JPH10281191A - Motor-driven type disk brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To modify the supporting structure of a rotation member to be hardly influenced by a reaction force from a friction pad, in a disc brake to press a friction pad against a disc rotor by rotating a rotary member by a motor and converting the rotation into linear movement. SOLUTION: The support structure of a rotary member rotated by a motor 72 forms structure that the radial load of the rotation member 102 is applied to a plurality of spots 120 and 122 spaced away from each other axially of the rotation member 102. Thus, even when, during operation of a disc brake, a reaction force from the friction pad 20 is applied to the rotary member 102 as a deviated load, the rotary member 102 does not incline retative to a caliper 60 and a motor housing 60 and a rotor 84 does not incline retative to stator 82.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-driven disk brake using a motor as a drive source, and more particularly to a motor-driven disk brake which is rotated by a motor and thrusts a reaction force from a friction pad. The present invention relates to an improvement in a support structure of a rotating member that receives a load.

[0002]

2. Description of the Related Art The above-mentioned motor-driven disc brake is generally constructed as follows. That is, (a) a disk rotor having a friction surface and rotating together with the wheel, (b) a friction pad for suppressing rotation of the disk rotor by being pressed by the disk rotor on the friction surface, and (c) a rotor And (d) a rotating member rotated by the motor, and (e) a movable member arranged behind the friction pad in a direction intersecting the friction surface. A moving member, and (f) a movement converting mechanism that converts the rotational movement of the rotating member into a linear movement of the moving member, thereby pressing the friction pad against the disk rotor; (g) at least the moving member A caliper having a portion functioning as the motor housing;
(h) a rotating member supporting mechanism provided on the caliper and the rotating member, rotatably supporting the rotating member with respect to the caliper, and receiving at least a reaction force acting as a thrust load from the rotating member at the time of pressing by the caliper. It is configured to include Here, the caliper is generally supported by the mounting bracket so as to be movable in a direction intersecting the friction surface of the disk rotor. The mounting bracket is generally fixedly mounted on the vehicle body. That is, in the disk brake, generally, the friction pad is movably supported by the disk rotor by the cooperation of the caliper and the mounting bracket.

A conventional example of this type of disc brake is described in Japanese Patent Application Laid-Open No. 8-284980. In this conventional disk brake, the rotating member support mechanism receives one radial bearing of the rotating member and rotatably supports the rotating member with respect to the caliper, and receives a thrust load of the rotating member. One thrust bearing rotatably supports the rotating member with respect to the caliper, and the thrust bearing is provided between the rotating member and a portion of the caliper that functions as a motor housing. Further, in this conventional disc brake, the caliper has a portion close to the friction pad (hereinafter, referred to as a caliper main body) and a portion far away and including at least a portion functioning as a motor housing (hereinafter, simply referred to as “motor”). The housing is referred to as a separate component and screwed together.

[0004]

SUMMARY OF THE INVENTION Therefore, in this conventional disk brake, the influence of the first reaction force acting as an eccentric load on the rotating member from the moving member during the operation is given to the conventional disk brake. There is a problem that the rotary member is easily affected by the second reaction force acting on the caliper. Hereinafter, a specific description will be given.

In a disk brake, a reaction force generally acts as a thrust load from the friction pad directly to the moving member or indirectly via a pressing member such as a pressing piston during the operation. The reaction force acts on the caliper from the rotating member as a thrust load.

On the other hand, in a disk brake, since the mounting bracket is generally mounted on the vehicle body in a cantilever manner, when a frictional force is generated between the disk rotor and the friction pad during the operation of the disk brake, the mounting bracket is caused by the frictional force. A moment is generated, which displaces the mounting bracket and accordingly the caliper. Also, since the shape of the caliper is not completely symmetrical with respect to the direction of action of the reaction force from the friction pad, when a pressing force is generated between the disk rotor and the friction pad during the operation of the disk brake, the pressing force generates a moment on the caliper. Occurs, whereby the caliper is elastically deformed. Further, the relative positional accuracy among the friction pad, the moving member, the rotating member, and the caliper may be insufficient.

Due to these factors, in a disk brake, generally, the line of action of the reaction force acting on the moving member from the friction pad at the time of the operation deviates from the axis of the moving member. As a result, the line of action of the reaction force acting on the rotating member from the moving member may be deviated from the axis of the rotation axis. Also,
Even if the line of action of the reaction force from the friction pad does not deviate from the axis of the moving member, the line of action of the reaction force from the moving member may deviate from the axis of the rotation axis.

[0008] In short, in general, in a disk brake, a reaction force from the moving member to the rotating member at the time of its action causes the line of action to deviate from the axis of the rotating member (including tilting with respect to the axis of the rotating member). It will act as a load.

However, in the above-mentioned conventional disk brake, the rotating member is supported by the caliper via the radial bearing at only one place. Therefore, in this conventional disc brake, when an eccentric load acts on the rotating member, there is a problem that the rotating member is easily inclined with respect to the caliper. When the rotating member is tilted, the rotational resistance of the rotating member increases, which may cause a problem that smooth rotation of the rotating member is hindered.

In this conventional disk brake, the motor is an ultrasonic motor, and the stator is fixedly mounted on the motor housing, while the rotor is mounted coaxially with the rotating member and cannot rotate relative thereto. . Therefore, when the rotating member is inclined with respect to the caliper (including the motor housing), the rotor is also inclined with respect to the stator, and the rotor and the stator do not contact uniformly in the circumferential direction. As a result, in the conventional disk brake, when the rotating member is tilted, the vibration of the stator is not transmitted to the rotor normally, and the driving torque of the ultrasonic motor is reduced. This problem may occur not only in the ultrasonic motor but also in a motor in which the stator and the rotor are arranged via an air gap.

As is apparent from the above description, in this conventional disk brake, a reaction force (first reaction force) acts on the rotating member from the moving member at the time of the operation, so that the rotating member is applied to the caliper. The motor may be affected by the fact that the rotor is tilted with respect to the stator and its driving torque is reduced due to the increase in the rotational resistance of the rotating member. There was a nature.

In general, in a disk brake, it is desired that the frictional force of the friction pad, that is, the brake operating force, responds quickly to the operation of the motor during, for example, antilock control, traction control, and sudden braking. Is done. As a measure to satisfy this demand for improved operation responsiveness, there are, of course, measures to improve the operation responsiveness of the motor.However, when the disc brake is actuated, the caliper reacts to it as much as possible. There is also a measure to improve the caliper rigidity so that it does not deform.

On the other hand, in the above-mentioned conventional disk brake, at the time of its operation, a reaction force acts on the motor housing from the rotating member via the thrust bearing.
A reaction force acts on the caliper body from the motor housing. Further, in this conventional disc brake, as described above, since the original portion of the caliper and the motor housing are connected by fixing means such as bolts, the reaction force acts on the caliper body from the motor housing via the fixing means. Will do. Therefore, in the conventional disk brake, in order to satisfy the above-mentioned demand for improving the operation response, not only the rigidity of the caliper body but also the rigidity of the motor housing must be increased. The material of the motor housing is made of steel and its plate thickness must be increased. Therefore, this conventional disk brake is liable to increase the size and weight of the motor housing. There is also a problem that the whole is easily increased in size and weight. Further, in the conventional disk brake, there is a problem that measures must be taken to minimize the elongation of the fixing means due to the reaction force in order to satisfy the demand for improved operation responsiveness.

As apparent from the above description, in this conventional disk brake, a reaction force (second reaction force) acts on the caliper main body via the motor housing from the rotating member during the operation. The load that the motor housing has to bear increases, which may have the effect that the motor has to increase the rigidity that the motor housing, a component of it, must have.

The present invention has been made in view of the above circumstances, and an object thereof is to improve a support structure of a rotating member in a motor-driven disc brake,
An object of the present invention is to improve the performance of a motor-driven disc brake by solving the above-mentioned problems.

This problem is solved by a motor-driven disc brake of the following mode. In the following description, each aspect of the present invention will be described in the same form as the claims, with the respective items numbered. This is to clarify the possibility of adopting the features described in each section in combination.

(1) (a) a disk rotor having a friction surface and rotating together with the wheel; and (b) a friction pad for suppressing rotation of the disk rotor by being pressed by the disk rotor on the friction surface. (c) a motor having a rotor, a stator and a motor housing that houses them, (d) a rotating member rotated by the motor,
(e) a moving member disposed behind the friction pad so as to be movable in a direction intersecting the friction surface, and (f) converting a rotational motion of the rotating member into a linear motion of the moving member, whereby A motion converting mechanism for pressing the friction pad against the disk rotor, (g) a caliper supporting at least the moving member, and having a portion functioning as the motor housing, (h) the caliper and the rotation A rotating member supporting mechanism provided on the member and rotatably supporting the rotating member with respect to the caliper, and a rotating member supporting mechanism for receiving at least a reaction force acting as a thrust load from the rotating member at the time of pressing by the caliper. In the rotating member support mechanism, at least one of the rotating member and the motor, when the disc brake acts, the It has a reaction force reduction support structure that is less likely to receive at least one of the influence of the first reaction force acting as an offset load on the rotating member from the moving member and the influence of the second reaction force acting on the caliper from the rotation member. A motor-driven disc brake (Claim 1). Therefore, according to this disc brake, the rotating member supporting mechanism is of a reaction force effect reducing type in which at least one of the rotating member and the motor is hardly affected by the reaction force from the friction pad when the disk brake operates, The effect is obtained that the performance of the motor-driven disk brake is improved despite the presence of the reaction force. In this disc brake, the “motor” may be, for example, an ultrasonic motor or a winding motor. Also,
In this disc brake, the "moving member" can be configured to directly engage the friction pad from behind, or to engage the friction pad from behind via a pressing member. In this disc brake, the "caliper" may be a divided structure in which the caliper main body and the main body of the motor housing are separated from each other and screwed together, or may be an integrated structure integrated with each other. it can. Further, the “calipers” can be of a floating type or a fixed type. Generally, in a disc brake in which the caliper is floating, the friction surface has
A pair of friction surfaces formed on both sides of the disk rotor, the friction pad is a pair of friction pads pressed from both sides of the disk rotor, and a caliper is formed between the pair of friction pads and the disk rotor. At the time of pressing, one of the pair of friction pads on which the moving member is disposed behind the friction pad transmits a reaction force received from the disk rotor to the other friction pad.

(2) The support structure for reducing the influence of the reaction force includes a first structure that prevents the axis of the rotating member from being inclined with respect to the caliper due to the first reaction force when the disc brake operates. The motor-driven disc brake according to the above item (2). Therefore, according to this disc brake, the rotation member is prevented from tilting with respect to the caliper during the operation, so that an effect that the rotation resistance of the rotation member does not need to be increased can be obtained.

(3) The rotating member is coaxially mounted on the rotor so as to be non-rotatable relative to the rotor, and the first structure is configured such that the axis of the rotating member is adjusted by the first reaction force when the disc brake is actuated. The motor-driven disc brake according to claim 2, further comprising a structure that suppresses tilting with respect to the caliper, thereby suppressing the axis of the rotor from tilting with respect to the stator. Therefore, according to the disc brake, the rotation member is prevented from tilting with respect to the caliper (including a portion functioning as a motor housing) during the operation, and thereby, the rotor is prevented from tilting with respect to the stator. Therefore, an effect that the driving torque of the motor does not need to be reduced can be obtained.

(4) The first structure includes a structure in which the rotating member is rotatably supported by receiving a radial load of the rotating member at a plurality of locations separated in the axial direction of the rotating member (2) or (3). ) The motor-driven disc brake according to the above item (Claim 4). Therefore, according to the disc brake, an effect is obtained that the inclination of the rotating member can be suppressed with a simple structure during the operation.

(5) In the above structure, at least a plurality of bearings rotatably supporting the rotating member under a radial load of the rotating member are arranged at a plurality of locations separated in the axial direction of the rotating member. A motor-driven disc brake according to item (4).

(6) The rotor is coaxially and non-rotatably mounted on the rotating member, whereby the rotating member is partitioned by the rotor into a front portion near the friction pad and a rear portion far from the friction pad. A motor-driven disc brake according to item (5).

(7) The motor-driven disc brake according to (6), wherein each of the plurality of bearings is disposed on one of the front portion and the rear portion.

(8) The motor-driven disc brake according to the above mode (6), wherein at least one of the plurality of bearings is arranged at the front portion and the rest is arranged at the rear portion.

(9) The motor according to (5), (6) or (8), wherein the plurality of bearings include two bearings arranged on the rotating member in the vicinity of both ends thereof, respectively. Driven disc brake.

(10) The plurality of bearings receives at least one radial bearing of the rotating member to rotatably support the rotating member, and the radial load and the thrust load of the rotating member are different from each other. The motor-driven disc brake according to any one of (5) to (9), including at least one radial thrust bearing that receives both of them and rotatably supports the rotating member. Therefore, according to this disc brake, a radial thrust bearing that receives both the radial load and the thrust load of the rotating member is used, so that the number of bearings in the disc brake can be reduced.

(11) The support structure for reducing the influence of reaction force has a second structure that does not transmit the second reaction force to the motor when the disc brake operates. Motor-driven disc brake (claim 5). Therefore, according to this disc brake, the second reaction force of the rotating member is not transmitted to the motor during the operation, so that the rigidity of the motor housing does not need to be increased,
When the caliper body and the motor housing are screwed together as separate parts, the effect of improving the brake responsiveness can be obtained without increasing the rigidity of fixing means such as screws.

(12) In the second structure, a reaction force transmitting portion for transmitting the second reaction force to the caliper is formed on the rotating member so as to face the side opposite to the friction pad, At a position closer to the friction pad than a portion of the caliper, which functions as the motor housing, of the caliper, the second reaction force is opposed to the reaction force transmission portion in the axial direction of the rotating member from the reaction force transmission portion. A reaction force receiving portion is formed, and the reaction force transmitting portion and the reaction force receiving portion sandwich a bearing that at least receives a thrust load of the rotating member and rotatably supports the rotating member with respect to the caliper. The motor-driven disk brake according to the mode (11) including a structure (claim 6). Therefore, according to this disc brake, an effect is obtained that the brake responsiveness can be improved with a simple structure.

(13) The reaction force transmitting portion includes a rearward facing surface formed on the rotating member facing away from the friction pad, and the reaction force receiving portion includes a rearward facing surface formed on the caliper. (12) The motor-driven disc brake according to (12), including a forward facing surface formed to face the rotating member in the axial direction.

(14) In the caliper, a portion of the caliper closer to the friction pad than the reaction force receiving portion is formed of the same member.
The motor-driven disc brake according to any one of (11) to (13). Therefore, according to this disc brake, the rigidity of the caliper can be easily improved as compared with the case where a portion of the caliper on the friction pad side from the reaction force receiving portion is formed by screwing a plurality of members together. As a result, an effect is obtained that the brake responsiveness can be easily improved.

(15) The motor is an ultrasonic motor which applies an ultrasonic vibration to the stator to generate a surface wave and rotates the rotor by a frictional force acting between the stator and the rotor. The motor-driven disc brake according to any one of (1) to (14). In this disc brake, the "ultrasonic motor" may be of a traveling wave type or a standing wave type.

(16) The support structure for reducing the influence of the reaction force includes the first structure according to any one of (2) to (10), and (11) to (11).
(1) Including both of the second structure according to any one of the above paragraphs (1)
Motor-driven disc brake according to the item. According to this disc brake, the effect of suppressing the increase in the rotational resistance of the rotating member during the operation and the decrease in the driving torque of the motor can be obtained, and without increasing the rigidity of the motor housing, The effect that the operation response of the brake can be improved can be obtained.

(17) Further, there is provided a self-servo mechanism for increasing the frictional force itself based on the frictional force generated between the disk rotor and the friction pad when the disk brake operates (1) to (16). The motor-driven disc brake according to any one of the above items (7). Therefore, according to this disk brake, a large wheel braking force can be obtained by the self-servo mechanism in proportion to the driving torque of the motor, so that the motor can be easily reduced in size and weight.

(18) The self-servo mechanism causes the friction pad to function as a wedge between the disk rotor and the moving member when the disk brake is actuated, thereby generating a friction pad between the disk rotor and the friction pad. (17) The motor-driven disc brake according to item (17), which is a wedge type that increases the frictional force itself based on the frictional force generated. Therefore, according to this disc brake,
The advantage is that the structure of the self-servo mechanism can be simplified easily.

(19) The self-servo mechanism comprises: (a) a pad support mechanism for supporting the friction pad so as to be able to rotate with the disk rotor by the frictional force thereof; and (b) the moving member and the friction pad. A direction in which the distance between the friction surface and the friction pad increases with the movement of the friction pad while moving integrally with the friction pad. (18). The motor-driven disc brake according to (18), further including: a slope inclined with respect to the friction surface. Therefore,
According to this disc brake, an effect is obtained that a specific embodiment of a wedge-type self-servo mechanism is provided. In this disc brake, "moving member"
Can be directly engaged with the friction pad or indirectly engaged with the friction pad via a pressing member. In the former mode, the moving member is brought into contact with the friction pad via the inclined surface, while in the latter mode, the pressing member is brought into contact with the friction pad via the inclined surface.

(20) A servo prohibition mechanism for prohibiting operation of the self-servo mechanism when the force that presses the friction pad toward the disk rotor by the motor is smaller than a reference value. The motor-driven disc brake according to any one of the above aspects (17) to (19) (claim 8). By the way, the brake operation by the driver includes “normal brake operation” and “emergency brake operation”.
And can be classified. Here, the "normal brake operation" means that the vehicle body deceleration is performed at a normal speed and a normal height (for example, the vehicle body deceleration to be realized is larger than 0 and 0.5 to 0.6G
In the following range). The "emergency brake operation" should be originally defined as a brake operation in which the vehicle body is decelerated by the brake at a speed higher than usual and at a height higher than usual. However, in an emergency, the driver may actually operate the brake operation member more quickly and harder than usual, but the actual operation force may be insufficient. Therefore, in the present specification, the "emergency brake operation" is defined as a brake operation for causing the vehicle to decelerate at a speed higher than normal or at a height higher than normal by the brake. The relationship between the various types of brake operations described above and the necessity of operating the self-servo mechanism will be described. From the viewpoint of increasing the vehicle deceleration, the necessity of operating the self-servo mechanism is determined during the emergency brake operation. At the time of normal brake operation. In the operation state of the self-servo mechanism,
The change gradient of the actual value of the pressing force of the friction pad with respect to the motor command signal supplied to the motor based on the command value of the pressing force of the friction pad becomes steep, and the actual pressing force accurately matches the pressing force command value. Control becomes difficult.
Further, if it becomes difficult to control the actual pressing force value, and the tendency that the actual pressing force value becomes excessive or insufficient with respect to the pressing force command value becomes strong, for example, it may cause a deterioration in brake operation feeling or the like. . Therefore, from the viewpoint of improving the controllability of the actual pressure value, the necessity of operating the self-servo mechanism is larger during the emergency brake operation than during the normal brake operation. Thus, it can be seen that it may be desirable for the self-servo mechanism not to freely transition from the non-operative state to the active state, but to limit the transition. Based on the above findings, in the motor-driven disc brake described in (20), the operation of the self-servo mechanism is prohibited when the pressing force of the friction pad is smaller than a reference value. Therefore, according to this disc brake, the operation of the self-servo mechanism is prohibited in a state where it is not necessary, and is permitted only when it is necessary. The effect is obtained that it can be appropriately adjusted in relation to the operation feeling and the like. "Standard value" for this disc brake
For example, may be a value that is expected to take an actual pressing force value when the brake operation force is at the upper limit of the normal use range (the range of change in the brake operation force during normal brake operation).

(21) The self-servo mechanism prevents the movement of the slope when the force that presses the friction pad toward the disk rotor by the motor is smaller than a reference value. The motor-driven disk brake according to item (19), including a servo inhibition mechanism that inhibits operation of the mechanism. In this disc brake, the “reference value” can be considered in the same manner as in the disc brake described in the above item (20).

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some specific embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a motor-driven disc brake (hereinafter simply referred to as "brake") 10 for a four-wheeled vehicle according to one embodiment of the present invention. The brake 10 is provided as a wheel brake for each wheel in the vehicle as one component of the brake device.
One brake 10 is shown as a representative.

The brake 10 has a disk rotor 12 as a rotating body that rotates with the wheels. Both surfaces of the disk rotor 12 are friction surfaces 14, and a pair of friction pads 20, 20 are disposed facing the friction surfaces 14. Each friction pad 20 has a friction material 22 that contacts the friction surface 14 on the front surface, and has a structure in which a steel back plate 24 is fixed to the rear surface of the friction material 22.

The brake 10 includes a pad supporting mechanism 26 and a pad pressing mechanism 28. First, the pad supporting mechanism 26 will be described.

The brake 10 has a mounting bracket 30, as shown in FIG. The mounting bracket 30 is cantilevered and fixedly attached to the vehicle body so as to straddle the disk rotor 12. The mounting bracket 30 includes: (a) a portion that movably supports the pair of friction pads 20 in a direction intersecting each friction surface 14 at positions sandwiching the disk rotor 12 from both sides; and (b) a portion that supports each friction pad 20 and the disk rotor. And a portion (receiving member) that receives a frictional force generated in each friction pad 20 at the time of contact with the friction pad 12.

The mounting bracket 30 is mounted on the vehicle body,
When the figure is viewed in the upright direction, the upper part in the figure is attached to the front side of the vehicle body, the right side part is located outside the vehicle body, and the left side part is located inside the vehicle body. The mounting bracket 30 is attached to the vehicle body in such a manner that the design reference line L1 is inclined with respect to the rotation axis L2 of the disk rotor 12 such that a portion of the mounting bracket 30 inside the vehicle body is shifted toward the front of the vehicle body. Here, the design reference line L1 passes through both centers of the pair of friction pads 20 and passes through each friction pad 2.
It is a straight line extending parallel to the movement direction of 0. In the figure, “X” represents a rotor rotation direction in which a portion of the disk rotor 12 that passes through the mounting bracket 30 rotates when the vehicle body moves forward, and “Y” represents a pad movement direction in which each friction pad 20 moves. Is represented.

The front surface of each friction material 22 is a slope 34. Direction of design reference line L1 (parallel to pad movement direction Y)
Is not perpendicular to the rotor rotation direction X, but in the illustrated non-operating state of the brake 10, between the corresponding front surface of each friction material 22 and each friction surface 14 in the rotor rotation direction X with the same width. This is to ensure an extended brake clearance. Therefore, the slope 34 of the inner side (left side in the figure) of the friction pad 20 with respect to the design reference plane S1 is the design reference plane of the friction pad 20 as it advances on the friction pad 20 toward the front of the vehicle body. While it is inclined so as to approach S1, the friction pad 20 on the outer side (right side in the figure) moves from the design reference plane S1 of the friction pad 20 as it advances on the friction pad 20 toward the front of the vehicle body. It is inclined so as to be separated.

As described above, the mounting bracket 30 supports each of the friction pads 20 so as to be movable in the pad movement direction Y.
While the corotation with the disk rotor 12 is positively allowed, the outer friction pad 20 is supported in a state where the corotation is substantially prevented. Therefore, the inner friction pad 20 is moved in the pad rotation direction Z parallel to the rotor rotation direction X by the frictional force between the inner friction pad 20 and the disk rotor 12 in a pressed state.

However, the rotation of the inner friction pad 20 is not always allowed, and the friction pad 20 is designed to be stopped until the frictional force of the friction pad 20 reaches a reference value. Specifically, the inner friction pad 20 and the mounting bracket 30 are linked via an elastic control mechanism 40. The elastic control mechanism 40 controls the relative movement of the friction pad 20 and the mounting bracket 30 in the pad rotation direction Z without elastic deformation until the load input from the inner friction pad 20 reaches the reference value. Blocking, thereby preventing the friction pad 20 from rotating, and, after the input load exceeds a reference value, elastically deforming to allow its relative movement, thereby allowing the friction pad 20 to rotate. It is a mechanism that allows.

The elastic control mechanism 40 can adopt various types. In this embodiment, (a) an elastic member 42 having a U-shape and having a pair of arms; The structure includes an adjustment mechanism 44 that adjusts the initial load of the elastic member 42 by changing the amount of elastic deformation of the elastic member 42. Here, the “initial load” refers to a load applied by the elastic member 42 to the friction pad 20 when the friction pad 20 starts moving in the pad rotation direction Z against the elastic force of the elastic member 42. The elastic member 42 is arranged such that a pair of arms thereof extend in the left-right direction of the vehicle body, and one of the arms is linked to the mounting bracket 30 and the other arm is linked to the inner friction pad 20. I have. Adjustment mechanism 44
Includes a length adjusting bolt extending substantially parallel to the pad rotation direction Z and connecting the pair of arms of the elastic member 42 so as to be accessible to each other and inseparable from each other, and by changing the amount of elastic deformation of the elastic member 42, The initial load of the member 42 is adjusted.

In this embodiment, the elastic control mechanism 4
The “reference value” at 0 is set to a value that is expected to take the input load when the brake 10 causes a deceleration of about 0.5 to 0.6 G in the vehicle body. Therefore, during the normal brake operation, the rotation of the friction pad 20 is prevented, whereby the self-servo effect described later does not occur. On the other hand, during the emergency brake operation (accurately, during the strong brake operation), the frictional force is reduced. The rotation of the pad 20 is allowed, whereby a self-servo effect occurs.

Next, the pad pressing mechanism 28 will be described. The brake 10 has a caliper 60. As shown in FIG. 1, the caliper 60 is
a, the motor mounting portion 60b, and the support portion 60c are integrated with the caliper main body portion 61;
Are separate parts from each other and are screwed. As shown in FIG. 2, the caliper main body 61 further includes a pair of arms 62 extending in the vehicle longitudinal direction. The pair of arms 62 are also formed integrally with the caliper main body 61.

The caliper main body 61 is slidably supported by the mounting bracket 30 in the pad moving direction Y at the pad pressing portion 60a. Caliper 60
Is floating. At the distal end of each arm 62, two pins 63 extending in parallel to the pad moving direction Y are attached, and these two pins 63 are fitted to the mounting bracket 30 so as to be slidable in the pad moving direction Y. Have been. The caliper body 61 is provided with the pad pressing-related portion 6.
Oa and the two pins 63 are slidably supported by the mounting bracket 30.

The pad pressing related portion 60a includes a pressing portion 64 located behind the inner friction pad 20, a reaction portion 66 located behind the outer friction pad 20, and a connecting portion 68 straddling the disk rotor 12. The structures are integrated with each other.

As shown in FIG. 1, a pressing piston 70 as a pressing member is provided on the pressing portion 64 with the inner friction pad 20.
Is slidably fitted behind. The pressing piston 70 is brought into contact with the rear surface of the friction pad 20 at the front surface thereof. Behind the pressing piston 70, an ultrasonic motor 72 is coaxially arranged. The pressing piston 70 and the ultrasonic motor 72 are both arranged in parallel to the pad moving direction Y and are coaxially connected by a ball screw mechanism 74 as a motion conversion mechanism. An axis L3 common to the pressing piston 70, the ultrasonic motor 72, and the ball screw mechanism 74 is parallel to the design reference line L1 of the mounting bracket 30, as shown in FIG. It is offset by a predetermined distance in the rotor rotation direction X.

As is apparent from the above description, in the present embodiment, the disk rotor 12 and the pressing piston 70
And the inner friction pad 20 is disposed so as to be able to rotate along with the disk rotor 12, and
The disc rotor 12 and the pressing piston 70 are engaged via the inclined surface 34 of the friction pad 20. Therefore, when the inner friction pad 20 rotates along with the disk rotor 12, the friction pad 20 functions as a wedge, and the frictional force generated between the friction pad 20 and the disk rotor 12 causes the friction between the disk rotor 12 and the pressing piston. 7
0 is converted to an axial force in a direction that separates them from each other. As a result, the pressing force between the pair of friction pads 20 and the disk rotor 12 increases, and as a result, the inner friction pads 2
The frictional force between 0 and the disk rotor 12 increases. That is, when the inner friction pad 20 rotates along with the disk rotor 12, the brake 10 has a self-servo effect.

The ultrasonic motor (hereinafter simply referred to as "motor") 72 is of a traveling wave type. As is well known, the motor 72 applies ultrasonic vibration to the stator to generate a surface wave, and rotates the rotor by frictional force acting between the stator and the rotor. Motor 72
As shown in FIG. 1, the motor housing 80 has a bottomed cylindrical shape and a stator 82 and a rotor 84 are accommodated coaxially.

The motor housing 80 has a main body portion 80a having a through hole at the bottom and a closing portion 80 for closing the through hole.
b are separate parts from each other and are screwed. The motor housing 80 is screwed to the motor mounting portion 60b at an opening thereof.

The rotor 84 is pressed against the stator 82 by the pressing contact mechanism 94 so that a necessary frictional force is obtained between the two. A friction material is adhered to a portion of the rotor 84 that contacts the stator 82. Thereby, the traveling wave vibration generated in the stator 82 is transmitted to the rotor 84, and the rotor 84 is rotated. Due to the pressing contact mechanism 94, a constant frictional force is generated between the stator 82 and the rotor 84 even in a non-energized state (OFF state) where no voltage is applied to the piezoelectric body 92. In the present embodiment, the pressing contact mechanism 94 is of a type having a disc spring 96 as a main component. However, it is needless to say that the pressing contact mechanism 94 can be of a type having a coil spring as a main component.

The ball screw mechanism 74 has a structure in which a male screw member (screw shaft) 100 and a female screw member (screw nut) 102 are screwed together via a plurality of balls (not shown). Male thread member 100
Is a member whose rotation is restricted but whose axial movement is permitted, while the female screw member 102 is a member whose rotation is permitted but whose axial movement is restricted. That is, in the present embodiment, the male screw member 100 functions as a “moving member”, and the female screw member 102 functions as a “rotating member”.

The male screw member 100 is connected to the motor housing 8.
At 0, it is non-rotatably attached by a spline fitting portion 104. The spline fitting portion 104 is provided at a fixed position in the motor housing 80.

The rotor 84 is attached to the female screw member 102 together with the pressing contact mechanism 94 so as not to rotate relatively. Therefore, when the rotor 84 rotates forward, the female screw member 102 also rotates forward, and when the female screw member 102 rotates forward, the male screw member 100 moves forward (moves to the right in the drawing) and the pressing piston 70 frictionally moves. The pad 20 moves in a direction to approach the disk rotor 12. Conversely, when the rotor 84 rotates in the reverse direction, the female screw member 102 also rotates in the reverse direction. When the female screw member 102 rotates in the reverse direction, the male screw member 100 retreats (moves to the left in the drawing) and the pressing piston 70 Is allowed to move in a direction in which the friction pad 20 approaches the disk rotor 12.

The female screw member 102 is rotated by the rotor 84
A front portion 104 which is a portion on the side of the inner friction pad 20
And a rear portion 106 which is a portion opposite to the friction pad 20. The front part 104 is supported by the support part 60c. The support part 60c
The front portion 104 is provided at a boundary position between the caliper main body 61 and the motor housing 80, so that the front portion 104 is disposed so as to straddle the caliper main body 61 and the motor housing 80. Caliper body 6 of front side 104
The portion corresponding to 1 is stepped, and a large-diameter shaft portion 110 is formed at a position near the inner friction pad 20 and a small-diameter shaft portion 112 is formed at a position far from the friction pad 20. Accordingly, the front portion 104 of the caliper body 61 is
The hole into which is inserted is also stepped. Large diameter shaft 11
A large-diameter hole 116 is formed at a position corresponding to 0, and a small-diameter hole 118 is formed at a position corresponding to the small-diameter shaft portion 112.

The female screw member 102 has a radial bearing 120 and a radial thrust bearing 12 which are spaced apart in the axial direction thereof.
2 and rotatably supported by the support portion 60c of the caliper main body 61. The radial bearing 120 is a bearing that receives a radial load of the female screw member 102, and is configured such that an outer ring and an inner ring are relatively rotatably mounted via a plurality of rolling elements. On the other hand, the radial thrust bearing 122 is a bearing that receives both the radial load and the thrust load of the female screw member 102, and a plurality of shaft washer is mounted so as to be relatively rotatable via a plurality of rolling elements. It is composed. Examples of the radial thrust bearing 122 include a tapered roller bearing and a self-aligning roller bearing.

More specifically, the radial bearing 120 and the radial thrust bearing 122 are both disposed on the front portion 104, and the radial bearing 120 is on the side of the rotor 84, and the radial thrust bearing 122 is on the inner friction pad 20. , Respectively. The radial bearing 120 has the outer ring fixed to the small-diameter hole 118 and the inner ring fixed to the small-diameter shaft 112 between the female screw member 102 and the support portion 60c. On the other hand, the radial thrust bearing 122 includes the female screw member 102 and the support portion 6.
0c, the plurality of shaft washers of the radial thrust bearing 122 that are closest to the inner friction pad 20 have a large-diameter shaft portion 110 and a small-diameter shaft portion 112 on the front portion 104.
The annular shoulder surface 126 as a rearward surface formed backward (toward the side of the rotor 84) between the rotor 8 and the rotor 8
4 has an annular shoulder surface 130 as a forward facing surface formed in the caliper body 61 between the large-diameter hole 116 and the small-diameter hole 118 (toward the inner friction pad 20). It is fixed and attached to.

The female screw member 102 is provided with a snap ring 134 as fixing means in an annular groove formed on the outer peripheral surface thereof, and the snap ring 13
By sandwiching the radial bearing 120, the motor mounting portion 60 b, and the radial thrust bearing 122 between the inner shaft 4 and the large-diameter shaft portion 110, the axial movement of the female screw member 102 is restricted. Although it is possible to design the brake 10 in a state where the axial movement is substantially prevented, it is possible to design the brake 10 in a state where the axial movement is allowed within a certain range. In the latter case, for example, when the brake 10 is not operating, the gap between the stator 82 and the rotor 84 is larger than when the brake 10 is operating, and the stator 82 is
4, the force of the pressing is reduced. Therefore, brake 1
0, the state of the stator 8
2 becomes easy to vibrate, and as a result, the effect of improving the rise characteristic of the driving torque of the motor 72 is obtained.

A load sensor 140 is coaxially attached to the tip of the male screw member 100.
Engages the pressing piston 70 from behind through the load sensor 140. Therefore, based on the output signal from the load sensor 140, the pressing force when the motor 72 presses the friction pad 20 can be detected.

FIG. 3 is a block diagram showing an electric configuration of the brake device including the brake 10 described above. The brake device includes a controller 200. The controller 200 controls the brake 10 by controlling the pressing force (hereinafter, simply referred to as “pressing force”) of the friction pad 20 by the motor 72 at the time of the brake operation, and includes a computer including a CPU, a ROM, and a RAM. It is configured as a subject.

A brake operation force sensor 202 is connected to the input side of the controller 200 as an operation state amount sensor for detecting the operation state amount (operation force or operation stroke) of the brake operation member. The brake device includes: (a) a brake pedal (not shown) as a brake operation member depressed by a driver; and (b) a brake operation device (not shown) that generates a brake operation force in accordance with depression of the brake pedal. The brake operation force sensor 202 detects the generated brake operation force as a brake operation state amount. Controller 200
Further, the load sensor 140 is connected to the input side of. On the other hand, the output side of the controller 200 is connected to the motor 72 via a motor drive circuit (not shown).

FIG. 4 is a flowchart showing a brake control routine stored in the ROM of the computer of the controller 200.

This routine will be described in brief. This routine is executed to perform pad pressure control during brake operation. In the pad pressure control, the motor 72 is controlled such that the actual pressure value F _{S of} each wheel is equal to the pressure command value F ^* . Here, the pressing force command value F for each wheel
^In the present embodiment, ^* is determined so that the braking force is appropriately distributed to the front and rear wheels. When braking,
The deceleration of the height corresponding to the brake operation force is generated in the vehicle body, and the rear wheel is determined not to lock before the front wheel.

Next, the contents of this routine will be specifically described with reference to FIG. Note that this routine is repeatedly and sequentially executed for the four wheels, but for simplicity of description, the following description will be made on the assumption that the routine is repeatedly executed at the control cycle T for the same wheel.

In each execution of this routine, first, in step S1 (hereinafter simply referred to as S1; the same applies to other steps), the brake operation force sensor 2 is used.
From 02, an operation force signal indicating the brake operation force is input. Next, in S2, the brake operation force f is calculated based on the operation force signal, and based on the brake operation force f, the distribution of the braking force to the front and rear wheels becomes appropriate.
A pressing force command value F ^* corresponding to the wheel is calculated. Then, in S3, the load sensor 1 corresponding to the wheel
From 40, a load signal representing the actual force F _S of the wheel is input, and the actual force F _S corresponding to the wheel is calculated based on the load signal. Subsequently, in S4, a motor command signal to be output to the motor 72 corresponding to the wheel is determined based on a comparison result between the actual pressing force value F _S and the pressing force command value F ^*. Controlled by the motor 72. Thereby, the motor 72 is controlled such that the actual pressing force value F _S corresponding to the wheel is equal to the pressing force command value F ^* . This completes one execution of this routine.

As is apparent from the above description, in the present embodiment, at least a plurality of bearings 120 and 122 that receive the radial load of the female screw member 102 are arranged apart from each other in the axial direction of the female screw member 102. Even if an uneven load is applied to the female screw member 102 when the brake 10 operates, the female screw member 102 is prevented from tilting with respect to the caliper body 61 and the motor housing 80. As a result, the internal thread member 102 is prevented from being twisted in the caliper main body 61 or the motor housing 80, and an effect of suppressing an increase in the rotational resistance of the internal thread member 102 is obtained.

Further, in the present embodiment, even if an eccentric load is applied to the female screw member 102 when the brake 10 is operated, the rotor 84 is prevented from tilting with respect to the stator 82, so that the stator 82 is always vibrated. Is normally in rotor 8
4 to suppress the decrease in the driving torque of the motor 72.

Further, in the present embodiment, the thrust load from the female screw member 102 passes through the shoulder surface 126 as the reaction force transmitting portion, the radial thrust bearing 122 and the shoulder surface 130 as the reaction force receiving portion in this order, and the caliper body portion. 61 to the motor housing 80 from the female screw member 102.
Is not transmitted to

Therefore, according to this embodiment, if the rigidity of the caliper body 61 is increased, the motor housing 80
The responsiveness of the brake 10 to the operation of the motor 72 can be improved without increasing the rigidity of the brake.
For example, it is possible to make the motor housing 80 made of a synthetic resin or to reduce the thickness, separately from the problem of the operation responsiveness. Therefore, according to the present embodiment, it is possible to obtain an effect that the motor housing 80 does not need to be large and the weight does not increase in order to improve the operation response of the brake 10.

Furthermore, in the present embodiment, the pad pressing related portion 60a and the support portion 60c are integrated. Therefore, according to the present embodiment, the caliper main body 61 is compared with a case where the pad pressing related portion 60a and the support portion 60c are separate parts and screwed.
The rigidity of the brake 10 is improved, which also has the effect of improving the operation response of the brake 10.

Further, in the present embodiment, a radial thrust bearing 122 that receives both the radial load and the thrust load of the female screw member 102 by one piece is used. Therefore, according to the present embodiment, the brake 10
In this case, the number of bearings becomes two, and the effect that the brake 10 can be easily reduced in size, size, weight, and cost can be easily obtained.

As is apparent from the above description, in the present embodiment, the portion of the female screw member 102 forming the shoulder surface 126, the portion of the support portion 60c forming the shoulder surface 130, and the radial bearing 120 And the radial thrust bearing 122 cooperate with each other to form an example of a “rotational member supporting mechanism”, and the female screw member 102 is separated from the axially separated radial bearing 120 and the radial thrust bearing 122 by an axial direction. The structure supported by the support portion 60c corresponds to an example of a “first structure”, and the structure in which the screw member 102 is stepped and supported by the support portion 60c via the radial thrust bearing 122 corresponds to “first structure”. This corresponds to an example of “two structures”. In addition, pad support mechanism 2
6, a portion for supporting the inner friction pad 20 so as to be able to rotate along with the disk rotor 12 and the slope 34 of the friction pad 20 cooperate with each other to constitute an example of the "self-servo mechanism" in the present invention. In addition, the elastic control mechanism 40 constitutes an example of the “servo inhibition mechanism”.

Next, some other embodiments will be described. All of these embodiments have many elements in common with the embodiment shown in FIG. 1 (hereinafter, referred to as the first embodiment), and are different. This is only for the support structure of the female screw member 102 as a rotating member. Therefore, only that portion will be described in detail, and the other components will be omitted from detailed description by using the same reference numerals.

FIG. 5 shows a brake 2 according to another embodiment.
50 is shown. In this brake 250,
Instead of the radial thrust bearing 122 in the first embodiment, a thrust bearing 252 which receives a thrust load of the female screw member 102 is used, and a radial bearing 254 in addition to the radial bearing 120 in the first embodiment.
Is also used. Thrust bearing 252 is located between shoulder surfaces 126 and 130 as in the earliest embodiment. On the other hand, the radial bearing 254 is
02 and the motor housing 80. That is, in the present embodiment, two radial bearings 120 and 254 are provided, one of which is the front portion 10.
Fourth, the other is disposed on a different side with respect to the rotor 84, such as the rear portion 106.

Therefore, according to the present embodiment, when the brake 250 operates, the female screw member 102 and the rotor 84
Is suppressed, and the effect that the operation responsiveness of the brake 250 can be improved without increasing the rigidity of the motor housing 80 is obtained.

As is apparent from the above description, in the present embodiment, the portion of the female screw member 102 forming the shoulder surface 126, the portion of the support portion 60c forming the shoulder surface 130, and the radial bearing 120 And 254 and the thrust bearing 252 cooperate with each other to form a “rotating member support mechanism”.
A structure in which the female screw member 102 is supported by the support portion 60c via radial bearings 120 and 254 spaced apart in the axial direction of the female screw member 102 corresponds to an example of a “first structure”. , The stepped screw member 102
The structure supported by the support portion 60c via the thrust bearing 252 corresponds to an example of the “second structure”.

FIG. 6 shows a brake 300 according to still another embodiment. In the brake 300, a radial bearing 302 disposed between the rear portion 106 of the female screw member 102 and the motor housing 80 is used instead of the radial bearing 120 in the first embodiment.

Therefore, according to this embodiment, the female screw member 102 and the rotor 84
Of the brake 300 can be suppressed, the operation responsiveness of the brake 300 can be improved without improving the rigidity of the motor housing 80, and the brake 30 can be improved.
This has the effect of reducing the number of bearings at zero.

Further, in the present embodiment, at least the bearing 122 which receives the radial load of the female screw member 102 is provided.
And 302 are disposed near both ends of the female screw member 102, so that an effect that the inclination of the female screw member 102 can be effectively suppressed can be obtained.

As is apparent from the above description, in the present embodiment, the portion of the female screw member 102 forming the shoulder surface 126, the portion of the support portion 60c forming the shoulder surface 130, and the radial bearing 302 And the radial thrust bearing 122 cooperate with each other to form an example of a “rotating member support mechanism”, and the female screw member 102 is separated from the axial thrust bearing by a radial thrust bearing 122 and a radial bearing 302. The structure supported by the support portion 60c corresponds to an example of a “first structure”, and the structure in which the screw member 102 is stepped and supported by the support portion 60c via the radial thrust bearing 122 corresponds to “first structure”. This corresponds to an example of “two structures”.

FIG. 7 shows a brake 350 according to still another embodiment. Unlike the earliest embodiment, the brake 350 has a structure in which the thrust load of the female screw member 102 is transmitted to the caliper main body 61 via the motor housing 80, and the brake 350 according to the earliest embodiment. Radial thrust bearing 12
2, the female screw member 102 and the motor housing 80
And a radial thrust bearing 352 disposed between them.

The front portion 104 of the female screw member 102
A stopper 354 is formed on the outer peripheral surface of the intermediate portion of the above. The stopper 354 is provided to limit the axial movement of the female screw member 102.

Therefore, according to the present embodiment, at least the bearing 12 which receives the radial load of the female screw member 102
Since 0 and 352 are arranged apart from each other in the axial direction of the female screw member 102, an effect is obtained that the female screw member 102 and the rotor 84 are prevented from tilting when the brake 300 operates.

Further, in this embodiment, since the radial thrust bearing 352 is used as a single bearing that receives both the radial load and the thrust load, the number of bearings in the brake 350 can be reduced. Is also obtained.

As is clear from the above description, in this embodiment, the radial bearing 120 and the radial thrust bearing 352 cooperate with each other to constitute an example of a “rotating member supporting mechanism”. However, the structure supported by the support portion 60c via the radial bearing 120 and the radial thrust bearing 352 separated from each other in the axial direction corresponds to an example of the "first structure".

FIG. 8 shows a brake 400 according to still another embodiment. Unlike the first embodiment, the brake 400 has a structure in which the thrust load of the female screw member 102 is transmitted to the caliper main body 61 via the motor housing 80.
Further, in the present embodiment, a radial bearing 402 and a thrust bearing 404 are used instead of the radial thrust bearing 122 in the first embodiment,
Both the radial bearing 402 and the thrust bearing 404 are arranged between the rear portion 106 of the female screw member 102 and the motor housing 80. Further, the radial bearing 402 and the thrust bearing 404 are sandwiched by an annular spacer 406.

Therefore, according to the present embodiment, at least the bearing 12 which receives the radial load of the female screw member 102 is provided.
Since the reference numerals 0 and 402 are arranged apart from each other in the axial direction of the female screw member 102, an effect is obtained that the female screw member 102 and the rotor 84 are prevented from tilting when the brake 400 operates.

As is clear from the above description, in the present embodiment, the radial bearings 120 and 402 and the thrust bearing 404 cooperate with each other to constitute an example of a "rotating member supporting mechanism". The structure in which the support 102 is supported by the support portion 60c via the radial bearings 120 and 402 separated from each other in the axial direction thereof corresponds to an example of the “first structure”.

FIG. 9 shows a brake 450 according to still another embodiment. Unlike the earliest embodiment, the brake 450 has a structure in which the thrust load of the female screw member 102 is transmitted to the caliper main body 61 via the motor housing 80.
Further, in the present embodiment, a radial bearing 452 and a thrust bearing 454 are used instead of the radial thrust bearing 122 in the first embodiment,
The front part 10 of the radial bearing 452 female screw member 102
4. The thrust bearing 454 is disposed on the rear portion 106, respectively.

Therefore, according to the present embodiment, at least the bearing 12 which receives the radial load of the female screw member 102 is provided.
Since 0 and 452 are arranged apart from each other in the axial direction of the female screw member 102, an effect is obtained that the female screw member 102 and the rotor 84 are prevented from tilting when the brake 450 operates.

As is clear from the above description, in this embodiment, the radial bearings 120 and 452 and the thrust bearing 454 cooperate with each other to constitute an example of a "rotating member supporting mechanism". The structure in which the support 102 is supported by the support portion 60c via the radial bearings 120 and 452 spaced apart from each other in the axial direction thereof corresponds to an example of the “first structure”.

It should be noted that, in any of the embodiments described above, at least a plurality of bearings for receiving the radial load of the female screw member 102 are arranged at a distance from each other in the axial direction of the female screw member 102. Member 10
Although the inclination of 2 is suppressed, for example, it is also possible to achieve the object by making at least one of the outer ring and the inner ring of the radial bearing wider than usual.

As described above, some embodiments of the present invention have been described in detail with reference to the drawings. In addition to these, various modifications may be made based on the knowledge of those skilled in the art without departing from the scope of the claims. Of course, the present invention can be implemented in an improved form.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a motor-driven disc brake according to an embodiment of the present invention.

FIG. 2 is a plan view showing the disc brake.

FIG. 3 is a block diagram showing an electrical configuration of a brake device including the disc brake.

FIG. 4 is a flowchart illustrating a brake control routine stored in a ROM of a computer of the controller in FIG. 3;

FIG. 5 is a side sectional view showing a motor-driven disc brake according to another embodiment of the present invention.

FIG. 6 is a side sectional view showing a motor-driven disc brake according to still another embodiment of the present invention.

FIG. 7 is a side sectional view showing a motor-driven disc brake according to still another embodiment of the present invention.

FIG. 8 is a side sectional view showing a motor-driven disc brake according to still another embodiment of the present invention.

FIG. 9 is a side sectional view showing a motor-driven disc brake according to still another embodiment of the present invention.

[Explanation of symbols]

10, 250, 300, 350, 400, 450 Motor-driven disc brake 12 Disc rotor 20 Friction pad 60 Caliper 60a Pad pressing related part 60b Motor mounting part 60c Supporting part 61 Caliper body 72 Ultrasonic motor 74 Motion conversion mechanism 80 Motor Housing 82 Stator 84 Rotor 100 Male thread member 102 Female thread member 120, 254, 302, 402, 452 Radial bearing 122 Radial thrust bearing 252, 352, 404, 454 Thrust bearing

Claims (8)

[Claims] (A) a disk rotor having a friction surface and rotating together with a wheel; (b) a friction pad for suppressing rotation of the disk rotor by being pressed by the disk rotor on the friction surface; c) a motor having a rotor, a stator and a motor housing for housing them,
(d) a rotating member rotated by the motor, and (e)
A moving member disposed behind the friction pad so as to be movable in a direction intersecting the friction surface, and (f) converting a rotational motion of the rotating member into a linear motion of the moving member, whereby the friction pad (G) a caliper that supports at least the moving member, the caliper having a portion functioning as the motor housing, and (h) a caliper and the rotating member. A motor-driven disc brake that includes a rotating member supporting mechanism that rotatably supports the rotating member with respect to the caliper, and that receives a reaction force acting as a thrust load from at least the rotating member at the time of pressing with the caliper. When at least one of the rotating member and the motor is actuated by the disc brake, the rotating member supporting mechanism is moved. It has a reaction force reduction support structure that is less likely to receive at least one of the influence of the first reaction force acting as an offset load on the rotating member from the moving member and the influence of the second reaction force acting on the caliper from the rotation member. A motor-driven disc brake characterized by the following. 2. The support structure for reducing the influence of the reaction force includes a first structure for suppressing the axis of the rotating member from being inclined with respect to the caliper by the first reaction force when the disc brake operates. 2. A motor-driven disc brake according to claim 1. 3. The rotating member is mounted coaxially and non-rotatably on the rotor, and the first structure is configured such that an axis of the rotating member is moved by the first reaction force when the disc brake is actuated. The motor-driven disc brake according to claim 2, further comprising a structure that suppresses tilting with respect to the stator, thereby preventing the axis of the rotor from tilting with respect to the stator. 4. The structure according to claim 2, wherein the first structure includes a structure for supporting the rotating member rotatably by receiving a radial load of the rotating member at a plurality of locations separated in the axial direction of the rotating member. Motor-driven disc brake. 5. The motor-driven system according to claim 1, wherein said reaction force influence reducing support structure has a second structure that does not transmit said second reaction force to said motor when said disc brake operates. Disc brake. 6. The caliper, wherein the second member has a reaction force transmitting portion formed on the rotating member for transmitting the second reaction force to the caliper in a direction opposite to a side of the friction pad. At a position closer to the friction pad than a portion of the caliper that functions as the motor housing,
A reaction force receiving portion that receives the second reaction force from the reaction force transmitting portion is formed opposite to the reaction force transmitting portion in the axial direction of the rotating member, and the reaction force transmitting portion and the reaction force receiving portion are formed. ,
6. The motor-driven disc brake according to claim 5, further comprising a structure that sandwiches a bearing that rotatably supports the rotating member with respect to the caliper by receiving at least a thrust load of the rotating member. 7. A self-servo mechanism according to claim 1, further comprising a self-servo mechanism for increasing the frictional force itself based on a frictional force generated between said disk rotor and said friction pad when said disk brake operates. A motor-driven disc brake according to any one of the above. 8. A servo inhibition mechanism for inhibiting the operation of the self-servo mechanism when a force applied by the motor to the friction pad toward the disk rotor is smaller than a reference value. The motor-driven disc brake according to claim 7, including: