WO2019065318A1

WO2019065318A1 - Electric booster

Info

Publication number: WO2019065318A1
Application number: PCT/JP2018/034264
Authority: WO
Inventors: 力弥吉津; 大地野村
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2017-09-27
Filing date: 2018-09-14
Publication date: 2019-04-04
Also published as: JPWO2019065318A1; CN111094091B; CN111094091A; JP6838214B2

Abstract

[Problem] To provide an electric booster which is easy to manufacture and has improved installability in vehicles. [Solution] This electric booster 1 comprises: an input pinion 55 which rotates in response to the movement of an input rod 50 and an input rack 51; an electric motor 67 which is driven in response to the rotation of the input pinion 55; an output pinion 83 which is rotated by means of the rotation of the input pinion 55 and the rotation from the electric motor 67 being transmitted to a single receiving portion 91 disposed along the rotation direction of the electric motor 67 or the rotation direction of the input pinion 55; and an output rod 108 and an output rack 105 whereto is transferred the rotation of the output pinion 83, causing a primary piston 7 of a master cylinder 2 to move. Due to the above, this electric booster 1 is easy to manufacture and has improved installability in vehicles.

Description

Electric booster

The present invention relates to an electric booster that is incorporated in a brake device of a vehicle such as an automobile and generates an brake hydraulic pressure in a master cylinder using an electric motor.

As a conventional electric booster, for example, the electric booster described in Patent Document 1 is connected to an input member that moves with the operation of a brake pedal, and the input member, and its tip portion is a master cylinder And a ball screw mechanism which transmits rotation of the electric motor to press the piston of the master cylinder. In the electric booster, the axis of the input member and the axis of the ball screw mechanism are coaxially disposed, and the axial direction of the input member and the axial direction of the output shaft of the electric motor are disposed in parallel. ing.

The brake control device described in Patent Document 2 includes an input member connected to a brake pedal, an output member connected to the input member, and an output member connected to a master cylinder, and an output member for driving power of an electric motor. And a worm screw mechanism and a ball screw mechanism that transmit to the vehicle. Then, in the brake control device, the axis of the input member and the axis of the output member are coaxially disposed, and the axial direction of the output shaft of the electric motor and the axial direction of the output member are orthogonally disposed. ing. Moreover, in the brake control device, the electric motor is disposed at a position different by 90 ° in the circumferential direction of the master cylinder with respect to the position of the reservoir.

However, in the electric booster (brake control device) according to

Patent Documents

1 and 2 described above, the electric booster increases in size along the axial direction and the radial direction of the master cylinder, and the mountability to the vehicle decreases. There is a risk. Furthermore, in the above-described electric booster, in order to provide a through hole for inserting the input member in the screw shaft of the ball screw mechanism, in detail, the processing cost of the through hole is high, and the outer diameter of the screw shaft There is also a need to increase the size, and an increase in size is inevitable.

Further, in the electric booster disclosed in Patent Document 3, the brake pedal is connected to the sun gear of the planetary gear mechanism, and the electric motor is connected to the ring gear of the planetary gear mechanism. Further, the output rod is connected to the planetary carrier, and the output rod is connected to the piston of the master cylinder. Then, when the sun gear is rotated by operating the brake pedal, the planetary pinion rotates and revolves, and the planetary carrier rotates to advance the output rod and press the piston to generate the fluid pressure in the master cylinder, By controlling the electric motor according to the rotation of the sun gear to rotate the ring gear and causing the sun gear to follow, the rotation servo force of the electric motor is applied to the rotation of the planetary carrier.

However, in the electric booster according to Patent Document 3 described above, the necessary stroke for the output rod can not be secured at the time of failure of the electric motor, the controller, etc., and the necessary brake fluid pressure may not be secured. There is.

JP, 2016-124344, A JP, 2016-193637, A JP, 2011-93472, A

As described above, in the electric boosters according to Patent Documents 1 to 3, there is a possibility that problems relating to the mountability to a vehicle and the manufacture may occur.

Then, the present invention has been made as an object to provide an electric motor-driven booster which facilitates the manufacture and improves the mountability to a vehicle.

In order to solve the above problems, a first electric booster according to the present invention includes an input member that rotates in response to the operation of an input shaft member, an electric motor that is driven in response to the rotation of the input member, and An output member in which the rotation of the input member and the rotation from the electric motor are transmitted to one receiving portion disposed opposite to the rotation direction of the electric motor or the rotation direction of the input member, and the output And an output shaft member for transmitting the rotation of the member to move the piston of the master cylinder.

Further, according to the second electric booster of the present invention, an input member which rotates in response to the operation of the input shaft member, an electric motor driven in accordance with the rotation of the input member, and rotation of the electric motor are transmitted. , An output member that receives and rotates the rotation of the input member and the rotation of the assist member on the surface in the rotation direction of the assist member or the rotation direction of the input member, and the rotation of the output member An output shaft member which is transmitted to move the piston of the master cylinder;
The assist member is characterized in that when the output member is rotated only by the rotation of the input member, the assist member is separated from the input member and the output member in the rotational direction.

Furthermore, according to a third electric booster of the present invention, an input member that rotates with the linear movement of the input shaft member, an electric motor driven according to the linear movement of the input shaft member, and the electric motor An assist member connected to a rotary shaft and rotated in the same direction as the electric motor and the input member by driving the electric motor, rotation of the input member and rotation of the assist member are both transmitted, and the input member is It is characterized by comprising: an output member which rotates in the same direction as the assist member; and an output shaft member which linearly moves with the rotation of the output member to move a piston of a master cylinder.

The electric booster according to the present invention can be easily manufactured to improve the mountability to a vehicle.

It is a perspective view of an electric booster of this embodiment. It is a perspective view of an electric booster of this embodiment. It is a typical sectional view of an electric booster of this embodiment, and only a part of gear housing is illustrated. It is an exploded perspective view of an electric booster of this embodiment. FIG. 4 is a cross-sectional view taken along the line BB of FIG. 3; FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3;

Hereinafter, the electric booster 1 according to the present embodiment will be described in detail with reference to FIGS. As shown in FIG. 1, the electric booster 1 according to the present embodiment has a structure in which a master cylinder 2 of a tandem type is connected. In the following description, the master cylinder 2 side is described as the front side, and the brake pedal 40 side is described as the rear side. In addition, illustration of the brake pedal 40 is abbreviate | omitted except FIG.

First, the master cylinder 2 will be described in detail based on FIG.
The rear portion of the master cylinder 2 is inserted into and connected to a third opening 46 provided at the lower part of the front wall of the gear housing 41 of the electric motor-driven booster 1. A reservoir 3 for supplying the brake fluid to the master cylinder 2 is attached to an upper portion of the master cylinder 2. A bottomed cylinder bore 4 is formed in the master cylinder 2. The primary piston 7 is disposed on the opening side of the cylinder bore 4. The front of the primary piston 7 is disposed in the cylinder bore 4 of the master cylinder 2. The rear of the primary piston 7 extends from the cylinder bore 4 into the gear housing 41 via the third opening 46 of the gear housing 41.

The front and the rear of the primary piston 7 are each formed in a cup shape, and are formed in an H-shaped cross section as a whole. A spherical recess 11 is formed on the rear surface of the intermediate wall 10 provided substantially at the center of the primary piston 7 in the axial direction. The spherical surface 110 of the output rod 108 of the electric booster 1 described later abuts on the spherical recess 11. A cup-shaped secondary piston 8 is disposed on the bottom side of the cylinder bore 4. A primary chamber 13 is formed between the primary piston 7 and the secondary piston 8 in the cylinder bore 4 of the master cylinder 2, and a secondary chamber 14 is formed between the bottom of the cylinder bore 4 and the secondary piston 8.

The primary chamber 13 and the secondary chamber 14 of the master cylinder 2 are hydraulically connected to the two hydraulic ports 16, 16 (see FIG. 1) of the master cylinder 2 via two actuation lines (not shown), respectively. It communicates with a control unit (not shown). The fluid pressure control unit is in communication with wheel cylinders (not shown) of the respective wheels via four foundation pipes (not shown). Then, the hydraulic pressure of the brake fluid generated by the master cylinder 2 or the hydraulic pressure control unit is supplied to the wheel cylinder of each wheel to generate a braking force.

The master cylinder 2 is provided with

reservoir ports

18 and 19 for connecting the primary chamber 13 and the secondary chamber 14 to the reservoir 3 respectively. On the inner peripheral surface of the cylinder bore 4,

annular piston seals

20, 21, 22, 23 in contact with the primary piston 7 and the secondary piston 8 in the axial direction for partitioning the inside of the cylinder bore 4 into the primary chamber 13 and the secondary chamber 14. Are arranged at predetermined intervals. The

piston seals

20 and 21 are disposed so as to sandwich one reservoir port 18 (rear side) in the axial direction. When the primary piston 7 is in the unrestrained position shown in FIG. 3, the primary chamber 13 communicates with the reservoir port 18 via a piston port 25 provided on the side wall of the primary piston 7. Then, when the primary piston 7 advances from the non-braking position and the piston port 25 reaches one piston seal 21 (front side), the primary chamber 13 is shut off from the reservoir port 18 by the piston seal 21 to generate hydraulic pressure. .

Similarly, the remaining two piston seals 22 and 23 are arranged axially across the other reservoir port 19 (front side). When the secondary piston 8 is in the non-braking position shown in FIG. 3, the secondary chamber 14 communicates with the reservoir port 19 via a piston port 26 provided on the side wall of the secondary piston 8. Then, when the secondary piston 8 advances from the non-braking position and the piston port 26 reaches one piston seal 23 (front side), the secondary chamber 14 is shut off from the reservoir port 19 by the piston seal 23 to generate hydraulic pressure. .

A compression coil spring 28 is interposed between the primary piston 7 and the secondary piston 8. The compression coil spring 28 biases the primary piston 7 and the secondary piston 8 away from each other. Inside the compression coil spring 28, an expansion and contraction member 29 which can expand and contract within a certain range is disposed. The telescopic member 29 has a retainer guide 30 that is in contact with the intermediate wall 10 of the primary piston 7 and a retainer rod 31 whose front end is in contact with the secondary piston 8 and is axially movable in the retainer guide 30; It consists of

A compression coil spring 71 is interposed between the bottom of the cylinder bore 4 and the secondary piston 8. The compression coil spring 71 biases the bottom of the cylinder bore 4 and the secondary piston 8 away from each other. Also within the compression coil spring 71, an expandable member 72 which can expand and contract within a certain range is disposed. The telescopic member 72 has a retainer guide 73 whose front end is in contact with the bottom of the cylinder bore 4 and a retainer rod 74 whose rear end is in contact with the secondary piston 8 and axially movable in the retainer guide 73; It consists of

Next, the electric booster 1 according to the present embodiment, to which the above-described master cylinder 2 is connected, will be described in detail based on FIGS.
The electric booster 1 according to the present embodiment is connected to an input rod 50 which moves in the axial direction along with the operation of the brake pedal 40 and the input rod 50 as shown in FIGS. 3 and 4. The input rack 51, an input pinion 55 that rotates with the linear movement of the input rack 51, the electric motor 67 driven according to the linear movement of the input rod 50 and the input rack 51, the rotation of the input pinion 55 The rotation of the electric motor 67 is transmitted, and an output pinion 83 that rotates in the same direction, an output rack 105 that linearly moves with the rotation of the output pinion 83, and the output rack 105 are connected. It includes an output rod 108 for pressing the primary piston 7, an input rack 51 including an input rod 50, an input pinion 55, an output pinion 83 and an output rod 108. It includes a gear housing 41 that houses the power rack 105 or the like, the.

In the gear housing 41, components such as an input pinion 55, an input rack 51, an output pinion 83, and an output rack 105 are accommodated. A cylindrical portion 42 is integrally protruded rearward on the upper portion of the rear surface of the gear housing 41. The cylindrical portion 42 communicates with the inside of the gear housing 41. In the upper wall portion of the gear housing 41, a substantially circular first opening 43 penetrating in the vertical direction is formed substantially throughout the entire area. An input pinion 55 and an output pinion 83 including a rotary shaft 69 from the electric motor 67 are accommodated in the gear housing 41 through the first opening 43. A motor housing 71 housing the electric motor 67 is connected around the first opening 43 on the upper wall surface of the gear housing 41. A substantially circular second opening 44 (see also FIG. 5) penetrating in the front-rear direction is formed in the upper part of the front wall of the gear housing 41. The input rod 50 and the input rack 51 are accommodated in the gear housing 41 through the second opening 44. The cover 45 closes the second opening 44.

At the lower portion of the front wall portion of the gear housing 41, a third opening 46 penetrating in the front-rear direction is formed. The output rod 108 and the output rack 105 are accommodated in the gear housing 41 through the third opening 46. The rear of the primary piston 7 of the master cylinder 2 is disposed in the gear housing 41 through the third opening 46, and the rear of the master cylinder 2 is inserted into the third opening 46 and bolted. Inside the gear housing 41, a support rod 48 supporting an output pinion portion 85 of an output pinion 83, which will be described later, via a needle bearing 73C protrudes upward from the bottom surface thereof.

Referring also to FIGS. 1 and 2, mounting plate 112 is fixed to the rear surface of gear housing 41 by a plurality of mounting bolts 114 (three in this embodiment). The mounting plate 112 is formed in a substantially rectangular shape. A substantially circular opening 113 is penetrated through the mounting plate 112 at a substantially central portion thereof. The mounting plate 112 is fixed to the gear housing 41 in a state where the cylindrical portion 42 of the gear housing 41 is inserted into the opening 113 thereof. At the four corners of the mounting plate 112, a plurality of stud bolts 115 are attached so as to pass therethrough. Then, the electric booster 1 projects the input rod 50 extending from the cylindrical portion 42 of the gear housing 41 into the vehicle compartment from a dash panel (not shown) which is a partition between the engine room and the vehicle compartment of the vehicle. , And placed in the engine room and secured to the dash panel using a plurality of stud bolts 115.

As shown in FIGS. 3 and 4, the input rod 50 extends in the same direction as the axial direction of the master cylinder 2. The input rod 50 is an axis different from the master cylinder 2 and is disposed above the master cylinder 2. The input rod 50 is inserted into the cylindrical portion 42 of the gear housing 41. The input rod 50 is axially movably supported in the gear housing 41. A clevis 60 is connected to the rear end of the input rod 50. The input rod 50 is connected to the brake pedal 40 via the clevis 60. Thus, by operating the brake pedal 40, the input rod 50 linearly moves along the axial direction. Connected to the input rod 50 is a return compression coil spring (not shown) that biases the input rod 50 toward the initial position. The front end of the input rod 50 is disposed within the gear housing 41. An input rack 51 is integrally connected to the front end of the input rod 50.

The input rack 51 is accommodated in the gear housing 41 through the second opening 44 of the gear housing 41 in a state in which the front end of the input rod 50 is integrally connected to the rear end thereof. The input rack 51 is movably supported in the gear housing 41 along the axial direction of the input rod 50. The input rack 51 is formed in the shape of a long block along the axial direction of the input rod 50. In the input rack 51, one surface on the side of the input pinion 55 is formed as a vertical surface, and the other surface on the opposite side is formed as a convex wedge surface that protrudes outward. Referring also to FIG. 5, a rack gear portion 52 in which the input pinion 55 meshes with one surface of the input rack 51 is formed along the axial direction of the input rod 50. The input rod 50 including the input rack 51 corresponds to an input shaft member. A stroke sensor 54 is disposed to face the other surface of the input rack 51. The travel distance of the input rod 50 and the input rack 51 is measured by the stroke sensor 54. The stroke sensor 54 is attached to the wall of the gear housing 41.

The input pinion 55 is in mesh with the rack gear portion 52 of the input rack 51, and rotates with the linear movement of the input rod 50 and the input rack 51. The input pinion 55 corresponds to an input member. The input pinion 55 is accommodated in the gear housing 41 through the first opening 43 of the gear housing 41. The input pinion 55 is rotatably supported in the gear housing 41. The input pinion 55 is formed in a cylindrical shape. The axial direction of the input pinion 55 and the axial direction of the input rod 50 are orthogonal to each other. The input pinion 55 includes an input pinion portion 57 and an input coupling portion 58 integrally formed below the input pinion portion 57. The input pinion portion 57 meshes with the rack gear portion 52 of the input rack 51. The input flange 62 is integrally connected to the outer peripheral surface of the input coupling portion 58 so as not to be relatively rotatable.

The input flange 62 has an annular input side flange portion 64 formed larger in diameter than the input pinion portion 57 of the input pinion 55, and a lower end of the input side flange portion 64 from a part in the circumferential direction going downward. And an input-side pressing portion 65 vertically installed. The inner peripheral surface of the input side flange portion 64 of the input flange 62 is, for example, spline-connected to the outer peripheral surface of the input coupling portion 58 of the input pinion 55, and is connected non-rotatably to the input pinion 55. The outer diameter of the input side flange portion 64 substantially matches the inner diameter of the outer cylindrical portion 88 in the output rotary portion 84 of the output pinion 83 described later.

Referring also to FIG. 6, input side pressing portion 65 is formed in an arc shape having a predetermined thickness. The input side pressing portion 65 is formed in an arc shape whose outer peripheral surface is continuous from the outer peripheral surface of the input side flange portion 64 and contacts the inner peripheral surface of the outer cylindrical portion 88 in the output rotating portion 84 of the output pinion 83 described later. It is formed to be in contact. The input side pressing portion 65 is formed such that the circumferential length thereof is smaller than the circumferential distance between the receiving portion 91 and the restricting projection portion 92 in the output rotating portion 84 of the output pinion 83 described later. The input side pressing portion 65 is formed such that its thickness is substantially the same as the amount of protrusion of the restricting protrusion portion 92 in the output rotating portion 84 of the output pinion 83 described later. Of the circumferentially opposite end surfaces of the input side pressing portion 65, the end surface on the receiving portion 91 side of the output rotating portion 84 of the output pinion 83 described later acts as the input surface 66.

The electric motor 67 is driven along with the linear movement of the input rod 50 and the input rack 51. The electric motor 67 is disposed above the gear housing 41 and in line with the reservoir 3 along the axial direction of the master cylinder 2. In other words, the electric motor 67 is located behind the reservoir 3. The electric motor 67 is accommodated in a cylindrical motor housing 71 having a top surface portion. The lower end surface of the motor housing 71 is connected to the upper end surface around the first opening 43 of the gear housing 41. A roller reducer, so-called coaxial reducer 70 is connected to the output shaft 68 of the electric motor 67. A rotary shaft 69 is extended from the coaxial reduction gear 70. The rotation shaft 69 is disposed in the gear housing 41 through the first opening 43 of the gear housing 41. The axial direction of the rotary shaft 69 is orthogonal to the axial direction of the master cylinder 2 and the input rod 50. The rotating shaft 69 is relatively rotatably inserted in the input pinion 55 in the gear housing 41 via the needle bearing 73A. An assist flange 75 is connected to the outer peripheral surface of the rotary shaft 69 at a position below the input pinion 55 so as to be relatively non-rotatable. The tip of the rotary shaft 69 is relatively rotatably supported inside the inner cylindrical portion 87 of an output rotary portion 84 of an output pinion 83 described later via a needle bearing 73B.

The assist flange 75 corresponds to an assist member. The assist flange 75 is formed in an annular shape of an assist side flange 78 having a smaller diameter than the input side flange 64 of the input flange 62, and the lower end of the assist side flange 78 is directed downward from a part of the circumferential direction. And an assist side pressing portion 79 which is vertically installed. The inner peripheral surface of the assist side flange portion 78 of the assist flange 75 is, for example, spline-connected to the lower outer peripheral surface from the input pinion 55 by the rotation shaft 69, and is connected non-rotatably relative to the rotation shaft 69. Referring also to FIG. 6, assist side pressing portion 79 is formed in an arc shape having a predetermined thickness.

The assist side pressing portion 79 is formed such that its outer peripheral surface is formed in an arc shape continuous from the outer peripheral surface of the assist side flange portion 78 and abuts on the inner peripheral surface of the input side pressing portion 65 of the input flange 62. . The inner circumferential surface of the assist side pressing portion 79 is formed in an arc shape that abuts on the outer circumferential surface of the inner cylindrical portion 87 in the output rotating portion 84 of the output pinion 83 described later. The assist side pressing portion 79 is formed to have a circumferential length such that both circumferential end surfaces thereof coincide with circumferential end surfaces of the input side pressing portion 65 of the input flange 62. The assist-side pressing portion 79 is formed such that its thickness can pass between the regulating projection 92 and the outer peripheral surface of the inner cylindrical portion 87 in the output rotating portion 84 of the output pinion 83 described later. Of the circumferentially opposite end surfaces of the assist-side pressing portion 79, the end surface on the receiving portion 91 side of the output rotating portion 84 of the output pinion 83 described later acts as the assist surface 81. The area of the assist surface 81 of the assist flange 75 on the assist surface 81 is set larger than the area of the input surface 66 of the input pressure section 65 on the input flange 62.

In the gear housing 41, there is accommodated an output pinion 83 which is rotated by the rotation from the input pinion 55 and the rotation from the electric motor 67 being transmitted. The output pinion 83 corresponds to an output member. The output pinion 83 is disposed in the gear housing 41 through the second opening 44 of the gear housing 41. The output pinion 83 is rotatably supported in the gear housing 41. The output pinion 83 is integrally and concentrically connected to the bottom surface of a bottomed double cylindrical output rotating portion 84 rotatably supported by the gear housing 41 via a ball bearing 86, and the bottom surface of the output rotating portion 84. And a cylindrical output pinion portion 85.

The output rotary portion 84 is formed to have a diameter larger than that of the output pinion portion 85. Referring also to FIG. 6, the output rotating portion 84 includes an inner cylindrical portion 87, an outer cylindrical portion 88 concentrically spaced apart from the inner cylindrical portion 87, an inner cylindrical portion 87 and an outer side. And a disc-like bottom portion 89 closing the lower end opening of the cylindrical portion 88. An annular space 90 is formed between the inner cylindrical portion 87 and the outer cylindrical portion 88. A receiving portion 91 which divides the annular space 90 into two chambers is bridged between the inner cylindrical portion 87 and the outer cylindrical portion 88. A restricting projection 92 is formed at a position away from the receiving portion 91 in a predetermined range in the clockwise direction in FIG. The restriction projection 92 is protruded from the inner wall surface of the outer cylindrical portion 88 toward the annular space 90. In the receiving portion 91, the surface on the side of the control protrusion 92 acts as a receiving surface 93.

In the output rotating portion 84, a gap to the extent that the assist side pressing portion 79 of the assist flange 75 can pass is provided between the tip of the restriction protrusion 92 in the radial direction and the outer peripheral surface of the inner cylindrical portion 87. ing. The input-side pressing portion 65 of the input flange 62 and the assist-side pressing portion 79 of the assist flange 75 contact in the radial direction between the receiving portion 91 and the restricting protrusion portion 92 in the output rotating portion 84 of the output pinion 83 It is arranged while. The input side pressing portion 65 of the input flange 62 is disposed on the outer cylindrical portion 88 side of the output rotating portion 84, and the assist side pressing portion 79 of the assist flange 75 is disposed on the inner cylindrical portion 87 side of the output rotating portion 84. A reaction plate 98 is disposed between the input side pressing portion 65 and the assist side pressing portion 79 and the receiving portion 91 of the output rotating portion 84. Specifically, the reaction plate 98 is disposed to abut on substantially the entire receiving surface 93 of the receiving portion 91 in the output rotating portion 84.

The input surface 66 of the input-side pressing portion 65 of the input flange 62 and the assist surface 81 of the assist-side pressing portion 79 of the assist flange 75 abut on substantially the entire surface of the reaction plate 98 on the regulation projection 92 side. Ru. The reaction plate 98 is made of an elastic material such as rubber. The reaction plate 98 is formed in a substantially rectangular plate shape. The reaction plate 98 is formed to be gradually thicker from the inner cylindrical portion 87 to the outer cylindrical portion 88. The area of the assist surface 81 of the assist-side pressing portion 79 of the assist flange 75 contacting the reaction plate 98 is larger than the area of the input surface 66 of the input-side pressing portion 65 of the input flange 62 contacting the reaction plate 98 .

In the output rotating portion 84 of the output pinion 83, the circumferential distance between the receiving portion 91 and the restricting protrusion 92 is equal to the circumferential length of the input-side pressing portion 65 of the input pinion 55. The length is slightly larger than the length obtained by adding the thickness of the portion where the input side pressing portion 65 abuts. Then, when the input surface 66 of the input side pressing portion 65 of the input pinion 55 is arranged to abut on the reaction plate 98, the circumferential direction on the opposite side of the restricting protrusion 92 and the receiving surface 93 of the input side pressing portion 65 A clearance S is provided between the end face. The relative rotation between the input pinion 55 and the output pinion 83 is permitted by an amount corresponding to the clearance S. In other words, relative rotation such that the input pinion 55 and the output pinion 83 exceed the clearance S is restricted. The tip of a rotary shaft 69 to which rotation from the electric motor 67 (output shaft 68) is transmitted via the coaxial reduction gear 70 in the inner cylindrical portion 87 of the output rotary portion 84 of the output pinion 83 via a needle bearing 73B. It is supported relatively rotatably.

As shown in FIG. 3, a substantially circular support recess 100 is recessed on the bottom surface of the disk-shaped bottom 89 of the output rotary unit 84. The upper end of the output pinion portion 85 is accommodated in the support recess 100, and the output pinion portion 85 is integrally connected concentrically with the output rotating portion 84. The output pinion portion 85 is formed in a cylindrical shape. The output pinion portion 85 of the output pinion 83 and the input pinion portion 57 of the input pinion 55 have substantially the same outer diameter. The output pinion portion 85 of the output pinion 83 and the input pinion portion 57 of the input pinion 55 have substantially the same axial length. Inside the lower end of the output pinion portion 85, a support rod 48 protruding upward from the bottom surface in the gear housing 41 via a needle bearing 73C is inserted. Thus, the output pinion 83 is rotatably supported by the gear housing 41. The rotary shaft 69 to which the rotation from the electric motor 67 (output shaft 68) is transmitted, the input pinion 55, and the output pinion 83 are arranged concentrically in the gear housing 41.

The output rack 105 meshes with the output pinion portion 85 of the output pinion 83. The output rack 105 is accommodated in the gear housing 41 through the third opening 46 of the gear housing 41. The output rack 105 is movably supported in the gear housing 41 along the axial direction of the output rod 108. The output rack 105, like the input rack 50, is formed in a long block shape along the axial direction of the output rod 108 described later. In the output rack 105, one surface on the side of the output pinion 83 is formed as a vertical surface, and the other surface on the opposite side is formed as a convex wedge surface protruding outward. A rack gear portion 106 in which the output pinion 83 meshes with one surface of the output rack 105 is formed along the axial direction of the output rod 108. The output rack 105 is disposed at a lower position in the gear housing 41 at a distance from the input rack 51. The lengths of the output rack 105 and the input rack 51 in the vertical direction are substantially the same. The lengths of the output rack 105 and the input rack 51 in the front-rear direction are also substantially the same.

An output rod 108 is integrally connected to the front end of the output rack 105. The output rod 108 is accommodated in the gear housing 41 through the third opening 46 of the gear housing 41 with its rear end integrally connected to the front end of the output rack 105. The output rod 108 is extended toward the master cylinder 2 in the gear housing 41. The axial direction of the output rod 108 is the same as the axial direction of the input rod 50 and is parallel to each other. The output rod 108 is disposed separately from the input rod 50, and in particular, coaxially with the master cylinder 2 below the input rod 50. The output rod 108 including the output rack 105 corresponds to an output shaft member. The output rod 108 including the output rack 105 and the input rod 50 including the input rack 51 are disposed in parallel with each other. Further, the output rod 108 including the output rack 105 and the input rod 50 including the input rack 51 are disposed so as to partially overlap in the axial direction. The front end face of the output rod 108 is formed in a spherical surface 110. A sleeve 109 is provided on the outer peripheral surface of the output rod 108. A spherical surface 110 at the front end of the output rod 108 abuts on a spherical recess 11 provided on the rear surface of the intermediate wall 10 of the primary piston 7 of the master cylinder 2.

The controller 118 is disposed on one side in the front-rear direction with respect to the electric motor-driven booster 1 as shown in FIGS. 1 and 2. Specifically, the controller 118 is disposed laterally of the electric motor 67 (motor housing 71) and the gear housing 41. The controller 118 is connected to the upper end of the motor housing 71 by the bracket 120 and the gear housing 41. The controller 118 detects an amount of movement of the input rod 50 and the input rack 51, a stroke sensor 54, rotation angle detection means (not shown) for detecting the rotation angle of the output shaft 68 (rotation shaft 69) of the electric motor 67, and the electric motor The drive of the electric motor 67 is controlled based on detection signals from various sensors such as a current sensor (not shown) for detecting a current value supplied to the sensor 67. Then, by controlling the driving of the electric motor 67 by the controller 118, the output pinion portion 85 of the output pinion 83 is rotated via the rotary shaft 69 and the assist flange 75, and the output rod 108 is propelled to achieve desired boosting power. The brake fluid pressure can be generated in the primary chamber 13 and the secondary chamber 14 of the master cylinder 2 with a ratio.

Next, the operation of the electric motor-driven booster 1 when it is energized will be described.
When the brake pedal 40 is operated from the non-operated state of the brake pedal 40, that is, when the brake pedal 40 is depressed, the input rack 51 together with the input rod 50 is returned and advanced against the biasing force of the compression coil spring. As the input rod 50 and the input rack 51 move forward, the input pinion portion 57 of the input pinion 55 rotates and the input surface 66 of the input side pressing portion 65 of the input flange 62 rotates the reaction plate 98 in the rotation direction of the input pinion 55 Press along. When the input rod 50 and the input rack 51 move forward with the operation of the brake pedal 40, the stroke sensor 54 detects the amount of movement of the input rod 50 and the input rack 51, and the rotation angle detection means The rotation angle of the output shaft 68 (rotation shaft 69) of 67 is detected, and the drive of the electric motor 67 is controlled by the controller 118 based on the detection result and the like.

Then, when the electric motor 67 is driven and the rotary shaft 69 starts to rotate, the rotation is transmitted to the assist side pressing portion 79 of the assist flange 75, and the assist surface 81 of the assist side pressing portion 79 acts as a reaction plate 98. Is pressed along the rotation direction of the rotation shaft 69. As a result, the driving force from the input flange 62 (the input surface 66 of the input side pressing portion 65) with the operation of the brake pedal 40 and the assist flange 75 (the assist surface 81 of the assist side pressing portion 79 with the driving of the electric motor 67). ) Is transmitted to the receiving surface 93 of the receiving portion 91 of the output rotating portion 84 of the output pinion 83 via the reaction plate 98, and the output pinion 83 rotates in the rotational direction of the input flange 62 and the assist flange 75. Rotate along. Thereafter, with the rotation of the output pinion 83, the output rack 105 and the output rod 108 move forward to push the primary piston 7 and the secondary piston 8 of the master cylinder 2 forward by the output rod 108. When the electric motor 67 is driven, the rotation direction of the rotation shaft 69, the rotation direction of the assist flange 75 (assist side pressing portion 79), and the rotation direction of the output pinion 83 become the same.

As a result, hydraulic pressure is generated in the primary chamber 13 and the secondary chamber 14 of the master cylinder 2, respectively, and the brake hydraulic pressure generated in the primary chamber 13 and the secondary chamber 14 is transmitted to the wheel of each wheel via the hydraulic control unit. It is supplied to the cylinder and a braking force is generated by friction braking. When the hydraulic pressure in master cylinder 2 is generated, the hydraulic pressure of primary chamber 13 and secondary chamber 14 is received by input surface 66 of input side pressing portion 65 of input flange 62 through reaction plate 98, and the reaction force by the hydraulic pressure The reaction force obtained by adding the biasing force of the compression coil spring is transmitted to the brake pedal 40 via the input rack 51 and the input rod 50.

The ratio of the pressure receiving area of the input surface 66 of the input side pressing portion 65 of the input flange 62 to the pressure receiving area of the assist surface 81 of the assist side pressing portion 79 of the assist flange 75 by the fluid pressure in the master cylinder 2 The ratio of the distance from the center of rotation of the input surface 66 of the side pressing portion 65 to the distance from the center of rotation of the assist surface 81 of the assist side pressing portion 79 is And the desired braking force can be generated. In the present embodiment, the pressure receiving area of the assist surface 81 of the assist flange 75 (assist side pressing portion 79) is larger than the pressure receiving area of the input surface 66 of the input flange 62 (input side pressing portion 65). The ratio of the hydraulic pressure output to the 40 operating inputs can be more than doubled to generate the desired braking force.

Next, when the operation of the brake pedal 40 is released, that is, when the depression on the brake pedal 40 is released, the output rack 105 is retracted due to the reaction force by the hydraulic pressure from the master cylinder 2 (primary chamber 13 and secondary chamber 14). While the output pinion 83 rotates in the reverse direction, the input-side pressing portion 65 of the input flange 62 retracts toward the initial position, and the input pinion 55 reversely rotates, thereby retracting the input rack 51 and returning compression coil spring The input rod 50 is retracted to the initial position while the biasing force is applied. At the same time, the stroke detection device 7 detects the amount of retraction of the input rod 50 and the input rack 51, and the rotation angle detection means detects the rotation angle of the output shaft 68 (rotation shaft 69) of the electric motor 67. The controller 118 controls the drive (reverse rotation) of the electric motor 67 based on the detection result, and the reverse rotation is transmitted to the assist flange 75, and the assist side pressing portion 79 retracts toward the initial position. It will be.

By the way, even if the assist flange 75 becomes inoperable due to a failure of the electric motor 67 or the controller 118, the input rod 50 and the input rack 51 are advanced by the operation of the brake pedal 40 and the input pinion The input surface 66 of the input side pressing portion 65 of the input flange 62 at 55 presses the reaction plate 98. Then, the propulsive force from the input flange 62 accompanying the operation of the brake pedal 40 is transmitted to the receiving surface 93 of the receiving portion 91 of the output rotating portion 84 of the output pinion 83 via the reaction plate 98 to rotate the output pinion 83. Thus, the primary piston 7 and the secondary piston 8 of the master cylinder 2 can be pushed forward by the output rod 108.

At this time, the assist-side pressing portion 79 of the assist flange 75 is configured to be able to pass between the restriction protrusion 92 and the outer peripheral surface of the inner cylindrical portion 87 in the output rotating portion 84 of the output pinion 83. Even if the output rotating portion 84 of the output pinion 83 is rotated by the rotation of the input flange 62 of the input pinion 55 while the assist side pressing portion 79 is stopped, the assist side pressing portion 79 of the assist flange 75 The output pinion 83 can continue its rotation without any problem without interfering with the restricting projection 92 of the output rotating portion 84, and the assist-side pressing portion 79 of the assist flange 75 gradually rotates from the output pinion 83 and the input pinion 55 in the rotational direction. I will be leaving. Then, as the output rack 105 and the output rod 108 move forward with the rotation of the output pinion 83, the primary piston 7 and the secondary piston 8 of the master cylinder 2 move forward to generate the fluid pressure in the master cylinder 2. And the braking action can be maintained. As described above, in the electric booster 1 according to the present embodiment, even when the electric motor 67 or the controller 118 fails, a necessary stroke for the output rod 108 can be secured.

Further, in the electric motor-driven booster 1 according to the present embodiment, by providing the restricting protrusion 92 in the output rotating portion 84 of the output pinion 83, relative rotation exceeding the clearance S in the input pinion 55 and the output pinion 83 is restricted. It is done. Thereby, for example, in the case where the hydraulic pressure is generated in master cylinder 2 only by driving electric motor 67, assist flange 75 by the rotation of rotary shaft 69 to which the rotation from electric motor 67 (output shaft 68) is transmitted. Only the rotation of the assist side pressing portion 79 is transmitted to the reaction plate 98, and only the propulsive force from the assist flange 75 (assist surface 81 of the assist side pressing portion 79) accompanying the drive of the electric motor 67 is via the reaction plate 98. The output pinion 83 is rotated by being transmitted to the receiving surface 93 of the receiving portion 91 in the output rotating portion 84 of the output pinion 83.

Then, at this time, the input-side pressing portion 65 of the input flange 62 rotates with the output pinion 83 so as to be pressed by the restriction projection portion 92 in the output rotating portion 84 of the output pinion 83. Since the relative rotation exceeding the clearance S is restricted, the input pinion 55 also rotates in the same direction so as to follow the output pinion 83. As a result, the input rod 50 and the input rack 51 move forward, and the brake pedal 40 pivots about the fulcrum even if the pedal force is not applied to the brake pedal 40.

On the other hand, in the electric motor-driven booster 1 according to the other embodiment, the output rotary portion 84 of the output pinion 83 is not provided with the restriction projection 92, and the input pinion 55 and the output pinion 83 are configured to be relatively rotatable. Thereby, for example, in the case where the hydraulic pressure is generated in master cylinder 2 only by driving electric motor 67, assist flange 75 by the rotation of rotary shaft 69 to which the rotation from electric motor 67 (output shaft 68) is transmitted. Only the rotation of the assist side pressing portion 79 is transmitted to the reaction plate 98, and only the driving force from the assist flange 75 (the assist surface 81 of the assist side pressing portion 79) accompanying the driving of the electric motor 67 The power is transmitted to the receiving surface 93 of the receiving portion 91 in the output rotating portion 84 of the output pinion 83, and the output pinion 83 rotates. At this time, since the input pinion 55 and the output pinion 83 are configured to be relatively rotatable, the input pinion 55 does not rotate together with the rotation of the output pinion 83. As a result, the input rod 50, the input The rack 51 and the brake pedal 40 never operate.

As described above, in the electric booster 1 according to the present embodiment, the input pinion 55 rotates according to the operation of the input rod 50 and the input rack 51, and the electric motor driven according to the rotation of the input pinion 55. The rotation of the motor 67 and the rotation of the input pinion 55 and the rotation from the electric motor 67 are transmitted to one receiving portion 91 disposed opposite to the rotation direction of the electric motor 67 or the rotation direction of the input pinion 55 for rotation. An output pinion 83 and an output rack 105 and an output rod 108 for transmitting the rotation of the output pinion 83 to move the primary and secondary pistons of the master cylinder 2 are provided.
As a result, in the present electric booster 1, it is possible to realize miniaturization in the axial direction and the radial direction of the master cylinder 2, and to improve the mountability on a vehicle. Further, in the electric motor-driven booster 1, the ball screw mechanism is not employed as in the conventional electric motor-driven booster, so that the processing cost of the component members can be suppressed and the manufacture can be facilitated. Moreover, in the electric booster 1, even if the assist flange 75 becomes inoperable due to a failure or the like of the electric motor 67 or the controller 118, an output rod necessary to generate a desired fluid pressure in the master cylinder 2 The moving amount of 108 can be secured.

Further, in the electric booster 1 according to the present embodiment, since the input rod 50 and the input rack 51, and the output rod 108 and the output rack 105 are disposed so as to partially overlap in the axial direction, the electric double In the force device 1, in particular, the overall length along the axial direction of the master cylinder 2 can be shortened.

Furthermore, in the electric booster 1 according to the present embodiment, since the input rod 50 and the input rack 51, and the output rod 108 and the output rack 105 are disposed substantially in parallel, in the electric booster 1, In particular, the size can be reduced along the radial direction of the master cylinder 2. Thereby, the degree of freedom of the layout is improved when mounted on a vehicle.

Furthermore, in the electric booster 1 according to the present embodiment, the receiving surface 93 of the receiving portion 91 of the output pinion 83 (output rotating portion 84) is the input surface 66 of the input side pressing portion 65 of the input flange 62 The rotation in the same direction is received from the assist surface 81 of the assist side pressing portion 79 of the flange 75, so that the rotational force can be synthesized in the same rotation direction.

Furthermore, in the electric booster 1 according to the present embodiment, the receiving surface 93 of the receiving portion 91 of the output pinion 83 (output rotating portion 84), the input surface 66 of the input side pressing portion 65 of the input flange 62, and the assist flange Since the reaction plate 98 made of an elastic body is provided between the assist side pressing portion 79 and the assist surface 81 of the 75, when the reaction plate 98 is pressed by the input surface 66, the reaction force of the reaction plate 98 against the brake pedal 40 Improves the feeling of the pedals.

Furthermore, in the electric booster 1 according to the present embodiment, the pressure receiving area of the assist surface 81 of the assist side pressing portion 79 of the assist flange 75 with respect to the receiving surface 93 of the receiving portion 91 is the input side pressing portion of the input flange 62. Since the pressure receiving area of the input surface 66 of 65 to the receiving surface 93 of the receiving portion 91 is larger, the ratio (hydraulic ratio) of the hydraulic output to the operation input of the brake pedal 40 is more than twice, and the desired braking force Can be generated.

Furthermore, in the electric booster 1 according to the present embodiment, the rotation shaft of the input pinion 55 is arranged coaxially with the rotation shaft 69 to which the rotation from the electric motor 67 (output shaft 68) is transmitted. The electric motor-driven booster 1 can be miniaturized.

Furthermore, in the electric booster 1 according to the present embodiment, when the output pinion 83 is rotated only by the rotation of the electric motor 67, the input pinion 55 is configured to be rotated following the output pinion 83. There is. In this embodiment, when the fluid pressure is generated in the master cylinder 2 only by the rotation of the electric motor 67, the brake pedal 40 pivots about the fulcrum even without applying the stepping force to the brake pedal 40. Further, in the electric booster 1 according to the other embodiment, when the output pinion 83 is rotated only by the rotation from the electric motor 67, the input pinion 55 does not follow the output pinion 83 and remains stopped. Is configured as. In this other embodiment, when the fluid pressure is generated in the master cylinder 2 only by the rotation of the electric motor 67, the brake pedal 40 is not pivoted about the fulcrum, and remains at the initial position.

Furthermore, in the electric booster 1 according to the present embodiment, the rotary shaft 69 to which the rotation from the electric motor 67 (output shaft 68) is transmitted, the input rod 50 (input rack 51), and the output rod 108 (output rack And the electric motor 67 is arranged in line with the reservoir 3 attached to the master cylinder 2 along the axial direction of the master cylinder 2. As a result, in the electric motor-driven booster 1, in particular, the size can be reduced along the radial direction of the master cylinder 2, and the degree of freedom of the layout is improved when mounted on a vehicle.

As an electric booster 1 based on the embodiment described above, for example, one having an aspect described below can be considered.
In the first embodiment, the input member 55 is rotated according to the operation of the

input shaft members

50 and 51, the electric motor 67 driven according to the rotation of the input member 55, the rotation of the input member 55 and the electric operation An output member 83 which is transmitted by the rotation from the motor 67 and transmitted to one receiving portion 91 disposed opposite to the rotation direction of the electric motor 67 or the rotation direction of the input member 55, and the output member 83 And

output shaft members

105, 108 for transmitting the

pistons

7, 8 of the master cylinder 2.

In the second embodiment, the rotation of the electric motor 67 is transmitted by the input member 55 rotating in response to the operation of the

input shaft members

50 and 51, the electric motor 67 driven in accordance with the rotation of the input member 55, and An assist member 75, and an output member 83 that receives and rotates the rotation of the input member 55 and the rotation of the assist member 75 on the surface 93 in the rotation direction of the assist member 75 or the rotation direction of the input member 55; And

output shaft members

105, 108 for transmitting the rotation of the output member 83 to move the

pistons

7, 8 of the master cylinder 2. The assist member 75 is configured to output the output member only by rotating the input member 55. When 83 rotates, it separates from the input member 55 and the output member 83 in the rotational direction.

In the third aspect, an input member 55 which rotates with the linear movement of the

input shaft members

50, 51, an electric motor 67 driven according to the linear movement of the

input shaft members

50, 51, and the electric motor 67. The assist member 75 is connected to the rotary shaft 69 of the motor and rotates in the same direction as the electric motor 67 and the input member 55 by the drive of the electric motor 67, and the rotation of the input member 55 and the rotation of the assist member 75 An output member 83 which is transmitted together and rotates in the same direction as the input member 55 and the assist member 75, and linearly moves with the rotation of the output member 83 to move the

pistons

7 and 8 of the master cylinder 2 And

shaft members

105 and 108

According to a fourth aspect, in any one of the first to third aspects, the

input shaft members

50 and 51 and the

output shaft members

105 and 108 are disposed so as to partially overlap in the axial direction.
According to a fifth aspect, in any of the first to fourth aspects, the

input shaft members

50, 51 and the

output shaft members

105, 108 are disposed substantially in parallel.
According to a sixth aspect, in the first aspect, the receiving portion 91 rotates in the same direction from the input surface 66 provided on the input member 55 and the assist surface 81 to which the rotation from the electric motor 67 is transmitted. Receive

According to a seventh aspect, in the sixth aspect, an elastic body 98 is provided between the receiving portion 91, the input surface 66 and the assist surface 81.
According to an eighth aspect, in the sixth or seventh aspect, a pressure receiving area of the assist surface 81 with respect to the receiving portion 91 is larger than a pressure receiving area of the input surface 66 with respect to the receiving portion 91.
According to a ninth aspect, in any of the first to eighth aspects, the rotation shaft of the input member 55 is disposed coaxially with the rotation shaft 69 of the electric motor 67.

According to a tenth aspect, in the second aspect, when the output member 83 is rotated only by the rotation from the electric motor 67, the input member 55 is rotated following the output member 83.
In an eleventh aspect, in the second aspect, the input member 55 does not follow the output member 83 when the output member 83 rotates only by rotation from the electric motor 67.
According to a twelfth aspect, in any one of the first to eleventh aspects, the rotary shaft 69 of the electric motor 67, the

input shaft members

50, 51 and the

output shaft members

105, 108 are arranged to be orthogonal to each other The electric motor 67 is disposed in line with the reservoir 3 attached to the master cylinder 2 along the axial direction of the master cylinder 2.

Reference Signs List 1 electric booster, 2 master cylinder, 3 reservoir, 7 primary piston, 8 secondary piston, 50 input rod (input shaft member), 51 input rack (input shaft member), 55 input pinion (input member), 66 input surface , 67 electric motor, 69 rotating shaft, 75 assist flange (assist member), 81 assist surface, 83 output pinion (output member), 91 receiving portion, 93 receiving surface, 98 reaction plate (elastic body) 105 output rack (output shaft Member), 108 output rod (output shaft member),

Claims

An input member that rotates in response to the operation of the input shaft member;
An electric motor driven according to the rotation of the input member;
An output member that is transmitted by the rotation of the input member and the rotation from the electric motor to one receiving portion disposed opposite to the rotation direction of the electric motor or the rotation direction of the input member to rotate;
An output shaft member for transmitting the rotation of the output member to move the piston of the master cylinder;
An electric booster comprising:
An input member that rotates in response to the operation of the input shaft member;
An electric motor driven according to the rotation of the input member;
An assist member to which the rotation of the electric motor is transmitted;
An output member that receives and rotates the rotation of the input member and the rotation of the assist member on a surface in the rotation direction of the assist member or the rotation direction of the input member;
An output shaft member for transmitting the rotation of the output member to move the piston of the master cylinder;
Equipped with
The assist member is
When the output member is rotated only by the rotation of the input member, it is separated from the input member and the output member in the rotational direction.
An input member that rotates with linear movement of the input shaft member;
An electric motor driven according to the linear movement of the input shaft member;
An assist member connected to a rotation shaft of the electric motor and rotated in the same direction as the electric motor and the input member by driving the electric motor;
An output member that is both transmitted in rotation of the input member and the rotation of the assist member and rotates in the same direction as the input member and the assist member;
An output shaft member which linearly moves with the rotation of the output member to move the piston of the master cylinder;
An electric booster comprising:
The electric booster according to any one of claims 1 to 3, wherein
The electric booster according to claim 1, wherein the input shaft member and the output shaft member are arranged such that a part thereof is overlapped in the axial direction.
The electric booster according to any one of claims 1 to 4, wherein
The electric booster according to claim 1, wherein the input shaft member and the output shaft member are disposed substantially in parallel.
The electric booster according to claim 1, wherein
The receiving portion is
An electric booster according to claim 1, wherein rotation in the same direction is received from an input surface provided on the input member and an assist surface to which rotation from the electric motor is transmitted.
The electric booster according to claim 6, wherein
An elastic body is provided between the receiving portion, the input surface and the assist surface.
The electric booster according to claim 6 or 7, wherein
A pressure receiving area of the assist surface to the receiving portion is larger than a pressure receiving area of the input surface to the receiving portion.
The electric booster according to any one of claims 1 to 8, wherein
The rotary shaft of the input member is disposed coaxially with the rotary shaft of the electric motor.
The electric booster according to claim 2, wherein
The input member is
When the said output member rotates only by rotation from the said electric motor, it follows and rotates the said output member.
The electric booster according to claim 2, wherein
The input member is
When the output member is rotated only by rotation from the electric motor, it does not follow the output member.
The electric booster according to any one of claims 1 to 11, wherein
The rotation shaft of the electric motor, and the input shaft member and the output shaft member are arranged to be orthogonal to each other,
The electric booster according to claim 1, wherein the electric motor is disposed in line with a reservoir attached to the master cylinder along an axial direction of the master cylinder.