WO2014025010A1

WO2014025010A1 - Electric disc brake apparatus

Info

Publication number: WO2014025010A1
Application number: PCT/JP2013/071640
Authority: WO
Inventors: 英紀柿崎; 田島　顕之
Original assignee: 曙ブレーキ工業株式会社
Priority date: 2012-08-09
Filing date: 2013-08-09
Publication date: 2014-02-13
Also published as: JP5946399B2; JP2014052068A

Abstract

This electric actuator is provided with an electric motor (8a), a pressing unit (20), a plate spring (21), a booster unit (22), and a booster ratio conversion unit (23). The booster unit (22) is configured to include a plurality of levers (29) that swing around roller (28), and is displaced in a direction in which a pressing plate (30) constituting the pressing unit (20) protrudes from a cylinder space (6a). The booster ratio conversion unit (23) displaces each roller (28) in the circumferential direction of each lever (29), thereby altering the booster ratio.

Description

Electric disc brake device

This invention relates to an improvement of an electric disc brake device.

The electric disc brake device that uses an electric motor as a drive source eliminates the need for piping compared to a hydraulic disc brake that has been widely used in the past, and facilitates manufacturing and reduces costs. Research is being conducted because it has many advantages, such as the fact that used brake fluid is not generated and the environmental load is small, and that there is no movement of the brake fluid, so that responsiveness can be improved. In such an electric disc brake device, it is necessary to convert the rotational motion of the electric motor into linear motion while increasing the force, and to strongly press the pair of pads against both side surfaces of the rotor. In view of such circumstances, various electric disc brake devices that combine a gear-type reduction gear and a booster have been conventionally proposed as described in Patent Documents 1 to 4.

FIG. 8 shows an example of the conventional structure described in

Patent Documents

1 and 2. In this electric disc brake device, as with a general hydraulic disc brake, an inner pad 2 and an outer pad 3 are installed so as to be capable of displacement in the axial direction of the rotor 1 with a rotor 1 rotating together with a wheel interposed therebetween. ing. For this reason, a support (not shown) is supported on the vehicle body (fixed to a knuckle constituting the suspension device) in a state adjacent to the rotor 1. The inner pad 2 and the outer pad 3 are in a state where the rotor 1 is sandwiched from both sides in the axial direction, and the axial direction (the outer side is the outside in the width direction of the vehicle body when assembled to the vehicle body, and the inner side is the same as the inner side. The axial direction refers to the rotational axis direction of the rotor 1. Unless otherwise specified, the displacement is the same in the description of the entire specification and claims). Possible support is supported by the support.

In addition, the caliper 4 is assembled to the support so as to be capable of axial displacement. The caliper 4 is provided with a caliper claw 5 at an outer side end portion, and a cylinder space 6 inside an inner side portion. The caliper claw 5 faces the outer side surface of the outer pad 3 and the inner pad 2 is pressed toward the inner side surface of the rotor 1 by a thrust generator 7 provided in the cylinder space 6. It is configured. At the time of braking, when the inner pad 2 is pressed against the inner side surface of the rotor 1 by the thrust generating device 7, the caliper 4 is displaced toward the inner side, and the caliper claw 5 moves the outer pad 3 toward the outer side surface of the rotor 1. Press on. As a result, the rotor 1 is strongly clamped from both sides in the axial direction, and braking is performed. The above configuration and operation are the same as those of a widely used hydraulic disc brake.

In the case of the electric disc brake device, the inner pad 2 is pressed against the inner side surface of the rotor 1 using the electric motor 8 as a driving source. Therefore, the output shaft 9 of the electric motor 8 and the inner pad 2 are inner. A gear-type reduction gear 10, the thrust generating device 7, and a piston 11 are provided between the side surfaces. The rotational force decelerated by the speed reducer 10 and increased in torque is transmitted to a drive-side rotor 13 constituting a ball / ramp type booster device via a feed screw device 12. It is rotated. The drive-side rotor 13 is moved parallel to the outer side by the function of the feed screw device 12 until the clearance between the inner pad 2 and the outer pad 3 and the side surface of the rotor 1 is eliminated. To do. On the other hand, after the gap is eliminated and the function of the feed screw device 12 is stopped, it rotates. Then, a plurality of driving

side ramp grooves

14, 14 provided on the outer side surface of the driving side rotor 13 and a plurality of driven side lamps provided on the inner side surface of the driven side stator 15 attached to the inner side surface of the piston 11. Based on the engagement (rolling contact) between the driving

side ramp grooves

16 and 16 and the plurality of balls 17 sandwiched between the two

lamp grooves

14 and 16, the driving side rotor 13 and the driven side The space | interval with the stator 15 is expanded with big force. As a result, the outer side surface of the piston 11 is strongly pressed against the inner side surface of the inner pad 2.

The electric disc brake device having the conventional structure as described above cannot sufficiently increase the braking force associated with the inner pad 2 and the outer pad 3 being pressed against both side surfaces of the rotor 1. Of course, the reduction ratio of the speed reducer 10 is increased, the reduction ratio of the feed screw device 12 is increased (the screw pitch is made fine), and the inclinations of the drive side ramp grooves 14 and the driven side ramp grooves 16 are increased. It is possible to increase the braking force by loosening the angle. However, when the reduction ratio of the speed reducer 10 or the feed screw device 12 is increased, the inner pad 2 and the outer pad 3 move forward from the non-braking state position to the brakeable position, and the linings 18 of the inner pad 2 and the outer pad 3, The time required for 18 to be pressed against both side surfaces of the rotor 1 becomes longer. That is, in the non-braking state, a clearance (clearance) exists between the both side surfaces of the rotor 1 and the friction surfaces of the

linings

18 and 18, so that the clearance is eliminated in order to exert the braking force. Need to be done. If the reduction ratio is increased, the time required to eliminate this clearance becomes longer, and the responsiveness of the electric disc brake device deteriorates.

Patent Documents 3 and 4 describe inventions relating to an electric disc brake device in which the elasticity of a spring is used and this elasticity is increased by a force-increasing mechanism such as a lever so that the pad lining is pressed against the rotor. . Among these, the invention described in Patent Document 3 increases the elasticity of the spring to generate a braking force, and releases the braking based on energization of the solenoid. Such a structure of the invention described in Patent Document 3 is considered to be limited in use as a braking device for automobiles because the braking force cannot be adjusted. In the structure of the invention described in Patent Document 4, a braking force is generated by a balance between the ball cam mechanism and the elasticity of the leaf spring. Such a structure is considered to be limited in use as a braking device for automobiles because, for example, it is necessary to increase the size of the ball cam mechanism in order to obtain a large braking force.

Japanese Unexamined Patent Publication No. 2004-169729 Japanese Unexamined Patent Publication No. 2010-265971 Japanese Patent No. 2511957 US Patent Application Publication No. 2010/0243387

The present invention has been made in view of the circumstances as described above, and an object of the present invention is to provide an electric disc having a structure capable of increasing a generated braking force and having a realistic size as a vehicle braking device. It is to provide a brake device.

The above object of the present invention is achieved by the following configurations (1) to (8).
(1) a rotor that rotates with the wheel;
A pad support portion supported by the vehicle body in a state adjacent to the rotor (a support in the case of a floating caliper type disc brake device, and a caliper in the case of an opposed piston type disc brake device, respectively);
A pair of pads on the outer side and the inner side supported by the pad support portion so as to be capable of displacement in the axial direction with the rotor sandwiched from both sides in the axial direction,
A pressing piece provided in a cylinder space provided in a portion facing at least one of the two pads so as to be capable of displacement in the axial direction of the rotor;
An electric disc brake device comprising: an electric actuator that uses the electric motor as a drive source to displace the pressing piece in a direction in which the pressing piece is pushed out of the cylinder space, so that the two pads are pressed against both axial sides of the rotor. Because
The electric actuator includes the electric motor, a pressing unit disposed concentrically in the cylinder space, a spring, a boosting unit, and a boosting ratio conversion unit.
In the electric motor, the output shaft is rotated in both directions based on energization,
The pressing unit is displaced in a direction protruding from the cylinder space based on the rotation of the output shaft, and the one pad facing the opening of the cylinder space is pressed against the axial side surface of the rotor. Yes,
In the spring, one end in the axial direction is brought into contact with a fixed portion on the inner surface of the cylinder space, and the other end in the axial direction is displaced in a direction in which the constituent member of the pressing unit protrudes from the cylinder space. It is an output part that gives the power of
The force-increasing unit is intermittently arranged in the circumferential direction, and a plurality of levers that are oscillated and displaced with each circumferential intermediate portion serving as a fulcrum, a fulcrum member that contacts each circumferential intermediate portion of each lever, and a shaft And a support plate member for supporting each fulcrum member on the opposite side to each lever with respect to the direction, and one end in the circumferential direction of each lever is oscillating and displaced to a pressed member pressed by the output portion of the spring The other end portion is also engaged with a part of the constituent member of the pressing unit so as to be able to swing and displace, so that the lever is swung in accordance with the elastic force of the spring. The pressing unit is displaced in a direction protruding from the cylinder space;
The force increase ratio conversion unit is configured such that each fulcrum member is displaced in the circumferential direction of each lever, whereby the distance between each fulcrum member and one circumferential end on the input side of each lever, and each fulcrum member And the elastic force of the spring determined by the ratio of the distance between the lever and the other end in the circumferential direction on the output side of the lever, and the pressing unit is displaced in the direction protruding from the cylinder space based on the elastic force of the spring. An electric disc brake device in which an increase ratio, which is a ratio to the magnitude of the force to be changed, changes.

(2) An electric disc brake device having the configuration of (1) above,
A locking plate is supported on the inner side of the cylinder space near the opening in a state where displacement in the direction of exiting from the cylinder space is prevented.
An anchor plate, which is a member to be pressed by the booster unit, is provided at an intermediate portion in the axial direction of the cylinder space in a state in which rotation in the cylinder space is prevented and can be displaced in the axial direction. And
An electric disc brake device in which a disc spring, which is the spring, is sandwiched between the locking plate and the anchor plate.

(3) An electric disc brake device having the above configuration (1) or (2),
Each fulcrum member is a cylindrical roller, and each roller is rotatably held in a plurality of pockets provided in a radial direction on the cage,
The portion where the peripheral surface of each roller in each lever abuts is a flat bearing surface,
Each of the rollers is provided between the bearing surface and one axial surface of the support plate portion that constitutes the boost ratio conversion unit,
The electric disc brake device, wherein the support plate portion is rotatably supported at a back end portion of the cylinder space by a thrust bearing provided between the other axial surface and the back end surface of the cylinder space.

(4) An electric disc brake device having any one of the constitutions (1) to (3),
The pressing unit includes an adjusting screw, an adjusting nut, and a pressing plate;
The adjustment screw has a distal end engaged with a proximal end side surface of the pressing piece, and a proximal end from the intermediate portion to a male screw, and can be displaced in the axial direction while being prevented from rotating. Provided in the cylinder space,
The adjustment nut is provided with a screw hole to be screwed with the male screw portion at the center, and an outward flange-shaped flange on the outer peripheral surface of the tip portion.
The pressing plate is annular, and one end in the circumferential direction of each lever is in contact with a plurality of circumferential positions on one axial side that is the back end face side of the cylinder space on both axial sides, and the axial direction The inner peripheral edge portion of the other surface is engaged with the flange portion, and the force in the direction protruding from the cylinder space applied along with the swinging displacement of each lever can be transmitted to the adjustment nut. Electric disc brake device.

(5) An electric disc brake device having the configurations of (3) and (4) above,
A planetary gear type transmission is provided between the output shaft of the electric motor and the support plate portion and the adjustment nut,
A sun gear of the planetary gear type transmission is rotationally driven by the output shaft, and the support plate portion is also rotationally driven by the ring gear, and a plurality of planetary gears meshed with the sun gear and the ring gear, respectively. An electric disc brake device in which the adjusting nut is rotationally driven by a supported carrier.

(6) An electric disc brake device having the configuration of (5) above,
In the process in which a resistance mechanism that provides resistance against the rotation of the ring gear is provided, and the rotor is clamped by the two pads based on energization of the electric motor, and braking force is generated,
Based on the resistance force applied to the ring gear by the resistance mechanism, the sun gear rotates until the clearance between the pressing surfaces of the pads and the both axial sides of the rotor is eliminated. Accordingly, the carrier is rotated without rotating the ring gear,
The electric disc brake device in which the ring gear is rotated after the clearance is eliminated and the pressing surfaces of the pads are pressed against both axial sides of the rotor.

(7) An electric disc brake device having the configurations of (2) and (4) above,
An elastic member such as a compression coil spring or a leaf spring is provided between the locking plate and the flange portion of the adjustment nut,
An electric disc brake device in which the adjustment nut is prevented from rattling in the cylinder space during non-braking.

(8) An electric disc brake device having the configuration of the above (7),
One end of the elastic member is abutted against one member of the locking plate and the flange of the adjustment nut,
Similarly, an electric disc brake device in which a thrust bearing is provided between the other member and the other end of the elastic member.
In addition, as such a thrust bearing, for example, a sliding bearing made of a metal material such as a synthetic resin or a metal containing a low friction coefficient, or a thrust rolling bearing can be used. In addition, a lubricant such as grease can be interposed between the aforementioned portions.

In the electric disc brake device having the configuration of (1), the force by which the linings of the two pads are pressed against both side surfaces of the rotor so that the braking force is generated is the spring elasticity, each of which is centered on the fulcrum member. Is generated by being transmitted to the constituent members of the pressing unit by a plurality of levers that are rockingly displaced. The electric disk brake device having the configuration (1) operates as follows, and the lining of the pair of pads is pressed against both side surfaces of the rotor, and braking is performed.

When the pressing unit is displaced in a direction protruding from the cylinder space based on energization of the electric motor so that a braking force is generated, a gap is formed between the linings of the two pads and both side surfaces of the rotor. While the power unit is present, the boosting unit and the power boosting ratio exchanging unit do not function, and the pressing unit is quickly displaced in the direction protruding from the cylinder space. For this reason, the said clearance gap can be eliminated quickly and responsiveness can be ensured. That is, until the gap is eliminated, the booster unit including the levers does not need to operate, and the moving speed of the pressing unit can be increased regardless of the booster ratio of the booster unit.

After the clearance is eliminated, the fulcrum member is moved by the action of the boost ratio conversion unit, and the boost ratio of the boost unit including the levers can be increased. For this purpose, the pressing unit is pressed in a direction protruding from the cylinder space with a force sufficiently larger than the elasticity of the spring. As a result, the linings of the two pads are pressed against both side surfaces of the rotor with a sufficiently large force to obtain a sufficient braking force.

Further, the pressing unit, the spring, the boosting unit, and the boosting ratio conversion unit that constitute the electric actuator are each configured in an annular shape or a cylindrical shape, and can be arranged coaxially. Therefore, the electric actuator can be made compact.
As a result, according to the configuration of the above (1), the time required until the braking force is generated can be shortened, and the generated braking force can be increased. Type disc brake device can be realized.

Further, according to the configuration of (7), it is possible to prevent the adjustment nut constituting the pressing unit from rattling in the cylinder space when the electric disk brake device is not braked. For this reason, at the time of non-braking, it is possible to prevent a collision noise from occurring between the screw hole of the adjusting nut and the male screw portion of the adjusting screw, or damage such as wear to these both members.

FIG. 1 is a sectional view showing a first example of an embodiment of the present invention. FIG. 2 is an exploded perspective view showing the internal mechanism of FIG. FIG. 3 is a perspective view showing the assembled boosting unit and boosting ratio conversion unit shown in FIG. FIGS. 4A and 4B are views in the direction of the arrow X in FIG. 3 showing a state (A) and a state (B) in which the boosting ratio is small, with the support plate member omitted. FIGS. 5A and 5B are schematic views showing a change state of the force increase ratio accompanying the displacement of the roller as the fulcrum member. FIG. 6 is a diagram showing the relationship between the control input torque T and the pressing axial force P in the structure of the embodiment of the present invention and the conventional structure. FIG. 7 is an enlarged cross-sectional view corresponding to a Y portion of FIG. 1 showing a second example of the embodiment of the present invention. FIG. 8 is a sectional view showing an example of a conventional structure.

[First example of embodiment]
1 to 5 show a first example of an embodiment of the present invention corresponding to the above configurations (1) to (6). The electric disc brake device of the first example is characterized in that the output shaft 9a of the electric motor 8a constituting the electric actuator and the pressing piece 19 that presses the inner pad 2 toward the rotor 1 (see FIG. 8). The press unit 20, the disc spring 21, which is a spring, the force-increasing unit 22, and the force-increasing-ratio converting unit 23 are provided. In the case of the first example, by adopting a configuration having such a feature, the structure can be made compact. At the start of braking, the

linings

18 and 18 of the both sides of the rotor 1 and the inner pad 2 and the outer pad 3 are provided. The gap existing between the two friction surfaces is quickly filled, and then the friction surfaces of both the

linings

18 and 18 are strongly pressed against both side surfaces of the rotor 1 to realize a structure capable of generating a large braking force. . Since the structure and operation of other parts are the same as those conventionally known including the structure shown in FIG. 8 described above, the overlapping description will be omitted or simplified. The description will focus on the features of the example. In the following description of the embodiment, the left end side in FIGS. 1 to 3 that is the end closer to the rotor 1 is the front end, and the right end in FIGS. 1 to 3 that is the opposite end is the base end. .

In the case of the first example, the inner surface of the cylinder space 6a provided in the caliper 4a is covered with the holding case 24. Then, inside the holding case 24, in order from the back side (base end side) of the cylinder space 6a, a thrust needle bearing 25 as a thrust bearing and a boost ratio converting sleeve 27 provided with a support plate portion 26. And a plurality (three in the illustrated example) of

rollers

28, 28, the same number of

levers

29, 29 as each of the

rollers

28, 28, a pressing plate 30, an adjusting nut 31, The anchor plate 32 which is a member to be pressed, the disc spring 21, the locking plate 33, and the adjustment screw 34 are assembled. The pressing piece 19 is installed in the opening of the cylinder space 6a so as to be axially displaceable. Based on the rotation of the output shaft 9a of the electric motor 8a, the pressing piece 19 is displaced in the axial direction so that braking and release thereof are possible. The pressing piece 19 is a member corresponding to a piston of a general disc brake device. However, in the case of the first example, the outer diameter of the pressing piece 19 is sufficiently smaller than the inner diameter of the cylinder space 6a. In the case of the first example, the pressing piece 19 is prevented from rotating via an adjusting screw 34 described below.

The pressing unit 20 includes the adjusting screw 34, the adjusting nut 31, and the pressing plate 30.
Of these, the adjusting screw 34 has a truncated cone-shaped head portion 35 provided at the distal end portion thereof and a recessed portion 36 in which the rear half portion provided on the proximal end side surface of the pressing piece 19 has a partially conical concave shape. The conical convex surface and the conical concave surface are brought into close contact with each other, and the retaining ring 37 prevents the concavity from coming off. In this state, the adjusting screw 34 and the pressing piece 19 are combined so as to be concentric with each other and inadvertently rotate relatively. A base end portion from the middle portion of the adjustment screw 34 is a male screw portion 38.

The adjustment nut 31 is provided with a screw hole 39 that is screwed with the male screw portion 38 of the adjustment screw 34 at the center, and an outward flange-shaped flange portion 40 is provided on the outer peripheral surface of the tip portion.
Further, the pressing plate 30 is formed of a metal plate having sufficient strength and rigidity, and is formed in a substantially clover shape (substantially screw propeller shape) as a whole. The substantially

U-shaped notches

42 and 42 are provided at a plurality of circumferentially equidistant positions. The inner diameter of the circular hole 41 is slightly larger than the outer diameter of the portion of the adjustment nut 31 excluding the flange 40, and is sufficiently smaller than the outer diameter of the flange 40.

In order to constitute the pressing unit 20, the male screw portion 38 of the adjusting screw 34 is screwed into the screw hole 39 of the adjusting nut 31, and the pressing plate 30 is externally fitted to the adjusting nut 31. The distal end side surface of the plate 30 and the proximal end side surface of the flange portion 40 are brought into contact with each other. In this state, the displacement of the pressing plate 30 in the distal direction becomes the pressing unit 20 that is transmitted to the pressing piece 19 through the adjusting nut 31 and the adjusting screw 34. The base end portion of the adjustment nut 31 is held at the central portion of the boost ratio converting sleeve 27 so that it can be rotated and slightly displaced in the axial direction.
Then, the elastic force of the disc spring 21 is transmitted to the pressing plate 30 via the boosting unit 22, and the pressing piece 19 is pressed toward the rotor 1 based on the elastic force of the disc spring 21. Like.

The disc spring 21 is elastically compressed in the axial direction between the anchor plate 32 and the locking plate 33, and has a repulsive force (elasticity, thrust) required to obtain a braking force to be described later. Force). For this reason, the locking plate 33 as a fixed portion is supported inside the end of the holding case 24 close to the opening in a state where displacement in the direction of coming out of the holding case 24 (direction toward the front end side) is prevented. Has been. The supporting strength of the locking plate 33 with respect to the holding case 24 is sufficiently larger than the maximum value of the elasticity of the disc spring 21 so that the locking plate 33 does not come out of the holding case 24. It is configured like this. For this purpose, means for securing the necessary support strength, such as welding or caulking, with respect to the holding case 24 when the parts to be stored in the holding case 24 are stored. By the above, the coupling is fixed. Further, in the illustrated example, a protrusion 44 is formed on the inner peripheral surface of the center hole 43 provided for the insertion of the adjustment screw 34, and the protrusion 44 and a part of the adjustment screw 34 are axially formed. The formed guide groove (not shown) is engaged to prevent the adjustment screw 34 from rotating. With the above configuration, the anchor plate 32 is elastically pressed toward the base end side (the back side of the holding case 24) by the elasticity of the disc spring 21. The holding case 24 is fitted and fixed in the cylinder space 6a by an interference fit in a state where the respective parts are accommodated. Further, if necessary, a retaining ring formed on the inner peripheral surface of the opening of the cylinder space 6a prevents the cylinder space 6a from coming off.

The booster unit 22 includes the anchor plate 32, the

levers

29 and 29, the

rollers

28 and 28, and the support plate portion 26 of the boost ratio conversion sleeve 27. . Then, the elastic force applied to the anchor plate 32 as described above is transmitted to the pressing plate 30 after being increased at least at the final stage of the braking operation, and the pressing plate 30 is moved to the tip side (from the holding case 24). Pressed in the direction of exit). The anchor plate 32 has

anchor projections

46 and 46 each having a substantially U-shape at a plurality of circumferentially equidistant positions (three in the illustrated example) on the inner peripheral surface of the cylindrical holding cylinder 45. Locking

ridges

47, 47 that are long in the axial direction are formed at a plurality of locations (three locations in the example shown in the drawing) at equal intervals in the circumferential direction of the outer peripheral surface. The anchor protrusions 46 and 46 are engaged with the

notches

42 and 42 of the pressing plate 30 so as not to rattle, and the axial displacement of the pressing plate 30 is allowed. Further, the locking

protrusions

47, 47 are formed at a plurality of positions (three positions in the illustrated example) at equal intervals in the circumferential direction of the holding case 24, and the locking

notches

48, 48 each having a slit shape. Is engaged. Accordingly, the anchor plate 32 is held in the holding case 24 in a state in which the anchor plate 32 is prevented from rotating so that it can be displaced in the axial direction based on the elasticity of the disc spring 21.

The

levers

29 and 29 are provided in the same number as the anchor protrusions 46 and 46 (three in the illustrated example), and each has a thickness sufficient to ensure sufficient strength and rigidity. The shape seen from the axial direction is a partial arc shape. Further, at one end in the circumferential direction of the tip side surface of each of the

levers

29, 29, each is a partially spherical convex surface, and

projections

49, 49 serving as swing fulcrums are formed. In addition, holding

concave portions

50 and 50 each having a partial spherical concave surface are formed at the other circumferential end of the side surface of the tip. The

protrusions

49 and 49 are in contact with the base end surfaces of the anchor protrusions 46 and 46 of the anchor plate 32. Further, the tips of the

balls

51 and 51 whose base ends are in contact with the inner surfaces of the holding recesses 50 and 50 are in contact with the receiving recesses 52 formed on the base side surface of the pressing plate 30. Has been.

Furthermore, the end portions on the front end side of the rolling surfaces of the

rollers

28 and 28 are in contact (rolling contact) with the circumferential intermediate portions of the base end side surfaces of the

levers

29 and 29, respectively. These

rollers

28 and 28 are arranged in the radial direction in a state in which they are rotatably held in the pockets of the cage 53. In this state, the base end side end portion of the rolling surface of each of the

rollers

28 and 28 is in rolling contact with the front end side surface of the support plate portion 26. The

levers

29 and 29 are oscillated and displaced with the

rollers

28 and 28 as fulcrums, and the elastic force (thrust force) input from the disc spring 21 through the anchor plate 32 is applied to the pressing plate 30. The pressure plate 30 is transmitted and is configured to be pressed toward the tip side. The thrust force applied to the pressing plate 30 is such that the

rollers

28, 28 roll in the circumferential direction along the

levers

29, 29, and serve as swing fulcrums of the

levers

29, 29. , 28 is changed by changing the circumferential position. Note that, regardless of the position of the

rollers

28, 28, the rolling surfaces of the

rollers

28, 28, the proximal side surfaces of the

levers

29, 29, and the distal side surface of the support plate portion 26 In order to prevent an excessive surface pressure based on the edge load from acting on the contact portion, appropriate rolling is applied to the rolling surfaces of the

rollers

28 and 28. Alternatively, spherical rollers can be used as the

rollers

28 and 28.

The boost ratio conversion unit 23 is for the circumferential position of the

rollers

28 and 28 to change synchronously with respect to the

levers

29 and 29. In addition to the

rollers

28 and 28 and the cage 53, The thrust needle bearing 25 and the boost ratio converting sleeve 27 are provided. The increase ratio conversion sleeve 27 is formed in a state where a support cylindrical portion 54 protrudes toward the base end side on the inner peripheral edge of the support plate portion 26 having an annular shape. The support plate portion 26 is abutted against an annular end plate 55 constituting the holding case 24 via the thrust needle bearing 25. The support cylindrical portion 54 is inserted through an inner diameter side of the back end plate 55 and a circular through hole 57 formed in the back end wall 56 of the caliper 4a. And the base end part of the said support cylindrical part 54 protrudes from the base end surface of the said caliper 4a.

When the boost ratio converting sleeve 27 is rotated, the

rollers

28, 28 are arranged between the support plate portion 26 and the base end side surfaces of the

levers

29, 29. Rolled. For example, as shown in FIG. 3 and FIG. 4A and FIG. 5A, the rollers 28 are connected to the

protrusions

49, 49 at one end in the circumferential direction of the

levers

29, 29, respectively. If it is located on the side close to, the increase ratio by these

levers

29, 29 becomes small (a value less than 1). On the other hand, with the rotation of the support plate portion 26, the

rollers

28, 28 are closer to the side where the

balls

51, 51 are provided at the other circumferential end of the

levers

29, 29. When positioned, the force increase ratio by the

levers

29 and 29 increases. And the thrust force which presses the said adjustment nut 31 by the said press board 30 based on the elasticity of the said disk spring 21 becomes large because this force increase ratio becomes large.

In the case of the first example, the adjustment nut 31 of the pressing unit 20 and the boost ratio conversion sleeve 27 of the boost ratio conversion unit 23 are rotationally driven by the output shaft 9a of the electric motor 8a. Therefore, a planetary gear type transmission 58 is provided between the

members

9a, 31, 27. The planetary gear type transmission 58 includes a sun gear 59 and a ring gear 60 arranged concentrically with each other, and a plurality of

planetary gears

61 and 61. Each of the

planetary gears

61 and 61 is rotatably supported by the carrier 62 in a state where the

planetary gears

61 and 61 are arranged at equal intervals in the circumferential direction between the sun gear 59 and the ring gear 60. 59 and the ring gear 60 are engaged.

The sun gear 59 can be rotationally driven via the power transmission mechanism 63 by the output shaft 9a of the electric motor 8a. As the power transmission mechanism 63, a general belt transmission mechanism or a gear transmission mechanism can be adopted. Further, a coupling cylinder portion 64 provided concentrically with the ring gear 60 is provided at the distal end portion of the ring gear 60 so that torque can be transmitted to the outer peripheral surface of the base end portion of the support cylindrical portion 54 by serration engagement or the like. It is fitted. As the ring gear 60 rotates, the boost ratio converting sleeve 27 can be driven to rotate.
Further, a center shaft 65 projecting from the front end side center portion of the carrier 62 is serrated and engaged with a serration hole 66 provided in the base end portion of the adjustment nut 31. The adjustment nut 31 can be rotationally driven by the carrier 62.

Furthermore, a resistance mechanism 67 is provided in a state of being opposed to the outer peripheral surface of the ring gear 60. The resistance mechanism 67 provides resistance against the rotation of the ring gear 60. For example, a friction resistance member such as a spring element or a friction pad can be used. The resistance applied to the ring gear 60 by the resistance mechanism 67 is to prevent the ring gear 60 from rotating while the torque required to rotate the adjustment nut 31 by the carrier 62 is small. When this torque increases, the ring gear 60 is set to a size that allows rotation.

Specifically, the adjustment nut 31 is rotated in the process in which the rotor 1 is clamped by the inner pad 2 and the outer pad 3 and a braking force is generated based on energization of the electric motor 8a, and the adjustment screw 34 Is pushed out of the adjusting nut 31 until the

linings

18 and 18 of the inner pad 2 and the outer pad 3 are pressed against both side surfaces of the rotor 1, so that the ring gear 60 is prevented from rotating. In contrast, the

linings

18 and 18 of the inner pad 2 and the outer pad 3 are pressed against both side surfaces of the rotor 1, and the torque required to rotate the adjustment nut 31 to push out the adjustment screw 34 is large. In this case, the ring gear 60 is allowed to rotate.

The electric disc brake device of the first example configured as described above operates as follows, and the

linings

18 and 18 of the inner pad 2 and the outer pad 3 are pressed against both side surfaces of the rotor 1 to perform braking. Is done.
During non-braking, a gap exists between the

linings

18 and 18 of the inner pad 2 and the outer pad 3 and both side surfaces in the axial direction of the rotor 1. From this state, the electric motor 8a is energized to perform braking, and the sun gear 59 of the planetary gear type transmission 58 is rotated in a predetermined direction via the power transmission mechanism 63. In this state, the ring gear 60 constituting the planetary gear type transmission 58 does not rotate based on the resistance applied by the resistance mechanism 67. As a result, the

planetary gears

61 and 61 meshed with the ring gear 60 and the sun gear 59 revolve around the sun gear 59 while rotating. Of these, the revolving motion is transmitted to the adjustment nut 31 via the carrier 62, and the adjustment nut 31 rotates in a predetermined direction. Along with this rotation, the adjustment screw 34 is displaced in the direction of being pushed out from the cylinder space 6 a based on the screw engagement between the male screw portion 38 and the screw hole 39. As a result, the inner pad 2 is pressed against the inner side surface of the rotor 1 by the pressing piece 19, and the caliper 4 a is displaced toward the inner side, and the caliper claw 5 causes the outer pad 3 to be moved to the outer side of the rotor 1. Press against the side.

Thus, while the gap between the

linings

18 and 18 and the both side surfaces of the rotor 1 in the axial direction is eliminated, the boosting unit 22 and the boost ratio conversion unit 23 do not particularly function. That is, in the process of eliminating the gap, the

rollers

28 and 28 are moved at the circumferential ends of the

levers

29 and 29 as shown in FIG. 4A and FIG. It remains in the state that exists in the vicinity of each

protrusion

49, 49. For this reason, these

levers

29 and 29 do not increase the elasticity of the disc spring 21 and transmit it to the pressing plate 30. The speed at which the clearance is eliminated is determined by the reduction ratio of the power transmission mechanism 63 and the planetary gear type transmission 58 and the lead angles of the male screw portion 38 and the screw hole 39. Since the force required to eliminate the gap is small, it is not necessary to particularly increase the reduction ratio or particularly reduce the lead angle. As a result, the gap can be quickly eliminated and responsiveness can be improved.

When the gap is eliminated, the torque required to rotate the adjustment nut 31 increases so that the adjustment screw 34 is pushed out of the cylinder space 6a. As the torque increases, the rotational speed of the carrier 62 gradually decreases, and eventually the carrier 62 does not rotate. Then, the rotation of the sun gear 59 is transmitted to the ring gear 60 through the

planetary gears

61 and 61, and the ring gear 60 starts to rotate against the resistance by the resistance mechanism 67. Then, the ring gear 60 rotates the boost ratio conversion sleeve 27 in a predetermined direction (counterclockwise in FIGS. 4A and 4B).

As the force increase ratio conversion sleeve 27 rotates, the

rollers

28, 28 move between the front end side surface of the support plate portion 26 of the force increase ratio conversion sleeve 27 and the base end side surfaces of the

levers

29, 29. Roll between. Then, from the state shown in FIG. 4A and FIG. 5A to the state shown in FIG. 4B and FIG. It moves toward the portion where the balls 51 are in contact with each other at the other end in the direction. When the

levers

29 and 29 transmit the elasticity of the disc spring 21 to the pressing plate 30, the degree to which the elasticity is increased depends on the rolling surfaces of the

rollers

28 and 28 and the levers 29. , 29, and the length of the input side span, which is the distance between the

protrusion

49, 49 on the input side of each

lever

29, 29, and the contact portion with the base end side surface of each

lever

29, 29 increases. Contact portions between the rolling surfaces of the

rollers

28 and 28 and the base end side surfaces of the

levers

29 and 29, the holding recesses 50 and 50 and the balls 51 and the output side of the

levers

29 and 29, respectively. As the output-side span, which is the distance from the center of the contact portion with 51, becomes shorter, it becomes larger.

As described above, as the force increase ratio converting sleeve 27 rotates, the

rollers

28, 28 move toward the other circumferential end of the

levers

29, 29, so that the input side span is increased. Is longer and the output-side span is shorter. The elastic force of the disc spring 21 is transmitted to the pressing plate 30 as the

levers

29 and 29 are pivoted and displaced with the

rollers

28 and 28 as fulcrums. The pressing plate 30 presses the inner pad 2 against the inner side surface of the rotor 1 through the adjusting nut 31, the adjusting screw 34, and the pressing piece 19. In this state, the force increasing ratio of the force increasing unit 22 increases as the

rollers

28 and 28 roll. Therefore, the force by which the pressing piece 19 presses the inner pad 2 against the inner surface in the axial direction of the rotor 1 can be sufficiently increased, and a sufficient braking force can be obtained.

When releasing the brake, the sun gear 59 is rotated in a direction opposite to the predetermined direction based on energization of the electric motor 8a. Then, each part is displaced in the direction opposite to that at the time of braking described above, and the pressing piece 19 is retracted from the rotor 1. As a result, gaps exist between the

linings

18 and 18 of the inner pad 2 and the outer pad 3 and both axial side surfaces of the rotor 1.

In the case of the electric actuator of the first example configured as described above and acting as described above, the pressing unit 20, the plate spring 21, the booster unit 22, and the boost ratio conversion The units 23 are each configured in a ring shape or a cylindrical shape, and can be arranged coaxially. Then, a state in which these parts are assembled in the holding case 24 (sub-assembled state) is assembled in the cylinder space 6a of the carrier 4a. Therefore, the electric actuator can be configured in a small size and can be easily assembled.

Further, at the start of braking, until the gap between the

linings

18 and 18 of the inner pad 2 and the outer pad 3 and both side surfaces in the axial direction of the rotor 1 is eliminated, the boosting unit 22 and the boost ratio conversion are performed. Only when the unit 23 is not operated and a large braking force is generated, the force-increasing unit 22 and the force-increasing ratio converting unit 23 are operated. For this reason, the time required until the braking force is generated can be shortened. Further, a sufficiently large braking force can be obtained without particularly increasing the output of the electric motor 8a. For example, in the case of an electric disc brake device using a simple actuator, as shown by a broken line α in FIG. 6, in order to obtain a large pressing axial force (P) in order to obtain a large braking force, an electric motor Output torque (control input torque (T)) must be increased. On the other hand, according to the structure of the first example, a large pressing axial force (P) can be obtained even with a relatively small control input torque (T) as indicated by a solid line β in FIG. That is, as the resistance mechanism 67 is provided, the pressing shaft force starts to increase after the control input torque (T) increases to some extent, but when it starts to increase, the pressing shaft force increases rapidly. The control input torque (T) required for obtaining the force (P) can be kept low.

[Second Example of Embodiment]
FIG. 7 shows a second example of an embodiment of the present invention corresponding to the configurations (1) to (8). In the case of the second example, in order to prevent the adjustment nut 31 from rattling in the cylinder space 6a (see FIG. 1) when the electric disc brake device is not braked, the flange 40 and the locking plate of the adjustment nut 31 are prevented. A compression coil spring 68, which is an elastic member, is provided between 33a and 33a. For this purpose, a step portion 69 is provided near the inner diameter portion of the locking plate 33a, and one end portion (left end portion in FIG. 7) of the compression coil spring 68 is abutted against the step portion 69. An annular thrust bearing 70 is provided between the other end portion (right end portion in FIG. 7) of the compression coil spring 68 and the flange portion 40. As such a thrust bearing 70, a sliding bearing made of a synthetic resin material having a low friction coefficient such as polyamide resin or polytetrafluoroethylene resin, or a metal material having a low friction coefficient such as a contained metal or a copper-based alloy is used. Can be used. Alternatively, a thrust rolling bearing such as a thrust needle bearing can be used as the thrust bearing 70.

In the case of the second example, since the compression coil spring 68 elastically presses the adjustment nut 31 toward the base end side, the adjustment nut 31 rattles in the cylinder space 6a during non-braking. Can be prevented. As a result, it is possible to prevent a collision sound from being generated between the screw hole 39 of the adjustment nut 31 and the male screw portion 38 of the adjustment screw 34, or damage such as wear to the both

members

31 and 34. . Note that the pressing force by the compression coil spring 68 is made as small as possible to prevent rattling of the adjustment nut 31 during non-braking.
In the case of the structure of the second example, the friction coefficient between the two

members

68, 31 is set between the other end of the compression coil spring 68 and the flange 40 of the adjustment nut 31. A thrust bearing 70 is provided to keep it low. For this reason, at the time of braking (when the adjusting nut 31 is rotated), a large power loss does not occur based on the frictional resistance between the

members

68 and 31. As a result, it is possible to prevent the time required for generating the braking force from increasing and the power consumption of the electric motor 8a (see FIG. 1) from increasing. Instead of providing the thrust bearing 70, a lubricant such as grease may be interposed between the other end portion of the compression coil spring 68 and the flange portion 40 of the adjustment nut 31.
Since the configuration and operation of the other parts are the same as in the first example of the embodiment described above, overlapping illustrations and descriptions are omitted.

Here, the features of the embodiment of the electric disc brake device according to the present invention described above will be briefly summarized below.
[1] A rotor 1 that rotates together with wheels;
A pad support (support) supported by the vehicle body in a state adjacent to the rotor 1;
A pair of pads (inner pad and outer pad) 2 and 3 on the outer side and the inner side supported by the pad support portion (support) so as to be capable of displacement in the axial direction with the rotor 1 sandwiched from both sides in the axial direction; ,
The cylinder space 6a provided in a portion facing at least one of the pads (inner pad and outer pad) 2 and 3 (inner pad) 2 is provided so that the rotor 1 can be displaced in the axial direction. Pressing piece 19;
The pad 19 (inner pad and outer pad) 2 and 3 is pressed against both axial sides of the rotor 1 by displacing the pressing piece 19 in the direction of being pushed out of the cylinder space 6a using the electric motor 8a as a driving source. An electric disc brake device comprising an electric actuator,
The electric actuator includes the electric motor 8a, a pressing unit 20 that is concentrically disposed in the cylinder space 6a, a spring (plate spring) 21, a boosting unit 22, and a boosting ratio conversion unit 23. Have
In the electric motor 8a, the output shaft 9a is rotated in both directions based on energization,
The pressing unit 20 is displaced in a direction protruding from the cylinder space 6 a based on the rotation of the output shaft 9 a, and the one pad (inner pad) 2 facing the opening of the cylinder space 6 a is the rotor 1. Is pressed against the axial side surface of
The spring (between plate spring) 21 has one axial end abutting against a fixed portion (locking plate) 33 on the inner surface of the cylinder space 6 a and the other axial end is the configuration of the pressing unit 20. The member is an output unit that applies a force in a direction in which the member is displaced in a direction protruding from the cylinder space 6a.
The intensifying unit 22 is intermittently arranged in the circumferential direction, and a plurality of levers 29 swingingly displaced with the respective circumferential intermediate portions as fulcrums, and fulcrums that respectively contact the circumferential intermediate portions of the levers 29. A member (roller) 28; and a support plate member (cage) 53 for supporting each fulcrum member (roller) 28 on the opposite side of each lever 29 in the axial direction, and one end in the circumferential direction of each lever 29 The portion is engaged with a pressed member (anchor plate) 32 that is pressed by the output portion of the spring (dish plate spring) 21 so as to be swingable and displaceable. By being engaged with the (ball) 51 so as to be able to swing and displace, the pressing unit 20 moves away from the cylinder space 6a as the levers 29 swing and displace based on the elasticity of the spring (disc spring) 21. Is intended to be displaced in a direction out,
The force increase ratio conversion unit 23 is configured so that the fulcrum members (rollers) 28 are displaced in the circumferential direction of the levers 29, so that the fulcrum members (rollers) 28 and the levers 29 are input in the circumferential direction. Elasticity of the spring (between plate springs) 21 determined by the ratio between the distance to one end and the distance between each fulcrum member (roller) 28 and the other end in the circumferential direction on the output side of each lever 29 And a power increasing ratio that is a ratio of the force that displaces the pressing unit 20 in the direction in which the pressing unit 20 protrudes from the cylinder space 6a based on the elasticity of the spring (plate spring) 21 changes. Brake device.
[2] An electric disc brake device configured as described in [1] above,
A locking plate 33 is supported inside the end of the cylinder space 6a near the opening while being prevented from being displaced in the direction of exiting the cylinder space 6a.
An anchor plate 32 that is a pressed member of the booster unit 22 can be displaced in the axial direction at an intermediate portion in the axial direction of the cylinder space 6a while being prevented from rotating in the cylinder space 6a. It is provided in
An electric disc brake device in which a disc spring 21 as a spring is sandwiched between the locking plate 33 and the anchor plate 32.
[3] An electric disc brake device configured as described in [1] or [2] above,
Each fulcrum member is a cylindrical roller 28, and each roller 28 is rotatably held in a plurality of pockets provided in a radial direction in a cage 53,
The portion of each lever 29 with which the peripheral surface of each roller 28 abuts is a flat bearing surface,
Each of the rollers 28 is provided between the bearing surface and one axial surface of the support plate portion 26 constituting the force increase ratio conversion unit 23,
The support plate portion 26 is rotatably supported by a thrust bearing (thrust needle bearing) 25 provided between the other surface in the axial direction and the back end surface of the cylinder space 6a at the back end portion of the cylinder space 6a. Electric disc brake device.
[4] An electric disc brake device configured as described in [1] above,
The pressing unit 20 includes an adjusting screw 34, an adjusting nut 31, and a pressing plate 30;
The adjustment screw 34 has a distal end portion (head) 35 engaged with the proximal side surface of the pressing piece 19 and a proximal end portion from the middle portion to the male screw portion 38, and is prevented from rotating. Provided in the cylinder space 6a so that axial displacement is possible in the
The adjustment nut 31 is provided with a screw hole 39 that is screwed with the male screw portion 38 at the center, and an outward flange-shaped flange portion 40 is provided on the outer peripheral surface of the tip portion.
The pressing plate 30 has an annular shape, and one end in the circumferential direction of each lever 29 is in contact with a plurality of positions in the circumferential direction on one side in the axial direction that is the back end surface side of the cylinder space 6a on both sides in the axial direction. The inner peripheral edge portion of the other surface in the axial direction is engaged with the flange portion 40, and the force in the direction protruding from the cylinder space 6a applied with the swing displacement of each lever 29 is applied to the adjustment nut 31. Electric disc brake device that can be transmitted to
[5] An electric disc brake device configured as described in [2] above,
The pressing unit 20 includes an adjusting screw 34, an adjusting nut 31, and a pressing plate 30;
The adjustment screw 34 has a distal end portion (head) 35 engaged with the proximal side surface of the pressing piece 19 and a proximal end portion from the middle portion to the male screw portion 38, and is prevented from rotating. Provided in the cylinder space 6a so that axial displacement is possible in the
The adjustment nut 31 is provided with a screw hole 39 that is screwed with the male screw portion 38 at the center, and an outward flange-shaped flange portion 40 is provided on the outer peripheral surface of the tip portion.
The pressing plate 30 has an annular shape, and one end in the circumferential direction of each lever 29 is in contact with a plurality of positions in the circumferential direction on one side in the axial direction that is the back end surface side of the cylinder space 6a on both sides in the axial direction. The inner peripheral edge portion of the other surface in the axial direction is engaged with the flange portion 40, and the force in the direction protruding from the cylinder space 6a applied with the swing displacement of each lever 29 is applied to the adjustment nut 31. Electric disc brake device that can be transmitted to
[6] An electric disc brake device configured as described in [3] above,
The pressing unit 20 includes an adjusting screw 34, an adjusting nut 31, and a pressing plate 30;
The adjustment screw 34 has a distal end portion (head) 35 engaged with the proximal side surface of the pressing piece 19 and a proximal end portion from the middle portion to the male screw portion 38, and is prevented from rotating. Provided in the cylinder space 6a so that axial displacement is possible in the
The adjustment nut 31 is provided with a screw hole 39 that is screwed with the male screw portion 38 at the center, and an outward flange-shaped flange portion 40 is provided on the outer peripheral surface of the tip portion.
The pressing plate 30 has an annular shape, and one end in the circumferential direction of each lever 29 is in contact with a plurality of positions in the circumferential direction on one side in the axial direction that is the back end surface side of the cylinder space 6a on both sides in the axial direction. The inner peripheral edge portion of the other surface in the axial direction is engaged with the flange portion 40, and the force in the direction protruding from the cylinder space 6a applied with the swing displacement of each lever 29 is applied to the adjustment nut 31. Electric disc brake device that can be transmitted to
[7] An electric disc brake device having the configuration of [6] above,
A planetary gear type transmission 58 is provided between the output shaft 9a of the electric motor 8a, the support plate portion 26 and the adjustment nut 31.
The sun gear 59 of the planetary gear type transmission 58 is rotationally driven by the output shaft 9 a, and the support plate portion 26 is also rotationally driven by the ring gear 60, which mesh with the sun gear 59 and the ring gear 60, respectively. An electric disc brake device in which the adjusting nut 31 is rotationally driven by a carrier 62 supporting a plurality of planetary gears 61.
[8] An electric disc brake device configured as described in [7] above,
A resistance mechanism 67 is provided to provide a resistance against the rotation of the ring gear 60, and the rotor 1 is sandwiched between the pads (inner pads and outer pads) 2 and 3 based on energization of the electric motor 8a. In the process of generating braking force,
Based on the resistance force applied to the ring gear 60 by the resistance mechanism 67, the clearance between the pressing surfaces of the pads (inner pads and outer pads) 2, 3 and both side surfaces in the axial direction of the rotor 1 is eliminated. Until the sun gear 59 rotates, the ring gear 60 is not rotated and the carrier 62 is rotated.
The electric disc brake device in which the ring gear 60 is rotated after the clearance is eliminated and the pressing surfaces of the two pads (inner pads and outer pads) 2 and 3 are pressed against both side surfaces of the rotor 1 in the axial direction. .
[9] An electric disc brake device configured as described in [5] above,
An elastic member (compression coil spring) 68 is provided between the locking plate 33a and the flange portion 40 of the adjustment nut 31.
An electric disc brake device in which the adjustment nut 31 is prevented from rattling with respect to the cylinder space 6a during non-braking.
[10] An electric disc brake device configured as described in [9] above,
One end of the elastic member (compression coil spring) 68 is abutted against one member (locking plate) 33a of the locking plate 33a and the flange portion 40 of the adjustment nut 31.
Similarly, an electric disc brake device in which a thrust bearing 70 is provided in a portion between the other member (the flange portion) 40 and the other end portion of the elastic member (compression coil spring) 68.

The electric disc brake device of the present invention is not limited to the above-described embodiment, and can be appropriately modified and improved. In addition, the material, shape, dimensions, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.
This application is based on a Japanese patent application filed on August 9, 2012 (Japanese Patent Application No. 2012-177149) and a Japanese patent application filed on December 5, 2012 (Japanese Patent Application No. 2012-265955). The contents are incorporated herein by reference.

The structure of the present invention is such that the electric motor can be shared among a plurality of pressing pieces, but a booster unit, a boost ratio conversion unit, etc. are required for each pressing piece, etc. Compared to the device, the volume of the device portion that drives the pressing piece increases. Therefore, it is preferable to use a floating caliper type disc brake that requires only a small number of pressing pieces and can easily secure a space for the pressing piece installation portion. However, if it is possible to secure an installation space, such as for a large automobile, it is possible to use an opposed piston type disc brake.

1 Rotor 2 Inner pad (pad)
3 Outer pad (pad)
4, 4a Caliper 5 Caliper claw 6, 6a Cylinder space 7

Thrust generator

8,

8a Electric motor

9, 9a Output shaft 10 Reducer 11 Piston 12 Feed screw device 13 Drive side rotor 14 Drive side lamp groove 15 Drive side stator 16 Drive side lamp groove 17 Ball 18 Lining 19 Pressing piece 20 Pressing unit 21 Belleville spring (spring)
22 Boosting Unit 23 Boosting Ratio Conversion Unit 24 Holding Case 25 Thrust Needle Bearing (Thrust Bearing)
26 Support plate portion 27 Boosting ratio conversion sleeve 28 Roller (fulcrum member)
29 Lever 30 Pressing plate 31 Adjustment nut 32 Anchor plate (member to be pressed)
33, 33a Locking plate (fixed part)
34 Adjustment screw 35 Head 36 Recess 37 Retaining ring 38 Male thread part 39 Screw hole 40 Gutter part 41 Circular hole 42 Notch part 43 Center hole 44 Protrusion 45 Holding cylinder part 46 Anchor protrusion 47 Locking protrusion 48 Locking cut Notch 49 Projection 50 Holding recess 51 Ball 52 Receiving recess 53 Cage (support plate member)
54 support cylindrical portion 55 back end plate 56 back end wall 57 through hole 58 planetary gear type transmission 59 sun gear 60 ring gear 61 planetary gear 62 carrier 63 power transmission mechanism 64 coupling cylinder portion 65 central shaft 66 serration hole 67 resistance mechanism 68 Compression coil spring (elastic member)
69 Stepped portion 70 Thrust bearing

Claims

A rotor that rotates with the wheels;
A pad support portion supported by the vehicle body in a state adjacent to the rotor;
A pair of pads on the outer side and the inner side supported by the pad support portion so as to be capable of displacement in the axial direction with the rotor sandwiched from both sides in the axial direction,
A pressing piece provided in a cylinder space provided in a portion facing at least one of the two pads so as to be capable of displacement in the axial direction of the rotor;
An electric disc brake device comprising: an electric actuator that uses the electric motor as a drive source to displace the pressing piece in a direction in which the pressing piece is pushed out of the cylinder space, so that the two pads are pressed against both axial sides of the rotor. Because
The electric actuator includes the electric motor, a pressing unit disposed concentrically in the cylinder space, a spring, a boosting unit, and a boosting ratio conversion unit.
In the electric motor, the output shaft is rotated in both directions based on energization,
The pressing unit is displaced in a direction protruding from the cylinder space based on the rotation of the output shaft, and the one pad facing the opening of the cylinder space is pressed against the axial side surface of the rotor. Yes,
In the spring, one end in the axial direction is brought into contact with a fixed portion on the inner surface of the cylinder space, and the other end in the axial direction is displaced in a direction in which the constituent member of the pressing unit protrudes from the cylinder space. It is an output part that gives the power of
The boosting unit is intermittently arranged in the circumferential direction, and a plurality of levers that are oscillated and displaced with each circumferential intermediate portion serving as a fulcrum, and a fulcrum member that abuts each circumferential intermediate portion of each lever; A support plate member for supporting each fulcrum member on the opposite side to each lever with respect to the axial direction, and one end in the circumferential direction of each lever is oscillating and displaced to a pressed member pressed by the output portion of the spring The other end portion is also engaged with a part of the constituent member of the pressing unit so as to be able to swing and displace, so that the lever is swung in accordance with the elastic force of the spring. The pressing unit is displaced in a direction protruding from the cylinder space;
The force increase ratio conversion unit is configured such that each fulcrum member is displaced in the circumferential direction of each lever, whereby the distance between each fulcrum member and one circumferential end on the input side of each lever, and each fulcrum member And the elastic force of the spring determined by the ratio of the distance between the lever and the other end in the circumferential direction on the output side of the lever, and the pressing unit is displaced in the direction protruding from the cylinder space based on the elastic force of the spring. An electric disc brake device in which an increase ratio, which is a ratio to the magnitude of the force to be changed, changes.
A locking plate is supported on the inner side of the cylinder space near the opening in a state where displacement in the direction of exiting from the cylinder space is prevented.
An anchor plate, which is a member to be pressed by the booster unit, is provided at an intermediate portion in the axial direction of the cylinder space in a state in which rotation in the cylinder space is prevented and can be displaced in the axial direction. And
The electric disc brake device according to claim 1, wherein a disc spring, which is the spring, is sandwiched between the locking plate and the anchor plate.
Each fulcrum member is a cylindrical roller, and each roller is rotatably held in a plurality of pockets provided in a radial direction on the cage,
The portion where the peripheral surface of each roller in each lever abuts is a flat bearing surface,
Each of the rollers is provided between the bearing surface and one axial surface of the support plate portion that constitutes the boost ratio conversion unit,
The said support plate part is rotatably supported by the thrust bearing provided between the axial other surface and the back end surface of the said cylinder space at the back end part of the said cylinder space. The electric disc brake device described in 2.
The pressing unit includes an adjusting screw, an adjusting nut, and a pressing plate;
The adjustment screw has a distal end engaged with a proximal end side surface of the pressing piece, and a proximal end from the intermediate portion to a male screw, and can be displaced in the axial direction while being prevented from rotating. Provided in the cylinder space,
The adjustment nut is provided with a screw hole to be screwed with the male screw portion at the center, and an outward flange-shaped flange on the outer peripheral surface of the tip portion.
The pressing plate is annular, and one end in the circumferential direction of each lever is in contact with a plurality of circumferential positions on one axial side that is the back end face side of the cylinder space on both axial sides, and the axial direction The inner peripheral edge portion of the other surface is engaged with the flange portion, and the force in the direction protruding from the cylinder space applied along with the swinging displacement of each lever can be transmitted to the adjustment nut. The electric disc brake device according to claim 1.
The pressing unit includes an adjusting screw, an adjusting nut, and a pressing plate;
The adjustment screw has a distal end engaged with a proximal end side surface of the pressing piece, and a proximal end from the intermediate portion to a male screw, and can be displaced in the axial direction while being prevented from rotating. Provided in the cylinder space,
The adjustment nut is provided with a screw hole to be screwed with the male screw portion at the center, and an outward flange-shaped flange on the outer peripheral surface of the tip portion.
The pressing plate is annular, and one end in the circumferential direction of each lever is in contact with a plurality of circumferential positions on one axial side that is the back end face side of the cylinder space on both axial sides, and the axial direction The inner peripheral edge portion of the other surface is engaged with the flange portion, and the force in the direction protruding from the cylinder space applied along with the swinging displacement of each lever can be transmitted to the adjustment nut. The electric disc brake device according to claim 2.
The pressing unit includes an adjusting screw, an adjusting nut, and a pressing plate;
The adjustment screw has a distal end engaged with a proximal end side surface of the pressing piece, and a proximal end from the intermediate portion to a male screw, and can be displaced in the axial direction while being prevented from rotating. Provided in the cylinder space,
The adjustment nut is provided with a screw hole to be screwed with the male screw portion at the center, and an outward flange-shaped flange on the outer peripheral surface of the tip portion.
The pressing plate is annular, and one end in the circumferential direction of each lever is in contact with a plurality of circumferential positions on one axial side that is the back end face side of the cylinder space on both axial sides, and the axial direction The inner peripheral edge portion of the other surface is engaged with the flange portion, and the force in the direction protruding from the cylinder space applied along with the swinging displacement of each lever can be transmitted to the adjustment nut. The electric disc brake device according to claim 3.
A planetary gear type transmission is provided between the output shaft of the electric motor and the support plate portion and the adjustment nut,
A sun gear of the planetary gear type transmission is rotationally driven by the output shaft, and the support plate portion is also rotationally driven by the ring gear, and a plurality of planetary gears meshed with the sun gear and the ring gear, respectively. The electric disc brake device according to claim 6, wherein the adjusting nut is rotationally driven by a supported carrier.
In the process in which a resistance mechanism that provides resistance against the rotation of the ring gear is provided, and the rotor is clamped by the two pads based on energization of the electric motor, and braking force is generated,
Based on the resistance force applied to the ring gear by the resistance mechanism, the sun gear rotates until the clearance between the pressing surfaces of the pads and the both axial sides of the rotor is eliminated. Accordingly, the carrier is rotated without rotating the ring gear,
The electric disk brake device according to claim 7, wherein the ring gear is rotated after the clearance is eliminated and the pressing surfaces of the pads are pressed against both axial sides of the rotor.
An elastic member is provided between the locking plate and the flange of the adjustment nut,
The electric disc brake device according to claim 5, wherein the adjustment nut is prevented from rattling with respect to the cylinder space during non-braking.
One end of the elastic member is abutted against one member of the locking plate and the flange of the adjustment nut,
The electric disc brake device according to claim 9, wherein a thrust bearing is provided between the other member and the other end of the elastic member.