JP2016013721A - Input device and brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an input device which enables improvement of the productivity while reducing the costs.SOLUTION: An input device B includes: a push rod P1 which may move forward and rearward according to an amount of operation conducted to a brake controller; a secondary piston 23 which may displace in response to forward and rearward movement of the push rod P1; and a retainer 60 which holds a head part P1b of the push rod P1 so that the head part P1b may swing relative to the secondary piston 23. The retainer 60 is a resin member including: a contact part 61 which contacts with the head part P1b of the push rod P1; and a removal prevention part 62 which prevents the push rod P1 from being dropped from the secondary piston 23. The removal prevention part 62 includes a rear slit 62a extending in an axial direction of the secondary piston 23.

Description

  The present invention relates to an input device and a brake system.

  Conventionally, as an input device such as a master cylinder to which a brake operation element is connected, for example, Patent Document 1 has a configuration in which a spherical head formed at an end of an input rod is assembled to be swingable with respect to a piston. It is disclosed.

JP 2007-99058 A

  However, in the input device described in Patent Document 1, it is necessary to caulk the end of the piston so that the head of the input rod is held swingably with respect to the piston. Therefore, there has been a problem that the number of processing steps increases, leading to an increase in cost.

  This invention is made | formed in view of the said point, and makes it a subject to provide the input device and brake system which can improve productivity, reducing cost.

  An input device according to the present invention includes an input rod that can be moved forward and backward according to an operation amount with respect to an operation element, a piston that can be displaced according to the forward and backward movement of the input rod, and an end portion of the input rod with respect to the piston. And a substantially cylindrical retainer that is swingably retained. The retainer abuts against an end of the input rod, and a retaining portion that prevents the input rod from falling off the piston by being latched by a latching portion formed on the piston. The retaining member is elastically deformable in the radial direction of the cage by including a first slit extending in the axial direction of the piston.

  According to such a configuration, it is possible to reduce the man-hour for caulking the piston by realizing the retaining of the input rod by the retaining portion of the resin cage, and to easily prevent the retaining rod by assembling with the cage. Therefore, productivity can be improved while reducing costs.

  The contact portion may be configured to be elastically deformable in a radial direction of the cage by including a second slit extending in an axial direction of the piston.

  According to this configuration, the abutting portion can generate a resilient force toward the end portion of the input rod.

  The first slit and the second slit may be arranged at different positions in the circumferential direction of the piston.

  According to such a configuration, the slits can be arranged efficiently, and the mold and resin injection during resin molding can be balanced.

  The cage may include a plurality of the first slits and a plurality of the second slits, and the first slits and the second slits may be alternately arranged in a circumferential direction of the piston. Good.

  According to such a configuration, it is possible to realize a configuration in which the substantial portions of the contact portion and the retaining portion are arranged in a balanced manner and the cage receives a load evenly.

  The bottom part of said 1st slit may be the structure currently formed in the said piston side rather than the bottom part of said 2nd slit.

  According to this configuration, the cage can be reduced in weight while being easily elastically deformed by forming each slit deeply.

  The piston includes a bottomed cylinder portion in which the end of the input rod and the cage are accommodated, and expands toward the opening side from the bottom surface side to the opening side end portion of the inner peripheral surface of the cylinder portion. The structure in which the inclined surface which diameters is formed may be sufficient.

  According to such a configuration, the retainer can be suitably inserted into the cylindrical portion at the time of assembly, and the assemblability can be improved.

  The inner peripheral surface of the cage may have a contact surface for receiving a jig.

  According to this configuration, the input rod, the piston, and the cage can be suitably assembled with each other by the jig.

  The brake system of the present invention includes the input device and an electric actuator that generates a brake fluid pressure corresponding to the driver's operating force, and the input rod of the input device can be operated by the driver. A brake operator is connected, and the input device generates a brake fluid pressure by the piston in response to an input from the brake operator.

  According to such a configuration, it is possible to reduce the man-hour for caulking the piston by realizing the retaining of the input rod by the retaining portion of the resin cage, and to easily prevent the retaining rod by assembling with the cage. Therefore, productivity can be improved while reducing costs.

  According to the present invention, productivity can be improved while reducing costs.

It is a mimetic diagram showing a brake system for vehicles concerning an embodiment of the present invention. It is sectional drawing which shows the input device which concerns on embodiment of this invention. It is an exploded view which shows the input device which concerns on embodiment of this invention. It is a figure which shows the holder | retainer which concerns on embodiment of this invention, (a) is the figure seen from diagonally forward, (b) is the figure seen from diagonally back, (c) is X arrow sectional drawing of (b). It is. (A)-(c) is a figure for demonstrating the assembly | attachment method of the input device which concerns on embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the case where the input device of the present invention is applied to the master cylinder 20 and the push rod P1 of the vehicle brake system A shown in FIG. 1 will be described as an example. In FIG. 1, the master cylinder 20 and the push rod P1 are illustrated in a simplified manner, and the cage is omitted.

<Vehicle brake system>
As shown in FIG. 1, the vehicle brake system A includes a by-wire brake system that operates when a prime mover (such as an engine or an electric motor) is started, and a hydraulic system that operates when the prime mover is stopped. It is equipped with both the brake system.

The vehicle brake system A includes a brake fluid pressure generating device 1 that generates a brake fluid pressure according to an operation amount of the brake pedal P, and a fluid pressure control device 2 that supports stabilization of vehicle behavior.
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 automobile that uses a motor together, an electric vehicle that uses only a motor as a power source, a fuel cell automobile, and the like. .

The brake fluid pressure generating device 1 includes a master cylinder 20, a stroke simulator 30, a slave cylinder 40, and an electronic control device 50. The master cylinder 20 is a tandem type having two pistons 22 and 23 that generate brake fluid pressure by the depression force of the brake pedal P. The stroke simulator 30 applies a pseudo operation reaction force to the brake pedal P. The slave cylinder 40 is a tandem type having two pistons 42 and 43 that generate brake fluid pressure by driving a motor 46 (electric actuator) according to the operation amount of the brake pedal P.
In the brake fluid pressure generator 1, the master cylinder 20, the stroke simulator 30, the slave cylinder 40, and the electronic control device 50 are assembled on one base body 10.
In the base body 10, a first brake system K1 and a second brake system K2 are provided. The first brake system K1 is a brake fluid pressure path that is connected to a first pressure chamber 21b of the master cylinder 20 to be described later and is filled with brake fluid, and the second brake system K2 is a second pressure chamber of the master cylinder 20. A brake fluid pressure path connected to 21c and filled with brake fluid. The first brake system K1 is provided with a first main hydraulic pressure passage 11a that leads from the master cylinder 20 to one of the wheel brakes FL, RR, and the second brake system K2 includes from the master cylinder 20 to the other wheel brake RL, A second main hydraulic pressure passage 11b leading to the FR is provided. A branch hydraulic pressure passage 12, a first series passage 14a, and a second communication passage 14b are formed in the base body 10. A first pressure sensor 17 is provided in the second main hydraulic pressure path 11b. A second pressure sensor 18 is provided in the first series passage 14a.

  The master cylinder 20 includes a primary piston 22 and a secondary piston 23 inserted into a bottomed cylindrical first cylinder hole 21, and a first spring mechanism 24 and a second spring mechanism 25 housed in the first cylinder hole 21. It is equipped with. The master cylinder 20 is provided with a reservoir 26 for storing brake fluid.

A first pressure chamber 21 b is formed between the bottom surface 21 a of the first cylinder hole 21 and the primary piston 22. A first spring mechanism 24 having a coil spring is interposed in the first pressure chamber 21b.
A second pressure chamber 21 c is formed between the primary piston 22 and the secondary piston 23. A second spring mechanism 25 having a coil spring is interposed in the second pressure chamber 21c.
A pair of cup seals 27a and 27b are mounted on the inner peripheral surface of the first cylinder hole 21 via annular grooves.

The end of the secondary piston 23 is connected to the brake pedal P via the push rod P1. The primary piston 22 and the secondary piston 23 receive the depression force of the brake pedal P, slide in the first cylinder hole 21, and pressurize the brake fluid in both the pressure chambers 21b and 21c. The brake fluid pressurized in both pressure chambers 21 b and 21 c is output through output ports 28 a and 28 b provided in the first cylinder hole 21. The first pressure chamber 21 b is connected to the reservoir 26 via an input port 28 c provided in the first cylinder hole 21, and the second pressure chamber 21 c is connected to the input port provided in the first cylinder hole 21. It is connected to the reservoir 26 through 28d.
The first main hydraulic pressure path 11a is connected to the output port 28a corresponding to the first pressure chamber 21b, and the second main hydraulic pressure path 11b is connected to the output port 28b corresponding to the second pressure chamber 21c. Yes. The first main hydraulic pressure path 11a and the second main hydraulic pressure path 11b are connected to the hydraulic control device 2 on the downstream side.

  The stroke simulator 30 is a simulator mechanism that generates a brake fluid pressure for producing an operation reaction force for the driver. The stroke simulator 30 includes a simulator piston 32 inserted into the second cylinder hole 31 and two elastic members 33a and 33b that are coil springs interposed between the bottom surface 31a of the second cylinder hole 31 and the simulator piston 32. And.

  A pressure chamber 34 is formed in the second cylinder hole 31. The pressure chamber 34 is provided between the introduction port 31b and the simulator piston 32, and the first cylinder hole 21 has a first pressure via the branch hydraulic pressure path 12, the first main hydraulic pressure path 11a, and the output port 28a. It leads to the pressure chamber 21b. Therefore, when the brake pedal P is operated and the brake fluid pressure is generated in the first pressure chamber 21b of the master cylinder 20, the simulator piston 32 of the stroke simulator 30 moves against the urging force of the elastic members 33a and 33b. Thereby, a pseudo operation reaction force is applied to the brake pedal P.

  The slave cylinder 40 is an electric actuator that generates a brake fluid pressure corresponding to the operating force of the driver. The slave cylinder 40 includes a primary piston 42 and a secondary piston 43 inserted into a bottomed cylindrical third cylinder hole 41, a first spring mechanism 44 and a second spring mechanism 45 accommodated in the third cylinder hole 41, and The motor 46 and the drive transmission part 47 are provided.

A first pressure chamber 41 b is formed between the bottom surface 41 a of the third cylinder hole 41 and the primary piston 42. A first spring mechanism 44 having a coil spring is interposed in the first pressure chamber 41b.
A second pressure chamber 41 c is formed between the primary piston 42 and the secondary piston 43. The second pressure chamber 41c is provided with a second spring mechanism 45 having a coil spring.
The first pressure chamber 41b of the slave cylinder 40 communicates with the first main hydraulic pressure passage 11a through the first series passage 14a, and the second pressure chamber 41c passes through the second communication passage 14b. It leads to the pressure path 11b.
A pair of cup seals 49a and 49b are attached to the inner peripheral surface of the third cylinder hole 41 via an annular groove.

  The motor 46 is an electric servo motor that is driven and controlled by the electronic control unit 50. A drive gear 46 b that is a spur gear is attached to the output shaft 46 a of the motor 46. The drive gear 46b meshes with the driven gear 47c of the drive transmission unit 47 via the gear 46c.

The drive transmission unit 47 converts the rotational driving force of the output shaft 46a of the motor 46 into a linear axial force.
The drive transmission unit 47 is a rod 47a that is in contact with the secondary piston 43 of the slave cylinder 40, a cylindrical nut member 47b that surrounds the rod 47a, and a spur gear that is formed on the entire circumference of the nut member 47b. And a driven gear 47c.

A spiral thread groove is formed on the outer peripheral surface of the rod 47a. A plurality of balls 47d are rotatably accommodated in the thread groove, and the nut member 47b is screwed to each ball 47d. Thus, the ball screw mechanism is provided between the nut member 47b and the rod 47a.
The nut member 47b is rotatably supported around the rod 47a via bearings 47e disposed on both sides of the driven gear 47c.

When the output shaft 46a rotates, the rotational driving force is input to the nut member 47b through the drive gear 46b, the gear 46c, and the driven gear 47c. A linear screw force is applied to the rod 47a by the ball screw mechanism provided between the nut member 47b and the rod 47a, and the rod 47a moves forward and backward.
When the rod 47a moves to the secondary piston 43 side, the primary piston 42 and the secondary piston 43 receive the input from the rod 47a and slide in the third cylinder hole 41, and the brake fluid in both the pressure chambers 41b and 41c is discharged. Pressurize. The brake fluid pressurized in the pressure chambers 41 b and 41 c is output through the output ports 48 a and 48 b provided in the third cylinder hole 41.

Next, each hydraulic pressure path formed in the substrate 10 will be described.
The first main hydraulic pressure path 11 a and the second main hydraulic pressure path 11 b are both hydraulic pressure paths starting from the first cylinder hole 21 of the master cylinder 20.
The first main hydraulic pressure passage 11a communicates with the first pressure chamber 21b of the master cylinder 20 through the output port 28a. Further, the second main hydraulic pressure passage 11b communicates with the second pressure chamber 21c of the master cylinder 20 through the output port 28b. Pipes Ha and Hb leading to the hydraulic pressure control device 2 are connected to the two output ports 19 which are the end points of both the main hydraulic pressure paths 11a and 11b.

  The branch hydraulic pressure path 12 is a hydraulic pressure path from the pressure chamber 34 of the stroke simulator 30 to the first main hydraulic pressure path 11a. The branch hydraulic pressure path 12 is provided with a normally closed electromagnetic valve 13 as a valve. The normally closed solenoid valve 13 opens and closes the branch hydraulic pressure path 12.

  The first series passage 14 a and the second communication passage 14 b are both hydraulic pressure paths starting from the third cylinder hole 41 of the slave cylinder 40. The communication path 14a communicates with the first pressure chamber 41b of the slave cylinder 40 via the output port 48a. Further, the communication passage 14b communicates with the second pressure chamber 41c of the slave cylinder 40 via the output port 48c.

A first switching valve 15a, which is a three-way valve, is provided at a connection portion between the first main hydraulic pressure passage 11a and the first series passage 14a.
The first switching valve 15a is a 2-position 3-port solenoid valve. In the first position, the first switching valve 15a has an upstream side (master cylinder 20 side) of the first main hydraulic pressure passage 11a and a downstream side of the first main hydraulic pressure passage 11a (the output port 19 side, one wheel brake FL). , RR), the first series passage 14a and the downstream side of the first main hydraulic pressure passage 11a are shut off. In the second position, the first switching valve 15a shuts off the upstream side of the first main hydraulic pressure passage 11a and the downstream side of the first main hydraulic pressure passage 11a, and the first series passage 14a and the first main hydraulic pressure. It communicates with the downstream side of the path 11a.

A second switching valve 15b, which is a three-way valve, is provided at a connection portion between the second main hydraulic pressure passage 11b and the second communication passage 14b.
The second switching valve 15b is a 2-position 3-port solenoid valve. In the first position, the second switching valve 15b has an upstream side (master cylinder 20 side) of the second main hydraulic pressure passage 11b and a downstream side of the second main hydraulic pressure passage 11b (output port 19 side, the other wheel brake RL). , FR), and the second communication passage 14b and the downstream side of the second main hydraulic pressure passage 11b are cut off. In the second position, the second switching valve 15b blocks the second communication path 14b and the second main hydraulic pressure while blocking the upstream side of the second main hydraulic pressure path 11b and the downstream side of the second main hydraulic pressure path 11b. It communicates with the downstream side of the path 11b.
Note that the positions of the first switching valve 15 a and the second switching valve 15 b are switched by the electronic control device 50.

The first pressure sensor 17 and the second pressure sensor 18 detect the magnitude of the brake fluid pressure. Information (detected values) acquired by both pressure sensors 17 and 18 is input to the electronic control unit 50.
The first pressure sensor 17 is disposed in the second main hydraulic pressure path 11b on the upstream side of the second switching valve 15b. The first pressure sensor 17 functions as a master pressure sensor that detects the brake fluid pressure generated in the master cylinder 20.

The second pressure sensor 18 is disposed in the first series passage 14a on the downstream side of the first switching valve 15a. The second pressure sensor 18 detects the brake hydraulic pressure generated in the slave cylinder 40 when the downstream side of the first main hydraulic pressure passage 11a and the first series passage 14a are in communication with each other by the first switching valve 15a. To do.
As described above, the second pressure sensor 18 is arranged in a system (system of the first main hydraulic pressure path 11a) different from the system (system of the second main hydraulic pressure path 11b) in which the first pressure sensor 17 is arranged. Yes.

  The hydraulic path 16a, which is one of the hydraulic paths of the first brake system K1, is a pressure on the bottom surface 31a side of the port 28e corresponding to the first pressure chamber 21b of the master cylinder 20 and the simulator piston 32 of the stroke simulator 30. A port 31c corresponding to the chamber and a port 48c corresponding to the first pressure chamber 41b of the slave cylinder 40 are connected. The hydraulic pressure path 16b, which is one of the hydraulic pressure paths of the second brake system K2, includes a port 28f corresponding to the second pressure chamber 21c of the master cylinder 20 and a port 48d corresponding to the second pressure chamber 41c of the slave cylinder 40. And connected.

The electronic control device 50 accommodates a control board (not shown) therein and is attached to the side surface of the base 10.
The electronic control unit 50 operates the motor 46, normally closed electromagnetic, based on information (detected values) obtained from the various sensors such as the pressure sensors 17 and 18 and the stroke sensor ST, a program stored in advance, and the like. It controls the opening and closing of the valve 13 and the switching of both switching valves 15a and 15b.

  The hydraulic pressure control device 2 performs various hydraulic pressure controls such as anti-lock brake control and behavior stabilization control by appropriately controlling the brake hydraulic pressure applied to each wheel cylinder W of the wheel brakes FL, RR, RL, FR. The structure which can be performed is provided and is connected to each wheel cylinder W via piping.

  As shown in FIG. 1, the hydraulic control device 2 is disposed between the brake hydraulic pressure generating device 1 and the wheel brakes FL, RR, RL, FR. The pipes Ha and Hb connected to the output port 19 of the base body 10 are connected to the inlet port 121 of the hydraulic pressure control device 2. The wheel brakes FL, RR, RL, FR are connected to the outlet port 122 of the hydraulic pressure control device 2 through pipes, respectively. In a normal state, the brake fluid pressure output from the brake fluid pressure generator 1 through the main fluid pressure passages 11a and 11b corresponding to the depression force of the brake pedal P is the wheel brakes FL, RR, RL, and FR. It is applied to the cylinder W.

<Input device>
Next, the input device B according to the embodiment of the present invention will be described in detail with reference to FIGS. The input device B according to the present embodiment has a structure in which the end of the push rod P1 is held swingably with respect to the secondary piston 23 by a cage 60 (see FIG. 2). In the following description, the bottom surface 21a side of the first cylinder hole 21 is defined as the front side, and the opening side (brake pedal P side) of the first cylinder hole 21 is defined as the rear side.

  As shown in FIGS. 2 and 3, the input device B includes a push rod P <b> 1, a secondary piston 23, and a cage 60. The input device B generates brake fluid pressure by the secondary piston 23 in response to the input of the push rod P1.

《Push Rod》
The push rod P1 is an input rod capable of moving back and forth in the front-rear direction according to the amount of operation of the driver with respect to the brake operator P. The push rod P1 integrally includes a shaft portion P1a having a cylindrical shape extending in the front-rear direction and a spherical head portion P1b formed at the front end portion of the shaft portion P1a. A tip end portion (end portion on the head P1b side) of the shaft portion P1a is a reduced diameter portion P1c having a constriction. The head portion P1b is accommodated in the rear cylinder portion 23b of the secondary piston 23, and the front end edge of the head portion P1b is in contact with the bottom surface of the rear cylinder portion 23b.

《Secondary piston》
The secondary piston 23 is a piston that can be displaced in the front-rear direction in accordance with the advance / retreat operation of the push rod P1. The secondary piston 23 is integrally provided with a front cylinder part 23a (see FIG. 1), a rear cylinder part 23b, and a base part 23c therebetween. The rear cylinder part 23b is a cylinder whose bottom surface is the rear surface of the base part 23c, and the push rod P1 side of the rear cylinder part 23b is open. That is, the rear cylinder portion 23b constitutes a rod insertion hole into which the head P1b of the push rod P1 and the retainer 60 are inserted. Further, the bottom surface of the rear cylinder portion 23b has a tapered surface with which the head portion P1b of the push rod P1 comes into contact.

  An annular convex portion 23 d that protrudes toward the radial center of the secondary piston 23 is formed at the rear end portion of the rear cylinder portion 23 b. The annular convex portion 23d is an example of a locking portion to which the retaining portion 62 of the retainer 60 is abutted and locked. In addition, an inclined surface 23e whose diameter increases from the bottom surface side toward the opening side is formed at the rear end portion of the rear cylinder portion 23b (that is, the rear end portion of the inner peripheral surface of the annular convex portion 23d).

<Retainer>
The cage 60 is a resin member that holds the head P1b of the push rod P1 so as to be swingable with respect to the secondary piston 23. The cage 60 has a substantially cylindrical shape, and is inserted into the rear cylinder portion of the secondary piston 23 in a state of being externally fitted to the push rod P1. As shown in FIGS. 3 and 4, the retainer 60 is integrally provided with a contact portion 61 and a retaining portion 62.

  The contact portion 61 is a front portion of the retainer 60 and is externally fitted to the head portion P1b of the push rod P1. The inner peripheral surface of the contact portion 61 contacts the outer peripheral surface of the head P1b of the push rod P1. A plurality of (three in this embodiment) front slits (second slits) 61 a are formed in the contact portion 61. The front slit 61 a is a groove-shaped notch extending in the front-rear direction, and opens at the front end edge of the contact portion 61. That is, the contact portion 61 is divided into three contact pieces by the three front slits 61a. Each contact piece is elastically deformable in the radial direction of the secondary piston 23.

  The front slit 61a has a shape that gradually increases from the bottom surface (rear end) toward the opening (front end). In other words, the contact piece formed between the front slits 61a has a shape that becomes gradually narrower from the base end portion (rear end portion) toward the front end portion (front end portion). In addition, an inclined surface 61b that increases in diameter from the rear toward the front is formed at the front end of the inner surface of the front slit 61a (the tip of the inner surface of the contact piece).

  The minimum inner diameter (the inner diameter of the rear end portion) L1 of the contact portion 61 is larger than the maximum outer diameter L11 of the shaft portion P1a of the push rod P1 and smaller than the maximum outer diameter L12 of the head portion P1b. The maximum inner diameter (the inner diameter of the front end portion) L2 of the contact portion 61 is equal to or slightly smaller than the maximum outer diameter L12 of the head portion P1b of the push rod P1. The contact portion 61 (contact piece) is in contact with the shaft portion P1a side of the maximum diameter portion of the head portion P1b of the push rod P1. The maximum outer diameter L3 of the contact portion 61 passes through the annular convex portion 23d of the secondary piston 23 in a state where the contact portion 61 (contact piece) is elastically deformed in the diameter increasing direction by the head P1b of the push rod P1. The size is set as possible. The contact portion 61 (contact piece) is configured such that the inclined surface 61b contacts the shaft portion P1a side of the maximum diameter portion of the head portion P1b of the push rod P1 in the rear cylinder portion 23b of the secondary piston 23. It is elastically deformed in the diameter increasing direction, and the head P1b of the push rod P1 is pressed against the bottom surface of the rear cylinder portion 23c by a resilient force (restoring force).

  The retaining portion 62 is a rear portion of the cage 60 and is externally fitted to the shaft portion P1a of the push rod P1. The rear end edge of the retaining portion 62 contacts the annular convex portion 23d. A plurality of (three in this embodiment) rear slits (first slits) 62 a are formed in the retaining portion 62. The rear slit 62 a is a groove-shaped notch extending in the front-rear direction, and opens at the rear end edge of the retaining portion 62. That is, the retaining portion 62 is divided into three retaining pieces by the three rear slits 62a. Each retaining piece can be elastically deformed in the radial direction of the secondary piston 23.

  The rear slit 62a has a shape that gradually increases from the bottom surface (front end) toward the opening (rear end). In other words, the retaining piece formed between the rear slits 62a has a shape that gradually narrows from the base end (front end) toward the front end (rear end). Further, the retaining piece of the rear slit 62a has a shape that expands in the radial direction from the base end portion (front end portion) toward the tip end portion (rear end portion).

  The minimum inner diameter L4 of the retaining portion 62 is larger than the maximum outer diameter L11 of the shaft portion P1a of the push rod P1. The minimum inner diameter L4 of the retaining portion 62 is located on the outer peripheral side of the reduced diameter portion P1c when viewed in the axial direction of the push rod P1. The maximum outer diameter L5 of the rear end portion of the retaining portion 62 is larger than the inner diameter L21 of the annular convex portion 23d of the secondary piston 23, and is equal to or smaller than the inner diameter L22 of the rear end portion of the rear cylindrical portion 23. The thickness of the retaining part 62 is set so as to be able to pass through the annular convex part 23d of the secondary piston 23 in a state of being elastically deformed in the diameter reducing direction.

  The front slit 61 a and the rear slit 62 a are disposed at different positions in the circumferential direction of the secondary piston 23. Further, the front slits 61 a and the rear slits 62 a are alternately arranged in the circumferential direction of the secondary piston 23. In the present embodiment, three front slits 61a are arranged at intervals of 120 °, and three rear slits 62a are arranged at intervals of 120 °. The interval between the adjacent front slit 61a and rear slit 62a is set to 60 °.

  The bottom of the rear slit 62a is formed closer to the secondary piston 23 than the bottom of the front slit 61a. In other words, the front slit 61a and the rear slit 62a are formed so as to overlap in the front-rear direction. That is, the front slit 61a and the rear slit 62a overlap each other at the intermediate part in the front-rear direction of the cage 60, and the front part forward of the intermediate part constitutes the contact part 61, and The rear rear part also constitutes a retaining part 62.

  As shown in FIGS. 4B and 4C, a jig 70 (see FIG. 5) having a cylindrical shape is provided on the inner peripheral surface of the retainer 60, in this embodiment, the inner peripheral surface of the retaining portion 62. A contact surface 63 for receiving is formed. In other words, the retainer 60 has a stepped cylindrical shape having a stepped surface on the inner peripheral surface, and the stepped surface facing the rear constitutes the contact surface 63.

<Assembly method of input device>
Next, a method for assembling the input device B will be described with reference to FIG. First, as shown to Fig.5 (a), an operator makes the jig | tool 70 contact | abut on the contact surface 63 of the holder | retainer 60 in the state which fitted the holder | retainer 60 to the rear-end part of the push rod P1. In this state, the operator moves the retainer 60 to the front end side of the push rod P <b> 1 by pushing the retainer 60 forward with the jig 70. Thereby, the contact part 61 of the holder | retainer 60 contact | abuts to the push rod P1, and the push rod P1 and the holder | retainer 60 are assembled | attached.

  Subsequently, the operator pushes the retainer 60 and the push rod P1 forward with the jig 70, thereby inserting the head portion P1b of the push rod P1 and the retainer 60 into the rear cylinder portion 23 of the secondary piston 23. Here, the head P1b of the push rod P1 and the retainer 60 are suitably guided and inserted into the rear cylinder portion 23 by the inclined surface 23e of the annular convex portion 23d. Further, as shown in FIG. 5B, the retainer portion 62 (prevention piece) of the retainer 60 is formed with a rear slit 62a, so that the rear cylinder portion 23 is elastically deformed in the reduced diameter direction. Inserted inside. When the retaining portion 62 is inserted into the rear cylinder portion 23, as shown in FIG. 5C, the retaining portion 62 (a retaining piece) is restored in the diameter increasing direction. Further, in this state, the front end edge of the head P1b of the push rod P1 is in contact with the bottom surface of the rear cylinder portion 23, and the rear end edge of the retaining portion 62 of the retainer 60 contacts the annular convex portion 23e. It touches. Further, the contact portion 61 (contact piece) of the retainer 60 is elastically deformed in the diameter increasing direction by the head portion P1b of the push rod P1 due to the formation of the front slit 61a, and its elasticity (restoration) Force), the head P1b of the push rod P1 is pressed against the bottom surface of the rear cylinder part 23.

  Subsequently, the operator pulls the jig 70 backward to remove it. Thereby, as shown in FIG. 2, the assembly of the secondary piston 23, the push rod P1, and the cage 60 of the input device B is completed.

  In the input device B according to the embodiment of the present invention, the retaining portion 62 of the resin cage 60 has the rear slit 62a, and the retaining of the push rod P1 can be achieved. The number of steps for caulking can be reduced, and the retainer 60 can be easily assembled to prevent it from coming off, so that productivity can be improved while reducing costs.

  Moreover, since the contact part 61 of the resin-made cage | basket 60 has the front slit 61a, the input device B can generate | occur | produce the elastic force to the head P1b of the push rod P1.

  In addition, since the input device B has the front slit 61a and the rear slit 62a arranged at different positions in the circumferential direction of the secondary piston 23, each slit can be arranged efficiently and a mold for resin molding. And injection molding can be balanced.

  In the input device B, the cage 60 includes a plurality of front slits 61a and a plurality of rear slits 62a, and the front slits 61a and the rear slits 62a are alternately arranged in the circumferential direction of the secondary piston 23. It is possible to realize a configuration in which the substantial parts of the contact part 61 and the retaining part 62, that is, the contact piece and the retaining part are arranged in a balanced manner so that the cage 60 receives the load evenly.

  Moreover, since the bottom part of the rear slit 62a is formed in the secondary piston 23 side rather than the bottom part of the front slit, the input device B can be easily deformed elastically by forming the slits 61a and 62a deeply. 60 can be reduced in weight.

  In addition, since the input device B has the inclined surface 23e formed in the rear cylinder portion 23b, the retainer 60 can be suitably inserted into the rear cylinder portion 23b at the time of assembly, and the assemblability is improved. Can do.

  Moreover, since the holder | retainer 60 is provided with the contact surface 63, the push rod P1, the secondary piston 23, and the holder | retainer 60 can be suitably assembled | attached with the input device B with the jig | tool 70. FIG.

  Further, in the vehicle brake system A according to the embodiment of the present invention, since the retaining portion 62 of the resin cage 60 has the rear slit 62a, the cage is reduced while reducing the number of steps for caulking the secondary piston 23. 60 can prevent the push rod P1 from coming off, and can improve productivity while reducing costs.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably. For example, the number and shape of the front slit 61a and the rear slit 62a (that is, the number and shape of the retaining pieces and the contact pieces) are not limited to those described above. Moreover, the assembly method of the input device B is not limited to the above-described one. For example, the head P1b of the push rod P is held by the jig 70 in a state in which the head P1b is accommodated in the rear cylinder portion 23b of the secondary piston 23. The retainer 60 may be inserted into the rear cylindrical portion 23b by pushing the retainer 60 forward. Further, the input device of the present invention can be applied to other than the master cylinder 20 having the primary piston 22 and the secondary piston 23. The brake system of the present invention can also be applied to a brake system other than the above-described vehicle brake system, and the input device of the present invention can be applied to an input device other than the input device of the vehicle brake system. .

23 Secondary piston (piston)
23b Rear cylinder part (cylinder part)
23d Annular convex part (locking part)
23e inclined surface 30 stroke simulator (simulator mechanism)
40 Slave cylinder (electric actuator)
60 Cage 61 Abutting part 61a Front slit (second slit)
62 Retaining part 62a Rear slit (first slit)
63 Contact surface 70 Jig A Vehicle brake system (brake system)
B Input device P Brake operator (operator)
P1 push rod (input rod)
P1b end (head)

Claims (8)

An input rod capable of advancing and retracting according to the amount of operation with respect to the operation element
A piston displaceable in accordance with the advance / retreat operation of the input rod;
A substantially cylindrical cage that holds the end of the input rod swingably with respect to the piston;
With
The retainer abuts against an end of the input rod, and a retaining portion that prevents the input rod from falling off the piston by being latched by a latching portion formed on the piston. And a resin member comprising:
The input device according to claim 1, wherein the retaining portion includes a first slit extending in an axial direction of the piston, and is elastically deformable in a radial direction of the cage. The input device according to claim 1, wherein the abutting portion includes a second slit extending in an axial direction of the piston and is elastically deformable in a radial direction of the cage. The input device according to claim 2, wherein the first slit and the second slit are arranged at different positions in the circumferential direction of the piston. The cage includes a plurality of the first slits and a plurality of the second slits,
The input device according to claim 2 or 3, wherein the first slit and the second slit are alternately arranged in a circumferential direction of the piston. The input device according to any one of claims 2 to 4, wherein a bottom portion of the first slit is formed closer to the piston side than a bottom portion of the second slit. The piston includes an end portion of the input rod and a bottomed cylindrical portion in which the retainer is accommodated,
6. The inclined surface, whose diameter increases from the bottom surface side toward the opening side, is formed at the opening side end portion of the inner peripheral surface of the cylindrical portion. The input device described in 1. The input device according to any one of claims 1 to 6, wherein a contact surface for receiving a jig is formed on an inner peripheral surface of the cage. An input device according to any one of claims 1 to 7,
An electric actuator that generates brake fluid pressure corresponding to the operating force of the driver;
With
The input rod of the input device is connected to a brake operator operable by a driver,
The brake system according to claim 1, wherein the input device generates brake fluid pressure by the piston in response to an input from the brake operator.

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