JP2014021791A - Operation amount detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve detection accuracy of operation amount detection means.SOLUTION: An operation amount detector comprises: a stroke sensor 202 that detects a pedal stroke of a pedal part 200 through partial rotation of a sensor body 214 performed accompanied with an operation of the pedal part 200; a fixing part 220 that is provided at the sensor body 214 and fixes the sensor body 214 to a bracket 206; and a pair of projection parts 222 that are arranged symmetrically on both sides across a rotation center O2 of a sensor arm 218 and position the stroke sensor 202 at a predetermined position by being respectively inserted into positioning holes 224 of the bracket 206.

Description

  The present invention relates to an operation amount detection device capable of detecting an operation amount of a pedal portion.

  For example, Patent Literature 1 discloses a vehicle braking device provided with a stroke sensor that detects a pedal stroke of a brake pedal of a vehicle. In this vehicle braking device, there is no disclosure or suggestion about a specific mounting structure of the stroke sensor to the brake pedal.

  Moreover, in the vehicle brake device proposed by the present applicant as a reference, the stroke sensor is fixed to the bracket via two bolts (Japanese Patent Application No. 2011-249516).

JP 2008-132966 A

  By the way, when the pedal rotation shaft that pivotally supports the brake pedal and the sensor rotation shaft that pivotally supports the stroke sensor are arranged at different positions, the pedal depends on the mounting position of the stroke sensor. An error may occur in the detection accuracy of the stroke. Further, for example, rattling occurs in the stroke sensor due to a manufacturing error or the like, and the detection accuracy of the pedal stroke by the stroke sensor may be reduced.

  The present invention has been made in view of the above points, and an object thereof is to provide an operation amount detection device capable of improving the detection accuracy of the operation amount detection means.

  In order to achieve the above object, the present invention provides an operation amount detection means for detecting an operation amount of the pedal portion by rotating a part of the sensor body in accordance with an operation of the pedal portion, and the sensor body. A fixing portion that fixes the sensor body to another member, and a plurality of positioning means that are arranged symmetrically with a rotation center of the operation amount detection means interposed therebetween. To do.

  According to the present invention, by disposing a plurality of positioning means at symmetrical positions with the rotation center of the operation amount detection means in between, the operation amount detection means can be positioned and fixed at a predetermined position. As a result, for example, even when the pedal rotation shaft and the sensor rotation shaft are arranged at different positions, the detection accuracy of the operation amount detection unit and the positioning accuracy of the operation amount detection unit can be improved. In addition, since the plurality of positioning means are arranged at symmetrical positions with the rotation center in between, it is possible to suppress backlash caused by manufacturing errors and improve detection accuracy.

  Further, in the present invention, the other member is a bracket, and the fixing portion has an extending portion extending toward the bracket side, and when the extending portion is fixed to the bracket, the sensor body and the bracket A gap is provided between the two.

  According to the present invention, the gap is provided between the sensor body and the bracket, so that, for example, even when the driver accidentally attracts the magnet to the bracket, the detection amount of the operation amount detection means is improved. Can be avoided.

  In the present invention, an operation amount detection device capable of improving the detection accuracy of the operation amount detection means can be obtained.

1 is a schematic configuration diagram of a vehicle brake system in which an operation amount detection device according to an embodiment of the present invention is incorporated. It is a perspective view which shows the state by which the operation amount detection apparatus was attached to the brake pedal. It is a disassembled perspective view of a brake predal, a bracket, and a stroke sensor. FIG. 3 is a side view of FIG. 2. FIG. 5 is a schematic cross-sectional view of the stroke sensor along the line BB in FIG. 4. It is an enlarged arrow view seen from the arrow A direction of FIG.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a schematic configuration diagram of a vehicle brake system in which an operation amount detection device according to an embodiment of the present invention is incorporated.

  The vehicle brake system 10 shown in FIG. 1 transmits a hydraulic signal to a by-wire type brake system that transmits an electrical signal to operate the brake for normal use and a fail-safe type for use. It is configured with both of the traditional hydraulic brake systems that actuate the brakes.

  Therefore, as shown in FIG. 1, the vehicle brake system 10 basically includes an input device 14 that inputs an operation when the brake pedal 12 is operated by an operator, and a motor that controls the brake hydraulic pressure. The cylinder device 16 and a vehicle stability assist device 18 (hereinafter referred to as VSA device 18; VSA; registered trademark) that supports stabilization of vehicle behavior are separately provided.

  In addition, the brake pedal 12 of the input device 14 is provided with an operation amount detection device including a stroke sensor 202 that detects a pedal stroke of the pedal unit 200 that is rotated by an operator's stepping operation. This manipulated variable detection device will be described in detail later.

  These input device 14, motor cylinder device 16, and VSA device 18 are connected by, for example, a hydraulic path formed of a tube material such as a hose or a tube, and input as a by-wire type brake system. The device 14 and the motor cylinder device 16 are electrically connected by a harness (not shown).

  Of these, the hydraulic path will be described. The connection port 20a of the input device 14 and the introduction port 26a of the VSA device 18 are connected via a piping tube. Further, the other connection port 20b of the input device 14 and the other introduction port 26b of the VSA device 18 are connected through a piping tube.

  Further, the branch port 20c communicating with the connection port 20a of the input device 14 and the output port 24a of the motor cylinder device 16 are connected via a piping tube. Furthermore, the branch port 20d communicating with the other connection port 20b of the input device 14 and the other output port 24b of the motor cylinder device 16 are connected via a piping tube. In FIG. 1, the output ports 24a and 24b of the motor cylinder device 16 are shown on the lower side for convenience, unlike the actual positions.

  The VSA device 18 is provided with a plurality of outlet ports 28a to 28d. The first outlet port 28a is connected to a wheel cylinder 32FR of the disc brake mechanism 30a provided on the right front wheel by a piping tube. The second outlet port 28b is connected to a wheel cylinder 32RL of the disc brake mechanism 30b provided on the left rear wheel by a piping tube. The third outlet port 28c is connected to a wheel cylinder 32RR of a disc brake mechanism 30c provided on the right rear wheel by a piping tube. The fourth outlet port 28d is connected to a wheel cylinder 32FL of a disc brake mechanism 30d provided on the left front wheel by a piping tube.

  In this case, the brake fluid is supplied to the wheel cylinders 32FR, 32RL, 32RR, 32FL of the disc brake mechanisms 30a-30d by piping tubes connected to the outlet ports 28a-28d, and the wheel cylinders 32FR, 32RL, 32RR are supplied. As the hydraulic pressure in the 32FL rises, each wheel cylinder 32FR, 32RL, 32RR, 32FL is actuated and braking force is applied to the corresponding wheel (right front wheel, left rear wheel, right rear wheel, left front wheel). Is granted.

  The vehicle brake system 10 is provided so as to be mountable on various vehicles including, for example, an automobile driven only by an engine (internal combustion engine), a hybrid automobile, an electric automobile, and a fuel cell automobile.

  The input device 14 includes a tandem master cylinder 34 that can generate brake fluid pressure by a driver (operator) depressing the brake pedal 12, and a first reservoir 36 attached to the master cylinder 34. In the cylinder tube 38 of the master cylinder 34, two pistons 40a and 40b spaced apart by a predetermined distance along the axial direction of the cylinder tube 38 are slidably disposed. One piston 40 a is disposed in the vicinity of the brake pedal 12, is connected to the brake pedal 12 via the push rod 42, and is directly moved. Further, the other piston 40b is arranged farther from the brake pedal 12 than the one piston 40a.

  A pair of cup seals 44a and 44b are respectively attached to the outer peripheral surfaces of the one and the other pistons 40a and 40b via annular step portions. Back chambers 48a and 48b communicating with supply ports 46a and 46b, which will be described later, are formed between the pair of cup seals 44a and 44b, respectively. A spring member 50a is disposed between the one and the other pistons 40a and 40b, and another spring member 50b is disposed between the other piston 40b and the side end of the cylinder tube 38. The The pair of cup seals 44a and 44b may be mounted on the inner wall side of the cylinder tube 38 via an annular groove.

  The cylinder tube 38 of the master cylinder 34 is provided with two supply ports 46a and 46b, two relief ports 52a and 52b, and two output ports 54a and 54b. In this case, each supply port 46a (46b) and each relief port 52a (52b) are provided so as to join and communicate with a reservoir chamber (not shown) in the first reservoir 36, respectively.

  Further, in the cylinder tube 38 of the master cylinder 34, a first pressure chamber 56b and a second pressure chamber 56a for generating a brake fluid pressure corresponding to the depression force of the driver depressing the brake pedal 12 are provided. The first pressure chamber 56b is provided so as to communicate with the connection port 20b via the first hydraulic pressure path 58b, and the second pressure chamber 56a is communicated with the connection port 20a via the second hydraulic pressure path 58a. Is provided.

  A first shut-off valve 60b composed of a normally open type (normally open type) solenoid valve is provided between the master cylinder 34 and the connection port 20b and upstream of the first hydraulic pressure path 58b. A pressure sensor Pp is provided on the downstream side of the one hydraulic pressure path 58b. The pressure sensor Pp detects the downstream hydraulic pressure on the first hydraulic pressure path 58b that is closer to the wheel cylinders 32FR, 32RL, 32RR, and 32FL than the first shutoff valve 60b.

  A pressure sensor Pm is disposed between the master cylinder 34 and the connection port 20a upstream of the second hydraulic pressure path 58a, and a normally open type is provided downstream of the second hydraulic pressure path 58a. A second shut-off valve 60a composed of a (normally open) solenoid valve is provided. The pressure sensor Pm detects the upstream hydraulic pressure on the master cylinder 34 side of the second shutoff valve 60a on the second hydraulic pressure path 58a.

  The normal open in the first shut-off valve 60b and the second shut-off valve 60a is a valve configured so that the normal position (the position of the valve body when not energized) is in the open position (normally open). Say. In FIG. 1, the first shut-off valve 60 b and the second shut-off valve 60 a respectively show valve closed states in which solenoids are energized and valve bodies (not shown) are activated.

  The first hydraulic pressure path 58b between the master cylinder 34 and the first shut-off valve 60b is provided with a branch hydraulic pressure path 58c branched from the first hydraulic pressure path 58b, and the branch hydraulic pressure path 58c is normally closed. A third shut-off valve 62 composed of a type (normally closed) solenoid valve and a stroke simulator 64 are connected in series. The normal close in the third shut-off valve 62 refers to a valve configured such that the normal position (the position of the valve body when not energized) is in the closed position (normally closed). In FIG. 1, the third shut-off valve 62 shows a valve open state in which a solenoid (not shown) is actuated by energizing a solenoid.

  The stroke simulator 64 is a device that generates a reaction force corresponding to the stroke of the brake at the time of by-wire control and makes the operator feel as if the braking force is generated by a pedaling force. It is on the path 58b and is disposed closer to the master cylinder 34 than the first shutoff valve 60b. The stroke simulator 64 is provided with a hydraulic pressure chamber 65 communicating with the branch hydraulic pressure path 58c, and brake fluid (brake fluid) led out from the first pressure chamber 56b of the master cylinder 34 via the hydraulic pressure chamber 65 is provided. It is provided so that it can be absorbed.

  The stroke simulator 64 is a simulator piston that is urged by a first return spring 66a having a high spring constant, a second return spring 66b having a low spring constant, and first and second return springs 66a and 66b arranged in series. 68, and the pedal feeling of the brake pedal 12 is provided to be equivalent to that of an existing master cylinder.

  The hydraulic pressure path is broadly divided into a first hydraulic pressure system 70b that connects the first pressure chamber 56b of the master cylinder 34 and the plurality of wheel cylinders 32RR and 32FL, a second pressure chamber 56a of the master cylinder 34, and a plurality of pressure paths. The second hydraulic system 70a is connected to the wheel cylinders 32FR and 32RL.

  The first hydraulic system 70b includes a first hydraulic path 58b that connects the output port 54b of the master cylinder 34 (cylinder tube 38) and the connection port 20b in the input device 14, and the connection port 20b of the input device 14 and the VSA device. A piping tube for connecting the 18 inlet port 26b, a piping tube for connecting the branch port 20d of the input device 14 and the output port 24b of the motor cylinder device 16, the outlet ports 28c and 28d of the VSA device 18 and each wheel cylinder. 32RR and 32FL are connected to each other.

  The second hydraulic system 70a includes a second hydraulic path 58a that connects the output port 54a of the master cylinder 34 (cylinder tube 38) and the connection port 20a in the input device 14, and the connection port 20a of the input device 14 and the VSA device. A piping tube for connecting the 18 inlet port 26a, a piping tube for connecting the branch port 20c of the input device 14 and the output port 24a of the motor cylinder device 16, the outlet ports 28a and 28b of the VSA device 18 and each wheel cylinder. It has a piping tube which connects 32FR and 32RL, respectively.

  As a result, the hydraulic path is constituted by the first hydraulic system 70b and the second hydraulic system 70a, so that each wheel cylinder 32RR, 32FL and each wheel cylinder 32FR, 32RL are independently operated, Mutually independent braking forces can be generated.

  The motor cylinder device 16 includes an actuator mechanism 74 having an electric motor (electric motor) 72 and a driving force transmission unit 73, and a cylinder mechanism 76 biased by the actuator mechanism 74. In this case, the electric motor 72, the driving force transmission unit 73, and the cylinder mechanism 76 are provided so as to be separable.

  The driving force transmission unit 73 of the actuator mechanism 74 converts a gear mechanism (deceleration mechanism) 78 that transmits the rotational driving force of the electric motor 72 and converts the rotational driving force into linear motion (axial force in a linear direction). It has a ball screw structure (conversion mechanism) 80 that transmits to the first and second slave pistons 88b, 88a side of the cylinder mechanism 76.

  The electric motor 72 is driven and controlled based on a control signal (electric signal) from a control means (not shown), for example, a servo motor, and is disposed above the actuator mechanism 74. By arranging and configuring in this way, it is possible to suitably avoid oil components such as grease in the driving force transmission unit 73 from entering the electric motor 72 due to gravity.

  The ball screw structure 80 includes a ball screw shaft (rod) 80a whose one end along the axial direction contacts the second slave piston 88a of the cylinder mechanism 76, and a helical shape formed on the outer peripheral surface of the ball screw shaft 80a. A plurality of balls 80b that roll along the thread groove, a substantially cylindrical nut member 80c that is fitted in a ring gear of the gear mechanism 78, rotates together with the ring gear, and is screwed into the ball 80b; The nut member 80c includes a pair of ball bearings 80d that rotatably support one end side and the other end side along the axial direction. The nut member 80c is, for example, press-fitted and fixed to the inner diameter surface of the ring gear of the gear mechanism 78.

  By configuring the driving force transmitting portion 73 in this way, after the rotational driving force of the electric motor 72 transmitted via the gear mechanism 78 is input to the nut member 80c, the driving force transmitting portion 73 is linearly moved by the ball screw structure 80. The axial force (linear motion) of the ball screw shaft 80a is moved back and forth along the axial direction.

  The motor cylinder device 16 transmits the driving force of the electric motor 72 to the first slave piston 88b and the second slave piston 88a of the cylinder mechanism 76 via the driving force transmission unit 73, and the first slave piston 88b and the second slave. The brake fluid pressure is generated by driving the piston 88a forward. In the following description, the displacement of the first slave piston 88b and the second slave piston 88a in the direction of the arrow X1 (see FIG. 1) is “forward”, and the displacement in the direction of the arrow X2 (see FIG. 1) is “backward”. ". The arrow X1 may indicate “front”, and the arrow X2 may indicate “rear”.

  The cylinder mechanism 76 includes a cylinder body 82 having a bottomed cylindrical shape and a second reservoir 84 attached to the cylinder body 82, and two pistons (a first slave piston 88 b and a second slave piston are provided in the cylinder body 82. 88a) is composed of a tandem type arranged in series. The second reservoir 84 is connected to the first reservoir 36 attached to the master cylinder 34 of the input device 14 by a piping tube 86, and the brake fluid stored in the first reservoir 36 is passed through the piping tube 86 to the second reservoir 84. 84 is provided so as to be supplied in the inside.

  The cylinder mechanism 76 is configured by integrally assembling peripheral components including the first slave piston 88b and peripheral components including the second slave piston 88a. And a second piston mechanism. The first piston mechanism and the second piston mechanism are configured to be integrally assembled so as to partially overlap each other via a connecting pin 79.

  The first piston mechanism is related to a first slave piston 88b disposed so as to face the first hydraulic chamber 98b in front of the cylinder body 82 and a through hole 91 formed at an intermediate portion of the first slave piston 88b. In combination, the stopper pin 102 that restricts the moving range of the first slave piston 88b is disposed between the first slave piston 88b and the side end (bottom wall) of the cylinder body 82, and the first slave piston 88b It has the 1st spring 96b pressed toward back (arrow X2 direction).

  The second piston mechanism includes a second slave piston 88a, a first slave piston 88b, and a second slave piston arranged to face the second hydraulic chamber 98a behind the first slave piston 88b (in the direction of the arrow X2). 88a, and a second spring 96a that urges the first slave piston 88b and the second slave piston 88a away from each other.

  A long hole 107 through which the connecting pin 79 is inserted is formed in the shaft portion 105 in front of the second slave piston 88a. The long hole 107 is formed so as to extend along the axial direction of the second slave piston 88a, and is formed so as to penetrate in a direction orthogonal to the axial direction. The connecting pin 79 inserted through the long hole 107 regulates the separation position between the first slave piston 88b and the second slave piston 88a and regulates the initial position of the second slave piston 88a.

  The second slave piston 88a is disposed in the vicinity of the ball screw structure 80, contacts the one end of the ball screw shaft 80a, and is integrated with the ball screw shaft 80a in the direction indicated by the arrow X1 or in the direction indicated by the arrow X2. It is provided to be displaced. The first slave piston 88b is disposed at a position farther from the ball screw structure 80 side than the second slave piston 88a.

  A first back chamber 94b and a second back chamber 94a communicating with reservoir ports 92a and 92b, which will be described later, are formed on the outer peripheral surfaces of the first and second slave pistons 88b and 88a, respectively.

  The cylinder body 82 of the cylinder mechanism 76 is provided with two reservoir ports 92a and 92b and two output ports 24a and 24b. In this case, the reservoir port 92a (92b) is provided so as to communicate with a reservoir chamber (not shown) in the second reservoir 84.

  Further, in the cylinder body 82, a first hydraulic pressure chamber 98b for controlling the brake hydraulic pressure output from the output port 24b to the wheel cylinders 32RR, 32FL side, and the output port 24a, output to the wheel cylinders 32FR, 32RL side. And a second hydraulic pressure chamber 98a for controlling the brake hydraulic pressure.

  The first slave piston 88b engages with a through hole 91 that penetrates in a direction substantially orthogonal to the axis of the first slave piston 88b, restricts the sliding range of the first slave piston 88b, and controls the second slave piston 88a. A stopper pin 102 is provided to prevent over-return to the side. This stopper pin 102 prevents the failure of the first hydraulic system 70b when the second hydraulic system 70a fails, particularly during backup when braking with the brake hydraulic pressure generated in the master cylinder 34. The stopper pin 102 is inserted from the opening of the reservoir port 92 b and is locked by a locking hole formed in the cylinder body 82.

  The VSA device 18 is a well-known device and controls the first hydraulic system 70b connected to the disc brake mechanisms 30c, 30d (wheel cylinder 32RR, wheel cylinder 32FL) of the right rear wheel and the left front wheel. 110b and a second brake system 110a for controlling the second hydraulic system 70a connected to the disc brake mechanisms 30a, 30b (wheel cylinder 32FR, wheel cylinder 32RL) of the right front wheel and the left rear wheel.

  The second brake system 110a is composed of a hydraulic system connected to a disc brake mechanism provided on the left front wheel and the right front wheel, and the first brake system 110b is a disc provided on the left rear wheel and the right rear wheel. A hydraulic system connected to the brake mechanism may be used. Further, the second brake system 110a includes a hydraulic system connected to a disc brake mechanism provided on the right front wheel and the right rear wheel on one side of the vehicle body, and the first brake system 110b includes the left front wheel and the left rear wheel on the vehicle body side. A hydraulic system connected to a disc brake mechanism provided on the wheel may be used.

  Since the first brake system 110b and the second brake system 110a have the same structure, the corresponding parts in the first brake system 110b and the second brake system 110a are assigned the same reference numerals, and The description of the first brake system 110b will be added in parentheses with a focus on the description of the two brake system 110a.

  The second brake system 110a (first brake system 110b) has a first common hydraulic pressure path 112 and a second common hydraulic pressure path 114 that are common to the wheel cylinders 32FR and 32RL (32RR and 32FL). The VSA device 18 includes a regulator valve 116 formed of a normally open type solenoid valve disposed between the introduction port 26a (introduction port 26b) and the first common hydraulic pressure path 112, and is disposed in parallel with the regulator valve 116. Allow the brake fluid to flow from the port 26a side (introduction port 26b side) to the first common hydraulic pressure path 112 side (block the brake fluid from the first common hydraulic pressure path 112 side to the introduction port 26a side) ) A first check valve 118, a first in-valve 120 including a normally open type solenoid valve disposed between the first common hydraulic pressure path 112 and the first derivation port 28a (fourth derivation port 28d); The first common liquid is arranged in parallel with the 1-in valve 120 from the first outlet port 28a side (fourth outlet port 28d side). A second check valve 122 that permits the flow of brake fluid to the path 112 side (blocks the flow of brake fluid from the first common hydraulic pressure path 112 side to the first outlet port 28a side), and a first common hydraulic pressure A second in-valve 124 comprising a normally open type solenoid valve disposed between the passage 112 and the second outlet port 28b (third outlet port 28c), and a second outlet port 28b disposed in parallel with the second inlet valve 124. Allow the brake fluid to flow from the first common hydraulic pressure passage 112 side to the first common hydraulic pressure passage 112 side (allow the brake fluid to flow from the first common hydraulic pressure passage 112 side to the second lead-out port 28b side). A third check valve 126 is provided.

  Further, the VSA device 18 includes a first out valve 128 including a normally closed solenoid valve disposed between the first outlet port 28a (fourth outlet port 28d) and the second common hydraulic pressure path 114, The second out valve 130 formed of a normally closed type solenoid valve disposed between the second outlet port 28b (third outlet port 28c) and the second common hydraulic pressure path 114, and connected to the second common hydraulic pressure path 114 Of the brake fluid from the second common hydraulic pressure path 114 side to the first common hydraulic pressure path 112 side disposed between the reservoir 132 and the first common hydraulic pressure path 112 and the second common hydraulic pressure path 114. A fourth check valve 134 that permits flow (blocks the flow of brake fluid from the first common hydraulic pressure path 112 side to the second common hydraulic pressure path 114 side), and a fourth check valve 134; A pump 136 disposed between the first common hydraulic pressure path 112 and supplying brake fluid from the second common hydraulic pressure path 114 side to the first common hydraulic pressure path 112 side; and suction valves 138 provided before and after the pump 136. And a discharge valve 140, a motor M for driving the pump 136, a suction valve 142 comprising a normally closed solenoid valve disposed between the second common hydraulic pressure path 114 and the introduction port 26a (introduction port 26b), Is provided.

  In the second brake system 110a, the brake fluid output from the output port 24a of the motor cylinder device 16 and controlled by the second hydraulic pressure chamber 98a of the motor cylinder device 16 is provided on the hydraulic pressure path close to the introduction port 26a. A pressure sensor Ph for detecting pressure is provided. Detection signals detected by the pressure sensors Pm, Pp, and Ph are introduced into control means (not shown). Further, the VSA device 18 includes ABS control in addition to VSA control.

  2 is a perspective view showing a state where an operation amount detection device according to an embodiment of the present invention is attached to a brake pedal, FIG. 3 is an exploded perspective view of a brake pedal, a bracket, and a stroke sensor, and FIG. FIG. 5 is a schematic cross-sectional view of the stroke sensor along line BB in FIG. 4, and FIG. 6 is an enlarged arrow view seen from the direction of arrow A in FIG.

  As shown in FIGS. 2 and 3, the brake pedal 12 is pivotally supported with respect to a bracket (another member) 206 fixed to the dashboard 204 (see FIG. 4). The bracket 206 is divided into an upper bracket 206 a that covers the stroke sensor 202 and a lower bracket 206 b that is fixed to the dashboard 204. When both the upper bracket 206a and the lower bracket 206b are generically referred to, they are simply referred to as the bracket 206. In the present embodiment, the upper bracket 206a and the lower bracket 206b are divided and configured, but a single bracket 206 in which the upper bracket 206a and the lower bracket 206b are integrally molded may be used. .

  The brake pedal 12 includes a pedal portion 200 that is depressed by a driver, a pedal rotation shaft 208 that is pivotally attached to the lower bracket 206b and pivotally supports the upper end of the pedal portion 200, and the pedal portion 200. A substantially arc-shaped pedal arm 210 that is fixed to the upper end of the pedal and rotates integrally with the pedal portion 200, and a direction that is fixed to the upper end of the pedal arm 210 and that is substantially orthogonal to the extending direction of the pedal arm 210 (on the stroke sensor 202 side). And a pin 212 protruding from the bottom.

  The pedal rotation shaft 208 has one end fixed to the lower bracket 206b and cantilevered, and a cylindrical rod 208a that is externally fitted to the rod 208a and slides in the circumferential direction along the outer peripheral surface of the rod 208a. And a cylindrical body 208b. In this case, the upper end of the pedal part 200 and the lower end of the pedal arm 210 are fixed to the cylindrical body 208b by welding or the like, for example, so that the rod 208a can be rotated about the rotation center O1.

  The operation amount detection device includes a stroke sensor (operation amount detection means) 202 that detects a stroke (pedal stroke) of the tread surface 200 a of the pedal unit 200. The stroke sensor 202 includes a sensor main body 214, a sensor arm (part of the sensor main body) 218 provided so as to be rotatable with respect to the sensor main body 214 around the sensor rotation shaft 216 as a rotation center O 2, and the sensor main body 214 as a bracket. A fixing portion 220 that is fixed to 206, and a pair of protrusions (positioning means) 222 that are disposed at symmetrical positions with the rotation center O2 of the sensor arm 218 interposed therebetween. The ends of the pair of protrusions 222 are inserted into a pair of positioning holes 224 formed in the bracket 206, whereby the stroke sensor 202 is positioned at a predetermined position of the bracket 206 (see FIG. 3).

  “Symmetric position with the rotation center O2 of the sensor arm 218 interposed therebetween” means that the axis T of the pair of protrusions 222 and the sensor rotation shaft 216 passing through the rotation center O2, as shown in FIG. The distances D1 and D2 between the two are set equal to each other (D1 = D2). Further, the protrusions 222 are not limited to a pair as in the present embodiment, but may be at least two. Note that the separation distances D1 and D2 may be slightly different depending on the structure and mounting location of the stroke sensor 202, even if they are not completely equal.

  The stroke sensor 202 is fixed to the bracket 206 with a pair of bolts 242 so as to be adjacent to the pedal rotation shaft 208. That is, as shown in FIG. 3, the bolts 242 are fastened by screwing a pair of bolts 242 through the insertion holes 244 formed in the bracket 206 and into the fastening holes 246 formed in the fixing portion 220. The

  As shown in FIG. 6, the fixing portion 220 extends from the lower side of the outer peripheral surface of the housing 226 toward the bracket 206 side, and has an extending portion 250 formed of a leg portion. When the extending portion 250 is fixed to the bracket 206, a gap portion 252 is provided between the bottom surface of the sensor main body 214 and the wall surface of the bracket 206. By providing the gap 252, for example, even when the driver accidentally attracts a magnet (not shown) to the bracket 206, the malfunction of the stroke sensor 202 can be suppressed.

  As shown in FIG. 3, the sensor arm 218 has a pair of branch portions 254 that are bifurcated and extend substantially in parallel. Between the pair of branch portions 254, a guide groove 256 is provided that extends in a radially outward direction from the sensor rotation shaft 216 and has a linear shape. A pin 212 fixed to the pedal arm 210 is slidably engaged with the guide groove 256. A return spring (not shown) is engaged with the pin 212, and the pedal portion 200 is provided so as to return to the initial position by the spring force of the return spring.

  When the driver depresses the pedal portion 200, the brake pedal 12 rotates forward (in the direction of the arrow X1) about the pedal rotation shaft 208 as the rotation center O1 against the spring force of the return spring. The pedal arm 210 fixed to the upper end of the pedal portion 200 is interlocked, and the pedal arm 210 rotates backward (in the direction of the arrow X2) about the pedal rotation shaft 208 as the rotation center O1. In conjunction with the pedal arm 210, the pin 212 fixed to the pedal arm 210 presses the guide groove 256 of the branch portion 254, so that the sensor arm 218 rotates about the sensor rotation shaft 216 as the rotation center O2. As a result, the stroke sensor 202 outputs a voltage corresponding to the rotational position of the sensor arm 218, and the pedal stroke of the brake pedal 12 corresponding to this voltage is detected.

  The vehicle brake system 10 in which the operation amount detection device according to the present embodiment is incorporated is basically configured as described above. Next, the function and effect will be described.

  When the vehicle brake system 10 functions normally, the first shut-off valve 60b and the second shut-off valve 60a, which are normally open type solenoid valves, are energized by energization to be closed, and the normal close type solenoid valves are used. The third shut-off valve 62 is excited by energization to enter a valve open state. Accordingly, since the first hydraulic pressure system 70b and the second hydraulic pressure system 70a are blocked by the first cutoff valve 60b and the second cutoff valve 60a, the brake hydraulic pressure generated in the master cylinder 34 of the input device 14 (first Is not transmitted to the wheel cylinders 32FR, 32RL, 32RR, 32FL of the disc brake mechanisms 30a-30d.

  At this time, the brake hydraulic pressure generated in the first pressure chamber 56b of the master cylinder 34 is transmitted to the hydraulic pressure chamber 65 of the stroke simulator 64 via the branch hydraulic pressure path 58c and the third shut-off valve 62 in the valve open state. Is done. When the simulator piston 68 is displaced against the spring force of the first and second return springs 66a and 66b by the brake hydraulic pressure supplied to the hydraulic pressure chamber 65, the stroke of the brake pedal 12 is allowed, and A pseudo pedal reaction force is generated and applied to the brake pedal 12. As a result, it is possible to obtain a brake feeling that is comfortable for the driver.

  In such a system state, when the control means (not shown) detects depression of the brake pedal 12 by the driver, the control means drives the electric motor 72 of the motor cylinder device 16 to urge the actuator mechanism 74, and the first spring 96b and The first slave piston 88b and the second slave piston 88a are displaced (advanced) in the direction of the arrow X1 in FIG. 1 against the spring force of the second spring 96a. Due to the displacement of the first slave piston 88b and the second slave piston 88a, the brake fluid pressure in the first fluid pressure chamber 98b and the second fluid pressure chamber 98a is pressurized to generate a desired brake fluid pressure. .

  The brake hydraulic pressure in the first hydraulic pressure chamber 98b and the second hydraulic pressure chamber 98a in the motor cylinder device 16 is applied to the disc brake mechanism 30a via the first and second inlet valves 120 and 124 in the valve open state of the VSA device 18. To 30d wheel cylinders 32FR, 32RL, 32RR, 32FL, and the wheel cylinders 32FR, 32RL, 32RR, 32FL are operated to apply a desired braking force to each wheel.

  In other words, in the vehicle brake system 10, the brake pedal 12 is braked when the driver depresses the brake pedal 12 when the motor cylinder device 16 that functions as a power hydraulic pressure source or an ECU (not shown) that performs by-wire control is operable. A state in which communication between the master cylinder 34 that generates hydraulic pressure and the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, and 32FL) that brake each wheel is blocked by the first cutoff valve 60b and the second cutoff valve 60a. Thus, a so-called brake-by-wire brake system in which the disc brake mechanisms 30a to 30d are operated with the brake fluid pressure (second brake fluid pressure) generated by the motor cylinder device 16 becomes active.

  On the other hand, when the motor cylinder device 16 or the like becomes abnormal, the first cutoff valve 60b and the second cutoff valve 60a are opened, and the third cutoff valve 62 is closed so that the master cylinder 34 The generated brake fluid pressure (first brake fluid pressure) is transmitted to the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, 32FL) and the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR). , 32FL) is activated, the so-called traditional hydraulic brake system is activated.

  In the present embodiment, the stroke sensor 202 can be positioned and fixed at a predetermined position by arranging the pair of protrusions 222 at symmetrical positions with the rotation center O2 of the sensor arm 218 of the stroke sensor 202 interposed therebetween. it can. As a result, for example, even when the pedal rotation shaft 208 and the sensor rotation shaft 216 are arranged at different positions, the detection accuracy and positioning accuracy of the stroke sensor 202 can be improved.

  Further, in the present embodiment, the pair of protrusions 222 are disposed at symmetrical positions with the rotation center O2 of the sensor arm 218 interposed therebetween, thereby suppressing rattling caused by manufacturing errors and improving detection accuracy. Can be made. Although it is conceivable that the protrusion 222 is provided at the rotation center O2 of the sensor arm 218, in the present embodiment, a lid member 234 that is configured separately from the sensor body 214 and closes the opening of the housing 226 (FIG. 5). Therefore, the pair of protrusions 222 are arranged at positions offset by an equal distance from the rotation center O2.

  Furthermore, in the present embodiment, the gap 252 is provided between the bottom surface of the sensor body 214 and the bracket 206, for example, when the driver accidentally attracts a magnet (not shown) to the bracket 206. In addition, adverse effects on the detection capability of the stroke sensor 202 can be avoided. For example, even when the driver accidentally attracts a magnet (not shown) to the bracket 206 in the vicinity of the stroke sensor 202, the malfunction of the stroke sensor 202 can be suppressed.

  Furthermore, in the present embodiment, a virtual straight line that connects the centers of the pair of fixing parts 220 fastened by the bolts 242 and a virtual straight line that connects the centers of the pair of protrusions 222 intersect each other orthogonally or substantially orthogonally. Therefore, the detection accuracy of the stroke sensor 202 can be further improved.

  In the present embodiment, the protrusion 222 is formed on the sensor body 214 side and the positioning hole 224 is formed on the bracket 206 side. For example, a protrusion (projection) (not shown) is provided on the bracket 206 side. An engagement recess (not shown) that engages with the protrusion (projection) may be formed on the sensor body 214 side.

  In addition, in this embodiment, the stroke sensor 202 is described as an operation amount detection unit. However, for example, a pedal stroke may be detected using a potentiometer (not shown).

12 Brake pedal 200 Pedal part 202 Stroke sensor (operation amount detection means)
206, 206a, 206b Bracket (other member)
208 Pedal rotation axis 214 Sensor body 216 Sensor rotation axis 218 Sensor arm (part of sensor body)
220 fixing part 222 protrusion part (positioning means)
250 extension part 252 gap part

Claims (2)

An operation amount detection means for detecting an operation amount of the pedal portion by rotating a part of the sensor body with the operation of the pedal portion;
A fixing portion provided on the sensor body, and fixing the sensor body to another member;
A plurality of positioning means disposed at symmetrical positions with the rotation center of the operation amount detection means interposed therebetween;
An operation amount detection device comprising: The operation amount detection device according to claim 1,
The other member is a bracket,
The fixing portion has an extending portion extending toward the bracket side,
An operation amount detection device, wherein a gap is provided between the sensor body and the bracket when the extension is fixed to the bracket.

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