to suppress the secondary piston from falling (tilting) due to the influence of the falling (tilting) of the primary piston.

  In the vehicle cylinder device, it is preferable that the biasing member disposed between the primary piston and the secondary piston is constituted only by a return spring. Moreover, the opposing surface facing the said return spring in the said primary piston is good to exhibit the flat surface.

  In this configuration, the contact portion of the primary piston with the return spring can be configured without processing. In addition, since the urging member is composed of only the return spring, not the spring mechanism, the influence of using the spring mechanism curved on the secondary side is eliminated, and a stable reaction force characteristic can be obtained.

  The present invention for solving the above-described problems is a vehicle brake system, which includes the vehicle cylinder device, a slave cylinder, and a stroke simulator. The vehicle cylinder device is a master cylinder that generates a brake fluid pressure when a driver operates a brake operator. The slave cylinder generates brake fluid pressure by driving an electric motor corresponding to the operation amount of the brake operator. The stroke simulator imparts a pseudo operation reaction force to the brake operator. The stroke simulator is connected to a hydraulic chamber defined by the primary piston and the secondary piston.

  In this configuration, the stroke simulator is connected to the hydraulic chamber on the secondary side, and the spring mechanism is arranged in the primary hydraulic chamber that is not connected to the stroke simulator. For this reason, the operation of the stroke simulator is not affected by the spring mechanism on the primary side. Thereby, it can suppress as much as possible that the reaction force characteristic at the time of brake operation changes.

  ADVANTAGE OF THE INVENTION According to this invention, the cylinder apparatus for vehicles and the brake system for vehicles which can suppress that the reaction force characteristic at the time of brake operation changes can be provided.

It is a figure showing typically composition of a brake system for vehicles concerning one embodiment of the present invention. (A) is a side view of the master cylinder device, and (b) is a front view of the same. It is sectional drawing which shows schematic structure of the master cylinder as a cylinder apparatus for vehicles which concerns on one Embodiment of this invention. (A) is a figure which shows a spring mechanism typically, (b) is a figure which shows typically the spring mechanism of the curved state. (A) is a figure for demonstrating a mode that a spring mechanism and a piston are inserted in the cylinder hole of the master cylinder which concerns on this embodiment, (b) is a spring mechanism and piston in the cylinder hole of the master cylinder which concerns on this embodiment. It is a figure for demonstrating the assembled state. (A) is a figure for demonstrating a mode that a spring mechanism and a piston are inserted in the cylinder hole of the master cylinder which concerns on a comparative example, (b) has assembled | attached the spring mechanism and piston to the cylinder hole of the master cylinder which concerns on a comparative example. It is a figure for demonstrating a state.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
Note that, in the drawings shown below, the same members are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

  The vehicle brake system A shown in FIG. 1 includes a By Wire type brake system that operates when a prime mover (such as an engine or a motor) is started, and a hydraulic brake system that operates when the prime mover is stopped. It has both. The vehicle brake system A includes a master cylinder device A1 that generates brake fluid pressure by the depression force of a brake pedal (brake operator) P, and a slave cylinder that generates brake fluid pressure using an electric motor (not shown). A2 and a hydraulic pressure control device A3 that supports stabilization of the vehicle behavior. The master cylinder device A1, the slave cylinder A2, and the hydraulic pressure control device A3 are configured as separate units and communicate with each other via an external pipe.

  The vehicle brake system A can be mounted not only on an automobile that uses only an engine (internal combustion engine) as a power source, but also on a hybrid car that uses a motor together, an electric car that uses only a motor as a power source, and a fuel cell car. .

  The master cylinder device A1 includes a tandem master cylinder (vehicle cylinder device) 1, a stroke simulator 2, a reservoir 3, normally open shut-off valves (solenoid valves) 4 and 5, and normally closed shut-off valves (solenoids). Valve) 6, pressure sensors 7, 8, main hydraulic pressure paths 9a, 9b, connecting hydraulic pressure paths 9c, 9d, and a branch hydraulic pressure path 9e.

  The master cylinder 1 converts the depression force of the brake pedal P into brake fluid pressure. The master cylinder 1 includes a primary piston (piston) 1a disposed on a bottom surface 140 (refer to FIG. 3, the same applies hereinafter) of a first cylinder hole (cylinder hole) 11a, a secondary piston 1b connected to a push rod R, It has. The master cylinder 1 includes a spring mechanism 1c disposed between the primary piston 1a and the bottom surface 140 of the first cylinder hole 11a, and a return spring 1d disposed between the pistons 1a and 1b. . The secondary piston 1b is connected to the brake pedal P via the push rod R. Both pistons 1a and 1b slide under the depression force of the brake pedal P to pressurize the brake fluid in the hydraulic chambers 1e and 1f. The hydraulic chambers 1e and 1f communicate with the main hydraulic pressure paths 9a and 9b.

  The stroke simulator 2 generates a pseudo operation reaction force, and includes a piston 2a that slides in the second cylinder hole 11b and two large and small return springs 2b and 2c that bias the piston 2a. Yes. The stroke simulator 2 communicates with the hydraulic pressure chamber 1f through the main hydraulic pressure passage 9b and the branch hydraulic pressure passage 9e, and is operated by the brake hydraulic pressure generated in the hydraulic pressure chamber 1f.

  The reservoir 3 is a container for storing brake fluid, and includes liquid supply ports 3a and 3b connected to the master cylinder 1 and a pipe connection port 3c to which a hose extending from a main reservoir (not shown) is connected. ing.

  The normally open type shut-off valves 4 and 5 open and close the main hydraulic pressure passages 9a and 9b, and both are normally open type solenoid valves. One normally open type shutoff valve 4 opens and closes the main hydraulic pressure path 9a upstream of the intersection of the main hydraulic pressure path 9a and the connecting hydraulic pressure path 9c. The other normally open type shutoff valve 5 opens and closes the main hydraulic pressure path 9b in a section from the intersection of the main hydraulic pressure path 9b and the branch hydraulic pressure path 9e to the intersection of the main hydraulic pressure path 9b and the connecting hydraulic pressure path 9d. To do.

  The normally closed shut-off valve 6 opens and closes the branch hydraulic pressure passage 9e, and is a normally closed electromagnetic valve.

  The pressure sensors 7 and 8 detect the magnitude of the brake fluid pressure. The pressure sensor 7 is mounted in a sensor mounting hole (not shown) leading to the main hydraulic pressure path 9b, and the pressure sensor 8 is mounted in a sensor mounting hole (not shown) leading to the main hydraulic pressure path 9a. Yes. One pressure sensor 7 is arranged on the downstream side of the normally open type shutoff valve 5 and when the normally open type shutoff valve 5 is closed (= the main hydraulic pressure passage 9b is shut off). In addition, the brake fluid pressure generated in the slave cylinder A2 is detected. The other pressure sensor 8 is arranged upstream of the normally open type shutoff valve 4 and is in a state where the normally open type shutoff valve 4 is closed (= the main hydraulic pressure passage 9a is shut off). In addition, the brake fluid pressure generated in the master cylinder 1 is detected. Information acquired by the pressure sensors 7 and 8 is output to an electronic control unit (ECU) (not shown).

  The main hydraulic pressure paths 9a and 9b are hydraulic pressure paths starting from the master cylinder 1. Tubes Ha and Hb reaching the hydraulic pressure control device A3 are connected to the output ports 15a and 15b which are the end points of the main hydraulic pressure paths 9a and 9b.

  The communication hydraulic pressure paths 9c and 9d are hydraulic pressure paths from the input ports 15c and 15d to the main hydraulic pressure paths 9a and 9b. Tubing materials Hc and Hd reaching the slave cylinder A2 are connected to the input ports 15c and 15d.

  The branch hydraulic pressure path 9 e is a hydraulic pressure path that branches from one main hydraulic pressure path 9 b and reaches the stroke simulator 2.

  The master cylinder device A1 communicates with the hydraulic pressure control device A3 via the pipes Ha and Hb, and the brake hydraulic pressure generated in the master cylinder 1 when the normally open type shut-off valves 4 and 5 are in the valve open state is The pressure is input to the hydraulic pressure control device A3 via the main hydraulic pressure paths 9a and 9b and the pipe materials Ha and Hb.

  Although not shown, the slave cylinder A2 includes a slave piston that slides in the slave cylinder, an actuator mechanism that includes an electric motor and a driving force transmission unit, and a reservoir that stores brake fluid in the slave cylinder. . The electric motor operates based on a signal from an electronic control unit (not shown). The driving force transmission unit converts the rotational power of the electric motor into forward / backward movement and transmits it to the slave piston. The slave piston slides in the slave cylinder under the driving force of the electric motor, and pressurizes the brake fluid in the slave cylinder. The brake hydraulic pressure generated in the slave cylinder A2 is input to the master cylinder device A1 via the pipe materials Hc and Hd, and is input to the hydraulic pressure control device A3 via the communication hydraulic pressure paths 9c and 9d and the pipe materials Ha and Hb. . A hose extending from a main reservoir (not shown) is connected to the reservoir.

  The hydraulic control device A3 has a configuration capable of executing anti-lock brake control (ABS control) for suppressing wheel slip, side slip control for stabilizing vehicle behavior, traction control, and the like. To the wheel cylinders W, W,. In addition, although illustration is abbreviate | omitted, hydraulic control apparatus A3 is a hydraulic unit provided with a solenoid valve, a pump, etc., a motor for driving a pump, an electronic control unit for controlling a solenoid valve, a motor, etc. It has.

Next, an outline of the operation of the vehicle brake system A will be described.
When the vehicle brake system A functions normally (during normal braking), the normally open shut-off valves 4 and 5 are closed and the normally closed shut-off valve 6 is opened. When the brake pedal P is operated in such a state, the brake hydraulic pressure generated in the master cylinder 1 is not transmitted to the wheel cylinder W but is transmitted to the stroke simulator 2, and the piston 2a is displaced, so that the stroke of the brake pedal P is increased. While being allowed, a pseudo operation reaction force is applied to the brake pedal P.

When the depression of the brake pedal P is detected by a stroke sensor (not shown) or the like, the electric motor of the slave cylinder A2 is driven, and the slave piston is displaced to pressurize the brake fluid in the cylinder.
An electronic control unit (not shown) compares the brake fluid pressure output from the slave cylinder A2 (the brake fluid pressure detected by the pressure sensor 7) with the required fluid pressure corresponding to the operation amount of the brake pedal P, and The number of revolutions of the electric motor is controlled based on the comparison result.

  The brake fluid pressure generated in the slave cylinder A2 is transmitted to the wheel cylinders W, W,... Via the fluid pressure control device A3, and each wheel cylinder W is actuated to apply a braking force to each wheel.

  In a situation where the slave cylinder A2 does not operate (for example, when electric power cannot be obtained), both the normally open type shutoff valves 4 and 5 are in the valve open state, and the normally closed type shutoff valve 6 is in the valve closed state. Therefore, the brake fluid pressure generated in the master cylinder 1 is transmitted to the wheel cylinders W, W,.

Next, a specific structure of the master cylinder device A1 will be described.
The master cylinder device A1 of the present embodiment is assembled with the above-mentioned various parts inside or outside the base body 10 shown in FIGS. 2 (a) and 2 (b), and electric parts (normally open type shut-off valves 4, 5, The normally closed shut-off valve 6 and the pressure sensors 7 and 8 (see FIG. 1) are formed by covering with a housing 20. In the housing 20, mechanical parts and the like may be accommodated.

  The base body 10 is a cast product made of an aluminum alloy, and includes a cylinder portion 11 (see FIG. 2B, the same applies hereinafter), a vehicle body fixing portion 12, and a reservoir mounting portion 13 (see FIG. 2B, the same applies hereinafter). A housing attachment portion 14 and a pipe connection portion 15. In addition, holes (not shown) that become main hydraulic pressure passages 9a and 9b and a branch hydraulic pressure passage 9e are formed in the base 10.

  The cylinder portion 11 is formed with a first cylinder hole (cylinder hole) 11a for the master cylinder and a second cylinder hole 11b for the stroke simulator (both shown by broken lines in FIG. 2B). Both the cylinder holes 11 a and 11 b are cylindrical with a bottom, open to the vehicle body fixing portion 12, and extend toward the pipe connection portion 15. Parts (primary piston 1a, secondary piston 1b, spring mechanism 1c, and return spring 1d) constituting master cylinder 1 (see FIG. 1) are inserted into first cylinder hole 11a. In addition, parts (piston 2a and return springs 2b and 2c) constituting the stroke simulator 2 are inserted into the second cylinder hole 11b.

  In the following description, the movement direction of the push rod R when the brake pedal P (see FIG. 1) is depressed is “front”, and the movement direction of the push rod R when the brake pedal P is returned is “rear”. Called.

  The vehicle body fixing portion 12 is fixed to a vehicle body side fixing portion such as a toe board (not shown). The vehicle body fixing portion 12 is formed on the rear surface portion of the base body 10 and has a flange shape. A bolt insertion hole (not shown) is formed in a peripheral portion of the vehicle body fixing portion 12 (a portion protruding from the cylinder portion 11), and the bolt 12a is fixed.

  As shown in FIG. 2B, the reservoir mounting portion 13 is a portion serving as a mounting seat for the reservoir 3, and two (only one is shown) are formed on the upper surface portion of the base body 10. The reservoir mounting portion 13 is provided with reservoir union ports 111 and 112 (see FIG. 3, the same applies hereinafter). The reservoir 3 is fixed to the base body 10 via a connecting portion (not shown) protruding from the upper surface of the base body 10.

  The reservoir union ports 111 and 112 have a cylindrical shape and communicate with the first cylinder hole 11a through holes 113 and 114 (see FIG. 3) extending from the bottom surface toward the first cylinder hole 11a. . The reservoir union ports 111 and 112 are connected to liquid supply ports 3a and 3b (see FIG. 1) projecting from the lower portion of the reservoir 3, respectively. The upper ends of the reservoir union ports 111 and 112 are connected to the container body of the reservoir 3. Is placed.

  A housing mounting portion 14 is provided on the side surface of the base 10. The housing mounting portion 14 is a portion that serves as a mounting seat for the housing 20. The housing attachment portion 14 has a flange shape. A female screw (not shown) is formed on the upper end portion and the lower end portion of the housing mounting portion 14, and the mounting screw 16 is screwed onto the female screw as shown in FIG. Is fixed to the housing mounting portion 14 (side surface of the base body 10).

  Although illustration is omitted, the housing mounting portion 14 is formed with three valve mounting holes and two sensor mounting holes. Normally open shut-off valves 4 and 5 and normally closed shut-off valve 6 (see FIG. 1) are assembled in the three valve mounting holes, and pressure sensors 7 and 8 (see FIG. 1) are installed in the two sensor mounting holes. Is assembled.

  The pipe connection portion 15 is a portion serving as a tube mounting seat, and is formed on the front surface portion of the base 10 as shown in FIG. As shown in FIG. 2B, the pipe connection portion 15 is formed with two output ports 15a and 15b and two input ports 15c and 15d. Tubing materials Ha and Hb (see FIG. 1) leading to the hydraulic pressure control device A3 are connected to the output ports 15a and 15b, and tubing materials Hc and Hd leading to the slave cylinder A2 are connected to the input ports 15c and 15d (see FIG. 1). Is connected.

  The housing 20 is a housing body that liquid-tightly covers components (normally open type shutoff valves 4 and 5, normally closed type shutoff valves 6 and pressure sensors 7 and 8, see FIG. 1, hereinafter the same) assembled to the housing mounting portion 14 21 and a lid member 30 attached to the opening of the housing main body 21.

  The housing body 21 includes a flange portion 22, a peripheral wall portion 23 erected on the flange portion 22 (see FIG. 2B, the same applies hereinafter), and a connector portion protruding from the peripheral wall surface of the peripheral wall portion 23. Two connectors 24 and 25 are provided.

  Although not shown, an electromagnetic coil for driving the normally open type shut-off valves 4 and 5 and the normally closed type shut-off valve 6 is housed inside the peripheral wall portion 23 of the housing body 21. A bus bar and the like reaching the pressure sensors 7 and 8 are accommodated.

  The flange portion 22 is a portion that is crimped to the housing mounting portion 14 (see FIG. 2B, the same applies hereinafter). The flange portion 22 is formed so as to extend to the outside of the housing main body 21 so as to be continuous with the boss portions 22a to 22d as mounting screw portions.

  The boss portions 22 a to 22 d are provided at the four corners of the housing body 21 in accordance with the position of the female screw of the housing mounting portion 14. A metal collar is embedded in each of the boss portions 22a to 22d, and screw insertion holes (screw holes) functioning as insertion holes are formed inside thereof. A mounting screw 16 (see FIG. 2A, the same applies hereinafter) as a fastening member is inserted through the screw insertion hole. When the housing 20 is fixed to the housing mounting portion 14 of the base body 10 (see FIG. 2A), the mounting screws 16 can be uniformly tightened.

Next, the master cylinder 1 will be described in detail with reference to FIG.
In the description of the master cylinder 1, the bottom surface 140 side of the first cylinder hole 11a is referred to as “front” and “front end”, and the side opposite to the bottom surface 140 side of the first cylinder hole 11a is referred to as “rear” and “base end”. .

  As shown in FIG. 3, the master cylinder 1 includes a primary piston 1a and a secondary piston 1b disposed in the first cylinder hole 11a. The primary piston 1a is located on the bottom surface 140 side of the first cylinder hole 11a, and the secondary piston 1b is located on the opposite side of the bottom surface 140 of the first cylinder hole 11a.

  The master cylinder 1 is a spring mechanism 1c that is disposed between the bottom surface 140 of the first cylinder hole 11a and the primary piston 1a, and an urging member that is disposed between the primary piston 1a and the secondary piston 1b. Return spring 1d. Here, the urging member is composed of only the return spring 1d. The facing surface 116 facing the return spring 1d in the primary piston 1a is a flat surface.

  Concave portions 1g and 1h are formed in front of the primary piston 1a and the secondary piston 1b, respectively. Further, a recessed portion 1i is formed on the rear side of the primary piston 1a. The rear side of the spring mechanism 1c is inserted into the concave portion 1g of the primary piston 1a. In addition, the front side of the return spring 1d is inserted into the concave portion 1i of the primary piston 1a, and the rear side of the return spring 1d is inserted into the concave portion 1h of the secondary piston 1b.

  A plurality of through-holes 1j are formed in the peripheral wall on the front side of the primary piston 1a having a concave portion 1g therein. Also, a plurality of through holes 1k are formed in the peripheral wall on the front side of the secondary piston 1b provided with the concave portion 1h.

  In the annular recesses 117 and 118 formed on the inner peripheral surface of the first cylinder hole 11a, annular seal members Sa and Sb are respectively provided. Such seal members Sa and Sb liquid-tightly seal between the inner peripheral surface of the first cylinder hole 11a and the outer peripheral surface of the primary piston 1a. Similarly, annular seal members Sc and Sd are provided in annular recesses 118 and 119 formed on the inner peripheral surface of the first cylinder hole 11a, respectively. Such seal members Sc, Sd liquid-tightly seal between the inner peripheral surface of the first cylinder hole 11a and the outer peripheral surface of the secondary piston 1b. That is, the master cylinder 1 is a so-called plunger-type master cylinder in which the seal members Sa to Sd are provided on the cylinder portion 11 side.

  The brake pedal P (see FIG. 1) side end of the cylinder part 11 and the cylinder part 11 side of the push rod R are covered with a rubber boot 201.

  The spring mechanism 1 c includes a retainer 121, a guide pin 122, a stopper 123, and a spring 124. The retainer 121 has a cylindrical shape. The guide pin 122 has a rod-shaped shaft portion 125 and a head portion 126 provided on the proximal end side of the shaft portion 125 and having a larger outer diameter than the shaft portion 125. The guide pin 122 is inserted into the retainer 121 so as to be movable in the axial direction, and the head portion 126 is locked to the distal end portion 133 of the retainer 121. The stopper 123 is attached to the distal end portion 128 of the guide pin 122. The spring 124 is contracted between the stopper 123 and the base end portion 132 of the retainer 121.

  The retainer 121 includes a truncated cone-shaped guide portion 131, a flange-shaped proximal end portion 132 formed on the proximal end side of the guide portion 131, and a distal end portion 133 formed on the distal end side of the guide portion 131. doing. However, the guide part 131 may be cylindrical. The distal end portion 133 of the guide portion 131 has an insertion hole 134 that locks the head portion 126 of the guide pin 122 and allows the shaft portion 125 of the guide pin 122 and the retainer 121 to move in the axial direction. .

  In the vicinity of the distal end portion 133 of the guide portion 131, a plurality of liquid passage holes 135 are formed at equal intervals in the circumferential direction. In addition, a slit 136 is formed in the axial direction from the edge of the base end portion 132 to each liquid passage hole 135. And the cylindrical convex part 143 which the opening part formed in the edge of the base end part 132 of the retainer 121 fits in the bottom face of the concave shape part 1g of the primary piston 1a protrudes ahead, and is provided. .

  The stopper 123 includes a cylindrical portion 137 that is fixed to the distal end portion 128 of the guide pin 122 and a support portion 138 that supports the front end of the spring 124. The support part 138 is located on the rear side of the cylindrical part 137. The support portion 138 is joined to the cylindrical portion 137 here, but may not be joined as long as the forward movement is restricted by the cylindrical portion 137. The method of fixing the cylindrical portion 137 to the distal end portion 128 of the guide pin 122 is arbitrary, and is performed by, for example, caulking, welding, screw fastening, or the like.

  The support portion 138 is a disc having a hole through which the guide pin 122 is inserted, for example. However, the support part 138 is not limited to this, and may have another form as long as it has a function of supporting the front end of the spring 124. For example, the support portion 138 includes a disk portion having a small outer diameter having a hole through which the guide pin 122 is inserted, and a belt-like plate portion extending radially (for example, in a cross shape) radially outward from the outer peripheral edge of the disk portion. The form which has this may be sufficient.

  The stopper 123 is not limited to the configuration shown in FIG. For example, the stopper 123 may be configured to restrict the forward movement of the support portion 138 with a retaining ring fitted in a groove formed in the distal end portion 128 of the guide pin 122.

  A concave portion 141 that accommodates the distal end portion 128 of the guide pin 122 is formed in the bottom surface 140 of the first cylinder hole 11a. The recess 141 has a cylindrical inner peripheral surface 142 extending forward from the bottom surface 140. Further, the guide pin 122 protrudes forward from the contact surface with the bottom surface 140 of the stopper 123, and the depth dimension L1 of the inner peripheral surface 142 of the recess 141 protrudes from the contact surface of the guide pin 122. It is set larger than the length. Therefore, the stopper 123 is in contact with the bottom surface 140 of the first cylinder hole 11a, while the tip end portion 128 of the guide pin 122 is accommodated in the recess 141 having the cylindrical inner peripheral surface 142.

  In the present embodiment, the diameter D1 of the inner peripheral surface 142 of the recess 141 is set smaller than the diameter D2 of the circle passing through the outermost edge of the support portion 138 of the stopper 123. The diameter D1 of the inner peripheral surface 142 of the recess 141 is set to be larger than twice the outer diameter of the distal end portion 128 of the guide pin 122.

  When the master cylinder 1 configured as described above is not braked, the primary piston 1a and the secondary piston 1b are disposed at the positions shown in FIG. 3 by the elastic force of the spring mechanism 1c and the return spring 1d. The hydraulic chambers 1e and 1f communicate with the reservoir 3 (see FIG. 1), respectively. In the present embodiment, the set load of the spring 124 of the spring mechanism 1c is set to be larger than the set load of the return spring 1d.

  When the push rod R pushes the secondary piston 1b during braking, the secondary piston 1b moves forward in the first cylinder hole 11a toward the bottom surface 140 side while compressing the return spring 1d in the hydraulic chamber 1f. When the through hole 1k of the secondary piston 1b is blocked by the seal member Sc, the fluid pressure chamber 1f and the reservoir 3 are disconnected from each other, thereby generating a fluid pressure in the fluid pressure chamber 1f. As a result, during normal braking, the piston 2a of the stroke simulator 2 is displaced, the stroke of the brake pedal P is allowed, and a pseudo operation reaction force is applied to the brake pedal P.

When the set load of the return spring 1d and the pressure of the hydraulic chamber 1f exceed the set load of the spring 124 of the spring mechanism 1c as the secondary piston 1b moves forward, the hydraulic chamber 1e is compressed to the hydraulic chamber 1e. Generate hydraulic pressure. Here, since the normally open shut-off valves 4 and 5 are closed during normal braking, the primary piston 1a is hydraulic after the through hole 1j is blocked by the seal member Sa (after the invalid stroke). It will be in a state of hardly moving by the lock.
When the braking is released, the primary piston 1a and the secondary piston 1b are returned to their initial positions by the spring mechanism 1c and the return spring 1d.

Next, assembly of the spring mechanism 1c and assembly of parts such as the spring mechanism 1c into the first cylinder hole 11a will be described.
The spring mechanism 1c locks the head 126 of the guide pin 122 to the distal end portion 133 of the retainer 121, and contracts the spring 124 between the base end portion 132 of the retainer 121 and the support portion 138 of the stopper 123, A stopper 123 is attached to the tip end portion 128 of the pin 122 for assembly.

  The spring mechanism 1c is normally assembled in a straight shape in the axial direction as shown in FIG. However, as described above, the spring mechanism 1c is assembled by applying an external force in advance and compressing the spring 124 by a predetermined amount. As shown in FIG. 4B, when the spring mechanism 1c is straight in the axial direction in the assembled state. It may be curved instead. However, it is shown here as an extreme example for convenience of explanation.

  The spring mechanism 1c assembled in this way is inserted into the first cylinder hole 11a as shown in FIG. At this time, the support portion 138 of the stopper 123 contacts the bottom surface 140 of the first cylinder hole 11a, and the tip portion 128 of the guide pin 122 is accommodated in the recess 141. Subsequently, the primary piston 1a is inserted into the first cylinder hole 11a. Then, by moving the primary piston 1a forward, the opening on the proximal end side of the retainer 121 is fitted to a convex portion 143 (see FIG. 3) provided on the bottom surface of the concave-shaped portion 1g of the primary piston 1a. . However, the primary piston 1a in which the spring mechanism 1c is attached in advance may be inserted into the first cylinder hole 11a by fitting the opening on the proximal end side of the retainer 121 to the convex portion 143. .

  Further, the return spring 1d and the secondary piston 1b are inserted into the first cylinder hole 11a. And as shown in FIG.5 (b), each components, such as the spring mechanism 1c, are arrange | positioned in the state to which the predetermined | prescribed initial pressing force was given to the predetermined position in the 1st cylinder hole 11a at the axial direction front, The assembly of each part into the first cylinder hole 11a is completed.

  In the present embodiment described above, as shown in FIG. 3, the master cylinder 1 has a primary piston 1a disposed in the first cylinder hole 11a, and a space between the bottom surface 140 of the first cylinder hole 11a and the primary piston 1a. And a spring mechanism 1c to be arranged. The bottom surface 140 of the first cylinder hole 11a is formed with a recess 141 that accommodates the distal end portion 128 of the guide pin 122 of the spring mechanism 1c. The recess 141 is a cylindrical inner peripheral surface that extends forward from the bottom surface 140. 142. Further, the guide pin 122 projects forward from the contact surface with the bottom surface 140 of the stopper 123, and the depth L1 of the inner peripheral surface 142 of the recess 141 is projected from the contact surface of the guide pin 122. Greater than length.

  According to the present embodiment, as shown in FIGS. 5A and 5B, the contact surface of the stopper 123 contacts the bottom surface 140 of the first cylinder hole 11a, while the distal end portion of the guide pin 122 128 is accommodated in a recess 141 having a cylindrical inner peripheral surface 142. For this reason, even when the curved spring mechanism 1c (see FIG. 4B) is assembled to the first cylinder hole 11a of the master cylinder 1, the guide pin 122 does not slide in contact with the inner surface of the recess 141, so that the spring mechanism 1c is centered. Never happen.

  On the other hand, in the comparative example shown in FIGS. 6 (a) and 6 (b), the recess 151 that accommodates the distal end portion 128 of the guide pin 122 of the spring mechanism 1c has an inner peripheral surface 152 having a tapered shape (conical shape). doing. Therefore, as shown in FIG. 6A, when the curved spring mechanism 1c (see FIG. 4B) is inserted into the first cylinder hole 11a of the master cylinder 1, the guide pin 122 or the cylindrical portion 137 of the spring mechanism 1c. The tip of the contact portion comes into contact with the tapered inner peripheral surface 152 of the recess 151. When the spring mechanism 1c is assembled in the first cylinder hole 11a in this state, the spring mechanism 1c is centered by the tapered inner peripheral surface 152 of the recess 151 as shown in FIG. That is, the distal end side of the spring mechanism 1c moves in the radial direction (C direction in FIG. 6B) toward the inner peripheral surface of the first cylinder hole 11a. For this reason, a lateral load (indicated by F in FIG. 6B) acting from the spring mechanism 1c is generated on the inner peripheral surface of the concave portion 1g of the primary piston 1a. When the driver operates the brake pedal P in this state and the primary piston 1a moves forward, the sliding resistance between the spring 124 and the inner peripheral surface of the concave portion 1g of the primary piston 1a increases. Further, since the primary piston 1a falls (inclined) due to the lateral load from the spring mechanism 1c to the inner peripheral surface of the concave portion 1g of the primary piston 1a, the primary piston 1a and the first cylinder when the primary piston 1a moves forward The sliding resistance with the inner peripheral surface of the hole 11a is also increased. As a result, there is a possibility that the reaction force characteristic at the time of brake operation changes.

  On the other hand, according to the present embodiment, as described above, the spring mechanism 1c is not centered. As a result, the lateral load acting from the spring mechanism 1c can be suppressed, and the primary piston 1a can be prevented from falling (tilting), so that when the driver operates the brake pedal P, the primary piston 1a moves forward. Resistance is reduced. Therefore, it is possible to suppress a change in the reaction force characteristic during the brake operation, and it is possible to keep the driver's brake feeling good.

  In the present embodiment, the diameter D1 of the inner peripheral surface 142 of the recess 141 is smaller than the outer diameter D2 when the support portion 138 of the stopper 123 is a disk, for example. For this reason, since the area | region where the stopper 123 contact | abuts to the bottom face 140 of the 1st cylinder hole 11a can be ensured, the stopper 123 does not fall in the recessed part 141. FIG. Thereby, it can prevent that the position of the axial direction of the spring mechanism 1c in the 1st cylinder hole 11a and by extension, the primary piston 1a shifts | deviates.

  Further, in the present embodiment, the diameter D1 of the inner peripheral surface 142 of the recess 141 is larger than twice the outer diameter of the distal end portion 128 of the guide pin 122. For this reason, it can prevent more reliably that the guide pin 122 slide-contacts to the inner surface of the recessed part 141. FIG.

  In the present embodiment, the primary piston 1a located on the bottom surface 140 side and the secondary piston 1b located on the opposite side of the bottom surface 140 are disposed in the first cylinder hole 11a. A spring mechanism 1c is arranged between the primary piston 1a. For this reason, the fall (inclination) of the primary piston 1a of the so-called tandem master cylinder 1 can be suppressed. In addition, it is possible to suppress the secondary piston 1b from falling (tilting) due to the influence of the falling (tilting) of the primary piston 1a.

  In the present embodiment, only the return spring 1d is provided between the primary piston 1a and the secondary piston 1b, and the opposed surface 116 of the primary piston 1a with which the return spring 1d abuts is formed flat. For this reason, it can comprise, without processing the contact part with the return spring 1d of the primary piston 1a. Further, since the urging member is constituted by only the return spring 1d instead of the spring mechanism 1c, the effect of using the spring mechanism 1c curved on the secondary side is eliminated, and a stable reaction force characteristic can be obtained.

  In the present embodiment, the primary piston 1a is connected to the brake operator P operated by the driver via the push rod R or the like. That is, the primary piston 1a is connected (connected) to the brake operator P so that the pressing force from the brake operator P is directly applied to the primary piston 1a. For this reason, compared with the configuration in which the brake operator P is connected to the primary piston via a booster such as a so-called negative pressure booster, a change in the reaction force characteristic due to the sliding resistance of the spring mechanism 1c is easily transmitted to the driver. . Especially in such a form, when the brake operator P pushes the primary piston 1a by a driver's operation, the sliding resistance when the primary piston 1a moves forward can be reduced, and a stable reaction force characteristic can be obtained. .

  In the present embodiment, the vehicle brake system A includes a master cylinder 1, a slave cylinder A 2, and a stroke simulator 2. The stroke simulator 2 is connected to a hydraulic chamber 1f defined by a primary piston 1a and a secondary piston 1b. In this configuration, the stroke simulator 2 is connected to the secondary hydraulic chamber 1 f, and the spring mechanism 1 c is arranged in the primary hydraulic chamber 1 e that is not connected to the stroke simulator 2. For this reason, the operation of the stroke simulator 2 during normal braking is not affected by the primary-side spring mechanism 1c. Thereby, it can suppress as much as possible that the reaction force characteristic at the time of brake operation changes.

  As described above, the present invention has been described based on the embodiment. However, the present invention is not limited to the configuration described in the embodiment, and the configuration can be appropriately changed without departing from the scope of the invention. Is. In addition, a part of the configuration of the embodiment can be added, deleted, and replaced.

  For example, in the above-described embodiment, the master cylinder 1 is configured by a tandem cylinder having two pistons, but the master cylinder may be configured by a cylinder using one piston.

  In the above-described embodiment, the master cylinder device A1, the slave cylinder A2, and the hydraulic pressure control device A3 are configured as separate units, but are not limited thereto. At least two of the master cylinder device A1, the slave cylinder A2, and the hydraulic pressure control device A3 may be configured as an integral unit.

1 Master cylinder (vehicle cylinder device)
1a Primary piston (piston)
DESCRIPTION OF SYMBOLS 1b Secondary piston 1c Spring mechanism 1d Return spring 1e, 1f Hydraulic chamber 1g, 1h, 1i Concave-shaped part 2 Stroke simulator 11a First cylinder hole (cylinder hole)
116 opposing surface 121 retainer 122 guide pin 123 stopper 124 spring 126 head 128 distal end 132 base end 133 distal end 140 bottom surface 141 recess 142 inner peripheral surface A vehicle brake system A1 master cylinder device A2 slave cylinder P brake pedal (brake Operator)

Claims (6)

A cylinder device for a vehicle that generates brake fluid pressure,
A piston disposed in the cylinder hole;
A spring mechanism disposed between the bottom surface of the cylinder hole and the piston,
The spring mechanism includes a cylindrical retainer, a guide pin that is inserted into the retainer and has a head locked to the tip of the retainer, and a stopper that is attached to the tip of the guide pin opposite to the head. And a spring contracted between the stopper and the base end of the retainer,
A recess is formed on the bottom surface of the cylinder hole to accommodate the tip of the guide pin.
The concave portion has a cylindrical inner peripheral surface extending forward from the bottom surface,
The guide pin protrudes forward from the contact surface with the bottom surface of the stopper,
Depth dimension of the inner peripheral surface of the recess is much larger than the projection length from the contact surface of the guide pin,
The diameter of the circle passing through the outermost edge of the stopper is larger than the diameter of the inner peripheral surface of the recess, the vehicular cylinder and wherein the smaller Ikoto than the diameter of the bottom surface of the cylinder bore. The diameter of the inner peripheral surface of the recess, vehicular cylinder device according to claim 1, wherein greater than 2 times the outer diameter of the distal end portion of the guide pin. Vehicular cylinder device according to claim 1 or claim 2, wherein said that the piston is connected to the brake operation element operated by the driver. In the cylinder hole, a primary piston located on the bottom surface side and a secondary piston located on the opposite side to the bottom surface are arranged,
The vehicular cylinder device according to any one of claims 1 to 3 , wherein the piston is the primary piston. The urging member disposed between the primary piston and the secondary piston is composed only of a return spring,
The vehicular cylinder device according to claim 4 , wherein a facing surface of the primary piston facing the return spring is a flat surface. The vehicular cylinder device according to claim 4 or 5 , which is a master cylinder that generates a brake fluid pressure when a driver operates a brake operator.
A slave cylinder that generates brake fluid pressure by driving an electric motor corresponding to the operation amount of the brake operator;
A stroke simulator that applies a pseudo operation reaction force to the brake operator,
The vehicle brake system according to claim 1, wherein the stroke simulator is connected to a hydraulic chamber defined by the primary piston and the secondary piston.

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