WO2017221939A1 - Electric brake apparatus - Google Patents

Abstract

This electric brake apparatus is configured to have: an electric motor (10); a rotary shaft (23) that rotates about the axis thereof by means of the rotary driving force of the electric motor (10); a linear motion member (24) that is provided so as to be movable in the axial direction of the rotary shaft (23); a motion conversion mechanism (25) that converts the rotation of the rotary shaft (23) into the movement of the linear motion member (24) in the axial direction; a friction pad (13) that is provided to one side of the linear motion member (24) in the axial direction and that moves in the axial direction along with the movement of the linear motion member (24) in the axial direction; and a pressing mechanism (15) that presses, by means of operation force applied by a driver, the rotary shaft (23) to one side in the axial direction while preventing the rotary shaft (23) from rotating about the axis, and moves the rotary shaft (23) and the linear motion member (24) integrally to one side in the axial direction.

Description

Electric brake device

The present invention relates to an electric brake device that generates a braking force by a rotational driving force of an electric motor.

The electric brake device transmits the rotational driving force of the electric motor to the rotating shaft through a gear, converts the rotation of the rotating shaft into the axial movement of the linear motion member by the motion conversion mechanism, and the shaft along with the linear motion member. The braking force is exerted by pressing the friction pad moving in the direction against the brake disc. The electric motor used in this electric brake device is driven by receiving electric power supplied from a battery mounted on the vehicle, so when troubles such as abnormal decrease in the charge amount of the battery, sensor failure, disconnection of electric wiring, etc. occur, There is a problem that the brake function cannot be exhibited.

Therefore, for example, as shown in Patent Document 1 below, an electric brake device having a fail-safe mechanism when the above trouble occurs may be employed (see FIG. 4 of Patent Document 1). In this electric brake device, an outer ring member disposed so as to surround the rotation shaft is employed as the linear motion member. Further, as the motion conversion mechanism, a plurality of planetary rollers circumscribing the rotating shaft and inscribed in the outer ring member, a carrier for supporting these planetary rollers so as to rotate and revolve, and an inner periphery of the outer ring member are provided. A planetary roller mechanism having a spiral ridge and a circumferential groove provided on the outer periphery of the planetary roller so as to engage with the spiral ridge can be employed. On the outer periphery of the rotating shaft, a collar portion is formed that supports the carrier from the rear in the axial direction.

Furthermore, a pressing force sensor can be incorporated in this electric brake device as shown in FIG. This pressing force sensor is a magnetic load sensor, a flange member that receives a load from the front in the axial direction and generates deflection, a support member that supports the flange member from the rear in the axial direction, a magnetic target that generates magnetic flux, And a magnetic sensor for detecting the magnetic flux generated by the magnetic target.

The flange member is an annular plate member. The support member is fitted on the outer peripheral edge of the flange member. The outer peripheral edge of the support member is supported on the inner surface of the caliper housing so as not to move. A cylindrical portion is continuously provided on the inner peripheral side of the support member so as to face the inner diameter side of the flange member. A plurality of bearings are mounted on the inner periphery of the cylindrical portion at intervals in the axial direction, and the rotary shaft and the magnetic load sensor are relatively rotatable around the axis. The magnetic target is fixed to the inner periphery of the flange member. The magnetic sensor is fixed to the outer periphery of the cylindrical portion of the support member so as to face the magnetic target in the radial direction (see FIG. 3 in Patent Document 2).

When the electric motor is normally driven by the electric power supplied from the battery, the rotational driving force of the electric motor is transmitted to the rotating shaft through the reduction mechanism, and the rotating shaft rotates around the shaft. When the rotating shaft rotates around the axis, the planetary roller circumscribing the rotating shaft revolves around the rotating shaft while rotating around the roller shaft by rolling contact with the rotating shaft. Since the spiral ridge provided on the outer ring member and the circumferential groove provided on the planetary roller are engaged, the outer ring member and the planetary roller relatively move in the axial direction as the planetary roller rotates. Here, the movement of the carrier supporting the planetary roller in the axial direction is restricted, and as a result of the rotation of the planetary roller, the outer ring member moves to the front side in the axial direction and is integrated with the outer ring member. The brake disc is pressed down by a friction pad provided so as to be movable in the axial direction.

As described above, when the friction pad is pressed against the brake disc, the axial load directed rearward in the axial direction is input to the flange member of the magnetic load sensor through the carrier plate and the thrust bearing as a reaction force backward in the axial direction. (See FIG. 7 in Patent Document 2). The flange member is deflected rearward in the axial direction by the axial load, and the magnetic target and the magnetic sensor are relatively displaced in the axial direction along with the deflection. Then, the output signal of the magnetic sensor changes corresponding to this relative displacement. By grasping in advance the relationship between the magnitude of this output signal and the magnitude of the axial load input to the flange member, the magnitude of the axial load applied to the flange member can be determined based on the output signal of the magnetic sensor. Can be detected.

On the other hand, when the electric motor does not drive normally due to troubles such as an abnormal decrease in the charge amount of the battery, the wire cable is pulled by the driver's operating force (braking force on the brake pedal), thereby the cam member Rotate. When this cam member rotates, the cam surface moves the slide member forward in the axial direction via the link member corresponding to the rotation angle. And this slide member presses a rotating shaft to the axial direction front via a spherical body.

When the rotary shaft is pressed by the slide member and moves forward in the axial direction, the flange provided on the outer periphery of the rotary shaft comes into contact with the carrier and moves forward in the axial direction together with the planetary roller supported by the carrier. When the planetary roller is moved forward in the axial direction, the outer ring member engaged through the spiral protrusion and the circumferential groove is also moved forward in the axial direction. As the outer ring member moves, the friction pad also moves forward in the axial direction, and the brake disc is pressed down.

Thus, by providing the fail-safe mechanism, even when trouble such as the electric motor not being driven normally occurs, the braking force can be exhibited by the driver's operation force, and safety is always ensured. . Moreover, this fail-safe mechanism can be used not only in an emergency but also as a normal parking brake.

JP2015-137667A JP 2014-16307 A

In the electric brake device according to Patent Document 1, the carrier is pressed forward in the axial direction while suppressing the rotation of the rotation shaft by bringing the collar portion provided on the rotation shaft into contact with the carrier. When the angle between the lead angle of the provided spiral ridge and the circumferential groove provided on the planetary roller is large, there is a possibility that slippage may occur at the engaging portion between them. When slipping occurs, the carrier rotates around the shaft together with the rotating shaft, and the pressing force that presses the outer ring member forward in the axial direction is lost, and the braking force may be insufficient.

Further, in the configuration in which the pressing force sensor according to Patent Document 2 is incorporated in the electric brake device according to Patent Document 1 as shown in FIG. 7 of Patent Document 2, it is provided on the rotating shaft during the operation of the fail-safe mechanism. Since the flange portion (see FIG. 4 in Patent Document 1) presses the outer ring member forward in the axial direction via the carrier, a pressing force sensor disposed in the axially rearward direction relative to the carrier (see FIG. 2). 7) and the carrier are separated from each other. For this reason, when the fail safe mechanism is operated, the reaction force in the rearward direction in the axial direction due to the friction pad being pressed against the brake disk is not transmitted to the pressing force sensor, and the pressing force cannot be detected. For this reason, even when the operating force by the driver is insufficient, the driver cannot recognize that fact, and the effectiveness of the fail-safe mechanism may remain insufficient.

Accordingly, the first object of the present invention is to reliably function the fail-safe mechanism of the electric brake device, and secondly to enable detection of the braking force when the fail-safe mechanism of the electric brake device is activated. Let it be an issue.

In order to solve this first problem, in the present invention, an electric motor, a rotating shaft that rotates around the axis by the rotational driving force of the electric motor, and an axial direction of the rotating shaft are provided. A linear motion member, a motion conversion mechanism that converts rotation of the rotary shaft into axial movement of the linear motion member, and provided on one axial side of the linear motion member, in the axial direction of the linear motion member A friction pad that moves in the axial direction along with the movement of the motor, and a rotation force around the axis of the rotating shaft is blocked by the driver's operating force, while pressing the rotating shaft toward the one side in the axial direction, and the rotating shaft And a pressing mechanism that integrally moves the linearly moving member to the one side in the axial direction.

As described above, when the rotation of the rotating shaft is prevented, it is possible to reliably prevent the pressing force from being released due to the rotating shaft rotating carelessly when the linear motion member is pressed by the pressing mechanism. For this reason, the fail safe mechanism of an electric brake device can be functioned reliably.

In the above-described configuration, the pressing mechanism moves in the axial direction while being in surface contact with the rotating shaft and preventing the rotation of the rotating shaft around the axis by frictional force, thereby moving the rotating shaft to the one side in the axial direction. It can be set as the structure which has the press member stopped around the axis | shaft which presses to the periphery.

In this way, the anti-rotation effect can be reliably exhibited with a simple configuration.

In the configuration having the pressing member, the pressing mechanism is moved in the axial direction in accordance with the rotation of the cam member and the cam member that is rotated by the operating force of the driver, and the pressing member is moved in the axial direction. And a link member to be moved.

Alternatively, the pressing mechanism is formed on the linear motion disk that functions as the pressing member in which an inclined groove whose depth changes along the circumferential direction is formed on one surface in the axial direction, and the linear motion disk. An inclined groove is formed between the linear motion disk and the axially moving disk so as to face the inclined groove, and an inclined groove whose depth varies along the circumferential direction is formed on a surface facing the linearly moving disk. Further, the rotating disk that is rotated by the operating force of the driver, the inclined groove that is formed on the linearly moving disk, and the inclined groove that is formed on the rotating disk are held in a rollable manner. A rolling element, and the relative rolling between the linear disk and the rotating disk causes the rolling element to roll in the both inclined grooves, thereby widening the interval, thereby causing the linear motion. Configuration to move the disk in the axial direction It is also possible to.

Thus, by configuring the pressing mechanism, the rotation based on the driver's operating force can be smoothly converted into the axial movement of the pressing member, and the braking force can be exhibited quickly.

Moreover, in each structure which has the said press member, the said press mechanism can be set as the structure which further has the urging | biasing member which urges | biases the said press member to the other side opposite to the said one side of an axial direction. .

Thus, by urging the pressing member to the other side with the urging member, when the driver's operating force is not acting, the rotating shaft and the pressing member are reliably separated, and the rotation loss of the rotating shaft is reduced. It can be prevented from occurring.

In each configuration having the pressing member, the rotating shaft is extended outward in the radial direction, and has an extending member that can rotate about the shaft integrally with the rotating shaft, and the pressing member has the extending portion. It can be set as the structure which contact | abutted to the installation member.

In this case, the detent action by the pressing member can be further improved by bringing the pressing member into contact with the extending member having a diameter larger than the outer diameter of the rotating shaft.

In order to solve the second problem of the present invention, the electric brake device according to each of the above-described configurations is provided between the pressing mechanism and the motion conversion mechanism, and the pressing force by the pressing mechanism is applied. The motor further includes a load sensor that detects a load applied to the brake disk by receiving a reaction force in the axial direction rearward when the friction pad is pressed against the brake disk while transmitting to the motion conversion mechanism side. A brake device was constructed.

In this way, by providing a load sensor between the pressing mechanism and the motion conversion device, when the fail safe mechanism is operated, the pressing force of the pressing mechanism can be smoothly transferred via the load sensor via the load sensor. While being able to transmit to a linear motion member, the braking force can be detected from the reaction force. For this reason, the driver can quickly recognize that the braking force is insufficient, and it is possible to prevent the fail-safe mechanism from remaining insufficient.

In the configuration having the load sensor, the load sensor is connected to the flange member that receives the reaction force and bendable with respect to the flange member, and receives a pressing force forward in the axial direction by the pressing mechanism. A support member, a magnetic target provided on one side of the flange member or the support member, and the other side of the flange member or the support member on the side where the magnetic target is provided so as to face the magnetic target. A magnetic load sensor having a magnetic sensor, a fulcrum portion where the flange member and the support member are connected, a reaction force portion where the flange member receives the reaction force, and the support member It can be set as the structure located in the radial direction outer side from the press part which receives the said pressing force.

In this way, the load can be detected with high sensitivity by the load sensor. That is, the magnetic target provided on one side of the flange member or the support member and the magnetic sensor provided on the other side of the flange member or support member on the side on which the magnetic target is provided are relatively moved in the opposite axial direction. For this reason, the relative movement amount becomes larger than when only one of them moves in the axial direction. For this reason, the detection sensitivity by this load sensor can be improved significantly.

In the configuration employing the magnetic load sensor, the pressing portion may be positioned radially inward from the reaction force portion.

In this way, the supporting member can be greatly deflected forward in the axial direction by the pressing force from the pressing mechanism, and the detection sensitivity of the load sensor can be further improved.

In each configuration having the load sensor, the pressing mechanism includes a pressing member that is prevented from rotating about an axis, and the frictional force generated by surface contact between the rotating shaft and the pressing member causes the rotation shaft to rotate. It can be set as the structure which prevented rotation around an axis | shaft.

Thus, if the rotation of the rotating shaft is prevented, it is possible to reliably prevent the rotating shaft from inadvertently rotating and releasing the pressing force when the linear motion mechanism is pressed by the pressing mechanism. For this reason, the fail safe mechanism of an electric brake device can be functioned reliably.

As described above, instead of bringing the rotating shaft and the pressing member into surface contact, the pressing mechanism has a pressing member that is prevented from rotating around the axis, and rotates about the axis integrally with the rotating shaft. Further, it is possible to prevent the rotation of the rotary shaft around the axis by a frictional force caused by surface contact between the extending member extending radially outward and the pressing member.

As described above, by making the pressing member abut on the extending member having a diameter larger than the outer diameter of the rotating shaft, it is possible to further improve the anti-rotation effect by the pressing member.

Each configuration having the load sensor further includes a warning device that warns the driver that the load is insufficient when the load detected by the load sensor is smaller than a predetermined load threshold. Can do.

Thus, by providing the warning device, it is possible to easily recognize that the driver is in a state of insufficient load, and it is possible to quickly take appropriate measures such as increasing the operating force.

In the electric brake device according to the present invention, the pressing mechanism that integrally moves the rotating shaft and the linear motion member to one side in the axial direction has a function of preventing the rotating shaft from rotating around the axis. When the linear motion member is pressed by this pressing mechanism, it is possible to reliably prevent the rotating shaft from rotating and releasing the pressing force. For this reason, the fail safe mechanism of an electric brake device can be functioned reliably.

Furthermore, in the electric brake device according to the present invention, since the load sensor for detecting the load applied to the brake disc is provided between the pressing mechanism and the motion conversion mechanism, when the fail safe mechanism is activated. Through this load sensor, the pressing force of the pressing mechanism can be smoothly transmitted to the motion conversion mechanism and the linear motion member, and the braking force is detected from the reaction force when the friction pad is pressed against the brake disc. can do. For this reason, it is possible to prevent the fail-safe mechanism from remaining in an insufficient state, and to ensure safety.

The longitudinal cross-sectional view which shows 1st embodiment of the electric brake device which concerns on this invention Sectional view along the line II-II in FIG. 1 is a longitudinal sectional view showing a main part of the electric brake device shown in FIG. Sectional view along line IV-IV in FIG. Partial sectional view taken along line VV in FIG. Sectional view along line VI-VI in FIG. It is a figure which shows the effect | action of the press mechanism shown in FIG. 2, Comprising: When the driver's operating force is not acting It is a figure which shows the effect | action of the press mechanism shown in FIG. 2, Comprising: When the operating force of a driver | operator is acting It is a figure which shows the effect | action of the other examples of the press mechanism shown in FIG. 2, Comprising: When the driver | operator's operating force is not acting It is a figure which shows the effect | action of the other example of the press mechanism shown in FIG. 2, Comprising: When the operating force of a driver | operator is acting The longitudinal cross-sectional view which shows the principal part of 2nd embodiment of the electric brake device which concerns on this invention Sectional view along the line XX in FIG. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 10 when the driver's operating force is not applied. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 10 when the driver's operating force is acting. FIG. 9 is a longitudinal sectional view showing another example of the pressing mechanism shown in FIG. The longitudinal cross-sectional view which shows the principal part of 3rd embodiment of the electric brake device which concerns on this invention Longitudinal sectional view showing a fourth embodiment of the electric brake device according to the present invention The longitudinal cross-sectional view which shows the principal part of the electric brake device shown in FIG. FIG. 15 is a longitudinal sectional view showing a further main part of the electric brake device shown in FIG. In the pressing mechanism shown in FIG. 14, a longitudinal sectional view showing a state in which the driver's operating force is acting. The longitudinal cross-sectional view which shows the principal part of 5th embodiment of the electric brake device which concerns on this invention FIG. 5 is a longitudinal sectional view showing a positional relationship between a fulcrum part in which a flange member and a support member of a load sensor are continuously provided, a pressing part on which a pressing force acts, and a reaction force part on which a reaction force acts, and the fulcrum part and the pressing part Are spaced apart in the radial direction FIG. 5 is a longitudinal sectional view showing a positional relationship between a fulcrum part in which a flange member and a support member of a load sensor are continuously provided, a pressing part on which a pressing force acts, and a reaction force part on which a reaction force acts, and the fulcrum part and the pressing part Configuration in which is approaching in the radial direction The figure which shows the relationship between the magnitude | size of the load which acts on a friction pad, and the output of a load sensor The longitudinal cross-sectional view which shows the principal part of 6th embodiment of the electric brake device which concerns on this invention The longitudinal cross-sectional view which shows the principal part of 7th embodiment of the electric brake device which concerns on this invention The longitudinal cross-sectional view which shows the principal part of 8th embodiment of the electric brake device which concerns on this invention The longitudinal cross-sectional view which shows the principal part of 9th embodiment of the electric brake device which concerns on this invention The longitudinal cross-sectional view which shows the principal part of 10th Embodiment of the electric brake device which concerns on this invention The longitudinal cross-sectional view which shows the principal part of 11th Embodiment of the electric brake device which concerns on this invention

1 to 8A and 8B show a first embodiment of an electric brake device according to the present invention. The electric brake device includes an electric motor 10, a rotating shaft 23 that rotates around the axis by the rotational driving force of the electric motor 10, a linear motion member 24 that is movable in the axial direction of the rotating shaft 23, and the rotating shaft 23. A motion conversion mechanism 25 that converts rotation into axial movement of the linear motion member 24, friction provided on one side of the linear motion member 24 in the axial direction and moving in the axial direction as the linear motion member 24 moves in the axial direction The rotating shaft 23 is pressed forward in the axial direction while preventing rotation around the axis of the rotating shaft 23 by the operation force of the pad 13 and the driver, and the rotating shaft 23 and the linear motion member 24 are axially integrated. The pressing mechanism 15 that moves to the one side is a main component. In the following, one side in the axial direction is referred to as the front, and the other side opposite to the one direction is referred to as the rear.

This electric brake device normally exerts a braking force by driving the electric motor 10 in accordance with a driver's brake operation. On the other hand, when troubles such as the electric motor 10 not being driven normally occur, a fail-safe mechanism is provided that obtains braking force by the driver's operating force. Hereinafter, the electric brake device will be described in detail.

As shown in FIGS. 1 to 3, the electric brake device includes a brake disk 11 that rotates integrally with a wheel (not shown), and a pair of friction pads 12 that are opposed to each other in the axial direction with the brake disk 11 in between. 13 and the electric motor 10 for moving the friction pads 12 and 13, and the braking force is generated by pressing the friction pads 12 and 13 against the brake disk 11 with the power transmitted from the electric motor 10. . In addition, this electric brake device can generate a braking force even in a state where the braking force by the electric motor 10 cannot be exerted due to some trouble, so that the wire cable 14 provided so as to be pulled by the operating force of the driver, And a pressing mechanism 15 connected to one end of the wire cable 14.

This electric brake device has a caliper body 19 having a shape in which a pair of facing portions 16 and 17 facing each other in the axial direction with the brake disc 11 in between are connected by a bridge 18 positioned on the outer diameter side of the brake disc 11. The friction pad 12 is disposed between one facing portion 16 of the caliper body 19 and the brake disk 11, and the friction pad 13 is disposed between the other facing portion 17 and the brake disk 11. The friction pads 12 and 13 are guided by pad pins (not shown) attached to the caliper body 19 and slide parts (not shown) provided on the caliper bracket 21 so as to be movable in the axial direction of the brake disc 11. Has been.

As shown in FIG. 4, the caliper body 19 includes a pair of slide pins 22 attached to a caliper bracket 21 fixed to a knuckle (not shown) that supports a wheel by bolts 20 (see FIG. 2). It is supported so as to be movable in the axial direction. Accordingly, when the friction pad 13 shown in FIG. 2 or the like moves forward in the axial direction and is pressed against the brake disc 11, the caliper body 19 moves rearward in the axial direction due to the reaction force received from the brake disc 11. As the caliper body 19 moves, the friction pad 12 on the opposite side is also pressed against the brake disk 11.

As shown in FIG. 2, one opposing portion 17 of the caliper body 19 includes a cylindrical caliper housing 17 </ b> A that is open at both front and rear ends in the axial direction, and an axially rearward end portion of the caliper housing 17 </ b> A that is perpendicular to the axial direction. The caliper flange 17B extends in a direction (a direction parallel to the brake disc 11).

The caliper housing 17A has a rotation shaft 23, an outer ring member functioning as a linear motion member 24 disposed so as to surround the rotation shaft 23 (hereinafter, the same reference numeral as the linear motion member 24), and the rotation shaft 23. Is incorporated with a planetary roller mechanism that functions as a motion conversion mechanism 25 that converts the rotation of the outer ring member 24 into an axial movement of the outer ring member 24 (hereinafter, the same reference numeral as the motion conversion mechanism 25 is attached). The friction pad 13 is disposed in front of the outer ring member 24 in the axial direction.

The electric motor 10 is attached to the caliper flange 17B. A reduction mechanism 26 is provided between the electric motor 10 and the rotary shaft 23 to reduce and transmit the rotation of the electric motor 10 to the rotary shaft 23. The speed reduction mechanism 26 is accommodated in a cover 27 provided so as to cover the end opening of the caliper housing 17A in the axial direction and the side surface of the caliper flange 17B (see FIG. 4).

As shown in FIGS. 4 and 5, the speed reduction mechanism 26 includes a first gear 26A that rotates around the shaft integrally with the rotor shaft 10A of the electric motor 10, a second gear 26B that meshes with the first gear 26A, and a second gear 26B. A third gear 26C that rotates about the axis integrally with the gear 26B and has a smaller number of teeth than the second gear 26B; a fourth gear 26D that meshes with the third gear 26C and rotates about the axis integrally with the rotary shaft 23; Have The rotation of the electric motor 10 is transmitted through the plurality of gears 26 </ b> A, 26 </ b> B, 26 </ b> C, 26 </ b> D after being sequentially decelerated and input to the rotary shaft 23.

As shown in FIG. 3, the planetary roller mechanism 25 includes a plurality of planetary rollers 25A circumscribing the rotating shaft 23 and inscribed in the outer ring member 24, and a carrier 25B that supports the planetary rollers 25A so that they can rotate and revolve. The spiral protrusion 25C provided on the inner periphery of the outer ring member 24 and the circumferential groove 25D provided on the outer periphery of the planetary roller 25A so as to engage with the spiral protrusion 25C.

As shown in FIG. 6, the plurality of planetary rollers 25A are arranged at equal intervals in the circumferential direction. Each planetary roller 25 </ b> A is in rolling contact with the outer periphery of the rotating shaft 23 and the inner periphery of the outer ring member 24. The contact portion of the rotating shaft 23 with respect to the planetary roller 25A is a cylindrical surface. When the rotary shaft 23 is rotated, the planetary rollers 25A, while rotating about the roller shaft 25B _4, revolves around the rotation axis 23. That is, the planetary roller 25 </ b> A rotates by the rotational force received from the outer periphery of the rotating shaft 23, and accordingly, the planetary roller 25 </ b> A rolls around the inner periphery of the outer ring member 24 and revolves.

The spiral ridge 25C on the inner periphery of the outer ring member 24 is a spiral ridge extending obliquely with respect to the circumferential direction. On the other hand, the circumferential groove 25D on the outer periphery of the planetary roller 25A is a groove extending in parallel to the circumferential direction. In this embodiment, the circumferential groove 25D having a lead angle of 0 degree is provided on the outer periphery of the planetary roller 25A. However, instead of the circumferential groove 25D, a spiral groove having a lead angle different from that of the spiral protrusion 25C may be provided. Good.

As shown in FIG. 3, the outer ring member 24 is supported by the inner surface of the caliper housing 17A so as to be movable in the axial direction. A contact portion of the inner surface of the caliper housing 17A with respect to the outer ring member 24 is a cylindrical surface. The outer ring member 24 has a concave portion 29 that engages with a convex portion 28 formed on the back surface of the friction pad 13, and is prevented from rotating with respect to the caliper housing 17 </ b> A by the engagement of the convex portion 28 and the concave portion 29. .

The carrier 25B extends in the axial direction between a pair of carrier plates 25B ₁ and 25B ₂ facing in the axial direction with the planetary roller 25A in between and the planetary rollers 25A adjacent in the circumferential direction, and the carrier plates 25B ₁ and 25B _2. having a connecting portion 25B ₃ for connecting to each other, and a roller shaft 25B ₄ which rotatably supports the respective planetary rollers 25A. Each of the carrier plates 25B ₁ and 25B ₂ is formed in an annular shape that penetrates the rotating shaft 23, and a sliding bearing 30 that is in sliding contact with the outer periphery of the rotating shaft 23 is mounted on the inner periphery thereof.

Both end portions of the roller shaft 25B ₄ is movably supported in the radial direction of the outer ring member 24 in the long hole 31 formed on a pair of carrier plate _25B 1, 25B _2. Further, at both ends of the roller shaft 25B _4, the elastic ring 32 so as to circumscribe the roller shaft 25B ₄ of all of the planetary rollers 25A in the circumferential direction spaced is stretched. The elastic ring 32 prevents slipping between the planetary roller 25 </ b> A and the rotary shaft 23 by pressing each planetary roller 25 </ b> A against the outer periphery of the rotary shaft 23.

A magnetic load sensor 33 is provided behind the outer ring member 24 in the axial direction. The magnetic load sensor 33 includes a flange member 33A that generates deflection when a load is input from the front in the axial direction, a support member 33B that supports the flange member 33A from the rear in the axial direction, a magnetic target 33C that generates magnetic flux, The magnetic sensor 33D detects the magnetic flux generated by the target 33C.

The flange member 33A is an annular plate member formed of a metal such as iron. The support member 33B is formed of a metal such as iron and is fitted on the outer peripheral edge of the flange member 33A. The outer peripheral edge of the support member 33B is supported by the inner surface of the caliper housing 17A so as not to move. A cylindrical portion 33E is continuously provided on the inner peripheral side of the support member 33B so as to face the inner diameter side of the flange member 33A. A plurality of bearings 34 are mounted on the inner periphery of the cylindrical portion 33E at intervals in the axial direction, and the rotary shaft 23 and the magnetic load sensor 33 are capable of relative rotation around the axis. The magnetic target 33C is fixed to the inner periphery of the flange member 33A. The magnetic sensor 33D is fixed to the outer periphery of the cylindrical portion 33E of the support member 33B so as to face the magnetic target 33C in the radial direction.

Between each planetary roller 25A and the carrier plate 25B ₂ of the axially rearward thrust bearing 35 which rotatably supports the planetary rollers 25A is incorporated. Further, revolving between the planetary roller 25A in the axial direction behind the carrier plate 25B ₂ and the magnetic load sensor 33 (the flange member 33A), a thrust plate 36 which revolves together with the carrier plate 25B _2, the thrust plate 36 A thrust bearing 37 is incorporated which can be supported.

When the outer ring member 24 moves forward in the axial direction and the brake disk 11 is pressed by the friction pads 12, 13, a magnetic load is applied as a reaction force in the rearward direction in the axial direction via the carrier plate 25 B ₂ and the thrust bearing 37. An axial load directed rearward in the axial direction is input to the flange member 33A of the sensor 33. The axial load causes the flange member 33A to bend backward in the axial direction, and the magnetic target 33C and the magnetic sensor 33D are relatively displaced in the axial direction along with the deflection. Then, the output signal of the magnetic sensor 33D changes corresponding to this relative displacement. By grasping in advance the relationship between the magnitude of this output signal and the magnitude of the axial load input to the flange member 33A, the axial load applied to the flange member 33A can be determined based on the output signal of the magnetic sensor 33D. The size can be detected.

Magnetic load sensor 33, the thrust plate 36, via the thrust bearing 37, by supporting the carrier plate 25B ₂ in the axial direction, and restrict the movement of the axially rearward of the carrier 25B. The carrier plate 25B ₁ of the axial forward movement of the axially forward is restricted by the stop ring 38 attached to the axial forward end of the rotary shaft 23. Therefore, the carrier 25B is restricted from moving in the axial direction forward and axially backward, and the planetary roller 25A held by the carrier 25B is also restricted from moving in the axial direction.

On the outer periphery of the rotary shaft 23, a flange 39 that supports the carrier 25B from the rear in the axial direction is formed. The flange portion 39 is disposed so as to face the axially rearward of the axially rearward of the carrier plate 25B _2, when the rotary shaft 23 is moved axially forward, axially forward collar portion 39 is a carrier plate 25B ₂ To move it. The flange 39 may be formed so as to have a seamless integrated structure with the rotary shaft 23, or may be formed by fixing another member on the outer periphery of the rotary shaft 23. It may also incorporate a thrust bearing between the flange portion 39 and the carrier plate 25B _2. Further, the flange portion 39 may support the carrier 25B from the rear in the axial direction through the thrust plate 36, and support the carrier 25B from the rear in the axial direction through the magnetic load sensor 33, the thrust bearing 37, or the like. It is also possible to configure as described above.

A seal cover 40 that closes the opening at the front end of the outer ring member 24 in the axial direction is attached to the end of the outer ring member 24 in the axial direction. The seal cover 40 prevents foreign matter from entering the outer ring member 24. In addition, one end of a cylindrical bellows 41 formed to be extendable in the axial direction is fixed to an axially forward end of the outer ring member 24, and the other end of the bellows 41 is an opening in the axially forward direction of the caliper housing 17A. It is fixed to the edge. The bellows 41 prevents foreign matter from entering between the sliding surfaces of the outer ring member 24 and the caliper housing 17A.

When the planetary roller mechanism 25 rotates the electric motor 10, the rotation of the electric motor 10 is input to the rotary shaft 23 via the speed reduction mechanism 26, and the planetary roller 25A revolves while rotating (see FIG. 3). At this time, the outer ring member 24 and the planetary roller 25A move relative to each other in the axial direction due to the difference in the lead angle between the spiral protrusion 25C and the circumferential groove 25D, but the planetary roller 25A is restricted from moving in the axial direction together with the carrier 25B. Therefore, the planetary roller 25A does not move in the axial direction, and the outer ring member 24 moves in the axial direction. Here, when the rotation in the direction in which the outer ring member 24 moves forward in the axial direction is input from the electric motor 10 to the rotation shaft 23, the outer ring member 24 presses the friction pad 13, thereby causing the friction pad shown in FIG. 12 and 13 are pressed against the brake disc 11 and a braking force is applied to the wheels that rotate integrally with the brake disc 11. Further, when rotation in the direction in which the outer ring member 24 moves rearward in the axial direction is input from the electric motor 10 to the rotary shaft 23, the friction pads 12 and 13 shown in FIG. The braking force is released.

As shown in FIGS. 7A and 7B, the pressing mechanism 15 is orthogonal to the axial direction of the rotary shaft 23 and the pressing member 15 </ b> B provided to be movable in the axial direction facing the rear end of the rotary shaft 23 in the axial direction. A wire to which a cam member 15A rotatably supported around the axis, a link member 15C incorporated between the pressing member 15B and the cam member 15A, and a wire end fitting provided at one end of the wire cable 14 are connected. And a lever 15D (see FIG. 7A). One end of the wire lever 15D is connected to the cam member 15A, and when the wire cable 14 connected to the other end of the wire lever 15D is pulled, the wire lever 15D and the cam member 15A rotate together. (See FIG. 7B).

The pressing member 15 </ b> B is slidably supported by the inner surface of a guide hole 42 provided in the cover 27 that extends in the axial direction. A protrusion extending in the axial direction is formed on the pressing member, and a guide groove for guiding the protrusion in the axial direction is formed on the inner surface of the guide hole 42, whereby the pressing member 15 </ b> B is prevented from rotating with respect to the cover 27. Is done. The end faces of the axially rearward of the pressing member 15B, the recess 15B ₁ that supports receiving one end of the link member 15C is formed. The outer periphery of the cam member 15A, the cam surface 15A ₁ is formed. Cam surface 15A _1, when the cam member 15A is rotated by pulling operation of the wire cable 14, in accordance with the rotation angle, with a shape that presses the pressing member 15B axially forward through the link member 15C It is formed as follows. The axially forward end surface of the pressing member 15B and the axially rearward end surface of the rotating shaft 23 are both processed into a flat surface. The wire lever 15D is attached with a return spring 15E that biases the wire lever 15D in a direction opposite to the turning direction of the wire lever 15D due to the pulling operation of the wire cable 14 (see FIG. 3).

When the wire cable 14 shown in FIG. 7A or the like is pulled by the driver's operating force, the pressing mechanism 15 rotates the cam member 15A by the pulling force, and the cam mechanism 15A rotates according to the rotation angle of the cam member 15A. surface 15A ₁ moves down the pressing member 15B axially forward via the link member 15C. As a result, the axially forward end face of the pressing member 15B presses the rotating shaft 23 forward in the axial direction. At this time, the axially rear end surface of the rotating shaft 23 having a flat surface shape and the axially forward end surface of the pressing member 15B are in surface contact.

Thus, when both end surfaces are brought into surface contact with each other, rotation around the axis of the rotary shaft 23 is prevented by the frictional force with the pressing member 15B that is prevented from rotating with respect to the cover 27. In this way, by preventing the rotation of the rotating shaft 23, the lead angle of the spiral ridge 25 </ b> C provided on the outer ring member 24 when the fail-safe mechanism is activated due to trouble such as the failure of the electric motor 10. Even when the angle between the circumferential groove 25D provided on the planetary roller 25A is large, it is possible to prevent slippage at the engaging portion between them, and the fail-safe mechanism functions reliably. Can be made.

Also, as shown in FIG. 8A and the like, a release spring that functions as a biasing member 15F that biases the pressing member 15B in the axial direction rearward (direction away from the rotating shaft 23) (hereinafter, the same reference numeral as the biasing member 15F). It is also possible to adopt a configuration in which the cover 27 is provided in the cover 27. In this way, by providing the release spring 15F, when the driver's operating force is not acting, the rotation shaft 23 and the pressing member 15B are reliably separated (see FIG. 8A), and the rotation loss of the rotation shaft 23 is reduced. On the other hand, when the driver's operating force is applied, the pressing member 15B is urged forward in the axial direction against the urging force of the release spring 15F, so that the rotating shaft 23 and the pressing member 15B are urged. The two end surfaces are brought into contact with each other (see FIG. 8B), and a frictional force can be applied between the both end surfaces.

As shown in FIG. 1, a brake pedal 43 operated by a driver's foot is attached with a wire connector portion 44 to which a wire end fitting provided at an end portion of the wire cable 14 is connected, and a clutch mechanism 45. It has been. The brake pedal 43 is supported so as to be swingable about a fulcrum shaft 46. The brake pedal 43 is provided with a stroke sensor (not shown) that detects the depression amount of the brake pedal 43. The wire connector portion 44 is swingably supported so as to have a swing center at the same position as the fulcrum shaft 46 of the brake pedal 43. Here, the wire connector portion 44 can swing independently of the brake pedal 43 so that the brake pedal 43 can swing independently of the wire connector portion 44.

As the clutch mechanism 45, a reverse operation type electromagnetic clutch configured to be disconnected when energized and to be connected when energization is stopped can be employed. In this way, by adopting the reverse operation type electromagnetic clutch, the clutch mechanism 45 is in the connected state when the energization to the clutch mechanism 45 is stopped, so even when the electric brake device loses power, A braking force can be secured. The clutch mechanism 45 performs brake control based on detection results of sensors such as a stroke sensor, a magnetic load sensor 33, and a battery sensor (not shown) that detects a charge amount of a battery that supplies electric power to the electric motor 10. Controlled by a unit (not shown).

As described above, even when the electric motor 10 does not operate, the electric brake device pushes the rotating shaft 23 forward in the axial direction by pulling the wire cable 14 with the driver's operating force, and the rotating shaft 23 and the outer ring. The friction pad 13 can be pressed against the brake disc 11 by moving the member 24 integrally in the axial direction. Therefore, the braking force can be generated even when an electrical failure occurs.

In addition, since the axially rear end surface of the rotating shaft 23 and the axially front end surface of the pressing member 15B are brought into surface contact, the frictional force between the carrier 25B and the rotation of the rotating shaft 23 is prevented. Around rotation is prevented. For this reason, even if the angle between the lead angle of the spiral ridge 25C provided on the outer ring member 24 and the circumferential groove 25D provided on the planetary roller 25A is large, the slippage is caused by the engagement portion between them. Can be prevented, and the fail-safe mechanism can function reliably.

In this embodiment, the end surface on the rear side in the axial direction of the rotating shaft 23 and the end surface on the front side in the axial direction of the carrier 25B are both flat surfaces, but as long as sufficient frictional force is exerted between the both end surfaces. The end surface shape is not limited, and for example, one end surface may be a concave curved surface, and the other end surface may be a convex curved surface having the same curvature as the concave curved surface.

This electric brake device can generate a braking force when the driver operates the brake pedal 43 when an electrical failure occurs, as in the case where no electrical failure occurs. Therefore, it is excellent in operability when an electrical failure occurs.

9 to 12 show a second embodiment (main part) of the electric brake device according to the present invention. This electric brake device has the same basic configuration as the electric brake device according to the first embodiment, but the configuration of the pressing mechanism 15 is different. As shown in FIG. 9, the pressing mechanism 15 includes a linear motion disk 15 </ b> G corresponding to the pressing member 15 </ b> B in the first embodiment and an axial rearward direction of the linear motion disk 15 </ b> G. And a ball that is a rolling element 15I provided between the linear movement disk 15G and the rotation disk 15H (hereinafter, the same reference numeral as that of the rolling element 15I). And a wire lever 15D to which one end of the wire cable 14 is connected. The linear motion disk 15G is supported so as to be movable in the axial direction while being prevented from rotating about the axis, like the pressing member 15B in the first embodiment. The rotating disk 15H is rotatably supported in a state where the axial rearward movement is restricted by the thrust bearing 47.

As shown in FIG. 10, on the facing surface relative to the linear motion disk 15G of the rotation disk 15H, circumferentially spaced plurality of inclined grooves 15H ₁ are formed. Similarly, the opposing surface against rotation disk 15H of the linear motion disk 15G, circumferentially spaced plurality of inclined grooves 15G ₁ is formed (see FIG. 9).

As shown in FIG. 11A, FIG. 11B, the inclined groove 15G ₁ includes, from the deepest portion 15G ₂ in one circumferential direction is formed so as gradually become shallower, inclined groove 15H ₁ are circumferentially from the deepest 15H ₂ other It is formed to become gradually shallower in the direction. The ball 15I is incorporated between both the inclined grooves 15G ₁ and 15H ₁ .

As shown in FIG. 9, one end of the wire lever 15D is connected to the rotating disk 15H, and when the wire cable 14 connected to the other end of the wire lever 15D is pulled, the wire lever 15D and the rotating disk are connected. 15H rotates together. A return spring 15E that urges the wire lever 15D in a direction opposite to the rotation direction of the wire lever 15D by the pulling operation of the wire cable 14 is attached to the wire lever 15D.

When the wire mechanism 14 is pulled, the pressing mechanism 15 rotates the rotating disk 15H by a tensile force acting on the wire cable 14 as shown in FIG. 11B. As a result, the ball 15I is inclined to the inclined grooves 15G ₁ , 15H. since rolls ₁ in a direction becomes shallower from the deepest _15G 2, 15H _2, axial spacing of the rotating disk 15H and the linear motion disk 15G is enlarged in accordance with the rotation angle of the rotation disk 15H. Here, since the rotation disc 15H is restricted from moving rearward in the axial direction, the linear motion disc 15G moves forward in the axial direction, and the rotary shaft 23 is pushed forward in the axial direction by the linear motion disc 15G. Move.

In the pressing mechanism 15 shown in FIG. 9, the rotary shaft 23 is directly pressed by the linear motion disk 15G. However, as shown in FIG. You may make it press the linearly-moving disk 15G from the axial direction to the gear (4th gear 26D) which is the extending member 48 which rotates around a shaft integrally with the shaft 23. Since the extending member 48 has a larger diameter than the outer diameter of the rotating shaft 23, the rotating shaft 23 and the pressing member 15B (linear motion) are brought into contact with each other by bringing the extending member 48 into contact with the pressing member 15B (linear motion disk 15G). Compared with the case where the disk 15G is brought into contact, the rotation preventing action of the rotary shaft 23 can be further improved. This configuration can also be applied to the electric brake device according to the first embodiment.

FIG. 13 shows a third embodiment (main part) of the electric brake device according to the present invention. Unlike the first and second embodiments, this electric brake device converts the rotation of the rotary shaft 23 to which the rotation of the electric motor 10 is input into the axial movement of the linear member 24 that presses the friction pad 13. As the mechanism 25, a feed screw mechanism (hereinafter, the same reference numeral as that of the motion converting mechanism 25 is given) is adopted.

The feed screw mechanism 25 is formed on the outer periphery of a screw shaft 25E formed integrally with the rotary shaft 23, a nut 25F functioning as a linear motion member 24 provided so as to surround the screw shaft 25E, and the screw shaft 25E. A plurality of balls 25I incorporated between the screw groove 25G and the screw groove 25H formed on the inner periphery of the nut 25F, and a return tube (not shown) for returning the ball from the end point of the screw groove 25H of the nut 25F to the start point And have.

The nut 25F is provided in the caliper housing 17A so as to be movable in the axial direction while being prevented from rotating with respect to the caliper housing 17A. The axially rearward end of the screw shaft 25E, the flange 25E ₁ is formed radially outwardly. The axially rearward of the flange 25E _1, the thrust bearing 49 is provided. The thrust bearing 49 is supported by a bearing support member 50 fixed in the caliper housing 17 </ b> A, and can be relatively rotated around the shaft by the bearing 34. Flange 25E ₁ formed in the screw shaft 25E is, by contacting the thrust bearing 49 which is supported by the bearing support member 50 from moving in the axial rearward side of the screw shaft 25E is restricted.

When the electric motor 10 is rotated, the rotation of the electric motor 10 is input to the rotary shaft 23 via the speed reduction mechanism 26, and the nut 25F moves forward in the axial direction along with the rotation of the rotary shaft 23. A friction pad 13 provided forward in the direction is pressed against the brake disc 11. On the other hand, when trouble such as failure of the electric motor 10 occurs and the wire cable 14 is pulled by the driver's operating force, the cam member 15A is rotated by the tensile force, and the rotation angle of the cam member 15A is depending on, it pushes the pressing member 15B in the axial direction front cam surface 15A ₁ via the link member 15C. As a result, the axially forward end face of the pressing member 15B presses the rotating shaft 23 forward in the axial direction. At this time, the axially rear end surface of the rotating shaft 23 having a flat surface shape and the axially forward end surface of the pressing member 15B are in surface contact.

Thus, when both end surfaces are brought into surface contact, rotation around the axis of the rotating shaft 23 is prevented by the frictional force between the rotating shaft 23 and the pressing member 15B that is prevented from rotating about the cover 27. In this way, by preventing the rotation of the rotating shaft 23, when the fail-safe mechanism is activated due to a failure such as the failure of the electric motor 10, the screw groove 25G formed in the screw shaft 25E and the nut 25F are It is possible to prevent the slipping via the ball 25I from occurring between the formed screw groove 25H, and the fail-safe mechanism can function reliably.

14 to 17 show a fourth embodiment of the electric brake device according to the present invention. The electric brake device includes an electric motor 10, a rotary shaft 23 that rotates around the axis by the rotational driving force of the electric motor 10, a linear motion member 24 that is movable in the axial direction of the rotary shaft 23, and the rotation of the rotary shaft 23. Is converted to an axial movement of the linear motion member 24, a friction pad 13 provided in front of the linear motion member 24 in the axial direction and moved in the axial direction along with the axial movement of the linear motion member 24, While the rotation of the rotating shaft 23 is prevented by the driver's operating force, the rotating shaft 23 is pressed forward in the axial direction, and the rotating shaft 23 and the linear motion member 24 are integrally pressed forward in the axial direction. The pressing mechanism 15 to be moved, and provided between the pressing mechanism 15 and the motion conversion mechanism 25, transmit the pressing force by the pressing mechanism 15 to the motion conversion mechanism 25 side, while the friction pad 13 is connected to the brake disk 11. Press Receives a reaction force in the axially rearward when attached, it has a load sensor 33 for detecting the load applied to the brake disk 11 as main components.

This electric brake device normally exerts a braking force by driving the electric motor 10 in accordance with a driver's brake operation. On the other hand, when troubles such as the electric motor 10 not being driven normally occur, a fail-safe mechanism is provided that obtains braking force by the driver's operating force. Hereinafter, the electric brake device will be described in detail.

As shown in FIG. 14 (see also FIG. 1), this electric brake device includes a brake disk 11 that rotates integrally with a wheel (not shown), and a pair of frictions that face each other in the axial direction with the brake disk 11 in between. The pad 12 and 13 and the electric motor 10 for moving the friction pad 12 and 13 are provided. By pressing the friction pad 12 and 13 against the brake disc 11 with the power transmitted from the electric motor 10, the braking force is increased. generate. In addition, this electric brake device can generate a braking force even in a state where the braking force by the electric motor 10 cannot be exerted due to some trouble, so that the wire cable 14 provided so as to be pulled by the operating force of the driver, And a pressing mechanism 15 connected to one end of the wire cable 14.

This electric brake device has a caliper body 19 having a shape in which a pair of facing portions 16 and 17 facing each other in the axial direction with the brake disc 11 in between are connected by a bridge 18 positioned on the outer diameter side of the brake disc 11. The friction pad 12 is disposed between one facing portion 16 of the caliper body 19 and the brake disk 11, and the friction pad 13 is disposed between the other facing portion 17 and the brake disk 11. Each of the friction pads 12 and 13 is supported by a caliper bracket 21 so as to be movable in the axial direction of the brake disk 11.

As shown in FIG. 14 (see also FIG. 4), the caliper body 19 is composed of a pair of slide pins 22 attached to a caliper bracket 21 fixed to a knuckle (not shown) for supporting wheels by bolts 20, and a brake disc. 11 is supported so as to be movable in the axial direction. Accordingly, when the friction pad 13 shown in FIG. 14 or the like moves forward in the axial direction and is pressed against the brake disc 11, the caliper body 19 moves rearward in the axial direction by the reaction force received from the brake disc 11, and the caliper The friction pad 12 on the opposite side is also pressed against the brake disk 11 by the movement of the body 19.

As shown in FIG. 14, the other facing portion 17 of the caliper body 19 includes a cylindrical caliper housing 17A that is open at both front and rear ends in the axial direction, and a right angle with respect to the axial direction from the axially rear end of the caliper housing 17A. The caliper flange 17B extends in a direction (a direction parallel to the brake disc 11).

The caliper housing 17A has a rotation shaft 23, an outer ring member functioning as a linear motion member 24 disposed so as to surround the rotation shaft 23 (hereinafter, the same reference numeral as the linear motion member 24), and the rotation shaft 23. A planetary roller screw mechanism that functions as a motion conversion mechanism 25 that converts the rotation of the outer ring member 24 into an axial movement of the outer ring member 24 (hereinafter, the same reference numeral as that of the motion conversion mechanism 25 is attached). The friction pad 13 is disposed in front of the outer ring member 24 in the axial direction.

The electric motor 10 is attached to the caliper flange 17B. A reduction mechanism 26 is provided between the electric motor 10 and the rotary shaft 23 to reduce and transmit the rotation of the electric motor 10 to the rotary shaft 23. The speed reduction mechanism 26 is accommodated in a cover 27 provided so as to cover the end opening at the rear in the axial direction of the caliper housing 17A and the side surface of the caliper flange 17B (see FIG. 16).

As shown in FIG. 16 (see also FIG. 4), the speed reduction mechanism 26 includes a first gear 26A that rotates integrally with the rotor shaft 10A of the electric motor 10 and a second gear 26B that meshes with the first gear 26A. The fourth gear that rotates about the axis integrally with the second gear 26B, the third gear 26C that has fewer teeth than the second gear 26B, and the third gear 26C that meshes with the rotary shaft 23 to rotate about the axis. And a gear 26D. The rotation of the electric motor 10 is transmitted through the plurality of gears 26 </ b> A, 26 </ b> B, 26 </ b> C, 26 </ b> D after being sequentially decelerated and input to the rotary shaft 23.

As shown in FIG. 15 and the like, the fourth gear 26 </ b> D is supported by the caliper flange 17 </ b> B and the cover 27, and is restricted from moving in the axial direction and is relatively movable in the axial direction with respect to the rotating shaft 23. ing.

As shown in FIG. 15, the planetary roller screw mechanism 25 includes a plurality of planetary rollers 25A circumscribing the rotary shaft 23 and inscribed in the outer ring member 24, and a carrier 25B that supports the planetary rollers 25A so that they can rotate and revolve. And a spiral protrusion 25C provided on the inner periphery of the outer ring member 24, and a circumferential groove 25D provided on the outer periphery of the planetary roller 25A so as to engage with the spiral protrusion 25C.

As shown in FIG. 6, the plurality of planetary rollers 25A are arranged at equal intervals in the circumferential direction. Each planetary roller 25 </ b> A is in rolling contact with the outer periphery of the rotating shaft 23 and the inner periphery of the outer ring member 24. The contact portion of the rotating shaft 23 with respect to the planetary roller 25A is a cylindrical surface. When the rotating shaft 23 rotates, the planetary roller 25A revolves around the rotating shaft 23 while rotating around the roller shaft. That is, the planetary roller 25 </ b> A rotates by the rotational force received from the outer periphery of the rotating shaft 23, and accordingly, the planetary roller 25 </ b> A rolls around the inner periphery of the outer ring member 24 and revolves.

The spiral ridge 25C on the inner periphery of the outer ring member 24 is a spiral ridge extending obliquely with respect to the circumferential direction. On the other hand, the circumferential groove 25D on the outer periphery of the planetary roller 25A is a groove extending in parallel to the circumferential direction. In this embodiment, the circumferential groove 25D having a lead angle of 0 degree is provided on the outer periphery of the planetary roller 25A. However, instead of the circumferential groove 25D, a spiral groove having a lead angle different from that of the spiral protrusion 25C may be provided. Good.

As shown in FIG. 15, the outer ring member 24 is supported on the inner surface of the caliper housing 17A so as to be movable in the axial direction. A contact portion of the inner surface of the caliper housing 17A with respect to the outer ring member 24 is a cylindrical surface. The outer ring member 24 has a concave portion 29 that engages with a convex portion 28 formed on the back surface of the friction pad 13, and is prevented from rotating with respect to the caliper housing 17 </ b> A by the engagement of the convex portion 28 and the concave portion 29. .

The carrier 25B extends in the axial direction between a pair of carrier plates 25B ₁ and 25B ₂ facing in the axial direction with the planetary roller 25A in between and the planetary rollers 25A adjacent in the circumferential direction, and the carrier plates 25B ₁ and 25B _2. having a connecting portion 25B ₃ for connecting to each other, and a roller shaft 25B ₄ which rotatably supports the respective planetary rollers 25A. Each of the carrier plates 25B ₁ and 25B ₂ is formed in an annular shape that penetrates the rotating shaft 23, and a sliding bearing 30 that is in sliding contact with the outer periphery of the rotating shaft 23 is mounted on the inner periphery thereof.

Both end portions of the roller shaft 25B ₄ is movably supported in the radial direction of the outer ring member 24 in the long hole 31 formed on a pair of carrier plate _25B 1, 25B _2. Further, at both ends of the roller shaft 25B _4, the elastic ring 32 so as to circumscribe the roller shaft 25B ₄ of all of the planetary rollers 25A in the circumferential direction spaced is stretched. The elastic ring 32 prevents slippage between the planetary roller 25 </ b> A and the rotary shaft 23 by pressing each planetary roller 25 </ b> A against the outer periphery of the rotary shaft 23.

A load sensor 33 is provided behind the outer ring member 24 in the axial direction so as to be interposed between the pressing mechanism 15 and the planetary roller screw mechanism 25. This load sensor 33 is a magnetic load sensor (hereinafter, the same reference numeral as that of the load sensor 33), and includes a flange member 33A and a flange member 33A that cause deflection when a load is input from the front in the axial direction. The support member 33B is supported from the rear in the axial direction, includes a magnetic target 33C that generates magnetic flux, and a magnetic sensor 33D that detects the magnetic flux generated by the magnetic target 33C.

The flange member 33A is an annular plate member formed of a metal such as iron. The support member 33B is formed of a metal such as iron, like the flange member 33A, and is fitted into the outer peripheral edge of the flange member 33A. The fitting portion between the flange member 33A and the support member 33B acts as a fulcrum portion A (see FIGS. 19A and 19B) for bending the flange member 33A with respect to the support member 33B. The outer peripheral edge of the support member 33B is supported by the inner surface of the caliper housing 17A so as to be movable in the axial direction. A cylindrical portion 33E is continuously provided on the inner peripheral side of the support member 33B so as to face the inner diameter side of the flange member 33A. A plurality of bearings 34 are mounted on the inner periphery of the cylindrical portion 33E at intervals in the axial direction, and the rotary shaft 23 and the magnetic load sensor 33 are capable of relative rotation around the axis. The magnetic target 33C is fixed to the inner periphery of the flange member 33A. The magnetic sensor 33D is fixed to the outer periphery of the cylindrical portion 33E of the support member 33B so as to face the magnetic target 33C in the radial direction.

Between each planetary roller 25A and the carrier plate 25B ₂ of the axially rearward thrust bearing 35 which rotatably supports the planetary rollers 25A is incorporated. Between the axially aft of the carrier plate 25B ₂ and the magnetic load sensor 33 of the planetary roller 25A (flange member 33A), a thrust plate 36 which revolves together with the carrier plate 25B ₂ are provided. A thrust bearing 37 is incorporated between the thrust plate 36 and the flange member 33A of the magnetic load sensor 33. The flange member 33A and the thrust bearing 37 are in contact with each other at the reaction force portion R (see FIGS. 19A and 19B) of the flange member 33A. The thrust plate 36 can be rotated relative to the magnetic load sensor 33 around the axis by the thrust bearing 37.

Magnetic load sensor 33, the thrust plate 36, via the thrust bearing 37, by supporting the carrier plate 25B ₂ in the axial direction, and restrict the movement of the axially rearward of the carrier 25B. The carrier plate 25B ₁ of the axial forward movement of the axially forward is restricted by the first stopper ring 38a mounted on the axial forward end of the rotary shaft 23. Therefore, relative movement of the carrier 25B and the planetary roller 25A held by the carrier 25B is restricted relative to the rotating shaft 23 in the axial front and the axial rear.

A second retaining ring 38b is mounted on the outer periphery of the rotary shaft 23 near the rear in the axial direction. The second retaining ring 38b is in contact with a pusher 51 provided coaxially with the rotary shaft 23 from the rear in the axial direction. The pusher wheel 51 is in contact with the pressing portion P (see FIG. 19A) on the inner diameter side of the support member 33B from the rear in the axial direction (hereinafter, the push wheel 51 that contacts the inner diameter side of the support member 33B is referred to as a small diameter pusher wheel 51a. .) The pressing portion P is located radially inward of the reaction force portion R, and is largely separated in the radial direction from the fulcrum portion A that bends the flange member 33A with respect to the support member 33B.

A seal cover 40 that closes the opening at the front end of the outer ring member 24 in the axial direction is attached to the end of the outer ring member 24 in the axial direction. The seal cover 40 prevents foreign matter from entering the outer ring member 24. In addition, one end of a cylindrical bellows 41 formed to be extendable in the axial direction is fixed to an axially forward end of the outer ring member 24, and the other end of the bellows 41 is an opening in the axially forward direction of the caliper housing 17A. It is fixed to the edge. The bellows 41 prevents foreign matter from entering between the sliding surfaces of the outer ring member 24 and the caliper housing 17A.

When the planetary roller screw mechanism 25 rotates the electric motor 10, the rotation of the electric motor 10 is input to the rotating shaft 23 via the speed reduction mechanism 26, and the planetary roller 25A revolves while rotating (see FIG. 15). At this time, the outer ring member 24 and the planetary roller 25A move relative to each other in the axial direction due to the difference in the lead angle between the spiral protrusion 25C and the circumferential groove 25D, but the planetary roller 25A along with the carrier 25B is relative to the rotating shaft 23 in the axial direction. Since the movement is restricted, the planetary roller 25A does not move in the axial direction, and only the outer ring member 24 moves in the axial direction. Here, when the rotation in the direction in which the outer ring member 24 moves forward in the axial direction is input from the electric motor 10 to the rotation shaft 23, the outer ring member 24 presses the friction pad 13, thereby causing the friction pad shown in FIG. 12 and 13 are pressed against the brake disc 11, and a braking force is applied to the wheels that rotate integrally with the brake disc 11. Further, when rotation in the direction in which the outer ring member 24 moves rearward in the axial direction is input from the electric motor 10 to the rotary shaft 23, the friction pads 12 and 13 shown in FIG. The braking force is released.

When the electric motor 10 is operated and the friction pads 12 and 13 are pressed against the brake disk 11, the reaction force is magnetically transmitted through the outer ring member 24, the planetary roller screw mechanism 25, the thrust plate 36, and the thrust bearing 37. It is transmitted to the flange member 33A of the type load sensor 33. When the reaction force is transmitted to the flange member 33A, the flange member 33A bends in the axial direction with the fulcrum A as a fulcrum, and the magnetic target 33C fixed to the flange member 33A and the magnetic target fixed to the support member 33B. The sensor 33D is relatively displaced in the axial direction. Then, the output signal of the magnetic sensor 33D changes corresponding to this relative displacement. By grasping in advance the relationship between the magnitude of this output signal and the magnitude of the axial load input to the flange member 33A, the axial load applied to the flange member 33A can be determined based on the output signal of the magnetic sensor 33D. The size can be detected.

As shown in FIG. 16, the pressing mechanism 15 includes a pressing member 15 </ b> B provided so as to be movable in the axial direction so as to face the rear end in the axial direction of the rotating shaft 23, and around an axis perpendicular to the axial direction of the rotating shaft 23. A cam member 15A rotatably supported, a link member 15C incorporated between the pressing member 15B and the cam member 15A, and a wire lever 15D to which a wire end fitting provided at one end of the wire cable 14 is connected. Have One end of the wire lever 15D is connected to the cam member 15A, and when the wire cable 14 connected to the other end of the wire lever 15D is pulled, the wire lever 15D and the cam member 15A rotate together. (See FIG. 17).

The pressing member 15 </ b> B is slidably supported by the inner surface of a guide hole 42 provided in the cover 27 that extends in the axial direction. The end faces of the axially rearward of the pressing member 15B, the recess 15B ₁ that supports receiving one end of the link member 15C is formed. The outer periphery of the cam member 15A, the cam surface 15A ₁ is formed. Cam surface 15A _1, when the cam member 15A is rotated by pulling operation of the wire cable 14, in accordance with the rotation angle, with a shape that presses the pressing member 15B axially forward through the link member 15C It is formed as follows.

A spherical body 52 is provided between the pressing member 15 </ b> B and the rotating shaft 23, and a pressing force is transmitted to the rotating shaft 23 through the spherical body 52. A return spring 15E that urges the wire lever 15D in a direction opposite to the rotating direction of the wire lever 15D by the pulling operation of the wire cable 14 is attached to the wire lever 15D (see FIG. 15).

When the wire cable 14 is pulled as shown in FIG. 17 by the operating force of the driver, the pressing mechanism 15 rotates the cam member 15A by the pulling force, and according to the rotation angle of the cam member 15A, cam surfaces 15A ₁ moves down the pressing member 15B axially forward via the link member 15C. Then, the pressing member 15 </ b> B presses the rotating shaft 23 forward in the axial direction via the sphere 52. When the rotary shaft 23 moves forward in the axial direction, the small diameter pusher wheel 40a is pressed forward in the axial direction by the second retaining ring 38b, and further, the support member 33B is pressed forward in the axial direction by the small diameter pusher wheel 40a. When the support member 33B is pressed forward in the axial direction, the flange member 33A fitted to the support member 33B is also pressed forward in the axial direction while the support member 33B is bent forward in the axial direction.

When the flange member 33A is pressed forward in the axial direction, the pressing force is transmitted to the planetary roller screw mechanism 25 via the thrust bearing 37 and the thrust plate 36. Then, the outer ring member 24 moves forward in the axial direction by the engagement between the spiral protrusion 25C provided on the planetary roller 25A of the planetary roller screw mechanism 25 and the circumferential groove 25D provided on the outer ring member 24. With this movement, the friction pad 13 also moves forward in the axial direction, and the friction pad 13 is pressed against the brake disc 11.

When the outer ring member 24 moves forward in the axial direction and the friction pads 12 and 13 are pressed against the brake disk 11, a magnetic load is applied via the carrier plate 25B ₂ and the thrust bearing 37 as a reaction force in the rearward direction in the axial direction. An axial load directed rearward in the axial direction is input to the reaction force portion R of the flange member 33A of the sensor 33. Then, due to this axial load, the flange member 33A bends rearward in the axial direction around the support portion A (see FIG. 19A and the like). At this time, the deflection in the axially rearward direction of the flange member 33A and the deflection in the axially forward direction of the support member 33B described above are superimposed (see the arrow in FIG. 19A), thereby causing a normal operation due to the operation of the electric motor 10. Compared to braking, the relative displacement amount of the magnetic target 33C and the magnetic sensor 33D at the same braking force is increased. As a result, as shown in FIG. 20, the output of the load sensor with respect to the load change of the friction pad 13 can be emphasized as compared with the normal braking by the driving force of the electric motor 10. The resolution for detecting the braking force when the operation is performed can be improved.

This electric brake device may be provided with a warning device that warns the driver of insufficient load when the load detected by the magnetic load sensor 33 (operating force by the driver) is smaller than a predetermined load threshold. it can. As described above, by providing the warning device, it is possible to easily recognize that the driver is in a state of insufficient load, and it is possible to quickly take appropriate measures such as increasing the operating force.

As shown in FIG. 1, the brake pedal 43 operated by the driver's foot includes a wire connector portion 44 to which a wire end fitting provided at an end portion of the wire cable 14 is connected, and a clutch mechanism 45. It is attached. The brake pedal 43 is supported so as to be swingable about a fulcrum shaft 46. The brake pedal 43 is provided with a stroke sensor (not shown) that detects the depression amount of the brake pedal 43. The wire connector portion 44 is swingably supported so as to have a swing center at the same position as the fulcrum shaft 46 of the brake pedal 43. Here, the wire connector portion 44 can swing independently of the brake pedal 43 so that the brake pedal 43 can swing independently of the wire connector portion 44.

As the clutch mechanism 45, a reverse operation type electromagnetic clutch configured to be disconnected when energized and to be connected when energization is stopped can be employed. In this way, by adopting the reverse operation type electromagnetic clutch, the clutch mechanism 45 is in the connected state when the energization to the clutch mechanism 45 is stopped, so even when the electric brake device loses power, A braking force can be secured. The clutch mechanism 45 performs brake control based on detection results of sensors such as a stroke sensor, a magnetic load sensor 33, and a battery sensor (not shown) that detects a charge amount of a battery that supplies electric power to the electric motor 10. Controlled by a unit (not shown).

As described above, even when the electric motor 10 does not operate, the electric brake device pushes the rotating shaft 23 forward in the axial direction by pulling the wire cable 14 with the driver's operating force, and the rotating shaft 23 and the outer ring. The friction pad 13 can be pressed against the brake disc 11 by moving the member 24 integrally in the axial direction. Therefore, even when trouble such as electrical failure occurs, a braking force can be generated, and high safety can be ensured.

FIG. 18 shows a fifth embodiment (main part) of the electric brake device according to the present invention. This electric brake device has the same basic configuration as the electric brake device according to the fourth embodiment (see FIG. 15), but the shape of the push wheel 51 that transmits the pressing force of the pressing mechanism 15 to the magnetic load sensor 33 is different. Yes. In other words, the pusher 51 according to the fifth embodiment has an outer diameter larger than that of the pusher 51 (small-diameter pusher 51a) according to the fourth embodiment, and the pusher 51 according to the fifth embodiment has a shaft on the outer diameter side pressing portion P (see FIG. 19B). Abutting from the rear in the direction (hereinafter, the pusher wheel 51 abutting on the outer diameter side of the support member 33B is referred to as a large-diameter pusher wheel 51b).

The pressing portion P of the large-diameter pusher wheel 51b is close to the fulcrum portion A that bends the flange member 33A with respect to the support member 33B in the radial direction. In this case, when the wire cable 14 is pulled by the driver's operating force and the friction pads 12 and 13 are pressed against the brake disk 11 as shown in FIG. 17, the flange member 33A acts as a reaction force in the axial rearward direction. Since the pressing portion P and the fulcrum portion A of the support member 33B are close to each other in the radial direction, the support member 33B is almost axially forward due to the pressing force from the pressing mechanism 15. Not sure (see arrow in FIG. 19B). For this reason, unlike the electric brake device according to the fourth embodiment (configuration employing the small diameter pusher 51a), the electric brake device (configuration employing the large diameter pusher 51b) according to the fifth embodiment is shown in FIG. As described above, the same load sensor output can be obtained during normal braking using the driving force of the electric motor 10 and when braking is performed using the driver's operating force.

FIG. 21 shows a sixth embodiment (main part) of the electric brake device according to the present invention. This electric brake device has the same basic configuration as the electric brake devices according to the fourth and fifth embodiments (see FIGS. 15 and 18), and the braking force is applied when the brake operation is performed by the driver's operation force. Although it is the same in that it can be detected, the configuration of the pressing mechanism 15 is different. That is, as shown in the figure, the pressing mechanism 15 includes a linearly moving disk 15G corresponding to the pressing member 15B according to the fourth embodiment, disposed behind the rotating shaft 23 in the axial direction, and the shaft of the linearly moving disk 15G. A structure having a rotating disk 15H disposed opposite to the rear in the direction, a ball 15I provided between the linearly moving disk 15G and the rotating disk 15H, and a wire lever 15D to which one end of the wire cable 14 is connected. (Ball lamp format).

The linear motion disk 15G is slidably supported on the inner surface of a guide hole 42 provided in the cover 27 extending in the axial direction. The linearly moving disk 15G has a protrusion extending in the axial direction, and a guide groove for guiding the protrusion in the axial direction is formed on the inner surface of the guide hole 42. It is movable in the axial direction while being prevented from rotating around the axis. The rotating disk 15H is rotatably supported by the guide hole 42 in a state where the axial rearward movement is restricted by the thrust bearing 47.

As shown in FIG. 10, on the facing surface relative to the linear motion disk 15G of the rotation disk 15H, a plurality of inclined grooves 15H ₁ at intervals in the circumferential direction are formed. Further, as shown in FIG. 11A, FIG. 11B, in the opposite plane to the rotation disk 15H of the linear motion disk 15G, circumferentially spaced plurality of inclined grooves 15G ₁ is formed.

As shown in FIG. 13, the inclined groove 15G ₁ includes, from the deepest portion 15G ₂ in one circumferential direction is formed so as gradually become shallower, inclined groove 15H ₁ is toward the deepest portion 15H ₂ in the other circumferential direction It is formed so as to become shallower. The ball 15I is incorporated between both the inclined grooves 15G ₁ and 15H ₁ .

As shown in FIG. 11A, one end of the wire lever 15D is connected to the rotating disk 15H, and when the wire cable 14 connected to the other end of the wire lever 15D is pulled, the wire lever 15D and the rotating disk are connected. 15H rotates together. A return spring 15E that urges the wire lever 15D in a direction opposite to the rotation direction of the wire lever 15D by the pulling operation of the wire cable 14 is attached to the wire lever 15D.

When the wire mechanism 14 is pulled, the pressing mechanism 15 rotates the rotating disk 15H by a tensile force acting on the wire cable 14 as shown in FIG. 11B. As a result, the ball 15I has the inclined grooves 15G ₁ , since rolls 15H ₁ in a direction becomes shallower from the deepest _15G 2, 15H _2, axial spacing of the rotating disk 15H and the linear motion disk 15G is enlarged in accordance with the rotation angle of the rotation disk 15H. Here, since the rotation disc 15H is restricted from moving rearward in the axial direction, the linear motion disc 15G moves forward in the axial direction, and the rotary shaft 23 is pushed forward in the axial direction by the linear motion disc 15G. Move.

FIG. 22 shows a seventh embodiment (main part) of the electric brake device according to the present invention. In the electric brake device according to the fourth to sixth embodiments (see FIGS. 15, 18, and 21), the caliper flange 17B and the cover 27 support the fourth gear 26D from both sides in the axial direction, and this fourth gear. Whereas the movement in the axial direction of 26D is limited, in the electric brake device according to the seventh embodiment, the second retaining ring 38b is provided on the axially rear side of the fourth gear 26D of the rotating shaft 23, The fourth gear 26D is configured to allow movement in the axial direction while preventing the fourth gear 26D from coming off the rotating shaft 23.

In this way, it is possible to press the pusher wheel 51 (small-diameter pusher wheel 51a in this embodiment) forward in the axial direction with the fourth gear 26D itself movable in the axial direction. In this configuration, since the caliper flange 17B that supports the fourth gear 26D from the front in the axial direction is not required, the axial length of the electric brake device can be reduced in size and weight.

FIG. 23 shows an eighth embodiment (main part) of the electric brake device according to the present invention. This electric brake device has the same basic configuration as the electric brake device according to the fourth embodiment (see FIG. 15), and can detect the braking force when the brake operation is performed by the driver's operation force. However, the transmission mechanism of the pressing force between the pressing mechanism 15 and the rotating shaft 23 is different. That is, in the electric brake device according to the fourth embodiment, the sphere 52 is provided between the pressing member 15 </ b> B of the pressing mechanism 15 and the rotating shaft 23, and the pressing force is transmitted through the sphere 52. However, in the electric brake device according to the eighth embodiment, without using the sphere 52, the axially forward end surface of the pressing member 15 </ b> B that is prevented from rotating with respect to the cover 27 and the axially rearward end surface of the rotary shaft 23. The pressure is transmitted by bringing the surface into direct surface contact.

As described above, when both end surfaces are brought into surface contact, rotation around the axis of the rotary shaft 23 is prevented by the frictional force between the pressing member 15B and the rotation of the cover 27. In this way, by preventing the rotation of the rotating shaft 23, the lead angle of the spiral ridge 25 </ b> C provided on the outer ring member 24 when the fail-safe mechanism is activated due to trouble such as the failure of the electric motor 10. Even when the angle between the circumferential groove 25D provided on the planetary roller 25A is large, it is possible to prevent slippage at the engaging portion between them, and the fail-safe mechanism functions reliably. Can be made.

In this embodiment, the end surface on the rear side in the axial direction of the rotating shaft 23 and the end surface on the front side in the axial direction of the carrier 25B are both flat surfaces, but as long as sufficient frictional force is exerted between the both end surfaces. The end surface shape is not limited, and for example, one end surface may be a concave curved surface, and the other end surface may be a convex curved surface having the same curvature as the concave curved surface.

FIG. 24 shows a ninth embodiment (main part) of the electric brake device according to the present invention. This electric brake device has the same basic configuration as the electric brake device according to the eighth embodiment (see FIG. 23), and can detect the braking force when the brake operation is performed by the driver's operating force. However, the configuration of the pressing mechanism 15 is different. That is, in the electric brake device according to the eighth embodiment, the cam-type pressing mechanism 15 is adopted, but in the electric brake device according to the ninth embodiment, the ball ramp-type pressing mechanism 15 is adopted. The axially forward end surface of the linear motion disk 15G of the pressing mechanism 15 that is prevented from rotating with respect to the cover 27 and the axially rearward end surface of the rotary shaft 23 are both flat surfaces. Thus, the pressing force is transmitted by bringing both end surfaces into contact with each other, and the sliding of the both engaging portions to prevent the rotating shaft 23 from rotating inadvertently and the fail-safe mechanism functions reliably. Like to do.

FIG. 25 shows a tenth embodiment (main part) of the electric brake device according to the present invention. This electric brake device is the same as the electric brake device according to the ninth embodiment (see FIG. 24) in that a ball ramp type pressing mechanism 15 is provided. The moving disk 15G is different in that the moving disk 15G is brought into surface contact with the fourth gear 26D which is an extending member extending radially outward of the rotating shaft 23 instead of the rotating shaft 23. Since the fourth gear 26D has a larger diameter than the outer diameter of the rotary shaft 23, the fourth gear 26D and the linear motion disk 15G are brought into surface contact to bring the rotary shaft 23 and the linear motion disc 15G into contact with each other. In comparison, the anti-rotation action of the rotating shaft 23 can be further improved.

FIG. 26 shows an eleventh embodiment (main part) of the electric brake device according to the present invention. This electric brake device has the same basic configuration as the electric brake device according to each of the above embodiments, and is the same in that the braking force can be detected when the brake operation is performed by the driver's operation force. However, unlike the electric brake device according to each of the embodiments described above, the motion conversion that converts the rotation of the rotating shaft 23 to which the rotation of the electric motor 10 is input into the axial movement of the linear motion member 24 that presses the friction pad 13. As the mechanism 25, a feed screw mechanism (hereinafter, the same reference numeral as that of the motion converting mechanism 25 is given) is adopted.

The feed screw mechanism 25 is formed on the outer periphery of a screw shaft 25E formed integrally with the rotary shaft 23, a nut 25F functioning as a linear motion member 24 provided so as to surround the screw shaft 25E, and the screw shaft 25E. A plurality of balls 25I incorporated between the screw groove 25G and the screw groove 25H formed on the inner periphery of the nut 25F, and a return tube (not shown) for returning the ball from the end point of the screw groove 25H of the nut 25F to the start point And have.

The nut 25F is provided in the caliper housing 17A so as to be movable in the axial direction while being prevented from rotating with respect to the caliper housing 17A. The axially rearward end of the screw shaft 25E, the flange 25E ₁ is formed radially outwardly. The axially rearward of the flange 25E _1, the thrust bearing 49 is provided. The thrust bearing 49 is in contact with the flange member 33A of the magnetic load sensor 33, and the reaction force received by the friction pad 13 from the brake disk 11 is transmitted to the flange member 33A via the thrust bearing 49.

When the electric motor 10 is rotated, the rotation of the electric motor 10 is input to the rotary shaft 23 via the speed reduction mechanism 26, and the nut 25F moves forward in the axial direction along with the rotation of the rotary shaft 23. A friction pad 13 provided forward in the direction is pressed against the brake disc 11. On the other hand, when trouble such as a failure of the electric motor 10 occurs and the wire cable 14 is pulled by the driver's operating force, the linear motion disk 15G and the rotating disk 15H are relatively rotated around the axis by the tensile force. At the same time, the linear motion disk 15G moves forward in the axial direction, and the end face of the linear motion disk 15G in the axial direction and the fourth gear 26D come into surface contact.

Thus, when the linear motion disk 15G and the fourth gear 26D are brought into surface contact with each other, the frictional force between the linear motion disk 15G that is prevented from rotating with respect to the cover 27 prevents the rotation of the rotary shaft 23 around the axis. The As a result, when the fail-safe mechanism is activated due to a trouble such as a failure of the electric motor 10, it is possible to prevent the feed screw mechanism 25 from operating in reverse due to the reaction force that the friction pad 13 receives from the brake disk 11. The fail-safe mechanism can function reliably.

The electric brake device according to each of the above embodiments is merely an example, and the first problem of the present invention that the fail-safe mechanism of the electric brake device functions reliably or the operation of the fail-safe mechanism of the electric brake device As long as the second problem of the present invention that the braking force can be detected sometimes can be solved, the configuration of the motion conversion mechanism 25 and the pressing mechanism 15 and the shape, arrangement, material, and the like of each component are appropriately changed. You can also For example, in each of the embodiments described above, the magnetic load sensor 33 is employed, but a strain detection type load sensor may be employed instead.

DESCRIPTION OF SYMBOLS 10 Electric motor 11 Brake disc 13 Friction pad 15 Press mechanism 15A Cam member 15B Press member 15C Link member 15F Biasing member (release spring)
15G linear motion disk 15G ₁ inclined groove 15H rotating disk 15H ₁ inclined groove 15I rolling element (ball)
23 Rotating shaft 24 Linear motion member (outer ring member)
25 Motion conversion mechanism (planet roller mechanism, feed screw mechanism)
26D Extension member 33 Load sensor (magnetic load sensor)
33A Flange member 33B Support member 33C Magnetic target 33D Magnetic sensor 48 Extension member A Supporting point R Reaction force part P Pressing part

Claims (12)

1. An electric motor (10);
   A rotating shaft (23) that rotates about the axis by the rotational driving force of the electric motor (10);
   A linear motion member (24) movably provided in the axial direction of the rotation shaft (23);
   A motion conversion mechanism (25) that converts the rotation of the rotary shaft (23) into an axial movement of the linear motion member (24);
   A friction pad (13) provided on one axial side of the linear motion member (24) and moving in the axial direction along with the axial movement of the linear motion member (24);
   While the rotation of the rotation shaft (23) is prevented by the driver's operating force, the rotation shaft (23) is pressed against the one side in the axial direction so that the rotation shaft (23) and the straight shaft A pressing mechanism (15) for moving the moving member (24) integrally to the one side in the axial direction;
   Electric brake device having
2. The pressing mechanism (15) is in surface contact with the rotating shaft (23) and moves in the axial direction while preventing rotation around the rotating shaft (23) by a frictional force, thereby rotating the rotating shaft (23). 2. The electric brake device according to claim 1, further comprising: a pressing member (15 </ b> B) that is prevented from rotating about an axis and presses the first side toward the one side in the axial direction.
3. The pressing mechanism (15)
   A cam member (15A) that is rotated by the operating force of the driver;
   A link member (15C) that moves in the axial direction in accordance with the rotation of the cam member (15A) and moves the pressing member (15B) in the axial direction;
   The electric brake device according to claim 2, further comprising:
4. The pressing mechanism (15)
   A linear motion disk (15G) functioning as the pressing member (15B) in which an inclined groove (15G ₁ ) whose depth varies along the circumferential direction is formed on _one surface in the axial direction;
   The linear motion disk (15G) is arranged with an axial interval between the linear motion disk (15G) so as to face the inclined groove (15G ₁ ) formed in the linear motion disk (15G). A rotating disk (15H) that is formed with an inclined groove (15H ₁ ) whose depth changes along the circumferential direction on the surface facing the surface, and that is rotated by the driver's operating force;
   A rolling element held rotatably by the inclined groove (15G ₁ ) formed in the linear motion disk (15G) and the inclined groove (15H ₁ ) formed in the rotating disk (15H). (15I)
   The rolling element (15I) rolls in the inclined grooves (15G ₁ , 15H ₁ ) due to relative rotation between the linear motion disk (15G) and the rotating disk (15H). The electric brake device according to claim 2, wherein the linearly moving disk (15G) is moved in the axial direction by widening the interval.
5. The pressing mechanism (15) further includes a biasing member (15F) that biases the pressing member (15B) to the other side opposite to the one side in the axial direction. The electric brake device according to item.
6. The rotating shaft (23) has a radially extending outwardly extending member (48) that is rotatable about the shaft integrally with the rotating shaft (23), and the pressing member (15B) The electric brake device according to any one of claims 2 to 5, wherein the electric brake device can be brought into contact with the extending member (48).
7. The friction pad is provided between the pressing mechanism (15) and the motion converting mechanism (25), and transmits the pressing force by the pressing mechanism (15) to the motion converting mechanism (25). A load sensor (33) for detecting a load applied to the brake disk (11) in response to a reaction force axially rearward when the brake disk (13) is pressed against the brake disk (11).
   The electric brake device according to any one of claims 1 to 6, further comprising:
8. The load sensor (33)
   A flange member (33A) for receiving the reaction force;
   A support member (33B) connected to the flange member (33A) so as to be bendable and receiving a pressing force forward in the axial direction by the pressing mechanism (15);
   A magnetic target (33C) provided on one side of the flange member (33A) or the support member (33B);
   A magnetic sensor (33D) provided on the other side of the flange member (33A) or the support member (33B) on the side where the magnetic target (33C) is provided so as to face the magnetic target (33C);
   The fulcrum part (A) in which the flange member (33A) and the support member (33B) are connected to each other is a reaction force that the flange member (33A) receives the reaction force. The electric brake device according to claim 7, wherein the force portion (R) and the support member (33B) are positioned radially outward from the pressing portion (P) that receives the pressing force.
9. The electric brake device according to claim 8, wherein the pressing portion (P) is located radially inside the reaction force portion (R).
10. The pressing mechanism (15) includes a pressing member (15B) that is prevented from rotating about an axis, and the rotation is performed by a frictional force caused by surface contact between the rotating shaft (23) and the pressing member (15B). The electric brake device according to any one of claims 7 to 9, wherein rotation of the shaft (23) around the shaft is prevented.
11. The pressing mechanism (15) has a pressing member (15B) that is prevented from rotating about an axis, and rotates about the axis integrally with the rotating shaft (23). The rotation about the axis of the rotary shaft (23) is prevented by a frictional force due to surface contact between the extending member (26D) extending in the direction and the pressing member (15B). The electric brake device according to any one of 1 to 9.
12. The warning device according to any one of claims 7 to 11, further comprising a warning device that warns the driver that the load is insufficient when a load detected by the load sensor (33) is smaller than a predetermined load threshold. The electric brake device described.

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