CN111094091B - Electric booster - Google Patents

Abstract

The invention provides an electric booster which is easy to manufacture and has improved carrying performance on a vehicle. The electric booster (1) is provided with: an input pinion (55) that rotates in response to the movement of the input lever (50) and the input rack (51); an electric motor (67) driven in accordance with the rotation of the input pinion (55); an output pinion (83) which receives the rotation of the pinion (55) and the rotation from the electric motor (67) and rotates the output pinion (83) by transmitting the rotation to one receiving section (91) arranged along the rotation direction of the electric motor (67) or the rotation direction of the input pinion (55); an output rod (108) and an output rack (105), and the rotation of the output pinion (83) is transmitted to the output rod (108) and the output rack (105) to move the primary piston (7) of the master cylinder (2). Thus, the electric booster (1) is easy to manufacture and has improved mountability on a vehicle.

Description

Electric booster

technical field

The present invention relates to an electric booster, which is assembled in a brake device of a vehicle such as an automobile, and uses an electric motor to generate a brake hydraulic pressure in a master cylinder.

Background technique

As a conventional electric assist device, for example, the electric assist device described in Patent Document 1 includes an input member that moves in accordance with operation of a brake pedal, an input piston coupled to the input member, and a tip of the input piston The part is arranged in the brake fluid chamber of the master cylinder; the ball screw mechanism transmits the rotation from the electric motor to the ball screw mechanism to press the piston of the master cylinder. Furthermore, in this electric assist device, the axis of the input member and the axis of the ball screw mechanism are disposed on the same axis, and the axial direction of the input member and the axial direction of the output shaft of the electric motor are disposed parallel to each other.

In addition, 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 connected to a master cylinder, a worm gear mechanism and a ball screw mechanism, They transmit the driving force of the electric motor to the output member. Furthermore, in this brake control device, the axis of the input member and the axis of the output member are arranged on the same axis, and the axial direction of the output shaft of the electric motor and the axial direction of the output member are arranged to be orthogonal to each other. Furthermore, in this brake control device, the electric motor is arranged at a position shifted by 90° in the circumferential direction of the master cylinder with respect to the position of the reservoir tank.

However, in the electric assist devices (brake control devices) of the above-mentioned Patent Documents 1 and 2, the electric assist device increases in size along the axial and radial directions of the master cylinder, which may reduce the mountability in the vehicle. Furthermore, in the above-described electric assist device, in order to provide a through hole through which the input member is inserted in the ball screw mechanism, more specifically, in the screw shaft, the processing cost of the through hole increases, and it is also necessary to make the screw shaft. The outer diameter of the lever shaft increases, and it is difficult to avoid the enlargement.

Furthermore, in the electric assist device described 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. In addition, the output rod is connected to the carrier, and the output rod is connected to the piston of the master cylinder. Then, when the brake pedal is operated to rotate the sun gear, the planetary pinions rotate and revolve, the planetary carrier rotates to advance the output rod, the piston is pressed to generate hydraulic pressure in the master cylinder, and the electric motor is controlled according to the rotation of the sun gear. The rotation servo force of the electric motor is applied to the rotation of the carrier by rotating the ring gear to follow the sun gear.

However, in the electric assist device of the above-mentioned Patent Document 3, when the electric motor or the controller or the like fails, the required stroke of the output rod cannot be ensured, and there is a possibility that the required brake hydraulic pressure cannot be ensured.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2016-124344

Patent Document 2: Japanese Patent Laid-Open No. 2016-193637

Patent Document 3: Japanese Patent Laid-Open No. 2011-93472

SUMMARY OF THE INVENTION

The problem to be solved by the invention

As described above, in the electric power assist devices of Patent Documents 1 to 3, there may be problems related to the mountability to the vehicle and the manufacture.

Accordingly, the present invention has been accomplished with the aim of providing an electric assist device which is easy to manufacture and has improved mountability on a vehicle.

Technical solutions for solving problems

In order to solve the above-mentioned problems, a first aspect of the present invention provides an electric power assist device comprising: an input member that rotates in response to an operation of an input shaft member, and an electric motor that corresponds to the input member the rotation of the electric motor to drive the electric motor; the output member, the rotation of the input member and the rotation from the electric motor are transmitted to a receiving member arranged opposite the rotation direction of the electric motor or the rotation direction of the input member The output member rotates through the portion, and the output shaft member, the rotation of the output member is transmitted to the output shaft member to move the piston of the master cylinder.

In addition, according to a second aspect of the present invention, there is provided an electric assist device comprising: an input member that rotates in response to the operation of the input shaft member, and an electric motor that rotates in response to the rotation of the input member. drive the electric motor; an auxiliary member to which the rotation of the electric motor is transmitted; an output member that receives the The rotation of the input member and the rotation of the auxiliary member rotate; the output shaft member, the rotation of the output member is transmitted to the output shaft member to move the piston of the master cylinder;

When the output member is rotated only by the rotation of the input member, the auxiliary member is separated from the input member and the output member in the rotation direction.

In addition, a third aspect of the present invention provides an electric assist device comprising: an input member that rotates in accordance with linear motion of the input shaft member, and an electric motor corresponding to the input shaft member. Linear motion to drive the electric motor; an auxiliary member connected to a rotating shaft of the electric motor and rotated in the same direction as the electric motor and the input member by the driving of the electric motor; an output member, the rotation of the input member and the rotation of the auxiliary member are transmitted to the output member together, and rotate in the same direction as the input member and the auxiliary member; an output shaft member, the output shaft The member performs linear motion with the rotation of the output member, and moves the piston of the master cylinder.

Invention effect

In the electric power assist device of the present invention, the manufacture can be facilitated and the mountability to the vehicle is improved.

Description of drawings

FIG. 1 is a perspective view of an electric assist device according to the present embodiment.

FIG. 2 is a perspective view of the electric assist device of the present embodiment.

FIG. 3 is a schematic cross-sectional view of the electric assist device of the present embodiment, showing only a part of the gear housing.

FIG. 4 is an exploded perspective view of the electric assist device of the present embodiment.

FIG. 5 is a cross-sectional view taken along line BB of FIG. 3 .

FIG. 6 is a cross-sectional view taken along line AA of FIG. 3 .

Detailed ways

Hereinafter, the electric assist device 1 of the present embodiment will be described in detail based on FIGS. 1 to 6 . As shown in FIG. 1 , the electric assist device 1 of the present embodiment has a structure in which series-type master cylinders 2 are connected. In the following description, the master cylinder 2 side is the front side, and the brake pedal 40 side is the rear side. In addition, illustration of the brake pedal 40 is abbreviate|omitted except for FIG. 3. FIG.

First, the master cylinder 2 will be described in detail based on FIG. 3 .

The rear portion of the master cylinder 2 is connected to the front wall portion of the gear housing 41 of the electric assist device 1 through a third opening 46 provided in the lower portion of the gear housing 41 . A reservoir tank 3 for supplying brake fluid to the master cylinder 2 is attached to the upper portion of the master cylinder 2 . On the master cylinder 2, a bottomed pump chamber 4 is formed. The primary piston 7 is arranged on the side of the opening of the pump chamber 4 . The front part of the primary piston 7 is arranged in the pump chamber 4 of the master cylinder 2 . The rear portion of the primary piston 7 extends from the pump chamber 4 into the gear housing 41 via the third opening 46 of the gear housing 41 .

The front part and the rear part of the primary piston 7 are each formed in a cup shape, and the entirety is formed in an H-shape in cross section. A spherical concave portion 11 is formed on the rear surface of the intermediate wall 10 provided at the approximate center in the axial direction of the primary piston 7 . A spherical surface 110 of an output rod 108 of the electric assist device 1 to be described later is in contact with the spherical recess 11 . A cup-shaped secondary piston 8 is arranged on the bottom side of the pump chamber 4 . Also, in the pump chamber 4 of the master cylinder 2 , the primary chamber 13 is formed between the primary piston 7 and the secondary piston 8 , and the secondary chamber 14 is formed between the bottom of the pump chamber 4 and the secondary piston 8 .

The primary chamber 13 and the secondary chamber 14 of the master cylinder 2 pass from the two hydraulic ports 16 and 16 (refer to FIG. 1 ) of the master cylinder 2 respectively via the master cylinder assembly (acute) pipes (not shown in the figure) of the two systems. shown) communicates with the hydraulic control unit (not shown). The hydraulic control unit communicates with the wheel cylinders (not shown) of the respective wheels via four-system foundation pipes (not shown). Then, the brake force is generated by supplying the hydraulic pressure of the brake fluid generated by the master cylinder 2 or the hydraulic control unit to the wheel cylinders of the respective wheels.

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 tank 3, respectively. On the inner peripheral surface of the pump chamber 4 , in order to divide the inside of the pump chamber 4 into the primary chamber 13 and the secondary chamber 14 , rings which are in contact with the primary piston 7 and the secondary piston 8 are arranged at predetermined intervals along the axial direction. shaped piston seals 20, 21, 22, 23. The piston seals 20 and 21 are arranged to sandwich a reservoir port 18 (rear side) in the axial direction. When the primary piston 7 is in the non-braking position shown in FIG. 3 , the primary chamber 13 communicates with the reservoir port 18 via the piston port 25 provided on the side wall of the primary piston 7 . When the primary piston 7 advances from the non-braking position and the piston port 25 reaches a piston seal 21 (front side), the piston seal 21 blocks the primary chamber 13 from the reservoir port 18 to generate hydraulic pressure.

Similarly, the remaining two piston seals 22 and 23 are arranged to sandwich the other reservoir port 19 (front side) in the axial direction. 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 the piston port 26 provided on the side wall of the secondary piston 8 . When the secondary piston 8 advances from the non-braking position and the piston port 26 reaches the first piston seal 23 (front side), the secondary chamber 14 is blocked from the reservoir port 19 by the piston seal 23 to generate hydraulic pressure.

A compression spring 28 is sandwiched between the primary piston 7 and the secondary piston 8 . With the compression spring 28, the primary piston 7 and the secondary piston 8 are urged in a direction to separate from each other. Inside the compression spring 28, a telescopic member 29 that can expand and contract within a certain range is arranged. The telescopic member 29 includes a cage guide 30 abutting on the intermediate wall 10 of the primary piston 7 , and a cage rod 31 abutting on the secondary piston 8 at its tip and capable of moving in the axial direction within the cage guide 30 . constitute.

The compression spring 33 is sandwiched between the bottom of the pump chamber 4 and the secondary piston 8 . The bottom of the pump chamber 4 and the secondary piston 8 are urged away from each other by the compression spring 33 . Inside the compression spring 33, an expandable and contractible member 34 is arranged within a certain range. The telescopic member 34 includes a cage guide 35 whose front end is in contact with the bottom of the pump chamber 4 , and a cage rod 36 whose rear end is in contact with the secondary piston 8 and is axially movable within the cage guide 35 . constitute.

Next, the electric assist device 1 of the present embodiment to which the above-described master cylinder 2 is coupled will be described in detail based on FIGS. 1 to 6 .

As shown in FIGS. 3 and 4 , the electric assist device 1 of the present embodiment includes an input rod 50 that moves in the axial direction in response to the operation of the brake pedal 40 , an input rack 51 coupled to the input rod 50 , The input pinion 55 that rotates with the linear motion of the input rack 51 , the electric motor 67 that is driven in response to the linear motion of the input rod 50 and the input rack 51 , and the rotation of the input pinion 55 and the transmission from the input pinion 55 are transmitted. The output pinion 83 that rotates in the same direction by the rotation of the electric motor 67 , the output rack 105 that performs linear motion with the rotation of the output pinion 83 , and the primary stage that is connected to the output rack 105 and presses the master cylinder 2 The output rod 108 of the piston 7 , the gear housing 41 housing the input rack 51 including the input rod 50 , the input pinion 55 , the output pinion 83 , the output rack 105 including the output rod 108 , and the like.

Components such as the input pinion 55 , the input rack 51 , the output pinion 83 , and the output rack 105 are accommodated in the gear housing 41 . On the rear surface of the gear housing 41 , a cylindrical portion 42 is integrally protruded toward the rear at the upper portion of the rear surface. The cylindrical portion 42 communicates with the inside of the gear housing 41 . A substantially circular first opening 43 penetrating in the up-down direction is formed in substantially the entire area of the upper wall portion of the gear housing 41 . The input pinion 55 including the rotation shaft 69 of the electric motor 67 , the output pinion 83 , and the like are housed in the gear housing 41 through the first opening 43 . On the upper wall surface of the gear case 41 , a motor case 71 that accommodates the electric motor 67 is connected around the first opening 43 . In the front wall portion of the gear housing 41 , a substantially circular second opening portion 44 (see also FIG. 5 ) that penetrates in the front-rear direction is formed in the upper portion of the front wall portion. The input rod 50 and the input rack 51 are accommodated in the gear housing 41 through the second opening 44 . The second opening portion 44 is closed by the cover 45 .

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

1 and 2 as well, the mounting plate 112 is fixed to the rear surface of the gear housing 41 by a plurality of mounting bolts 114 (three in the present embodiment). The mounting plate 112 is formed in a substantially rectangular shape. A substantially circular opening 113 penetrates through a substantially central portion of the mounting plate 112 . 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 through the opening portion 113 . A plurality of stud bolts 115 penetrate and are attached to the four corners of the mounting plate 112 . In addition, in the present electric assist device 1, the input rod 50 extending from the cylindrical portion 42 of the gear housing 41 is in a state of protruding into the vehicle interior from the instrument panel (not shown) which is the partition wall between the engine room and the vehicle room of the vehicle. It is arranged in the engine room, and is fixed to the instrument 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 a shaft different from the master cylinder 2 and is arranged 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 supported in the gear housing 41 so as to be movable in the axial direction. An ear holder 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 ear holder 60 . Thus, by operating the brake pedal 40, the input rod 50 is linearly moved in the axial direction. A return compression spring (not shown) that biases the input rod 50 toward the initial position is connected to the input rod 50 . The front end portion of the input rod 50 is arranged in the gear housing 41 . An input rack 51 is integrally connected to the front end portion 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 where the front end portion of the input rod 50 is integrally connected to the rear end portion of the input rack 51 . 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 a block shape long along the axial direction of the input rod 50 . In the input rack 51, one surface on the input pinion 55 side is formed as a vertical surface, and the other surface on the opposite side of the surface is formed as a convex curved surface protruding outward. Referring also to FIG. 5 , a rack and pinion portion 52 in which the input pinion 55 is engaged 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 the input shaft member. A stroke sensor 54 is arranged so as 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 portion of the gear housing 41 .

The input pinion 55 meshes with the rack and pinion portion 52 of the input rack 51 , and rotates with the linear motion 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 is orthogonal to the axial direction of the input rod 50 . The input pinion 55 includes an input pinion portion 57 and an input coupling portion 58 integrally formed downward from the input pinion portion 57 . The input pinion portion 57 meshes with the rack and pinion portion 52 of the input rack 51 . The input flange 62 is integrally coupled to the outer peripheral surface of the input coupling portion 58 so as to be non-rotatable relative thereto.

The input flange 62 includes an annular input-side flange portion 64 having a diameter larger than that of the input pinion portion 57 of the input pinion 55 , and the input-side flange portion 64 extends from the input-side flange portion at the lower end of the input-side flange portion 64 . A part of the circumferential direction of 64 faces the input side pressing portion 65 vertically provided downward. The input flange 62 is connected to the input pinion 55 in a manner that the inner peripheral surface of the input side flange portion 64 is coupled to the outer peripheral surface of the input coupling portion 58 of the input pinion 55, for example, by splines. The outer diameter of the input-side flange portion 64 is substantially equal to the inner diameter of the outer cylindrical portion 88 of the output rotary portion 84 of the output pinion 83 to be described later.

Referring also to FIG. 6 , the input side pressing portion 65 is formed in an arc shape having a predetermined thickness. The outer peripheral surface of the input side pressing portion 65 is formed in an arc shape that is continuous from the outer peripheral surface of the input side flange portion 64 to match the inner peripheral surface of the outer cylindrical portion 88 of the output rotating portion 84 of the output pinion 83 described later. Formed in abutting manner. The circumferential length of the input side pressing portion 65 is formed to be smaller than the circumferential distance between the receiving portion 91 of the output rotating portion 84 of the output pinion 83 and the restriction protrusion portion 92 to be described later. The thickness of the input side pressing portion 65 is formed to be substantially the same as the protruding amount of the restricting protrusion portion 92 of the output rotating portion 84 of the output pinion 83 to be described later. Among the circumferential end surfaces of the input-side pressing portion 65 , the end surfaces on the receiving portion 91 side of the output rotating portion 84 of the output pinion 83 to be described later function as the input surfaces 66 .

The electric motor 67 is driven along with the linear motion of the input rod 50 and the input rack 51 . The electric motor 67 is arranged on the upper side of the gear housing 41 and is arranged side by side with the reservoir tank 3 along the axial direction of the master cylinder 2 . In other words, the electric motor 67 is located behind the reservoir tank 3 . The electric motor 67 is accommodated in a cylindrical motor case 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 . To the output shaft 68 of the electric motor 67, a so-called coaxial speed reducer 70, which is a roller speed reducer, is connected. The rotating shaft 69 is extended from the coaxial speed reducer 70 . The rotating 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 inserted through the input pinion 55 in the gear housing 41 through the needle bearing 73A so as to be relatively rotatable. An auxiliary flange 75 is connected to the outer peripheral surface of the rotating shaft 69 at a position below the input pinion 55 so as to be non-rotatable relative thereto. The front end of the rotating shaft 69 is relatively rotatably supported by the inside of the inner cylindrical portion 87 of the output rotating portion 84 of the output pinion 83 to be described later via the needle bearing 73B.

The auxiliary flange 75 corresponds to an auxiliary member. The auxiliary flange 75 includes an auxiliary flange portion 78 formed in an annular shape with a diameter smaller than that of the input flange portion 64 of the input flange 62 , and a circumferential direction from the lower end of the auxiliary flange portion 78 at the lower end of the auxiliary flange 78 . A part of the auxiliary side pressing part 79 vertically arranged downward. The auxiliary flange 75 is connected to the rotation shaft 69 so that the inner peripheral surface of the auxiliary side flange portion 78 is connected to the outer peripheral surface below the input pinion 55 via the rotation shaft 69 , for example, by splines. Referring also to FIG. 6 , the auxiliary side pressing portion 79 is formed in an arc shape having a predetermined thickness.

The outer peripheral surface of the auxiliary side pressing portion 79 is formed in an arc shape continuous from the outer peripheral surface of the auxiliary side flange portion 78 , and is formed to abut against the inner peripheral surface of the input side pressing portion 65 of the input flange 62 . The inner peripheral surface of the auxiliary-side pressing portion 79 is formed in an arc shape in contact with the outer peripheral surface of the inner cylindrical portion 87 of the output rotary portion 84 of the output pinion 83 to be described later. Both circumferential end surfaces of the auxiliary-side pressing portion 79 are formed to have circumferential lengths that match the circumferential end surfaces of the input-side pressing portion 65 of the input flange 62 . The thickness of the auxiliary-side pressing portion 79 is formed so as to pass between the restricting projection portion 92 of the output rotating portion 84 of the output pinion 83 and the outer peripheral surface of the inner cylindrical portion 87 , which will be described later. Among the circumferential end surfaces of the auxiliary-side pressing portion 79 , the end surfaces on the receiving portion 91 side of the output rotating portion 84 of the output pinion 83 to be described later function as auxiliary surfaces 81 . The area of the auxiliary surface 81 of the auxiliary-side pressing portion 79 of the auxiliary flange 75 is set to be larger than the area of the input surface 66 of the input-side pressing portion 65 of the input flange 62 .

The output pinion 83 is accommodated in the gear housing 41 , and the rotation from the input pinion 55 and the rotation from the electric motor 67 are transmitted to the output pinion 83 and the output pinion 83 rotates. 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 includes a bottomed double-cylinder-shaped output rotating portion 84 rotatably supported by the gear housing 41 via a ball bearing 86 , and a cylindrical output rotating portion 84 concentrically and integrally connected to the bottom surface of the output rotating portion 84 . gear part 85 .

The output rotating portion 84 is formed to have a larger diameter than 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 disposed concentrically with an outer space of the inner cylindrical portion 87 , and the inner cylindrical portion 87 and the outer cylindrical portion 88 . The outer cylindrical portion 88 has a disc-shaped bottom portion 89 whose lower end opening is closed. The annular space 90 is formed between the inner cylindrical portion 87 and the outer cylindrical portion 88 . The receiving portion 91 that divides the annular space 90 into two chambers is spanned between the inner cylindrical portion 87 and the outer cylindrical portion 88 . A restriction protrusion 92 is formed at a position away from the receiving portion 91 by a predetermined range in the clockwise direction in FIG. 6 . The restricting protrusions 92 are 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 restricting projection portion 92 functions as the receiving surface 93 .

The output rotary portion 84 is provided with a gap sufficient for the auxiliary side pressing portion 79 of the auxiliary flange 75 to pass between the radial end portion of the restricting projection portion 92 and the outer peripheral surface of the inner cylindrical portion 87 . The input side pressing portion 65 of the input flange 62 and the auxiliary side pressing portion 79 of the auxiliary flange 75 are in radial contact between the receiving portion 91 of the output rotating portion 84 of the output pinion 83 and the restricting projection portion 92 to configure. The input side pressing portion 65 of the input flange 62 is arranged on the outer cylindrical portion 88 side of the output rotary portion 84 , and the auxiliary side pressing portion 79 of the auxiliary flange 75 is arranged on the inner cylindrical portion 87 side of the output rotary portion 84 . A reaction force plate 98 is arranged between the input side pressing portion 65 and the auxiliary side pressing portion 79 and the receiving portion 91 of the output rotating portion 84 . Specifically, the reaction force plate 98 is arranged so as to abut on the receiving surface 93 of the receiving portion 91 of the output rotating portion 84 in substantially the entire area.

The input surface 66 of the input-side pressing portion 65 of the input flange 62 and the auxiliary surface of the auxiliary-side pressing portion 79 of the auxiliary flange 75 are respectively in contact with the substantially entire area of the surface of the reaction force plate 98 on the side of the restricting projection portion 92 . 81. The reaction force plate 98 is formed of an elastic body such as rubber. The reaction force plate 98 is formed in a substantially rectangular plate shape. The reaction force plate 98 is formed so that its thickness gradually increases from the inner cylindrical portion 87 toward the outer cylindrical portion 88 . It should be noted that the area in which the auxiliary surface 81 of the auxiliary-side pressing portion 79 of the auxiliary flange 75 is in contact with the reaction force plate 98 is larger than that of the input surface 66 of the input-side pressing portion 65 of the input flange 62 in contact with the reaction force plate 98 . area is large.

It should be noted that, in the output rotating portion 84 of the output pinion 83, the circumferential distance between the receiving portion 91 and the restricting projection portion 92 is configured to be smaller than the distance between the reaction force plate 98 and the input-side pressing portion 65 abutting. The thickness of the portion is slightly larger than the length obtained by adding the circumferential length of the input side pressing portion 65 of the input pinion 55 . Furthermore, when the input surface 66 of the input side pressing portion 65 of the input pinion 55 is arranged so as to abut against the reaction force plate 98 , the restriction protrusion 92 is opposite to the receiving surface 93 of the input side pressing portion 65 . A clearance S is provided between the circumferential end faces of the sides. The relative rotation of the input pinion 55 and the output pinion 83 to each other by an amount corresponding to the clearance S is allowed. In other words, with respect to the input pinion 55 and the output pinion 83, the relative rotation exceeding the above-mentioned clearance S is restricted. The rotation from the electric motor 67 (the output shaft 68 ) is transmitted to the rotating shaft 69 via the coaxial speed reducer 70 , and the front end of the rotating shaft 69 is relatively rotatably supported by the output rotating portion 84 of the output pinion 83 via the needle bearing 73B. inside the inner cylindrical portion 87 .

As shown in FIG. 3 , on the bottom surface of the disk-shaped bottom portion 89 of the output rotary portion 84 , a substantially circular support recessed portion 100 is recessed. The upper end of the output pinion gear portion 85 is accommodated in the support recessed portion 100 , so that the output pinion gear portion 85 and the output rotating portion 84 are concentrically connected integrally. 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 axial lengths of the output pinion portion 85 of the output pinion 83 and the input pinion portion 57 of the input pinion 55 are also substantially the same. The support rod 48 protruding upward from the bottom surface of the gear housing 41 via the needle bearing 73C is inserted into the lower end of the output pinion portion 85 . Thereby, the output pinion 83 is rotatably supported by the gear housing 41 . The rotating shaft 69 , the input pinion 55 , and the output pinion 83 are concentrically arranged in the gear housing 41 , and the rotation from the electric motor 67 (output shaft 68 ) is transmitted to the rotating shaft 69 .

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 . Like the input rack 50, the output rack 105 is formed in a block shape long along the axial direction of the output rod 108 to be described later. In the output rack 105, one surface on the output pinion 83 side is formed as a vertical surface, and the other surface on the opposite side of the surface is formed as a convex curved surface protruding outward. A rack and pinion portion 106 in which the output pinion 83 is meshed with one surface of the output rack 105 is formed along the axial direction of the output rod 108 . The output rack 105 is arranged at a lower position with a gap from the input rack 51 in the gear housing 41 . The lengths of the output rack 105 and the input rack 51 in the vertical direction are substantially the same. The lengths in the front-rear direction of the output rack 105 and the input rack 51 are also substantially the same.

The 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 in a state where the rear end portion thereof is integrally connected to the front end portion of the output rack 105 . The output rod 108 is extended in the gear housing 41 toward the master cylinder 2 . 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 arranged on a different shaft from the input rod 50 , and more specifically, is arranged on the same shaft as the master cylinder 2 at a position lower than the input rod 50 . The output rod 108 including the output rack 105 corresponds to the output shaft member. The output rod 108 including the output rack 105 and the input rod 50 including the input rack 51 are arranged parallel to each other. In addition, the output rod 108 including the output rack 105 and a part of the input rod 50 including the input rack 51 are arranged to overlap in the axial direction. The front end surface of the output rod 108 is formed as a spherical surface 110 . A sleeve 109 is provided on the outer peripheral surface of the output rod 108 . The spherical surface 110 of the front end of the output rod 108 is in contact with the spherical recess 11 provided on the rear surface of the intermediate wall 10 of the primary piston 7 of the master cylinder 2 .

As shown in FIGS. 1 and 2 , the controller 118 is arranged on the lateral side in the front-rear direction with respect to the electric assist device 1 . Specifically, the controller 118 is arranged on the side of the electric motor 67 (the motor housing 71 ) and the gear housing 41 . The controller 118 is connected to the upper end of the motor housing 71 via the bracket 120 and the gear housing 41 . The controller 118 is based on a stroke sensor 54 that detects the amount of movement of the input rod 50 and the input rack 51 , and a rotation angle detection unit (not shown) that detects the rotation angle of the output shaft 68 (rotation shaft 69 ) of the electric motor 67 , and the detection The driving of the electric motor 67 is controlled by detection signals of various sensors such as a current sensor (not shown) of the current value supplied to the electric motor 67 . Then, by controlling the driving of the electric motor 67 by the controller 118 to rotate the output pinion portion 85 of the output pinion 83 via the rotating shaft 69 and the auxiliary flange 75 to advance the output rod 108, it is possible to use the desired assist ratio. The primary chamber 13 and the secondary chamber 14 of the master cylinder 2 generate brake hydraulic pressure.

Next, the operation when the electric assist device 1 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 and the input rod 50 move forward against the elastic force of the return compression 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 follows the rotation direction of the input pinion 55 The reaction force plate 98 is pressed. In addition, when the input rod 50 and the input rack 51 move forward in accordance with the operation of the brake pedal 40, the stroke sensor 54 detects the movement amount of the input rod 50 and the input rack 51, and the rotation angle detection means detects the movement of the electric motor 67. The rotation angle of the output shaft 68 (rotation shaft 69 ) is controlled by the controller 118 to drive the electric motor 67 based on the respective detection results and the like.

Then, when the electric motor 67 is driven to start the rotation of the rotation shaft 69 , the rotation is transmitted to the auxiliary side pressing portion 79 of the auxiliary flange 75 , and the auxiliary surface 81 of the auxiliary side pressing portion 79 follows the rotation direction of the rotation shaft 69 . The reaction force plate 98 is pressed. As a result, the propulsion force from the input flange 62 (input surface 66 of the input side pressing portion 65 ) accompanying the operation of the brake pedal 40 and the auxiliary flange 75 (auxiliary side pressing portion 65 ) accompanying the driving of the electric motor 67 are combined. The propulsion force of the auxiliary surface 81 of 79 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 force plate 98, so that the output pinion 83 follows the input flange 62 and the auxiliary flange. 75 to rotate in the direction of rotation. After that, the output rack 105 and the output rod 108 advance along with the rotation of the output pinion 83 , whereby the primary piston 7 and the secondary piston 8 of the master cylinder 2 are pressed and advanced by the output rod 108 . In addition, when the electric motor 67 is driven, the rotation direction of the rotating shaft 69, the rotation direction of the auxiliary flange 75 (auxiliary side pressing part 79), and the rotation direction of the output pinion 83 are 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 supplied to the wheel cylinder of each wheel via the hydraulic control unit, generating a The braking force of friction braking. When the hydraulic pressure is generated in the master cylinder 2, the hydraulic pressure of the primary chamber 13 and the secondary chamber 14 is received by the input surface 66 of the input side pressing portion 65 of the input flange 62 via the reaction force plate 98, so that the elastic force of the return compression spring and the The reaction force obtained by adding the reaction forces due to the hydraulic pressure is transmitted to the brake pedal 40 via the input rack 51 and the input rod 50 .

Furthermore, the pressure receiving area of the input surface 66 of the input side pressing portion 65 of the input flange 62 caused by the hydraulic pressure of the master cylinder 2 and the pressure receiving area of the auxiliary surface 81 of the auxiliary side pressing portion 79 of the auxiliary flange 75 can be made equal to each other. The ratio and the ratio of the distance between the input surface 66 of the input side pressing portion 65 and the rotation center and the distance of the auxiliary surface 81 of the assisting side pressing portion 79 from the rotation center become the boost ratio (the hydraulic output of the brake pedal 40 with respect to the operation input). ratio) to produce the desired braking force. It should be noted that, in this embodiment, the pressure receiving area of the auxiliary surface 81 of the auxiliary flange 75 (auxiliary 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 ). Therefore, the ratio of the hydraulic output of the brake pedal 40 to the operation input can be more than doubled, so that the desired braking force can be generated.

Next, when the operation of the brake pedal 40 is released, that is, when the depression of the brake pedal 40 is released, the output rack 105 is moved backward due to the reaction force caused by the hydraulic pressure from the master cylinder 2 (primary chamber 13 and secondary chamber 14 ). In addition, the output pinion 83 rotates in the opposite direction, and at the same time, the input side pressing portion 65 of the input flange 62 retreats toward the initial position, and the input pinion 55 is reversed. As a result, the input rack 51 retreats and is urged by the return compression spring. The input lever 50 is retracted to the initial position. At the same time, the stroke detection device 7 detects the retraction amount 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 based on the respective detection results. , the controller 118 controls the driving (reverse) of the electric motor 67, and transmits the reverse to the auxiliary flange 75, so that the auxiliary-side pressing portion 79 retreats toward the initial position.

However, even when the auxiliary flange 75 cannot operate due to failure of the electric motor 67 or the controller 118, etc., 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 of 55 presses the reaction force plate 98 . Then, the propulsion 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 force plate 98 to cause the output pinion 83 to operate By rotating, 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 auxiliary-side pressing portion 79 of the auxiliary flange 75 is configured to pass between the restricting projection portion 92 of the output rotary portion 84 of the output pinion 83 and the outer peripheral surface of the inner cylindrical portion 87, so even if the auxiliary protrusion When the auxiliary side pressing portion 79 of the flange 75 is stopped, 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, and the auxiliary side pressing portion 79 of the auxiliary flange 75 does not. Interfering with the restricting protrusion 92 of the output rotating portion 84 of the output pinion 83, the output pinion 83 can continue to rotate without any problems, and the auxiliary side pressing portion 79 of the auxiliary flange 75 gradually moves away from the output pinion 83 in the rotational direction. and input pinion 55. In addition, the output rack 105 and the output rod 108 advance along with the rotation of the output pinion 83 , whereby the primary piston 7 and the secondary piston 8 of the master cylinder 2 advance, the master cylinder 2 can generate hydraulic pressure, and the braking function can be maintained. . In this way, in the electric assist device 1 of the present embodiment, even when the electric motor 67 or the controller 118 fails, the required stroke of the output rod 108 can be ensured.

Further, in the electric assist device 1 of the present embodiment, the relative rotation of the input pinion 55 and the output pinion 83 exceeding the clearance S is restricted by providing the restricting projections 92 on the output rotating portion 84 of the output pinion 83 . Thus, for example, when the master cylinder 2 generates hydraulic pressure only by driving the electric motor 67 , the rotation from the electric motor 67 (the output shaft 68 ) is transmitted to the rotating shaft 69 , and only the rotation of the rotating shaft 69 assists the master cylinder 2 . The rotation of the auxiliary side pressing portion 79 of the flange 75 is transmitted to the reaction force plate 98 , and only the propulsion force from the auxiliary flange 75 (the auxiliary surface 81 of the auxiliary side pressing portion 79 ) accompanying the driving of the electric motor 67 passes through the reaction force plate 98 is transmitted to the receiving surface 93 of the receiving portion 91 of the output rotating portion 84 of the output pinion 83 , thereby rotating the output pinion 83 .

In addition, at this time, the input side pressing portion 65 of the input flange 62 rotates together with the output pinion 83 so as to be pressed by the restricting projection portion 92 of the output rotating portion 84 of the output pinion 83 , that is, the input pinion 55 rotates relative to the output pinion 83 . Since the relative rotation of the pinion gear 83 beyond the clearance S is restricted, the input pinion gear 55 also rotates in the same direction so as to follow the output pinion gear 83 . As a result, the input rod 50 and the input rack 51 are moved forward, and the brake pedal 40 is rotated about the fulcrum even when no pedaling force is applied to the brake pedal 40 .

On the other hand, in the electric assist device 1 of another embodiment, the restriction protrusion 92 is not provided on the output rotating portion 84 of the output pinion 83, and the input pinion 55 and the output pinion 83 are configured to be relatively rotatable. Thus, for example, when the master cylinder 2 generates hydraulic pressure only by driving the electric motor 67 , the rotation from the electric motor 67 (the output shaft 68 ) is transmitted to the rotating shaft 69 , and the rotation of the rotating shaft 69 is caused only by the rotation of the rotating shaft 69 . , the rotation of the auxiliary side pressing portion 79 of the auxiliary flange 75 is transmitted to the reaction force plate 98, and only the propulsion force from the auxiliary flange 75 (the auxiliary surface 81 of the auxiliary side pressing portion 79) accompanying the driving of the electric motor 67 is transmitted through the counter. The force plate 98 is transmitted to the receiving surface 93 of the receiving portion 91 of the output rotating portion 84 of the output pinion 83 , thereby rotating the output pinion 83 . Furthermore, at this time, the input pinion 55 and the output pinion 83 are configured to be rotatable relative to each other, so the input pinion 55 does not rotate along with the rotation of the output pinion 83 . As a result, the input rod 50 and the input rack 51 And the brake pedal 40 does not operate.

As described above, the electric assist device 1 of the present embodiment includes the input pinion 55 that rotates in response to the operation of the input rod 50 and the input rack 51 , and the electric motor 67 that corresponds to the input pinion 55 The rotation of the electric motor 67 is driven; the output pinion 83, the rotation of the input pinion 55 and the rotation from the electric motor 67 are transmitted to a receiving part arranged opposite to the rotation direction of the electric motor 67 or the rotation direction of the input pinion 55 91 and the output pinion 83 rotates; the output rack 105 and the output rod 108, the rotation of the output pinion 83 is transmitted to the output rack 105 and the output rod 108 to move the primary and secondary pistons of the master cylinder 2.

As a result, in the electric assist device 1 of the present invention, the size of the master cylinder 2 in the axial direction and the radial direction can be reduced, and the mountability in the vehicle can be improved. In addition, in the electric assist device 1 of the present invention, a ball screw mechanism is not employed as in the conventional electric assist device, and therefore, the processing cost of the components can be suppressed, and the manufacture can be facilitated. Furthermore, in the electric assist device 1 of the present invention, even when the auxiliary flange 75 cannot operate due to failure of the electric motor 67 or the controller 118 or the like, the output rod required to generate the desired hydraulic pressure in the master cylinder 2 can be secured. 108 moves.

In addition, in the electric assist device 1 of the present embodiment, the input rod 50 and the input rack 51 and the output rod 108 and a part of the output rack 105 are arranged to overlap in the axial direction. Therefore, in the electric assist device 1, the In particular, the entire length in the axial direction of the master cylinder 2 can be shortened.

Furthermore, in the electric assist device 1 of the present embodiment, the input rod 50 and the input rack 51 and the output rod 108 and the output rack 105 are arranged substantially in parallel. The radial direction of the master cylinder 2 enables it to be miniaturized. Thereby, the degree of freedom of the layout at the time of mounting on the vehicle is improved.

Furthermore, in the electric assist device 1 of the present embodiment, the receiving surface 93 of the receiving portion 91 of the output pinion 83 (the output rotating portion 84 ) is assisted from the input surface 66 of the input side pressing portion 65 of the input flange 62 and the receiving surface 93 of the receiving portion 91 . Since the auxiliary surface 81 of the auxiliary-side pressing portion 79 of the flange 75 receives the rotation in the same direction, it is possible to synthesize the rotational force in the same rotation direction.

Furthermore, in the electric assist device 1 of the present embodiment, the receiving surface 93 of the receiving portion 91 of the output pinion 83 (the output rotating portion 84 ) and the input surface 66 and the input side pressing portion 65 of the input flange 62 Since the reaction force plate 98 made of an elastic body is provided between the auxiliary surfaces 81 of the auxiliary side pressing portion 79 of the auxiliary flange 75 , when the reaction force plate 98 is pressed by the input surface 66 , the brake pedal 40 can be applied to the brake pedal 40 . The reaction force of the reaction force plate 98 improves the pedal feel.

Furthermore, in the electric assist device 1 of the present embodiment, the pressure receiving area of the auxiliary surface 81 of the auxiliary side pressing portion 79 of the auxiliary flange 75 with respect to the receiving surface 93 of the receiving portion 91 is larger than that of the input side of the input flange 62 . Since the pressure receiving area of the input surface 66 of the pressing portion 65 relative to the receiving surface 93 of the receiving portion 91 is large, the ratio (assistance ratio) of the hydraulic output of the brake pedal 40 to the operation input can be made larger than twice, thereby producing the desired braking force.

Furthermore, in the electric assist device 1 of the present embodiment, the rotation shaft of the input pinion 55 is arranged on the same axis as the rotation shaft 69 , and the rotation from the electric motor 67 (output shaft 68 ) is transmitted to the rotation. Since the shaft 69 is provided, the electric assist device 1 can be reduced in size.

Furthermore, in the electric assist device 1 of the present embodiment, the input pinion 55 is configured to rotate following the output pinion 83 when the output pinion 83 is rotated only by the rotation of the electric motor 67 . In this embodiment, when hydraulic pressure is generated in the master cylinder 2 only by the rotation of the electric motor 67 , the brake pedal 40 is rotated about the fulcrum even if no pedaling force is applied to the brake pedal 40 . In addition, in the electric assist device 1 according to another embodiment, the input pinion 55 is configured so that 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 but is held stop state. In this other embodiment, when the master cylinder 2 generates hydraulic pressure only by the rotation of the electric motor 67, the brake pedal 40 does not rotate about the fulcrum, but stays at the initial position.

Furthermore, in the electric assist device 1 of the present embodiment, the rotation from the electric motor 67 (the output shaft 68 ) is transmitted to the rotating shaft 69 , and the rotating shaft 69 is connected to the input rod 50 (input rack 51 ) and the output rod 108 ( The output rack 105) is arranged orthogonally, and the electric motor 67 is arranged in parallel with the reservoir tank 3 attached to the master cylinder 2 along the axial direction of the master cylinder 2. As a result, in the electric assist device 1 , the size of the electric assist device 1 can be reduced particularly in the radial direction of the master cylinder 2 , and the degree of freedom of layout when mounted on a vehicle can be improved.

As the electric assist device 1 based on the above-described embodiment, for example, the following aspects are also conceivable.

In the first aspect, the electric assist device 1 includes the input member 55 that rotates in response to the operation of the input shaft members 50 and 51 , and the electric motor 67 that drives the electric motor 67 in response to the rotation of the input member 55 . The output member 83, the rotation of the input member 55 and the rotation from the electric motor 67 are transmitted to a receiving portion 91 arranged opposite to the rotation direction of the electric motor 67 or the rotation direction of the input member 55, and the output member 83 performs Rotation; output shaft members 105, 108, the rotation of the output member 83 is transmitted to the output shaft members 105, 108, and the pistons 7, 8 of the master cylinder 2 are moved.

In the second aspect, the electric assist device 1 includes an input member 55 that rotates in response to the operation of the input shaft members 50 and 51 , and an electric motor 67 that drives the electric motor 67 in response to the rotation of the input member 55 . auxiliary member 75, the rotation of the electric motor 67 is transmitted to the auxiliary member 75; output member 83, the output member 83 in the rotation direction of the auxiliary member 75 or the rotation direction of the input member 55 with surface 93 to receive the input member 55 The rotation and the rotation of the above-mentioned auxiliary member 75 rotate; the output shaft members 105 and 108, the rotation of the output member 83 is transmitted to the output shaft members 105 and 108 to move the pistons 7 and 8 of the master cylinder 2; in the above-mentioned output member 83 When the input member 55 is rotated only by the rotation, the auxiliary member 75 is separated from the input member 55 and the output member 83 in the rotational direction.

In the third aspect, the electric assist device 1 includes an input member 55 that rotates in accordance with the linear motion of the input shaft members 50 and 51 , and an electric motor 67 that rotates in accordance with the linear motion of the input shaft members 50 and 51 . drive electric motor 67; auxiliary member 75, which is connected to the rotating shaft 69 of the electric motor 67 and rotates in the same direction as the electric motor 67 and the input member 55 by the driving of the electric motor 67; output member 83. The rotation of the above-mentioned input member 55 and the rotation of the above-mentioned auxiliary member 75 are transmitted to the output member 83, and the output member 83 rotates in the same direction as the above-mentioned input member 55 and the above-mentioned auxiliary member 75; the output shaft members 105 and 108, The output shaft members 105 and 108 perform linear motion in accordance with the rotation of the output member 83 , and move the pistons 7 and 8 of the master cylinder 2 .

In the 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 partially overlapped and arranged in the axial direction.

In the fifth aspect, in any one of the first to fourth aspects, the input shaft members 50 and 51 and the output shaft members 105 and 108 are arranged substantially parallel to each other.

In the sixth aspect, in the first aspect, the receiving portion 91 receives rotation in the same direction from the input surface 66 and the auxiliary surface 81, the input surface 66 is provided on the input member 55, and the rotation from the electric motor 67 is transmitted to the above-mentioned Auxiliary surface 81 .

In the seventh aspect, in the sixth aspect, an elastic body 98 is provided between the receiving portion 91 , the input surface 66 , and the auxiliary surface 81 .

In the eighth aspect, in the sixth or seventh aspect, the pressure receiving area of the auxiliary surface 81 with respect to the receiving portion 91 is larger than the pressure receiving area of the input surface 66 with respect to the receiving portion 91 .

In the ninth aspect, in any one of the first to eighth aspects, the rotation shaft of the input member 55 is arranged on the same axis as the rotation shaft 69 of the electric motor 67 .

In the 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 the eleventh aspect and the second aspect, when the output member 83 is rotated only by the rotation from the electric motor 67 , the input member 55 does not follow the output member 83 .

In the twelfth aspect, in any one of the first to eleventh aspects, the rotating shaft 69 of the electric motor 67 is arranged to be orthogonal to the input shaft members 50 and 51 and the output shaft members 105 and 108 The electric motor 67 is arranged along the axial direction of the master cylinder 2 and the liquid storage tank 3 mounted on the master cylinder 2 in parallel.

Description of reference numerals

1 electric booster, 2 master cylinder, 3 reservoir, 7 primary piston, 8 secondary piston, 50 input rod (input shaft part), 51 input rack (input shaft part), 55 input pinion (input part) , 66 input surface, 67 electric motor, 69 rotating shaft, 75 auxiliary flange (auxiliary part), 81 auxiliary surface, 83 output pinion (output part), 91 receiving part, 93 receiving surface, 98 reaction force plate (elastomer ), 105 output rack (output shaft part), 108 output rod (output shaft part).

Claims (15)

1. An electric power assist device is characterized by comprising:

an input member that rotates in response to an operation of the input shaft member;

an electric motor that is driven in accordance with rotation of the input member;

an output member that rotates when the rotation of the input member and the rotation from the electric motor are transmitted to one receiving portion disposed opposite to a rotation direction of the electric motor and a rotation direction of the input member;

an output shaft member to which rotation of the output shaft member is transmitted to move a piston of a master cylinder;

the rotation of the input member is transmitted to the receiving surface of the receiving section.

2. An electric power assist device is characterized by comprising:

an input member that rotates in response to an operation of the input shaft member;

an electric motor that is driven in accordance with rotation of the input member;

an auxiliary member to which rotation of the electric motor is transmitted;

an output member that rotates in a rotation direction of the auxiliary member or a rotation direction of the input member by receiving the rotation of the input member and the rotation of the auxiliary member in a plane;

an output shaft member to which rotation of the output shaft member is transmitted to move a piston of a master cylinder;

when the output member is rotated only by the rotation of the input member, the auxiliary member is separated from the input member and the output member in the rotational direction.

3. An electric power assist device is characterized by comprising:

an input member that rotates in accordance with a linear motion of the input shaft member;

an electric motor that is driven in accordance with a linear motion of the input shaft member;

an auxiliary member that is coupled to a rotating shaft of the electric motor and rotates in the same direction as the electric motor and the input member by driving the electric motor;

an output member to which the rotation of the input member and the rotation of the auxiliary member are transmitted together, the output member rotating in the same direction as the input member and the auxiliary member;

and an output shaft member that moves linearly in accordance with rotation of the output member and moves a piston of the master cylinder.

4. An electric power assist device according to any one of claims 1 to 3,

the input shaft member and the output shaft member are partially arranged to overlap in a direction of a rotation axis of the electric motor when viewed in a cross section along the rotation axis of the electric motor.

5. An electric power assist device according to any one of claims 1 to 3,

the input shaft member and the output shaft member are arranged substantially in parallel.

6. The electric assist apparatus of claim 1,

the receiving portion receives rotation in the same direction from an input surface provided to the input member and an auxiliary surface to which rotation from the electric motor is transmitted.

7. The electric assist of claim 6, wherein,

an elastic body is provided between the receiving portion and the input surface and the auxiliary surface.

8. The electric booster of claim 6 or 7,

the pressure receiving area of the auxiliary surface with respect to the receiving portion is larger than the pressure receiving area of the input surface with respect to the receiving portion.

9. An electric power assist device according to any one of claims 1 to 3,

the rotation shaft of the input member is disposed on the same axis as the rotation shaft of the electric motor.

10. Electric power assist device according to claim 2,

when the output member is rotated only by rotation from the electric motor, the input member rotates following the output member.

11. The electric power assist device of claim 2,

the input member does not follow the output member when the output member is rotated only by rotation from the electric motor.

12. An electric power assist device according to any one of claims 1 to 3,

a rotation shaft of the electric motor is disposed so as to be orthogonal to the input shaft member and the output shaft member,

the electric motor is arranged in parallel with a liquid storage tank arranged on the master cylinder along the axial direction of the master cylinder.

13. An electric power assist device is characterized by comprising:

an input member that rotates in response to an operation of the input shaft member;

an electric motor that is driven in accordance with rotation of the input member;

an output member that rotates when 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;

an output shaft member to which rotation of the output member is transmitted to move a piston of a master cylinder,

the receiving unit receives rotation in the same direction from an input surface provided to the input member and an auxiliary surface to which rotation from the electric motor is transmitted.

14. The electric assist device of claim 13,

an elastic body is provided between the receiving portion and the input surface and the auxiliary surface.

15. The electric booster of claim 13 or 14,

the pressure receiving area of the auxiliary surface with respect to the receiving portion is larger than the pressure receiving area of the input surface with respect to the receiving portion.

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