WO2018097278A1

WO2018097278A1 - Electric booster

Info

Publication number: WO2018097278A1
Application number: PCT/JP2017/042348
Authority: WO
Inventors: 厚志小平
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2016-11-28
Filing date: 2017-11-27
Publication date: 2018-05-31
Also published as: JPWO2018097278A1

Abstract

The electric booster is provided with: first and second compression coil springs for biasing an input member and a boosting member in a direction away from each other along an axial direction; and a support member for supporting the second compression coil spring between the input member and the boosting member. When the input member moves in a direction toward a master cylinder, the support member comes into contact with the boosting member without coming into contact with an input plunger, whereas when the input member moves in a direction away from the master cylinder, the support member comes into contact with the input plunger and moves away from the boosting member. Consequently, hysteresis characteristics can be applied to the entire stroke of the input member, whereby an improved pedal feeling can be achieved.

Description

Electric booster

The present invention includes a booster member that assists thrust to the piston of the master cylinder by driving the electric motor as the input member moves in accordance with the brake pedal operation, and the resistance force acting on the input member is depressed by the brake pedal. The present invention relates to an electric booster having a hysteresis characteristic that changes between time and return.

For example, the electric booster described in Patent Document 1 is configured as follows. That is, when the movement distance of the input piston relative to the case by the operation of the brake pedal reaches a predetermined distance, the reaction force spring is compressed, and the spring force is applied to the brake pedal as a reaction force. As a result, the decrease in the amount of increase in the reaction force due to the stop of the primary piston can be compensated by the spring force of the reaction force spring of the reaction force mechanism, and the rigidity of the brake pedal can be maintained. It is possible to alleviate the uncomfortable feeling caused by the decrease in the increase in the reaction force after the output reaches the maximum output.

JP 2012-96649 A

However, the electric booster according to Patent Document 1 employs a structure in which the spring force of the reaction spring is applied to the brake pedal as a reaction force after the input piston has moved a predetermined distance. Cannot be granted.

And this invention provides the electric booster which can give a hysteresis characteristic with respect to the stroke of the input member accompanying a brake pedal operation, and improves a pedal feeling.

A first electric booster according to an embodiment of the present invention is driven by an electric motor and connected to a booster member that moves a piston of a master cylinder, an input rod connected to a brake pedal, and the input rod. An input member composed of an input plunger to which a part of the reaction force from the piston of the master cylinder is transmitted, a first urging member for applying an urging force to the input member in the return direction of the brake pedal, A second urging member that urges the input member and the booster member in a direction away from each other along the axial direction; and the second urging member between the input member and the booster member. A support member for supporting,
When the input member moves from a non-operating state of the brake pedal in a direction approaching the master cylinder, the support member does not contact the input plunger but contacts the boost member, When the input member moves in a direction away from the master cylinder, the support member is separated from the booster member while being in contact with the input plunger.

The second electric booster according to an embodiment of the present invention is driven by the thrust of the electric motor and is connected to a booster member that moves the piston of the master cylinder and a brake pedal, and is counteracted from the master cylinder. An input member to which a part of the force is transmitted, a first urging member that abuts on the input member and urges the input member toward the brake pedal, and the input member and the booster member. A second biasing member that is provided between the biasing member and biasing the input member toward the brake pedal,
The second urging member has one end in contact with the input member and the other end through the booster member and a support member that can be brought into contact with and separated from the input member according to the moving direction of the input member. Supported by a force member or the input member.

Furthermore, a third electric booster according to an embodiment of the present invention includes a booster member that is propelled by an electric motor and applies thrust to a master cylinder, an input rod connected to a brake pedal, and the input rod. An input member comprising an input plunger to which a part of the reaction force from the master cylinder is transmitted, two urging members for applying an urging force to the input member in the return direction of the brake pedal, A biasing member for supporting one of the biasing members between the input member and the booster member;
When the input member moves in a direction closer to the master cylinder from a non-operated state of the brake pedal, a biasing force is transmitted from both of the two biasing members, and the input member is separated from the master cylinder. When moving in the direction, the urging force is not transmitted from the one urging member but the urging force is transmitted from the other urging member.

In the electric booster according to one embodiment of the present invention, hysteresis characteristics can be imparted to the stroke of the input member accompanying the brake pedal operation, and pedal feeling can be improved.

It is sectional drawing which shows the electric booster of this embodiment, and shows the non-operation state of a brake pedal. It is a principal part enlarged view of the electric booster of FIG. In the electric booster of this embodiment, it is sectional drawing of the state in which the brake pedal was depressed. In the electric booster of this embodiment, it is sectional drawing just before the depression to a brake pedal is cancelled | released and an electric motor rotationally drives in a cancellation | release direction. It is a figure which shows the hysteresis characteristic by the resistive force provision mechanism employ | adopted as the electric booster of this embodiment. In the electric booster of this embodiment, it is a figure which shows the initial state from which depression to the brake pedal was cancelled | released. It is a figure which shows the state which the input plunger contact | abutted from the support member following FIG. It is a figure which shows the state which the support member continued from FIG. It is sectional drawing of the resistance-force provision mechanism which concerns on other embodiment. FIG. 9 is a cross-sectional view of a resistance applying mechanism according to another embodiment when a brake pedal is depressed. FIG. 10 is a diagram showing an initial state in which a stepping on a brake pedal is released, which is a resistance applying mechanism according to another embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
Hereinafter, the electric booster 1 according to the present embodiment will be described. In this description, the left side is referred to as the front side (the vehicle front side) and the right side is referred to as the rear side (the vehicle rear side) in FIGS.
As shown in FIG. 1, the electric booster 1 according to this embodiment is roughly an electric motor 2, a housing 3, an input member 4, a resistance applying mechanism 5, a ball screw mechanism 6, and a stroke detection device. (Not shown) and a controller 7. The electric motor 2 is provided in the housing 3. The input member 4 includes an input rod 10 and an input plunger 11. The input rod 10 is connected to the brake pedal 13 and extends in the housing 3 toward the master cylinder 15. The input plunger 11 is connected to the front end (ball joint 85) of the input rod 10, and part of the reaction force from the primary piston 31 and the secondary piston 32 of the master cylinder 15 is transmitted to the input plunger 11.

The resistance force applying mechanism 5 changes the resistance force (reaction force) to the input rod 10 and the input plunger 11 when the input rod 10 and the input plunger 11 are moved forward and backward (when the brake pedal 13 is depressed and returned). The hysteresis characteristic to be generated is generated. The ball screw mechanism 6 assists thrust to the primary piston 31 and the secondary piston 32 of the master cylinder 15 by the operation of the electric motor 2 as the input rod 10 moves forward with the operation of the brake pedal 13. The stroke detection device detects the stroke amount of the input rod 10 and the input plunger 11 with respect to the housing 3. The controller 7 is a control device that controls the operation of the electric motor 2 based on the movement position (stroke amount) of the input rod 10 and the input plunger 11 detected by the stroke detection device.

Below, this electric booster 1 is demonstrated in detail.
As shown in FIG. 1, the electric booster 1 has a structure in which a tandem master cylinder 15 is connected to the front side of the housing 3 (left side in FIG. 1). A reservoir 16 for supplying brake fluid to the master cylinder 15 is attached to the top of the master cylinder 15. The housing 3 includes a front housing 20 that houses the electric motor 2 and the ball screw mechanism 6 and the like, and a rear housing 21 that closes the rear end opening (the right end opening in FIG. 1) of the front housing 20.

The rear housing 21 has a cylindrical portion 22. The cylindrical portion 22 is concentric with the master cylinder 15 and integrally protrudes in a direction away from the master cylinder 15 (backward). A small diameter restricting portion 23 is integrally formed at the rear end of the cylindrical portion 22. A stopper member 25 is disposed inside the rear end of the cylindrical portion 22. The small diameter restricting portion 23 protrudes inward so as to cover the stopper member 25 located inside the rear end of the cylindrical portion 22 from the rear side. A mounting plate 27 is fixed around the cylindrical portion 22 of the rear housing 21. A plurality of stud bolts 28 are attached to the attachment plate 27. And this electric booster 1 is arrange | positioned in an engine room in the state which made the input rod 10 protrude from the dash panel (not shown) which is a partition of the engine room of a vehicle, and a vehicle interior, and faced the vehicle interior. And fixed to the dash panel using a plurality of stat bolts 28.

As shown in FIG. 1, the master cylinder 15 is attached to the front surface of the front housing 20. The master cylinder 15 is disposed in the housing 3 through an opening 29 provided at the rear end portion of the front housing 20. A bottomed cylinder bore 30 is formed in the master cylinder 15. A primary piston 31 is disposed on the opening side of the cylinder bore 30. The front portion of the primary piston 31 is disposed in the cylinder bore 30 of the master cylinder 15, and the rear portion of the primary piston 31 extends from the cylinder bore 30 of the master cylinder 15 into the housing 3 of the electric booster 1. The front part and the rear part of the primary piston 31 are each formed in a cup shape and formed in an H-shaped cross section. A spherical recess 35 is formed on the rear surface of the intermediate wall 34 provided substantially at the center in the axial direction of the primary piston 31. A spherical surface 143 at the front end of the pressing rod 142 described later is brought into contact with the spherical recess 35. A cup-shaped secondary piston 32 is disposed on the bottom side of the cylinder bore 30. A primary chamber 37 is formed between the primary piston 31 and the secondary piston 32 in the cylinder bore 30 of the master cylinder 15, and a secondary chamber 38 is formed between the bottom of the cylinder bore 30 and the secondary piston 32.

Each of the primary chamber 37 and the secondary chamber 38 of the master cylinder 15 is connected to each wheel via two hydraulic pressure circuits (not shown) from the two hydraulic pressure ports (not shown) of the master cylinder 15 via a hydraulic control unit (not shown). Connected to a wheel cylinder (not shown). Then, the brake fluid generated by the master cylinder 15 or the fluid pressure control unit is supplied to the wheel cylinder of each wheel to generate a braking force.

The master cylinder 15 is provided with

reservoir ports

44 and 45 for connecting the primary chamber 37 and the secondary chamber 38 to the reservoir 16, respectively. On the inner peripheral surface of the cylinder bore 30, annular piston seals 47, 48, 49, and 50 that abut against the primary piston 31 and the secondary piston 32 are provided in the axial direction so as to partition the cylinder bore 30 into a primary chamber 37 and a secondary chamber 38. Are arranged at predetermined intervals. The piston seals 47 and 48 are disposed so as to sandwich one reservoir port 44 (rear side) along the axial direction. When the primary piston 31 is in the non-braking position shown in FIG. 1, the primary chamber 37 communicates with the reservoir port 44 via the piston port 62 provided on the side wall of the primary piston 31. When the primary piston 31 moves forward from the non-braking position and the piston port 62 reaches one of the piston seals 48 (front side), the primary chamber 37 is shut off from the reservoir port 44 by the piston seal 48 to generate hydraulic pressure. .

Similarly, the remaining two

piston seals

49 and 50 are disposed so as to sandwich the other reservoir port 45 (front side) along the axial direction. When the secondary piston 32 is in the non-braking position shown in FIG. 1, the secondary chamber 38 communicates with the reservoir port 45 via a piston port 63 provided on the side wall of the secondary piston 32. Then, when the secondary piston 32 moves forward from the non-braking position and the piston port 63 reaches one piston seal 50 (front side), the secondary chamber 38 is shut off from the reservoir port 45 by the piston seal 50 to generate hydraulic pressure. .

A compression coil spring 65 is interposed between the primary piston 31 and the secondary piston 32. The compression coil spring 65 biases the primary piston 31 and the secondary piston 32 in a direction away from each other. Inside the compression coil spring 65, an extendable / contractible member 66 is disposed so as to restrict the space between the primary piston 31 and the secondary piston 32 at a predetermined interval. The telescopic member 66 includes a retainer guide 67 connected to the intermediate wall 34 of the primary piston 31 and a retainer rod 68 having a front end connected to the secondary piston 32 and movable in the retainer guide 67 in the axial direction. . The retainer guide 67 is formed in a cylindrical shape and has a stopper portion 67A that protrudes inwardly at the front end. The retainer rod 68 has a flange portion 68A that protrudes radially outward at the rear end thereof. By inserting the retainer rod 68 into the retainer guide 67, the relative movement of the two 67 and 68 along the axial direction becomes possible, and the stopper portion 67A of the retainer guide 67 and the flange portion 68A of the retainer rod 68 interfere with each other. At that time, the expansion / contraction member 66 becomes a predetermined extension.

A compression coil spring 71 is interposed between the bottom of the cylinder bore 30 and the secondary piston 32. The compression coil spring 71 biases the bottom of the cylinder bore 30 and the secondary piston 32 in a direction away from each other. Also in the compression coil spring 71, a telescopic member 72 that can be telescopically disposed is disposed so as to restrict the space between the bottom of the cylinder bore 30 and the secondary piston 32 at a predetermined interval. The telescopic member 72 includes a retainer guide 73 having a front end connected to the bottom of the cylinder bore 30 and a retainer rod 74 having a rear end connected to the secondary piston 32 and movable in the retainer guide 73 in the axial direction. . The retainer guide 73 is formed in a cylindrical shape, and has a stopper portion 73A that protrudes inwardly at the rear end. The retainer rod 74 has a flange portion 74A that protrudes radially outward at the front end thereof. By inserting the retainer rod 74 into the retainer guide 73, the relative movement of the two 73 and 74 along the axial direction becomes possible, and the stopper portion 73A of the retainer guide 73 and the flange portion 74A of the retainer rod 74 interfere with each other. At that time, the expansion / contraction member 72 becomes a predetermined extension.

Referring also to FIG. 2, the input rod 10 is disposed concentrically within the cylindrical portion 22 of the rear housing 18. The rear end side of the input rod 10 protrudes from the cylindrical portion 22 to the outside. The input rod 10 includes a small-diameter rod portion 80 that extends forward, a large-diameter rod portion 81 that integrally extends rearward from the small-diameter rod portion 80, and a radially outer portion between the small-diameter rod portion 80 and the large-diameter rod portion 81. And a stopper abutting portion 82 projecting integrally in a ring shape. The front end portion of the small diameter rod portion 80 is slightly reduced in diameter, and a ball joint portion 85 is formed at the front end of the small diameter rod portion 80. The ball joint portion 85 is connected to the rear end of the input plunger 11. An elastic member 86 is integrally fixed to the rear surface of the stopper contact portion 82 of the input rod 10 so as to cover the rear surface. Then, the stopper abutting portion 82 (elastic member 86) of the input rod 10 abuts against the stopper member 25 located inside the rear end of the cylindrical portion 22 of the rear housing 18, whereby the retracted position of the input rod 10 is defined. It has become so. A first spring receiving portion 4 a is formed around the small diameter rod portion 80 on the front surface of the stopper contact portion 82. A male screw portion 81A is formed at the rear end portion of the large-diameter rod portion 81 of the input rod 10, and a clevis 90 is connected to the male screw portion 81A. The input rod 10 is connected to the brake pedal 13 via a clevis 90. Thereby, the input rod 10 comes to move along an axial direction by operating the brake pedal 13.

The input plunger 11 is formed in a rod shape as a whole and is arranged concentrically with the input rod 10. The input plunger 11 includes a main rod portion 95, a front rod portion 96 that integrally extends forward from the main rod portion 95, and a rear rod portion 97 that integrally extends rearward from the main rod portion 95. . The outer peripheral surface of the main rod portion 95 abuts on the inner peripheral surface of a large-diameter opening 115 of a booster member 110 (a booster main body 112) described later. The outer diameter of the main rod portion 95 is larger than the outer diameters of the front rod portion 96 and the rear rod portion 97. A step portion between the main rod portion 95 and the front rod portion 96 acts as the second spring receiving portion 4b. The outer diameter of the front rod portion 96 and the outer diameter of the rear rod portion 97 are substantially the same. A cylindrical caulking portion 98 is integrally formed at the rear end of the rear rod portion 97 toward the rear. A spherical concave portion 100 to which the ball joint portion 85 of the input rod 10 is connected is formed in the central portion in the radial direction on the rear end surface of the rear rod portion 97.

The cylindrical caulking portion 98 has an outer diameter larger than the outer diameter of the rear rod portion 97 and smaller than the outer diameter of the main rod portion 95. A conical opening 102 that is gradually reduced in diameter toward the front is formed in the cylindrical caulking portion 98. The front end of the conical opening 102 is continuous with the rear end of the spherical recess 100. The rear end surface of the input plunger 11, specifically, the rear end surface of the cylindrical caulking portion 98 functions as a support member abutting portion 4 c that abuts on a spring support member 127 described later. The ratio plate 105 is disposed so as to contact the front end face of the front rod portion 96. The ratio plate 105 includes a disc-shaped pressing portion 106 and a rod portion 107 that extends integrally rearward from the radial center of the disc-shaped pressing portion 106 and has a smaller diameter than the disc-shaped pressing portion 106. It is configured. The rear end of the rod portion 107 of the ratio plate 105 is brought into contact with the front end surface of the front rod portion 96.

A booster member 110 is arranged on the outer side in the radial direction of the input plunger 11. The booster member 110 is formed in a cylindrical shape as a whole and is disposed concentrically with the input plunger 11. The booster member 110 is supported so as to be movable in the radial direction outward of the input plunger 11 along the axial direction. The booster member 110 includes a booster body 112 that is formed in a cylindrical shape, and a booster flange 113 that is integrally connected to the rear end of the booster body 112. The booster main body 112 includes a large-diameter opening 115 and a small-diameter opening 116 that is continuous from the large-diameter opening 115 and formed at the front end thereof. The outer peripheral surface of the main rod portion 95 of the input plunger 11 is brought into contact with the inner peripheral surface of the large-diameter opening 115 of the booster main body 112. The outer peripheral surface of the disk-shaped pressing portion 106 of the ratio plate 105 is brought into contact with the inner peripheral surface of the small diameter opening 116 of the booster main body 112. A spring receiving surface 117 is formed between the small-diameter opening 116 and the large-diameter opening 115 of the booster main body 112. A stopper portion 119 is formed at the rear end of the small-diameter opening 116 so as to project inwardly in an annular shape and restrict the backward movement of the disc-like pressing portion 106 of the ratio plate 105. The inner diameter of the stopper portion 119 substantially matches the outer diameter of the rod portion 107 of the ratio plate 105. An annular recess 120 extending in an annular shape is formed on the outer peripheral surface of the booster body 112 near the booster flange 113.

The length in the axial direction from the front end of the small-diameter opening 52 to the stopper 119 is formed longer than the length along the axial direction of the disk-like pressing portion 106 of the ratio plate 105. The booster member 110, the input rod 10, and the input plunger 11 are configured so that the front end surface of the front rod portion 96 of the input plunger 11 is a stopper of the booster member 110 from the retraction restricted position of the input plunger 11 with respect to the booster member 11 Relative movement is allowed within a range along the axial direction up to the position where the portion 119 contacts the rear surface.

The booster flange 113 of the booster member 110 includes a cylindrical connection portion 122 connected to the inner peripheral surface of the rear end portion (rear end portion of the large-diameter opening 115) of the boost body 112, and the cylindrical connection portion. A flange portion 123 that extends radially outward from the rear end of 122 and a cylindrical extension portion 124 that extends rearward from a radially inner portion of the flange portion 123 are provided. The outer diameter of the cylindrical extension 124 substantially matches the outer diameter of the booster body 112, while the inner diameter of the cylindrical extension 124 is formed larger than the inner diameter of the large-diameter opening 115 of the booster body 112. .

The resistance applying mechanism 5 includes a first compression coil spring 125 as a first urging member that urges the booster member 110 and the input member 4 in a direction away from each other along the axial direction, and a booster member. 110 and the input member 4 are biased in a direction away from each other along the axial direction, and the second compression coil spring 126 as the second biasing member and the second compression coil spring 126 are And a spring support member 127 as a support member that is supported between the input rod 10 and the input rod 10. The first compression coil spring 125 is disposed between the second spring receiving portion 4 b between the main rod portion 95 and the front rod portion 96 of the input plunger 11 and the spring receiving surface 117 of the booster member 110. The spring support member 127 is disposed at a position around the small-diameter rod portion 80 of the input rod 10 from the rear end of the cylindrical extension portion 124 of the booster member 110 (boost flange 113). The spring support member 127 projects in a ring shape radially inward from the front end of the cylindrical portion 130 and a cylindrical portion 130 extending along the axial direction inside the cylindrical extension 124 of the booster member 110. An inner support part 131 and an outer support part 132 projecting annularly outward in the radial direction from the rear end of the cylindrical part 130 are provided. The small-diameter rod portion 80 of the input rod 10 is inserted into the inner support portion 131 of the spring support member 127 so as to be movable in the axial direction.

The inner support portion 131 of the spring support member 127 faces the rear end surface of the input plunger 11, that is, the rear end surface of the cylindrical caulking portion 98 of the input plunger 11. On the other hand, the outer support portion 132 of the spring support member 127 contacts the rear end surface of the cylindrical extension portion 124 of the booster flange 113. The second compression coil spring 126 is disposed between the inner support portion 131 of the spring support member 127 and the first spring receiving portion 4a of the stopper contact portion 82 of the input rod 10. The outer shape of the second compression coil spring 126 is formed in a truncated cone shape whose diameter increases toward the front. The rear end of the second compression coil spring 126 serving as the small diameter portion contacts the stopper contact portion 82 of the input rod 10, and the front end of the second compression coil spring 126 serving as the large diameter portion is the inner support portion of the spring support member 127. 131 abuts. Then, the second compression coil spring 126 urges the booster member 110 and the input rod 10 in a direction away from each other along the axial direction.

The substantially disc-shaped reaction disk 135 is disposed so as to contact the front end surface of the booster member 110 (boost body 112). The reaction disk 135 is made of an elastic body such as rubber, and is elastically deformed by receiving a load. The output rod 137 includes a rod portion 138 having a substantially circular cross section, and a cup portion 139 provided integrally with a rear end of the rod portion 138 and having a substantially circular outer shape. The cup part 139 has a substantially circular cross section and is recessed at a predetermined depth. In the cup portion 139, the reaction disc 135 and the front end portion of the booster member 110 are concentrically arranged. A fixing hole 140 is formed in the front end surface of the rod portion 138 with a predetermined depth. A pressing rod 142 is fixed to the fixing hole 140. The front end surface of the pressing rod 142 is formed as a spherical surface 143. The front portion of the rod portion 138 of the output rod 137 and the pressing rod 142 extend toward the intermediate wall 34 of the primary piston 31, and the spherical surface 143 provided on the front end surface of the pressing rod 142 is an intermediate portion of the primary piston 31. It abuts on a spherical recess 35 provided on the rear surface of the wall 34.

A slide member 145 is disposed on the radially outer side of the boost body 112 of the boost member 110. The slide member 145 is formed in a cylindrical shape as a whole, and is arranged concentrically with the boost body 112 of the boost member 110. The slide member 145 is provided with a main opening 146, a relief recess 147 provided continuously in front of the main opening 146, and having an inner peripheral surface of the main opening 146 formed in an annular shape, and a front of the relief recess 147. And a conical opening 148 provided continuously. The outer peripheral surface of the booster main body 112 of the booster member 110 is brought into contact with the inner peripheral surface of the main opening 146. A plurality of longitudinal grooves 150 extending in the axial direction are formed on the inner peripheral surface of the main opening 146 along the circumferential direction. Each longitudinal groove 150 is formed to have a length that communicates with the annular recess 120 provided in the booster body 112 of the booster member 110 and communicates with the escape recess 147. The conical opening 148 is formed so as to increase in diameter toward the front. The rear end opening of the conical opening 148 continues to the escape recess 147. A cup portion 139 of the output rod 137 is disposed in a range from the conical opening 148 to the escape recess 147.

In the backward restricting position of the output rod 137 (when the brake pedal 13 is not operated in FIG. 1), the rear end of the cup portion 139 of the output rod 137 and the step surface 152 between the main opening 146 and the relief recess 147 A gap 153 along the axial direction is provided therebetween. A spring support portion 155 is integrally formed at the front end of the slide member 145 so as to project annularly outward in the radial direction. At the front end of the outer periphery of the spring support portion 155, a spring receiving portion 156 cut out in an L shape is formed. Further, the flange 123 of the booster member 110 (boost flange 113) is brought into contact with the rear end surface of the slide member 145. A plurality of bulging portions 158 are formed on the outer peripheral surface near the rear of the slide member 145 at intervals in the axial direction (two in this embodiment). Each bulging portion 158 extends in an annular shape. The ball screw mechanism 6 is disposed outside the slide member 145 in the radial direction.

The ball screw mechanism 6 is driven by an electric motor 2 disposed in the housing 3 and is configured as a rotation / linear motion conversion mechanism that converts rotational motion into linear motion and applies thrust to the primary piston 31. The ball screw mechanism 6 includes a nut member 160 and a screw shaft member 161. The screw shaft member 161 is formed in a cylindrical shape in which a slide member 145 is concentrically disposed. The screw shaft member 161 extends from the rear of the spring support portion 155 of the slide member 145 to the stopper member 25 in the cylindrical portion 22 of the housing 3, is movable along the axial direction, and does not rotate around the axis. Is supported by the housing 3. Each bulging portion 158 of the slide member 145 is in contact with the inner peripheral surface of the screw shaft member 161, and a gap is provided between the inner peripheral surface of the screw shaft member 161 and the outer peripheral surface of the slide member 145.

A plurality of protrusions 165 projecting inward are formed at the rear end of the screw shaft member 161 at intervals along the circumferential direction. Each protrusion 165 of the screw shaft member 161 is brought into contact with the rear surface of the flange portion 123 of the booster member 110 (boost flange 113). A spiral groove 166 is formed on the outer peripheral surface of the screw shaft member 161 over substantially the entire axial direction. A compression coil spring 173 is disposed between the spring receiving portion 156 of the spring support portion 155 of the slide member 145 and the bottom portion around the opening 29 of the front housing 20. By the biasing force of the compression coil spring 173, the slide member 145, the booster member 110, and the screw shaft member 161 are biased in the backward direction. A nut member 160 is disposed radially outward on the front side from the axial center of the screw shaft member 161.

The nut member 160 is disposed concentrically on the outer side in the radial direction of the screw shaft member 161. The nut member 160 is rotatably supported on the housing 3 by a bearing 163. A spiral groove 168 is formed on the inner peripheral surface of the nut member 160 over substantially the entire axial direction. A plurality of balls 170 are loaded together with grease between the spiral groove 166 of the screw shaft member 161 and the spiral groove 168 of the nut member 160. Thereby, along with the rotation of the nut member 160, each ball 170 rolls along the

spiral grooves

166 and 168, and the screw shaft member 161 moves in the axial direction. As described above, the ball screw mechanism 6 can convert the rotation-linear motion between the nut member 160 and the screw shaft member 161 to each other.

When the screw shaft member 161 moves forward with the rotation of the nut member 160 driven by the electric motor 2, the booster member 110 and the slide member 145 are attached to the compression coil spring 173 by the protrusions 165 of the screw shaft member 161. Move forward against the power. Even when the screw shaft member 161 does not move forward, the input rod 10 and the input plunger 11 are separated from the protrusions 165 of the screw shaft member 161 with respect to the booster member 110 as the brake pedal 13 is operated. You can move forward alone.

The electric motor 2 is housed in the housing 3 on a separate axis from the master cylinder 15, the input rod 10 and the ball screw mechanism 6. A pulley 175 is attached to the output shaft 2 A of the electric motor 2. The output shaft 2A is rotatably supported in the housing 3 by

bearings

178 and 178. A pulley 176 is attached to the nut member 160 of the ball screw mechanism 6. A belt 177 is wound around the pulley 175 of the output shaft 2 A and the pulley 176 of the nut member 160. The rotational torque from the output shaft 2A of the electric motor 2 is transmitted to the nut member 160 of the ball screw mechanism 6 via pulleys 175 and 176 and a belt 177.

In addition to the stroke detector (not shown), the electric booster 1 according to the present embodiment includes a rotational position sensor (not shown) that detects the rotational position of the electric motor 2, a primary chamber 37 of the master cylinder 15, and Each hydraulic pressure sensor (not shown) for detecting the hydraulic pressure in the secondary chamber 38 is provided. The controller 7 controls the operation of the electric motor 2 based on output signals from the rotational position sensor, the stroke detection device, and each hydraulic pressure sensor. The controller 7 can be appropriately connected to an in-vehicle controller or the like for executing various brake controls such as brake assist control and automatic brake control. In the figure, reference numeral 180 denotes a connector for wiring for supplying power to the electric motor 2, the controller 7, and the stroke detection device, and transferring control signals.

Next, the operation when the electric booster 1 is energized will be described.
When the brake pedal 13 is operated, that is, when the brake pedal 13 is depressed, the brake pedal 13 is operated from the non-operated state shown in FIG. 1 to the operated state of the brake pedal 13 shown in FIG. That is, when the brake pedal 13 is depressed, the input plunger 11 together with the input rod 10 moves forward against the urging force of the first and second

compression coil springs

125 and 126 and the ratio abutted against the input plunger 11 is reached. The plate 105 presses the reaction disk 135. Further, when the input rod 10 and the input plunger 11 move forward with the operation of the brake pedal 13, the stroke amount of the input rod 10 and the input plunger 11 is detected by the stroke detection device, and the electric motor 2 rotates based on the detection result. Driven.

Rotational drive from the electric motor 2 is transmitted to the nut member 160 of the ball screw mechanism 6 via pulleys 175 and 176 and a belt 178. Subsequently, as the nut member 160 rotates, the screw shaft member 161 of the ball screw mechanism 6 moves forward. As the screw shaft member 161 advances, the reaction disk 135 is moved forward while maintaining the relative displacement between the input rod 10 and the input plunger 11 so that the booster member 110 follows the input rod 10 and the input plunger 11. While pressing, the slide member 145 moves forward against the urging force of the compression coil spring 173. Note that when the brake pedal 13 is depressed, a state in which a gap S (see FIGS. 3 and 6) is generated between the rear end surface of the input plunger 11 and the spring support member 127 is maintained. The size of the gap S is constant when the relative displacement between the booster member 110, the input rod 10 and the input plunger 11 is maintained. Further, in the present embodiment, as shown in FIG. 3, the booster member 110 is configured to advance ahead of the input rod 10 and the input plunger 11 while maintaining the relative displacement.

Then, the propulsive force of the input rod 10 and the input plunger 11 accompanying the operation of the brake pedal 13 and the propulsive force of the booster member 110 from the electric motor 2 are transmitted to the output rod 137 via the reaction disk 135, As the output rod 137 moves forward, the primary piston 31 and the secondary piston 32 of the master cylinder 15 move forward.

Thereby, hydraulic pressure is generated in the primary chamber 37 and the secondary chamber 38 of the master cylinder 15, respectively, and the brake hydraulic pressure generated in the primary chamber 37 and the secondary chamber 38 is supplied to the wheel cylinder (not shown) of each wheel. Thus, a braking force is generated by friction braking. When hydraulic pressure is generated in the master cylinder 15, the hydraulic pressure in the primary chamber 37 and the secondary chamber 38 is received by the ratio plate 105 of the input plunger 11 via the reaction disk 135, and a resistance applying mechanism 5 against the reaction force due to the hydraulic pressure. A reaction force obtained by adding a resistance force from (the urging forces of the first and second compression coil springs 125 and 126) is transmitted to the brake pedal 13 via the input rod 10 and the input plunger 11. The ratio between the pressure receiving area of the front end face of the booster member 110 and the pressure receiving area of the front end face of the ratio plate 105 (disk-shaped pressing portion 106) of the input plunger 11 is the boost ratio (operation input of the brake pedal 13). The ratio of the hydraulic pressure output to the desired pressure) can be generated.

Next, when the operation of the brake pedal 13 is released, that is, when the depression to the brake pedal 13 is released, the input rod 10 and the input plunger 11 are moved to the master cylinder 15 (the primary chamber 37 and the secondary chamber 38 as shown in FIG. ) By the urging force from the first and / or second

compression coil springs

125 and 126 including the reaction force due to the hydraulic pressure from Subsequently, although not shown, the stroke detection means 9 detects the stroke amounts of the input rod 10 and the input plunger 11, and the electric motor 2 rotates reversely based on the detection result. It is transmitted to the nut member 160. Subsequently, with the reverse rotation of the nut member 160, the screw shaft member 161 of the ball screw mechanism 6 moves backward. Due to the retraction of the screw shaft member 161, the slide member 145 is retracted by the biasing force of the compression coil spring 173, so that the booster member 110 is retracted while maintaining the relative displacement between the input rod 10 and the input plunger 11. The spring support member 127 comes into contact with the input plunger 11 and returns to the initial position. As a result, the primary piston 31 and the secondary piston 32 of the master cylinder 15 retreat, the hydraulic pressure in the primary chamber 37 and the secondary chamber 38 of the master cylinder 15 is reduced, and the braking force is released.

Next, the transition of the reaction force from the resistance applying mechanism 5 to the input rod 10 and the input plunger 11 due to the operation of the brake pedal 13 will be described based on FIG. 5 and with reference to FIGS. FIG. 5 is a diagram showing hysteresis characteristics by the resistance applying mechanism 5 that accompanies the advancement and retraction of the input rod 10 and the input plunger 11.
First, when the brake pedal 13 is depressed and the input plunger 11 moves forward against the biasing force of the first and second

compression coil springs

125 and 126 together with the input rod 10, the stroke detection device causes the input rod 10 and the input plunger 11 to move. The stroke amount is detected, and the electric motor 2 is rotationally driven based on the detection result. When the screw shaft member 161 moves forward by the rotational drive of the electric motor 2, the relative displacement between the input rod 10 and the input plunger 11 is maintained so that the booster member 110 follows the input rod 10 and the input plunger 11. Advance. Accordingly, as shown in FIG. 5, the input rod 10 and the input plunger 11 are applied to the substantially constant biasing force F1 (the first compression coil spring 125 and the second compression coil from the first and second compression coil springs 125, 126). A combined spring constant (K1 + K2) with the spring 126 × relative displacement between the booster member 110 and the input rod 10 and the input plunger 11 + set load of the first compression coil spring 125 and the second compression coil spring 126) is given ( (A) to (B) in FIG. 5).

In FIG. 5, in the initial state in which the brake pedal 13 is depressed, that is, in a state where only the input rod 10 and the input plunger 11 are advanced and the booster member 110 is still stopped, Transition of the urging force from the first and second

compression coil springs

125 and 126 to the input rod 10 and the input plunger 11 in a state where the relative displacement between the input rod 10 and the input plunger 11 gradually increases is omitted. .

Further, in the above-described embodiment, the booster member 110 moves forward while maintaining the relative displacement between the input rod 10 and the input plunger 11, but the booster member 110 moves between the input rod 10 and the input plunger 11. The relative displacement may be advanced so as to gradually change. In this embodiment, the urging forces from the first and second

compression coil springs

125 and 126 applied to the input rod 10 and the input plunger 11 are as follows. As the input rod 10 and the input plunger 11 advance, they gradually increase or decrease.

Next, when the depression of the brake pedal 13 is released from the state shown in FIG. 6 (same as FIG. 3), the input rod 10 and the input plunger 11 are first and 2 Since the position of the booster member 110 does not change while retreating by the biasing force (combined spring constant (K1 + K2)) from the

compression coil springs

125 and 126, the booster member 110 and the input plunger 11 (input rod 10) are relatively Since the displacement gradually increases, the urging force from the first and second

compression coil springs

125 and 126 accompanying the relative displacement with the booster member 110 is applied to the input rod 10 and the input plunger 11 (see FIG. 5 (b) to (c), and the urging force from the first and second

compression coil springs

125 and 126 causes the input rod 10 and the input plunger 11 to retreat. Decreases gradually wants to).

Next, as shown in FIG. 7, referring also to FIG. 5, the support member abutting portion 4 c, which is the rear end surface of the (cylindrical caulking portion 98) of the input plunger 11, is connected to the inner support portion 131 of the spring support member 127. The spring receiving member 127 and the second compression coil spring 126 are integrated with the input member 4 (the second compression coil spring) at the time of contact with the front surface (time points (c) and (d) in FIG. 5). Therefore, as shown in FIG. 8 (same as FIG. 4), thereafter, only the biasing force of the first compression coil spring 125 is applied to the input rod 10 and the input plunger 11, as shown in FIG. And the spring support member 127 moves away from the rear end of the booster member 110 (cylindrical extension 124 of the booster flange 113) (in the range of (d) to (e) in FIG. 5), the first compression The reaction force from the coil spring 125 is the input plunger 11 Gradually decreases along the retreat distance). In the range of (d) to (e) in FIG. 5, the urging force (spring constant K1) of only the first compression coil spring 125 is applied to the input rod 10 and the input plunger 11; The inclination of the reaction force in the range from d) to (e) is smaller than the inclination of the reaction force in the range from (b) to (c) in FIG. Subsequently, the stroke amount of the input rod 10 and the input plunger 11 is detected by the stroke detection means 9, and when the electric motor 2 rotates reversely based on the detection result, the booster member 110 moves the input rod 10 and the input plunger 11. In order to follow, the input rod 10 and the input plunger 11 are retracted while maintaining the relative displacement between the input rod 10 and the input plunger 11, so that the input rod 10 and the input plunger 11 are applied with a substantially constant urging force F2 (from the first compression coil spring 125). A spring constant K2 of the first compression coil spring 125 × relative displacement between the booster member 110, the input rod 10, and the input plunger 11) is applied. (Range (e) to (f) in FIG. 5).

In the form shown by the broken line in FIG. 5, when the booster member 110 moves backward while maintaining the relative displacement between the input rod 10 and the input plunger 11, the urging forces of the first and second

compression coil springs

125 and 126 are both. Although the form provided to the input rod 10 and the input plunger 11 is shown, in the above-described form, the booster member 110 maintains the relative displacement between the input rod 10 and the input plunger 11 as compared with this form. When retreating, the biasing force of only the first compression coil spring 125 is applied to the input rod 10 and the input plunger 11, so that the hysteresis characteristic corresponding to the biasing force of the second compression coil spring 126 can be increased.

Even when the configuration shown by the broken line in FIG. 5 is adopted, the combined spring constant (K1 + K2) of the first and second compression coil springs 125, 126 is set to a large value (in the range of (b) to (c) in FIG. If the inclination of the force is set large, the hysteresis characteristic can be increased with the magnitude of the composite spring constant, but the pedaling force due to the relative displacement error between the booster member 110, the input rod 10 and the input plunger 11 can be increased. The fluctuation also becomes large, which is not preferable.

As described above, in the electric booster 1 according to the present embodiment, when the input rod 10 and the input plunger 11 are moved forward and backward in accordance with the operation of the brake pedal 13 (when the brake pedal 13 is depressed and returned). Is provided with a resistance force applying mechanism 5 that generates a hysteresis characteristic that changes the resistance force to the input rod 10 and the input plunger 11 in all strokes. Thereby, pedal feeling can be improved.

Further, in the resistance applying mechanism 5 employed in the electric booster 1 according to the present embodiment, the booster member 110 maintains the relative displacement between the input rod 10 and the input plunger when the brake pedal 13 is depressed. When moving forward, the urging force F1 of the first and second

compression coil springs

125 and 126 is applied to the input rod 10 and the input plunger, while the stepping on the brake pedal 13 is released, and the booster member 110 is When retracting while maintaining the relative displacement between the input rod 10 and the input plunger, only the urging force F2 of the first compression coil spring 125 is applied to the input rod 10 and the input plunger, and F1 >> F2. Configured as follows. Thus, the hysteresis characteristic can be increased without increasing the spring constant K1 of the first compression coil spring 125 and the spring constant K2 of the second compression coil spring 126, and the first compression coil spring 125 and the second compression coil can be increased. The spring design of the spring 126 is relatively free and easy.

Next, a resistance applying mechanism 5 according to another embodiment will be described based on FIG. 9 with reference to FIG. In describing the resistance applying mechanism 5 according to another embodiment, only differences from the resistance applying mechanism 5 shown in FIGS. 1 to 8 will be described.
The spring support member 127 includes a large-diameter cylindrical portion 130A that contacts the inner peripheral surface of the booster member 110, and a small-diameter cylindrical portion that extends forward from the front end of the large-diameter cylindrical portion 130A via the annular spring receiving portion 130C. 130B, an inner support 131 projecting radially inward from the front end of the small-diameter cylindrical portion 130B, and an outer support projecting annularly radially outward from the rear end of the large-diameter cylindrical portion 130A Part 132. The inner support portion 131 of the spring support member 127 faces the rear end surface of the input plunger 11 so as to be able to contact and separate. On the other hand, the outer support portion 132 of the spring support member 127 contacts the rear end surface of the booster member 110.

A first compression coil spring 125 is disposed between the rear end surface of the booster member 110 and the annular spring receiving portion 10B provided on the input rod 10 and projecting radially outward. The outer shape of the first compression coil spring 125 is formed in a truncated cone shape whose diameter is gradually reduced from the front end toward the rear end. The outer diameter of the front end of the first compression coil spring 125 is larger than the outer diameter of the outer support portion 132 of the spring support member 127, and the outer diameter of the rear end thereof is the outer diameter of the annular spring receiving portion 10 B of the input rod 10. It almost agrees. The biasing force of the first compression coil spring 125 biases the booster member 110, the input rod 10, and the input plunger 11 in the direction of separating from each other along the axial direction.

Further, the second compression coil spring 126 is disposed inside the first compression coil spring 125 between the annular spring receiving portion 130C of the spring support member 127 and the annular step portion 10A of the input rod 10. Similar to the first compression coil spring 125, the second compression coil spring 126 is formed in a truncated cone shape whose outer diameter is gradually reduced from the front end toward the rear end. The outer diameter of the front end of the second compression coil spring 126 substantially matches the inner diameter of the large-diameter cylindrical portion 130 A of the spring support member 127, and the outer diameter of the rear end thereof is the outer diameter of the annular stepped portion 10 A of the input rod 10. It almost matches. Then, the urging force of the second compression coil spring 126 urges the spring support member 127 and the input rod 10 in the direction in which they are separated from each other along the axial direction. The force member 110, the input rod 10, and the input plunger 11 are urged in a direction in which they are separated from each other along the axial direction.

When the brake pedal is depressed, the booster member 110 moves forward while maintaining the relative displacement between the input rod 10 and the input plunger 11 by the advancement of the screw shaft member 161 (the rear end surface of the input plunger 11 and the spring support member). In a state in which a gap is generated between the first and second

compression coil springs

125 and 126, a constant urging force F1 is applied to the input rod 10 and the input plunger 11 (in FIG. A) to (b)).

On the other hand, at the initial stage when the depression of the brake pedal 13 is released, the position of the booster member 110 changes while the input rod 10 and the input plunger 11 are retracted by the urging forces from the first and second

compression coil springs

125 and 126. Therefore, the urging force from the first and second

compression coil springs

125 and 126 accompanying the relative displacement with the booster member 110 is applied to the input rod 10 and the input plunger 11 ((B) to FIG. 5). (C) range). Subsequently, when the rear end of the input plunger 11 comes into contact with the spring support member 127 (at the time (c) and (d) in FIG. 5), the input member 4 has the spring receiving member 127 and the second compression coil spring 126. Therefore, only the urging force of the first compression coil spring 125 is applied to the input rod 10 and the input plunger 11 thereafter, and the spring support member 127 is compressed from the rear end of the booster member 110 to the first compression. They are separated so as not to interfere with the coil spring 125 (range (d) to (e) in FIG. 5). Subsequently, when the electric motor 2 rotates in the reverse direction based on the detection result of the stroke detection means, the booster member 110 moves backward while maintaining the relative displacement between the input rod 10 and the input plunger 11, so that the input rod 10 and the input Only the urging force F2 from the first compression coil spring 125 is applied to the plunger 11 (range (e) to (f) in FIG. 5).

According to the resistance applying mechanism 5 shown in FIG. 9, even when there is no permissible space around the input plunger 11, the same operational effects as the resistance applying mechanism 5 shown in FIGS. .

Next, a resistance applying mechanism 5 according to still another embodiment will be described based on FIGS. 10 and 11 with reference to FIG. In describing the resistance applying mechanism 5 according to another embodiment, only differences from the resistance applying mechanism 5 shown in FIGS. 1 to 8 will be described.
The spring support member 127 includes a large-diameter cylindrical portion 130A, a small-diameter cylindrical portion 130B that extends forward from the front end of the large-diameter cylindrical portion 130A via an annular spring receiving portion 130C, and a rear of the large-diameter cylindrical portion 130A. And an outer support portion 132 projecting annularly outward from the end in the radial direction. In addition, a cylindrical support member 140 is disposed outside the spring support member 127 in the radial direction. The inner peripheral surface of the cylindrical support member 140 abuts on the outer peripheral surface of the outer support portion 132. The spring support member 127 is movable in the axial direction within the cylindrical support member 140. A second compression coil spring 126 is disposed between the annular spring receiving portion 130 C of the spring support member 127 and the stopper contact portion 82 of the input rod 10. The sliding resistance between the outer peripheral surface of the outer support portion 132 of the spring support member 127 and the inner peripheral surface of the cylindrical support member 140 is substantially equal to the set load of the second compression coil spring 126. That is, when the input rod 10 and the input plunger 11 advance, the spring support member 127 slides in the cylindrical support member 140 immediately before the second compression coil spring 126 is compressed (sliding resistance is constant).

When the brake pedal 13 is depressed, the booster member 110 moves forward while maintaining the relative displacement between the input rod 10 and the input plunger 11 by the advancement of the screw shaft member 161 (the rear end surface of the input plunger 11 and the spring support). In a state in which a gap is generated between the member 127 and the member 127), the input rod 10 and the input plunger 11 are slid between the spring support member 127 and the cylindrical support member 140 by the biasing force of the first compression coil spring 125. A constant urging force F1 with resistance is applied.

On the other hand, at the initial stage when the depression of the brake pedal 13 is released, the input rod 10 and the input plunger 11 are retracted by the urging force from the first compression coil spring 125 and the position of the booster member 110 does not change. 10 and the input plunger 11 are given a biasing force from the first compression coil spring 125 due to relative displacement with the booster member 110. Subsequently, when the rear end of the input plunger 11 comes into contact with the spring support member 127 and the booster member 110 moves backward while maintaining the relative displacement between the input rod 10 and the input plunger 11, the input rod 10 and the input plunger 11. A constant urging force F2 obtained by subtracting the sliding resistance between the spring support member 127 and the cylindrical support member 140 from the urging force of the first compression coil spring 125 is applied.

10 and 11 can provide the same operational effects as the resistance applying mechanism 5 shown in FIGS. 1 to 8 described above.

As the electric booster 1 based on the embodiment described above, for example, the following modes can be considered.
As a first aspect, a booster member 110 that is propelled by the electric motor 2 and moves the

pistons

31 and 32 of the master cylinder 15, the input rod 10 coupled to the brake pedal 13, and the master connected to the input rod 10. An input member 4 including an input plunger 11 to which a part of reaction force from the

pistons

31 and 32 of the cylinder 15 is transmitted, and a first biasing force applied to the input member 4 in the return direction of the brake pedal 13. An urging member 125, a second urging member 126 that urges the input member 4 and the booster member 110 in a direction away from each other along the axial direction, and the second urging member 126. A support member 127 that is supported between the input member 4 and the booster member 110, and the input member 4 moves from the non-operating state of the brake pedal 13 to the master cylinder 15. When moving in the approaching direction, the support member 127 does not contact the input plunger 11 but contacts the booster member 110 so that the input member 4 moves away from the master cylinder 15. When moving, the support member 127 is separated from the booster member 110 while abutting against the input plunger 11.

As a second aspect, in the first aspect, the first urging member 125 urges the input member 4 and the booster member 110 in a direction to be separated from each other along the axial direction. It moves in the direction approaching the master cylinder 15 while maintaining the biased state between the force member 110 and the input member 4.
As a third aspect, in the first or second aspect, when the booster member 110 and the input member 4 move in a direction approaching the master cylinder 15, the input member 4 includes When the urging forces of the first and second urging

members

125 and 126 are respectively applied and the booster member 110 and the input member 4 move away from the master cylinder 15, the input member 4 The urging force of the first urging member 125 is applied to.
As a fourth aspect, in any one of the first to third aspects, the first and second urging

members

125 and 126 are configured by compression coil springs, respectively, and the second urging member 126. Is disposed radially inward of the first urging member 125.

As a fifth aspect, a booster member 110 that is propelled by the thrust of the electric motor 2 to move the

pistons

31 and 32 of the master cylinder 15 and a part of the reaction force from the master cylinder 15 that is connected to the brake pedal 13. Is transmitted, the first biasing member 125 that abuts on the input member 4 and biases the input member 4 toward the brake pedal 13, and the input member 4 and the booster member. 110, and a second urging member 126 that urges the input member 4 toward the brake pedal 13 with respect to the booster member 110, and the second urging member 126 has one end abutting on the input member 4 and the other end on the boosting member 110 and the input member 4 via the support member 127 that can be brought into contact with and separated from the input member 4 according to the moving direction of the input member 4. Member 11 Or it is supported on the input member 4.
As a sixth aspect, in the fifth aspect, the input member 4 has a first spring receiving portion 4a with which one end of the first urging member 125 abuts, and the second urging member 126. And a support member abutting portion 4c that can contact and separate from the support member 127.

As a seventh aspect, in the sixth aspect, when the input member 4 moves toward the master cylinder 15 from the non-operating state of the brake pedal 13, the support member 127 When the input member 4 is supported and moves in a direction away from the master cylinder 15, it is separated from the booster member 110 and supported by the input member 4.
As an eighth aspect, in the fifth or seventh aspect, when the input member 4 moves in a direction in which the booster member 110 and the input member 4 approach the master cylinder 15, When the urging forces of the

second urging members

125 and 126 are respectively applied and the booster member 110 and the input member 4 move away from the master cylinder 15, the second urging member 126. The biasing force 125 of the first biasing member is applied.
As a ninth aspect, in the fifth to eighth aspects, the first urging member 125 urges the input member 4 and the booster member 110 in a direction away from each other along the axial direction. Then, the biasing member 110 and the input member 4 are moved in the direction approaching the master cylinder 15 while maintaining the biased state.

As a tenth aspect, in the ninth aspect, the first and second urging

members

125 and 126 are constituted by compression coil springs, respectively, and the second urging member 126 is the first urging member 126. It is arranged on the radially inner side of the biasing member 125.
As an eleventh aspect, in the ninth aspect, the first and second urging

members

125 and 126 are constituted by compression coil springs, respectively, and the first urging member 125 and the second urging member are configured. The biasing member 126 is arranged in series in the axial direction.

As a twelfth aspect, a booster member 110 that is propelled by the electric motor 2 and applies thrust to the master cylinder 15, an input rod 10 that is coupled to the brake pedal 13, and the master cylinder 15 that is connected to the input rod 10 An input member 4 comprising an input plunger 11 to which a part of the reaction force is transmitted, and two urging

members

125 and 126 for applying an urging force to the input member 4 in the return direction of the brake pedal 13; A support member 127 for supporting one of the two urging members 126 between the input member 4 and the booster member 110, and the input member 4 includes the brake When the pedal 13 moves from the non-operating state in the direction approaching the master cylinder 15, the urging force is transmitted from both of the two urging

members

125 and 126, and the input Wood 4, when moving in a direction away from the master cylinder 15, the biasing force from the one of the urging member 126 urging force is transmitted from the other biasing member 125 is not transmitted.

In addition, this invention is not limited to the above-mentioned Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

This application claims priority based on Japanese Patent Application No. 2016-230221 filed on Nov. 28, 2016. The entire disclosure including the specification, claims, drawings, and abstract of Japanese Patent Application No. 2016-230221 filed on Nov. 28, 2016 is incorporated herein by reference in its entirety.

DESCRIPTION OF SYMBOLS 1 Electric booster, 2 Electric motor, 4 Input member, 4a 1st spring receiving part, 4b 2nd spring receiving part, 4c Support member contact part, 5 Resistance force grant mechanism, 13 Brake pedal, 10 Input rod (input) Member), 11 input plunger (input member), 13 brake pedal, 15 master cylinder, 31 primary piston, 32 secondary piston, 110 booster member, 125 first compression coil spring (first biasing member), 126 second Compression coil spring (second biasing member), 127 Spring support member (support member)

Claims

An electric booster, the electric booster is
A booster member driven by an electric motor to move the piston of the master cylinder;
An input member having an input rod coupled to the brake pedal, and an input plunger connected to the input rod and to which a part of the reaction force from the piston of the master cylinder is transmitted;
A first biasing member that imparts a biasing force to the input member in the return direction of the brake pedal;
A second urging member that urges the input member and the booster member in a direction away from each other along the axial direction of the input member;
A support member that supports the second biasing member between the input member and the booster member;
When the input member moves from a non-operating state of the brake pedal in a direction approaching the master cylinder, the support member does not contact the input plunger but contacts the boost member,
When the input member moves in a direction away from the master cylinder, the support member is separated from the boost member while being in contact with the input plunger.
The electric booster according to claim 1,
The first urging member urges the input member and the booster member in a direction in which the input member and the booster member are separated from each other in the axial direction, and when the input member moves in a direction close to the master cylinder, An electric booster that maintains a biased state between a force member and the input member.
The electric booster according to claim 1 or 2,
When the booster member and the input member move in a direction approaching the master cylinder, the first and second urging members apply respective urging forces to the input member,
When the booster member and the input member move in a direction away from the master cylinder, the first biasing member applies a biasing force to the input member, and the second biasing member An electric booster that does not apply a biasing force to the input member.
The electric booster according to any one of claims 1 to 3,
The first and second urging members are each constituted by a compression coil spring,
The electric booster, wherein the second urging member is disposed radially inside the first urging member.
An electric booster, the electric booster is
A booster member that is driven by the thrust of the electric motor and moves the piston of the master cylinder;
An input member connected to a brake pedal and transmitting a part of the reaction force from the master cylinder;
A first biasing member that contacts the input member and biases the input member toward the brake pedal;
A second urging member that is provided between the input member and the boost member and urges the input member toward the brake pedal with respect to the boost member;
The second biasing member has one end and the other end,
One end of the second biasing member is in contact with the input member,
The other end of the second urging member is supported by the boost member or the input member according to the moving direction of the input member via a support member that can contact and separate from the boost member and the input member. Electric booster.
The electric booster according to claim 5,
The input member includes
A first spring receiving portion with which one end of the first urging member abuts;
A second spring receiving portion with which one end of the second urging member abuts,
An electric booster comprising: a support member abutting portion that can contact and separate from the support member.
The electric booster according to claim 6,
The support member is supported by the booster member when the input member moves from a non-operating state of the brake pedal toward the master cylinder,
When the input member moves in a direction away from the master cylinder, the support member is separated from the boost member and supported by the input member.
The electric booster according to any one of claims 5 to 7,
When the booster member and the input member move in a direction approaching the master cylinder, the biasing force of the first biasing member and the biasing force of the second biasing member are applied to the input member,
When the booster member and the input member move in a direction away from the master cylinder, the biasing force of the second biasing member is not applied to the input member, and the biasing force of the first biasing member Is provided to the input member.
The electric booster according to any one of claims 5 to 8,
The first urging member urges the input member and the booster member in a direction in which the input member and the booster member are separated from each other in the axial direction, and when the input member moves in a direction close to the master cylinder, An electric booster that maintains a biased state between a force member and the input member.
The electric booster according to claim 9,
The first and second urging members are each constituted by a compression coil spring,
The electric booster, wherein the second urging member is disposed radially inside the first urging member.
The electric booster according to claim 9,
The first and second urging members are each constituted by a compression coil spring,
The electric booster, wherein the first biasing member and the second biasing member are arranged in series in the axial direction.
An electric booster, the electric booster is
A booster member that is propelled by an electric motor and applies thrust to the master cylinder;
An input member having an input rod coupled to the brake pedal, and an input plunger connected to the input rod to which a part of the reaction force from the master cylinder is transmitted;
Two urging members for applying an urging force to the input member in the return direction of the brake pedal;
A support member for supporting one of the two urging members between the input member and the booster member;
When moving from a non-operating state of the brake pedal in a direction approaching the master cylinder, a biasing force is transmitted from both of the two biasing members to the input member,
When the input member moves away from the master cylinder, a biasing force is not transmitted from the one biasing member to the input member, and a biasing force is transmitted from the other biasing member to the input member. Electric booster.